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1.
J Pediatr Gastroenterol Nutr ; 68(1): 116-123, 2019 01.
Article in English | MEDLINE | ID: mdl-30320665

ABSTRACT

OBJECTIVES: The purpose of the present randomized controlled clinical trial was to compare the use of donkey milk-derived fortifier (DF) with commercial bovine milk-derived fortifier (BF) in very preterm or very-low-birth-weight newborns, in terms of feeding tolerance. METHODS: This trial included 156 newborns born at <32 weeks of gestational age and/or with a birth weight ≤1500 g. Newborns were randomized 1:1 to receive enteral feeding with either a BF-arm, or a new, DF-arm for 21 days. The fortification protocol was the same for both study arms, and the 2 diets were designed to be isoproteic and isocaloric. Feeding tolerance was assessed by a standardized protocol. RESULTS: The risk of feeding intolerance tended to be lower in DF-arm than in BF-arm, with a relative risk reduction of 0.63 (95% confidence interval: -0.29, +0.90). The mean number of episodes per newborn of feeding intolerance and feeding interruptions (any duration) were consistently lower in the DF-arm than in the BF-arm. Episodes of bilious gastric residuals and vomiting were significantly lower in the DF-arm. Time needed to reach full enteral feeding (150 mL ·â€Škg ·â€Šday) and daily weight increase between the first day of exclusive enteral feeding (ie, without administering intravenous fluids) and discharge were similar in the BF- and DF-arms. CONCLUSIONS: These results suggest that DF improve feeding tolerance when compared with standard bovine-derived fortifiers, with a similar auxological outcome.


Subject(s)
Enteral Nutrition/methods , Food, Fortified , Infant, Premature/growth & development , Infant, Very Low Birth Weight/growth & development , Milk, Human , Milk , Animals , Equidae , Female , Humans , Infant Nutritional Physiological Phenomena , Infant, Newborn , Male , Nutritional Status , Weight Gain
2.
Nutr J ; 17(1): 6, 2018 01 09.
Article in English | MEDLINE | ID: mdl-29316931

ABSTRACT

BACKGROUND: Fortification of human milk is a standard practice for feeding very low birth weight infants. However, preterm infants often still experience suboptimal growth and feeding intolerance. New fortification strategies and different commercially available fortifiers have been developed. Commercially available fortifiers are constituted by a blend of ingredients from different sources, including plant oils and bovine milk proteins, thus presenting remarkable differences in the quality of macronutrients with respect to human milk. Based on the consideration that donkey milk has been suggested as a valid alternative for children allergic to cow's milk proteins, due to its biochemical similarity to human milk, we hypothesized that donkey milk could be a suitable ingredient for developing an innovative human milk fortifier. The aim of the study is to evaluate feeding tolerance, growth and clinical short and long-term outcomes in a population of preterm infants fed with a novel multi-component fortifier and a protein concentrate derived from donkey milk, in comparison to an analogous population fed with traditional fortifier and protein supplement containing bovine milk proteins. METHODS: The study has been designed as a randomized, controlled, single-blind clinical trial. Infants born <1500 g and <32 weeks of gestational age were randomized to receive for 21 days either a combination of control bovine milk-based multicomponent fortifier and protein supplement, or a combination of a novel multicomponent fortifier and protein supplement derived from donkey milk. The fortification protocol followed is the same for the two groups, and the two diets were designed to be isoproteic and isocaloric. Weight, length and head circumference are measured; feeding tolerance is assessed by a standardized protocol. The occurrence of sepsis, necrotizing enterocolitis and adverse effects are monitored. DISCUSSION: This is the first clinical study investigating the use of a human milk fortifier derived from donkey milk for the nutrition of preterm infants. If donkey milk derived products will be shown to improve the feeding tolerance or either of the clinical, metabolic, neurological or auxological outcomes of preterm infants, it would be an absolute innovation in the field of feeding practices for preterm infants. TRIAL REGISTRATION: ISRCTN - ISRCTN70022881 .


