Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 56
Filter
1.
Proteome Sci ; 15: 4, 2016.
Article in English | MEDLINE | ID: mdl-28270742

ABSTRACT

BACKGROUND: Eggshells which consist largely of calcareous outer shell and shell membranes, constitute a significant part of poultry hatchery waste. The shell membranes (ESM) not only contain proteins that originate from egg whites but also from the developing embryos and different contaminants of microbial and environmental origins. As feed supplements, during post hatch growth, the hatchery egg shell membranes (HESM) have shown potential for imparting resistance of chickens to endotoxin stress and exert positive health effects. Considering that these effects are mediated by the bioactive proteins and peptides present in the membrane, the objective of the study was to identify the protein profiles of hatchery eggshell membranes (HESM). METHODS: Hatchery egg shell membranes were extracted with acidified methanol and a guanidine hydrochloride buffer then subjected to reduction/alkylation, and trypsin digestion. The methanol extract was additionally analyzed by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS). The tryptic digests were analyzed by liquid chromatography and tandem mass spectrometry (LC-MS-MS) to identify the proteins. RESULTS: Our results showed the presence of several proteins that are inherent and abundant in egg white such as, ovalbumin, ovotransferrin, ovocleidin-116, and lysozyme, and several proteins associated with cytoskeletal, cell signaling, antimicrobial, and catalytic functions involving carbohydrate, nucleic acid, and protein metabolisms. There were some blood derived proteins most likely originating from the embryos and several other proteins identified with different aerobic, anaerobic, gram positive, gram negative, soil, and marine bacterial species some commensals and others zoonotic. CONCLUSION: The variety of bioactive proteins, particularly the cell signaling and enzymatic proteins along with the diverse microbial proteins, make the HESM suitable for nutritional and biological application to improve post hatch immunity of poultry.

2.
Mol Neurobiol ; 48(2): 363-7, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23813100

ABSTRACT

Dodecafluoropentane emulsion (DDFPe) in 250 nm nanodroplets seems to swell modestly to accept and carry large amounts of oxygen in the body at >29 °C. Small particle size allows oxygen delivery even into hypoxic tissue unreachable by erythrocytes. Using permanent cerebral embolic occlusion in rabbits, we assessed DDFPe dose response as a neuroprotectant at 7 and 24 h post-embolization without lysis of arterial obstructions and investigated blood pharmacokinetics. New Zealand White rabbits (N = 56) received cerebral angiography and embolic spheres (diameter = 700-900 µm) occluded middle and/or anterior cerebral arteries. Intravenous DDFPe dosing (2 % w/v emulsion) began at 60 min and repeated every 90 min until sacrifice at 7 or 24 h post-embolization. Seven-hour groups: (1) control (embolized without treatment, N = 6), and DDFPe treatment: (2) 0.1 ml/kg (N = 7), (3) 0.3 ml/kg (N = 9), (4) 0.6 ml/kg (N = 8). Twenty-four-hour groups: (5) control (N = 16), and DDFPe treatment: (6) 0.1 ml/kg (N = 10). Infarcts as percent of total brain volume were determined using vital stains on brain sections. Other alert normal rabbits (N = 8) received IV doses followed by rapid arterial blood sampling and GC-MS analysis. Percent infarct volume means significantly decreased for all DDFPe-treated groups compared with controls, p = <0.004 to <0.03. Blood DDFP (gas) half-life was 1.45 ± 0.17 min with R = 0.958. Mean blood clearance was 78.5 ± 24.9 ml/min/kg (mean ± SE). Intravenous DDFPe decreases ischemic stroke infarct volumes. Blood half-life values are very short. The much longer therapeutic effect, >90 min, suggests multiple compartments. Lowest effective dose and maximum effective therapy duration are not yet defined. Rapid development is warranted.