Subject(s)
Food, Fortified , Milk Proteins/therapeutic use , Milk, Human , Nutrition Surveys/statistics & numerical data , Nutritional Status , Weight Gain/drug effects , Animals , Equidae , Humans , Infant, Premature/growth & development , Infant, Very Low Birth Weight/growth & development , Italy , Milk Proteins/administration & dosage , Research Design
3.
J Biol Chem ; 290(19): 12403-14, 2015 May 08.
Article in English | MEDLINE | ID: mdl-25814665

ABSTRACT

Human rotavirus is the leading cause of severe gastroenteritis in infants and children under the age of 5 years in both developed and developing countries. Human lactadherin, a milk fat globule membrane glycoprotein, inhibits human rotavirus infection in vitro, whereas bovine lactadherin is not active. Moreover, it protects breastfed infants against symptomatic rotavirus infections. To explore the potential antiviral activity of lactadherin sourced by equines, we undertook a proteomic analysis of milk fat globule membrane proteins from donkey milk and elucidated its amino acid sequence. Alignment of the human, bovine, and donkey lactadherin sequences revealed the presence of an Asp-Gly-Glu (DGE) α2ß1 integrin-binding motif in the N-terminal domain of donkey sequence only. Because integrin α2ß1 plays a critical role during early steps of rotavirus host cell adhesion, we tested a minilibrary of donkey lactadherin-derived peptides containing DGE sequence for anti-rotavirus activity. A 20-amino acid peptide containing both DGE and RGD motifs (named pDGE-RGD) showed the greatest activity, and its mechanism of antiviral action was characterized; pDGE-RGD binds to integrin α2ß1 by means of the DGE motif and inhibits rotavirus attachment to the cell surface. These findings suggest the potential anti-rotavirus activity of equine lactadherin and support the feasibility of developing an anti-rotavirus peptide that acts by hindering virus-receptor binding.


Subject(s)
Antigens, Surface/chemistry , Glycolipids/chemistry , Glycoproteins/chemistry , Membrane Glycoproteins/chemistry , Milk Proteins/chemistry , Peptides/chemistry , Rotavirus Infections/metabolism , Amino Acid Motifs , Amino Acid Sequence , Animals , Cattle , Cell Membrane/metabolism , Cell Survival , Equidae , Horses , Humans , Inhibitory Concentration 50 , Integrins/chemistry , Lipid Droplets , Milk , Molecular Sequence Data , Proteomics , Rotavirus/metabolism , Rotavirus Infections/drug therapy , Sequence Homology, Amino Acid , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
4.
Int Arch Allergy Immunol ; 158(1): 9-17, 2012.
Article in English | MEDLINE | ID: mdl-22205234

ABSTRACT

BACKGROUND: Although rice (Oryza sativa) is one of the most common cereals produced and consumed around the world, there have been only a few reports on immediate hypersensitivity reactions after ingestion of rice. Few clinical studies on rice allergy in Asia have been reported concerning rhinitis, asthma and atopic dermatitis. In this case study, we identify allergens presumably responsible for anaphylaxis after ingestion of rice in a German patient. METHODS: Prick-to-prick tests, determination of specific IgE and the basophil activation test (BAT) were performed to confirm IgE-mediated allergy. IgE reactivity was further analyzed by immunoblotting of protein extracts from cooked commercial rice products. Rice allergens were purified, subjected to N-terminal sequencing and characterized by IgE binding and IgE inhibition assays using additional sera from 8 subjects with sensitization to rice and/or a history of hypersensitivity symptoms after rice ingestion. RESULTS: Prick-to-prick tests were positive to raw and cooked rice (basmati rice and long-grain rice) and preparations of different rice extracts. Specific IgE against rice (f9) was 1.87 kU(A)/l. The BAT showed specific IgE-mediated activation of basophils after stimulation with rice extracts. Four IgE-reactive rice proteins with an apparent molecular weight of 49, 52, 56 and 98 kDa were identified. Interestingly, only binding to the 56-kDa glycoprotein was at least partially independent from cross-reactive carbohydrate determinants (CCD), whereas IgE binding to the other rice proteins was completely inhibited by pre-incubation with the CCD MUXF derived from bromelain. CONCLUSIONS: Yet unidentified high-molecular-weight allergens from rice seeds, predominantly a 56-kDa glycoprotein, seem to be responsible for anaphylaxis after consumption of rice in a German patient.


Subject(s)
Anaphylaxis/immunology , Food Hypersensitivity/immunology , Glycoproteins/immunology , Immunoglobulin E/immunology , Oryza/adverse effects , Adult , Allergens/immunology , Anaphylaxis/diagnosis , Basophils/immunology , Bromelains/immunology , Food Hypersensitivity/diagnosis , Humans , Male , Oryza/immunology , Skin Tests
5.
Mol Immunol ; 48(15-16): 1983-92, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21784530

ABSTRACT

BACKGROUND: Published data on crustacean allergens are incomplete. The identification of tropomyosin (TM), arginine kinase (AK), sarcoplasmic Ca-binding protein (SCP) and myosin light chain (MLC) as shrimp allergens are all important contributions but additional allergens are required for the development of a complete set of reagents for component resolved diagnosis and the exploration of novel vaccination strategies. METHODS: The North Sea shrimp (Crangon crangon), which is frequently consumed in Europe, served as a model organism in this study. TM and AK were directly cloned from mRNA based on sequence homology and produced as recombinant proteins. Additional IgE-reactive proteins were isolated by preparative SDS-PAGE and identified by mass spectrometry and corresponding cDNAs were cloned and expressed in E. coli. The relevance of the 6 cloned crustacean allergens was confirmed with sera of 31 shrimp-allergic subjects, 12 of which had a positive double-blind, placebo-controlled food challenge (DBPCFC) to shrimp and 19 a convincing history of food allergy to shrimp, including 5 cases of anaphylaxis. Quantitative IgE measurements were performed by ImmunoCAP. RESULTS: Six recombinant crustacean proteins: TM, AK, SCP, a novel MLC, troponin C (TnC), and triosephosphate isomerase (TIM) bound IgE in ImmunoCAP analysis. Specific IgE to at least one of these single shrimp allergens was detected in 90% of the study population, thus the in vitro diagnostic sensitivity was comparable to that of shrimp extract (97%). In 75% of the subjects, the combined technical sensitivity was similar to or greater with single shrimp allergens than with natural shrimp extract. CONCLUSIONS: We identified six IgE-binding proteins from C. crangon, three of which have not before been described as allergens in crustaceans. This extensive panel of shrimp allergens forms a valuable asset for future efforts towards the identification of clinically relevant biomarkers and as a basis to approach patient-tailored immunotherapeutic strategies.


Subject(s)
Allergens/immunology , Allergens/isolation & purification , Crangonidae/immunology , Food Hypersensitivity/diagnosis , Food Hypersensitivity/immunology , Adolescent , Adult , Aged , Allergens/chemistry , Amino Acid Sequence , Animals , Blotting, Western , Child , Crangonidae/chemistry , Electrophoresis, Polyacrylamide Gel , Female , Humans , Immunoglobulin E/blood , Male , Mass Spectrometry , Middle Aged , Recombinant Proteins/immunology , Sensitivity and Specificity , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Young Adult
6.
Front Biosci (Elite Ed) ; 3(3): 818-29, 2011 06 01.
Article in English | MEDLINE | ID: mdl-21622093

ABSTRACT

The Holder method is the recommended pasteurization method for human milk banks, as it ensures the microbiological safety of human milk (HM). The loss of some biologically active milk components, due to the heat treatment, is a main limit to the diffusion of donor HM. High-temperature short-time (HTST) pasteurization may be an alternative to maintain the nutritional and immunological quality of HM. The aim of the present study was to compare the impact of Holder and HTST pasteurization on the HM protein profile. The protein patterns of HTST-treated milk and raw milk were similar. The Holder method modified bile salt-stimulated lipase, lactoferrin and components of the immune system. The HTST method preserved the integrity of bile salt-stimulated lipase, lactoferrin and, to some extent, of IgAs. Holder pasteurization decreased the amount of bile salt-stimulated lipase and inactivated the remaining molecules, while the HTST method did not alter its activity. Pasteurization increased the bioavailable lysine quantity. HTST pasteurization seems to better retain the protein profile and some of the key active components of donor HM.