Subject(s)
Cerebral Infarction/drug therapy , Fluorocarbons/therapeutic use , Neuroprotective Agents/therapeutic use , Stroke/drug therapy , Animals , Brain/drug effects , Brain/pathology , Cerebral Infarction/pathology , Disease Models, Animal , Emulsions , Fluorocarbons/blood , Fluorocarbons/pharmacology , Neuroprotective Agents/pharmacology , Rabbits , Stroke/pathology , Time Factors
3.
Curr Med Chem ; 18(1): 79-90, 2011.
Article in English | MEDLINE | ID: mdl-21110813

ABSTRACT

Globally, diabetes and obesity are two of the most common metabolic diseases of the 21(st) century. Increasingly, not only adults but children and adolescents are being affected. New approaches are needed to prevent and treat these disorders and to reduce the impact of associated disease-related complications. Industrial-scale production using plant-root cultures can produce quantities and quality of inexpensive bioactive small molecules with nutraceutical and pharmaceutical properties. Using this approach, and targeting these diseases, a next generation approach to tackling this emerging global health crisis may be developed. Adventitious roots cultured in bioreactors under controlled and reproducible conditions have been shown effective for production of natural products. The liquid-phase airlift bioreactor in particular has been used successfully for culturing roots on an industrial-scale and thus may provide an economical production platform for expressing promising plant-based antidiabetic and antioxidant molecules. This review focuses on a next-generation, scalable, bioprocessing approach for adventitious and hairy root cultures that are a pesticide-free, seasonally-independent, plant-based source of three molecules that have shown promise for the therapeutic management of diabetes and obesity: corosolic acid, resveratrol and ginsenosides.


Subject(s)
Antioxidants/metabolism , Bioreactors , Hypoglycemic Agents/metabolism , Antioxidants/chemistry , Antioxidants/pharmacology , Arachis/cytology , Arachis/metabolism , Biotechnology , Ginsenosides/biosynthesis , Ginsenosides/chemistry , Ginsenosides/pharmacology , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/pharmacology , Plant Roots/cytology , Plant Roots/metabolism , Resveratrol , Stilbenes/chemistry , Stilbenes/pharmacology , Triterpenes/chemistry , Triterpenes/pharmacology
4.
Avian Dis ; 54(4): 1166-71, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21313835

ABSTRACT

Tibial dyschondroplasia (TD) is a poultry leg problem that affects the proximal growth plate of the tibia, preventing its transition to bone. To understand the disease-induced proteomic changes, we compared the protein extracts of cartilage from normal and TD-affected growth plates. TD was induced by feeding thiram to chickens 2 wk before tissue harvest. Proteins were extracted from whole tissues and from conditioned media (CM) prepared by incubating appropriate growth plate tissues in serum-free culture medium for 48 hr. The extracts were prefractionated to contain proteins ranging between 10 and 100 kD. Equal amounts of proteins were subjected to 2D gel electrophoresis with three individual samples per group. The gels were silver stained, and digital images were compared and analyzed with Melanie software to determine differentially expressed protein spots. On comparison of two sets of gels, 47 matching spots were detected in tissue extracts and 27 in CM extracts. Among the matching spots, 12 were determined to be down-regulated in tissue extracts (P < or = 0.05) and two in CM extracts (P < or = 0.05) of TD-affected growth plates. Altogether, 32 protein spots could be identified in both tissue and CM extracts by in-gel trypsin digestion, followed by peptide mass fingerprinting and mass spectrometry (MS)/MS fragmentation. The down-regulated proteins included alpha-enolase, G protein, origin recognition complex, peptidyl prolyl isomerase, calumenin, type II collagen precursor, and the expressed sequence tag pgm2n.pk014.f20, a protein with homology to human reticulocalbin-3 (RCN3). Most of the downregulated proteins are associated with signal transduction, energy metabolism, and secretory functions that are integral to cell viability. Consistent with our earlier findings that the TD chondrocytes are nonviable, the current results suggest that thiram very likely interferes with basic metabolic functions of chondrocytes, leading to their death and, consequently, to the pathogenesis of TD.


Subject(s)
Cartilage/metabolism , Gene Expression Regulation/physiology , Growth Plate/metabolism , Osteochondrodysplasias/veterinary , Poultry Diseases/metabolism , Proteomics , Animals , Chickens , Osteochondrodysplasias/metabolism
5.
Poult Sci ; 88(2): 372-9, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19151352