Subject(s)
Milk Proteins/analysis , Milk, Human/chemistry , Sterilization/methods , Amino Acid Sequence , Blotting, Western , Electrophoresis, Polyacrylamide Gel , Humans , Mass Spectrometry , Oxidation-Reduction
7.
J Agric Food Chem ; 58(7): 4513-6, 2010 Apr 14.
Article in English | MEDLINE | ID: mdl-20222729

ABSTRACT

Green beans belong to the Fabaceae family, which includes widely consumed species, such as beans, peanuts, and soybeans. In the literature, few cases have described allergic reactions upon the exposure to green bean boiling steam or ingestion. Here, we describe five patients reporting documented adverse reactions upon the ingestion of cooked green beans, and we characterize the responsible allergen. Fresh and cooked green beans were tested by a prick + prick technique. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and IgE immunoblotting were performed with boiled vegetable extract, and the N-terminal sequence of the immunoreactive protein was obtained by analyzing the excised band in a protein sequencer. Immunoblotting inhibition of cooked green bean with in-house-purified peach lipid transfer protein (LTP) Pru p 3 was performed. An interesting green bean protein was chromatographically purified, tested with a pool serum, and inhibited with Pru p 3. Moreover, its molecular mass was determined by mass spectrometry. Prick + prick tests with raw and cooked green beans were positive for all of the patients. IgE immunoblotting showed that all of the patients reacted toward a unique IgE-binding protein at about 9 kDa. The obtained N-terminal sequence revealed the following amino acids: Ala-Ile-Ser-X-Gly-Qln-Val-Thr-Ser-Ser-Leu-Ala, corresponding to an LTP. A complete inhibition of the IgE binding to this protein, in both raw and purified extract, was obtained by purified peach Pru p 3, confirming previous IgE immunoblotting results.


Subject(s)
Carrier Proteins/immunology , Food Hypersensitivity/immunology , Immunoglobulin E/immunology , Phaseolus/immunology , Adolescent , Adult , Amino Acid Sequence , Antigens, Plant/immunology , Carrier Proteins/chemistry , Female , Humans , Immunoglobulin E/chemistry , Male , Molecular Sequence Data , Protein Binding , Young Adult
8.
Front Biosci (Elite Ed) ; 2(2): 526-36, 2010 01 01.
Article in English | MEDLINE | ID: mdl-20036899

ABSTRACT

Successful therapy in cow milk (CM) protein allergy rests upon completely eliminating CM proteins from the child's diet: it is thus necessary to provide a replacement food. Donkey milk (DM) has recently aroused scientific and clinical interest, above all among paediatric allergologists. A deeper knowledge of proteins in DM is necessary to evaluate the immunological and physiological properties of this natural substitute for cow's milk. The paper offers a detailed comparative analysis among the protein fractions of DM, CM and human milk, following an extensive proteomic study of the casein and whey proteins of DM performed by narrow pH range 2-DE. The detailed protein composition and structural features reported in this study provide insight into the molecular reasons for the hypoallergenicity of DM. Whole DM might constitute a valid substitute of CM in feeding children with CM protein allergy and it might also constitute the basis for formulas suitable for allergic subjects in the first year of life.


Subject(s)
Milk Hypersensitivity/prevention & control , Milk Proteins/analysis , Milk, Human/chemistry , Milk/chemistry , Animals , Cattle , Electrophoresis, Gel, Two-Dimensional , Equidae , Humans , Proteomics
9.
Front Biosci (Elite Ed) ; 2(2): 537-46, 2010 01 01.
Article in English | MEDLINE | ID: mdl-20036900

ABSTRACT

Donkey's milk (DM) has recently aroused scientific interest, above all among paediatric allergologists. A deeper knowledge of both proteins and fats in donkey's milk is necessary to evaluate the immunological, physiological and nutritional properties. By using the most refined techniques for fatty acids analysis, the paper offers a detailed comparative analysis of the lipid fractions of DM as well as of human and cow milk, also indicating the distribution of fatty-acid moieties among sn-1/3 and sn-2 positions of the glycerol backbone. In DM the position of fatty acids on glycerol backbone, above all of long chain saturated fatty acids, is very similar to that of human milk: this fact, in conjunction with the relatively high contents of medium-chain triglycerides, makes the lipids in DM, through quantitatively reduced, highly bioavailable. The high PUFA n-3 content of donkey's milk, and especially its low n-6/n-3 ratio, acquires particular interest in subjects affected by cow's milk protein allergy. Whole DM might also constitute the basis for formulas suitable for subjects in the first year of life.


Subject(s)
Lipids/analysis , Milk Hypersensitivity/prevention & control , Milk, Human/chemistry , Milk/chemistry , Animals , Cattle , Chromatography, High Pressure Liquid , Equidae , Gas Chromatography-Mass Spectrometry , Humans
10.
J Agric Food Chem ; 57(22): 10749-54, 2009 Nov 25.
Article in English | MEDLINE | ID: mdl-19919119

ABSTRACT

There is an increasing consumption of tomatoes worldwide: fresh in salads, cooked in household sauces, or industrially processed. Although many tomato allergens have been identified, there is no information in the literature on the allergenic components found in commercial tomato products. The primary aim of the study was to evaluate the allergenic profile of commercial tomato products by skin prick tests (SPTs) and IgE/immunoblotting in tomato-allergic subjects. The secondary end point was the study of the IgE-binding profile of tomato peel, pulp, and seeds. Forty tomato-allergic patients, reporting oral allergy syndrome (OAS) at different grades of severity for fresh and, in some cases, also for cooked tomato, were selected on the basis of positive tomato allergy history or open food challenge (OFC). They were evaluated by SPTs with different experimental tomato extracts. SDS-PAGE/immunoblotting was performed to detect tomato allergens, which were then identified by Edman degradation. Twenty-three patients (57.5%) presented first-grade OAS at the OFC, whereas 17 (42.5%) reported severe symptoms. Ten of these 17 patients (25%) reported allergic reactions to cooked tomatoes; in immunoblotting tests, their sera reacted only to lipid transfer protein (LTP). In commercial products, LTP was the only detectable allergen. In contrast to other LTP-containing fruits, in tomato, an IgE-binding LTP was identified not only in the peel but also in the pulp and seeds. This study demonstrates that, in fresh tomato, different LTP isoforms are present and allergenic. Industrial tomato derivatives still contain LTP, thus presenting a problem for LTP-allergic patients.


Subject(s)
Antigens, Plant/analysis , Antigens, Plant/immunology , Carrier Proteins/analysis , Carrier Proteins/immunology , Food Hypersensitivity/immunology , Fruit/immunology , Immunoglobulin E/metabolism , Plant Proteins/analysis , Plant Proteins/immunology , Solanum lycopersicum/immunology , Adult , Female , Fruit/chemistry , Humans , Immunoblotting , Male , Plant Extracts/immunology , Seeds/chemistry , Seeds/immunology , Skin Tests
11.
Anal Bioanal Chem ; 395(1): 93-102, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19669736

ABSTRACT

Italian patients with maize anaphylaxis have been shown to have IgE toward two major maize allergens: an alpha-amylase inhibitor and a 9-kDa LTP. A complete study on maize food allergens in patients with positive maize double-blind, placebo-controlled food challenge (DBPCFC) is lacking. The objective was to utilize the three maize protein fractions to identify and characterize the most relevant IgE-binding proteins recognized by the sera of Italian and Swiss patients with either a positive maize-DBPCFC or a history of maize-induced anaphylaxis. Osborne's protein fractions of maize were extracted to obtain water-soluble, total zein, and total protein fractions. Protein IgE-binding capacity was investigated by SDS-PAGE immunoblotting using the sera from DBPCFC-positive patients and from patients with maize-induced anaphylaxis. Purified maize LTP was used to inhibit the IgE immunoblotting of the three protein fractions. IgE immunoblotting demonstrated that the 9-kDa LTP was recognized by all the Italian patients and by none of the Swiss patients. Other allergens were: 14-kDa alpha-amylase inhibitor, 30-kDa endochitinases A and -B, 19 kDa zein-beta precursor, and 26 kDa zein-alpha precursor; a newly described allergen, the globulin-2 precursor, identified in the total protein fraction. It is noteworthy that maize LTP and endochitinase were cross-reactive with grape LTP and one grape endochitinase. LTP was found to be the only major allergen in Italian patients with either positive maize challenge or a history of maize-induced anaphylaxis. We have identified other maize allergens in subjects with maize food allergy, as grape cross-reactive endochitinase, however, the clinical significance of these proteins needs to be investigated in larger groups of patients with allergy to these food items.


Subject(s)
Carrier Proteins/immunology , Chitinases/immunology , Food Hypersensitivity/etiology , Serologic Tests/methods , Zea mays/immunology , Zein/immunology , Adult , Aged , Anaphylaxis/etiology , Antigens, Plant , Child , Double-Blind Method , Female , Food Hypersensitivity/immunology , Humans , Immunoglobulin E/metabolism , Italy , Male , Middle Aged , Placebos , Plant Proteins , Protein Binding , Young Adult
12.
Mol Nutr Food Res ; 52(12): 1486-96, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18720344

ABSTRACT

Soybean containing products are widely consumed, thus reliable methods for detection of soy in foods are needed in order to make appropriate risk assessment studies to adequately protect soy allergic patients. Six methods were compared using eight food products with a declared content of soy: a direct sandwich ELISA based on polyclonal rabbit antibody (ab) to raw soy flakes, a commercial and an in-house competitive ELISA both based on ab to denatured, 'renatured' soy protein, an enzyme-allergosorbent test (EAST) inhibition based on two sera from soy allergic patients, histamine release (HR) using basophils passively sensitized with patient serum and a PCR method detecting soy DNA. Eight food products were selected as model foods to test the performance of the methods. There was an overall good agreement between the methods in terms of ranks of soy content but not the quantity. The sandwich ELISA aimed at native soy proteins had the lowest detection limit of 0.05 ppm, but only identified soy in 5/8 products, and generally in lower amounts compared to other methods. The competitive ELISA had a higher detection limit of 21 ppm, but seemed more successful in detecting processed soy. Only HR, EAST inhibition and PCR detected soy in all eight products. In spite of a general good correlation in terms of ranks of soy content, more than a single method may be necessary to confirm the presence of soy in foods.


Subject(s)
Allergens/analysis , Glycine max/immunology , Animals , Enzyme-Linked Immunosorbent Assay , Food Hypersensitivity/diagnosis , Histamine Release , Humans , Polymerase Chain Reaction , Protein Denaturation , Rabbits , Risk Assessment , Soybean Proteins/analysis
13.
Mol Nutr Food Res ; 52(12): 1448-56, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18727006

ABSTRACT

Although several studies have aimed to identify mare's milk proteins, only the major whey proteins and some caseins have yet been characterized. Incomplete sequencing of the equine genome and the difficulty of recovering highly hydrophobic proteins mean that little is known to date about the proteins associated with milk fat globules, which have been shown to play an important role in newborns' defense mechanisms. The fat fraction, in particular the distribution of unsaturated fatty acids, has been more extensively studied, but complex lipids are only partially elucidated. This study reports a 2-DE approach combined with a powerful method for de novo protein sequencing, and quali-quantitative data on complex lipid composition determined by high performance TLC (HPTLC) and GC. The presence in mare's milk of long-chain highly unsaturated fatty acids, and the evidence of close similarity between equine and human milk fat globule membrane proteins, support the use of mare's milk for human nutrition.


Subject(s)
Glycolipids/analysis , Glycoproteins/analysis , Lipids/analysis , Milk Proteins/analysis , Amino Acid Sequence , Animals , Colostrum/chemistry , Fatty Acids/analysis , Female , Horses , Lipid Droplets , Milk Proteins/chemistry , Molecular Sequence Data , N-Acetylneuraminic Acid/analysis
14.
Mol Nutr Food Res ; 52 Suppl 2: S186-95, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18727010

ABSTRACT

Well-characterised and immunologically active recombinant allergens are of eminent importance for improvement of diagnostic tools and immunotherapy of allergic diseases. The use of recombinant allergens has several advantages such as the more precise quantification of the active substance compared to allergen extracts and the reduced risk of contamination with other allergenic proteins compared to purified natural allergens. Optimised standard protocols for expression and purification and a detailed physico-chemical characterisation of such recombinant allergens are necessary to ensure consistent quality and comparability of results obtained with recombinant material. In this study the major allergen Pen a 1 of brown shrimp (Penaeus aztecus) was expressed in E. coli and purified in two steps by immobilised metal chelate-affinity chromatography (IMAC) and size-exclusion chromatography. Identity and purity were verified with N-terminal sequencing and peptide mass fingerprinting. Circular dichroism and NMR-spectroscopy indicated an alpha-helical flexible structure of rPen a 1 which is in accordance with the known structure of tropomyosins. Finally, the recombinant allergen proved to be immunologically reactive in IgE Western blot analysis and ELISA. This study provides a protocol for the preparation of recombinant shrimp tropomyosin in standardised quality.


Subject(s)
Allergens/isolation & purification , Allergens/chemistry , Allergens/immunology , Amino Acid Sequence , Animals , Circular Dichroism , Humans , Immunochemistry , Magnetic Resonance Spectroscopy , Molecular Sequence Data , Protein Folding , Recombinant Proteins/isolation & purification
15.
Mol Nutr Food Res ; 52 Suppl 2: S262-71, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18686294

ABSTRACT

Several hazelnut allergens with different clinical relevance and crossreactive properties have been identified and characterized so far. The aim of this study was to develop protocols for producing relatively large amounts of three recombinant hazelnut allergens Cor a 1.04, Cor a 2, and Cor a 8 in a folded and immunologically active form. The availability of well-characterized, pure recombinant allergens will improve diagnostic in vitro tests for food allergy, by allowing a highly sensitive component resolved diagnosis. Depending on the individual hazelnut allergen, protocols for heterologous production - either as fusion or nonfusion protein - were developed to obtain homogenous protein batches. The resulting proteins were purified by a two-step FPLC method and their IgE antibody reactivity was verified. Identity was verified by N-terminal sequencing and MALDI-TOF-MS analysis. Their secondary and tertiary structure was controlled by circular dichroism (CD)-spectroscopy and NMR analysis. Decisions on the strategies for expression and purification of allergens on a large scale were made on a case by case basis: Preparation of rCor a 1.04 and rCor a 2 as fusion proteins in E. coli from inclusion bodies resulted in approximately 10 mg pure protein per liter whereas rCor a 8 expression in yeast as nonfusion protein yielded 30 mg/L.


Subject(s)
Allergens/isolation & purification , Corylus/immunology , Nut Hypersensitivity/etiology , Allergens/biosynthesis , Allergens/chemistry , Allergens/immunology , Amino Acid Sequence , Circular Dichroism , Humans , Magnetic Resonance Spectroscopy , Molecular Sequence Data , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/immunology , Recombinant Proteins/isolation & purification
17.
Adv Exp Med Biol ; 606: 129-41, 2008.
Article in English | MEDLINE | ID: mdl-18183927

ABSTRACT

The milk fat globule membrane (MFGM) is the membrane surrounding lipid droplets during their secretion in the alveolar lumen of the lactating mammary gland. MFGM proteins represent only 1-4% of total milk protein content; nevertheless, the MFGM consists of a complex system of integral and peripheral proteins, enzymes, and lipids. Despite their low classical nutritional value, MFGM proteins have been reported to play an important role in various cellular processes and defense mechanisms in the newborn. Using a proteomic approach, such as high-resolution, two-dimensional electrophoresis followed by direct protein identification by mass spectrometry, it has been possible to comprehensively characterize the subcellular organization of MFGM. This chapter covers the description of MFGM proteomics from the first studies about 10 years ago through the most recent papers. Most of the investigations deal with MFGMs from human and cow milk.


Subject(s)
Glycolipids/chemistry , Glycoproteins/chemistry , Proteomics , Animals , Glycolipids/metabolism , Glycoproteins/metabolism , Humans , Lipid Droplets , Mammary Glands, Animal/metabolism , Mammary Glands, Human/metabolism , Membrane Proteins/classification , Membrane Proteins/metabolism , Milk Ejection
18.
Int Arch Allergy Immunol ; 144(1): 10-22, 2007.
Article in English | MEDLINE | ID: mdl-17496422

ABSTRACT

BACKGROUND: Three main problems hamper the identification of wheat food allergens: (1) lack of a standardized procedure for extracting all of the wheat protein fractions; (2) absence of double-blind, placebo-controlled food challenge studies that compare the allergenic profile of Osborne's three protein fractions in subjects with real wheat allergy, and (3) lack of data on the differences in IgE-binding capacity between raw and cooked wheat. METHODS: Sera of 16 wheat-challenge-positive patients and 6 patients with wheat anaphylaxis, recruited from Italy, Denmark and Switzerland, were used for sodium dodecyl sulfate-polyacrylamide gel electrophoresis/immunoblotting of the three Osborne's protein fractions (albumin/globulin, gliadins and glutenins) of raw and cooked wheat. Thermal sensitivity of wheat lipid transfer protein (LTP) was investigated by spectroscopic approaches. IgE cross-reactivity between wheat and grass pollen was studied by blot inhibition. RESULTS: The most important wheat allergens were the alpha-amylase/trypsin inhibitor subunits, which were present in all three protein fractions of raw and cooked wheat. Other important allergens were a 9-kDa LTP in the albumin/globulin fraction and several low-molecular-weight (LMW) glutenin subunits in the gluten fraction. All these allergens showed heat resistance and lack of cross-reactivity to grass pollen allergens. LTP was a major allergen only in Italian patients. CONCLUSIONS: The alpha-amylase inhibitor was confirmed to be the most important wheat allergen in food allergy and to play a role in wheat-dependent exercise-induced anaphylaxis, too. Other important allergens were LTP and the LMW glutenin subunits.


Subject(s)
Allergens/metabolism , Antigens, Plant/immunology , Carrier Proteins/immunology , Enzyme Inhibitors/metabolism , Food Hypersensitivity/immunology , Glutens/immunology , Immunoglobulin E/physiology , Plant Proteins/immunology , Triticum/immunology , alpha-Amylases/antagonists & inhibitors , Adult , Allergens/immunology , Amino Acid Sequence , Antigens, Plant/metabolism , Carrier Proteins/metabolism , Child, Preschool , Double-Blind Method , Enzyme Inhibitors/immunology , Europe , Female , Food Hypersensitivity/enzymology , Food Hypersensitivity/metabolism , Glutens/chemistry , Glutens/metabolism , Humans , Immunoglobulin E/biosynthesis , Immunoglobulin E/blood , Infant , Male , Middle Aged , Molecular Sequence Data , Molecular Weight , Placebos , Plant Proteins/metabolism , Triticum/chemistry , Trypsin Inhibitors/metabolism
19.
Electrophoresis ; 28(10): 1633-8, 2007 May.
Article in English | MEDLINE | ID: mdl-17492720

ABSTRACT

Despite the large number of papers dealing with bacterial proteomes, very few include information about proteins with alkaline pI's, because of the limits inherent in 2-DE technology. Nonetheless, analyses of in silico proteomes of many prokaryotes show a bimodal distribution of their proteins based on their pI's; the most crowded areas lying between pI 4-7 and 9-11. The aim of the present research was to set up a general, simple, and standardizable 2-DE protocol suitable for studying the alkaline proteome of Lactobacillus hilgardii, a Gram-positive bacillus isolated from wine. The method has also been tested on a Gram-negative bacterium able to degrade aromatic pollutants, Acinetobacter radioresistens S13. Optimization of the method was mainly focused on improving protein extraction and IEF (pI 6-11) separation protocols. Concerning IEF, different methods for sample loading (in-gel rehydration and cup loading), and different reducing agents (DTT and bis(2-hydroxyethyl) disulfide (HED)) were tested and compared. The proposed protocol was found to resolve efficiently alkaline proteins from both of our Lactobacillus and Acinetobacter strains, in spite of their different external layers, thus, enabling a more comprehensive study of their proteomes.


Subject(s)
Bacterial Proteins/chemistry , Bacterial Proteins/isolation & purification , Cell Extracts/chemistry , Disulfides/chemistry , Electrophoresis, Gel, Two-Dimensional/methods , Ethanol/analogs & derivatives , Isoelectric Focusing/methods , Lactobacillus/chemistry , Lactobacillus/metabolism , Acinetobacter/chemistry , Ethanol/chemistry , Hydrogen-Ion Concentration , Isoelectric Point , Peptide Mapping/methods , Reproducibility of Results , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Trypsin/metabolism , Wine/microbiology
20.
Pediatr Allergy Immunol ; 18(3): 258-64, 2007 May.
Article in English | MEDLINE | ID: mdl-17433003

ABSTRACT

Successful therapy in cow's milk protein allergy rests on completely eliminating cow's milk proteins from the child's diet: it is thus necessary to provide a replacement food. This prospective study investigated tolerance of donkey's milk in a population of 46 selected children with cow's milk protein allergy, for whom it was not possible to use any cow's milk substitute. Thirty-eight children (82.6%) liked and tolerated donkey's milk at the challenge and for the entire duration of follow-up. Catch-up growth was observed in all subjects with growth deficit during cow's milk proteins challenge. The degree of cross-reactivity of immunoglobulin E (IgE) with donkey's milk proteins was very weak and aspecific. Donkey's milk was found to be a valid alternative to both IgE-mediated and non-IgE-mediated cow's milk proteins allergy, including in terms of palatability and weight-height gain.


Subject(s)
Milk Hypersensitivity/diet therapy , Milk , Adolescent , Animals , Child , Child, Preschool , Equidae , Female , Humans , In Vitro Techniques , Infant , Italy , Male , Milk/adverse effects , Milk Hypersensitivity/etiology , Prospective Studies , Treatment Outcome
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