ABSTRACT

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was used to screen avian heterophils in the m/z range of 1 to 20 kDa with an objective to identify specific cell-associated peptides that may be reflective of their functional physiology. The MALDI-TOF-MS profiles of crude heterophil extract showed a high intensity peak with average mass of m/z 3916.1 for chicken and m/z 4129.6 for turkey. To identify these peaks, we first purified m/z 3916.1 from chicken bone marrow extract using reverse-phase high performance liquid chromatography (RP-HPLC). Edman sequencing and peptide mass fingerprinting exclusively confirmed this peptide as beta-defensin 2 (BD2) or gallinacin-2, a broad-range antimicrobial peptide. A Uniprot database search followed by the MASCOT sequence query revealed m/z 4129.6 to be the corresponding turkey ortholog of avian beta-defensin 2 (AvBD2), also called turkey heterophil peptide 2. Both AvBD2 peptides are 36 amino acids long including a highly conserved region with 6 invariant cysteines forming the 3 disulfide bonds characteristic of defensins. The method confirmed the existence of the complete mature peptide sequence of the turkey heterophilic BD2 previously proposed based on cDNA analysis. These results demonstrate that screening of the crude extract by MALDI-TOF-MS can identify cell- or tissue-associated peptides in their functional or mature forms, raising the possibility that such peptides can be used as biomarkers in their altered physiological states.


Subject(s)
Antibodies, Heterophile/metabolism , Blood Cells/metabolism , Chickens/physiology , Turkeys/physiology , beta-Defensins/chemistry , beta-Defensins/isolation & purification , Amino Acid Sequence , Animals , Chromatography, High Pressure Liquid , Molecular Sequence Data , Spectrometry, Mass, Electrospray Ionization , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
6.
J Econ Entomol ; 102(6): 2224-32, 2009 Dec.
Article in English | MEDLINE | ID: mdl-20069852

ABSTRACT

The purpose of this study was to develop and evaluate lures for adult green June beetles, Cotinis nitida (L.) (Coleoptera: Scarabaeidae), for future use in a mass trapping program. Volatile organic compounds collected from headspace of green June beetles feeding on fermenting ripe apple (Malus spp.), the natural lure that elicits feeding aggregations, were identified and confirmed by gas chromatography and mass spectrometry. Yellow funnel traps baited with 91% isopropanol or the five component blend were equally effective in eliciting aggregation behavior and often more attractive to green June beetles than the natural lure. In 2008, three trap lines adjacent and parallel to the perimeter of two vineyards, each with 12 Xpando yellow funnel traps baited with either 91% isopropanol or the five component blend, differed in catch of green June beetles across sample dates, and sample date by bait interaction but there were no differences among these two baits. A season total of 324,007 green June beetle were captured by these 36 baited traps. A brief review is included of fermentation volatiles attractive to insects. We conclude with the potential cost to use mass trapping against adult green June beetles.


Subject(s)
Coleoptera/chemistry , Feeding Behavior , Insect Control , Pheromones/isolation & purification , Volatile Organic Compounds/isolation & purification , Animals , Female , Fermentation , Fruit , Male , Malus
7.
J Chem Inf Comput Sci ; 41(5): 1360-6, 2001.
Article in English | MEDLINE | ID: mdl-11604038

ABSTRACT

Five quantitative spectroscopic data-activity relationships (QSDAR) models for 50 steroidal inhibitors binding to aromatase enzyme have been developed based on simulated (13)C nuclear magnetic resonance (NMR) data. Three of the models were based on comparative spectral analysis (CoSA), and the two other models were based on comparative structurally assigned spectral analysis (CoSASA). A CoSA QSDAR model based on five principal components had an explained variance (r(2)) of 0.78 and a leave-one-out (LOO) cross-validated variance (q(2)) of 0.71. A CoSASA model that used the assigned (13)C NMR chemical shifts from a steroidal backbone at five selected positions gave an r(2) of 0.75 and a q(2) of 0.66. The (13)C NMR chemical shifts from atoms in the steroid template position 9, 6, 3, and 7 each had correlations greater than 0.6 with the relative binding activity to the aromatase enzyme. All five QSDAR models had explained and cross-validated variances that were better than the explained and cross-validated variances from a five structural parameter quantitative structure-activity relationship (QSAR) model of the same compounds. QSAR modeling suffers from errors introduced by the assumptions and approximations used in partial charges, dielectric constants, and the molecular alignment process of one structural conformation. One postulated reason that the variances of QSDAR models are better than the QSAR models is that (13)C NMR spectral data, based on quantum mechanical principles, are more reflective of binding than the QSAR model's calculated electrostatic potentials and molecular alignment process. The QSDAR models provide a rapid, simple way to model the steroid inhibitor activity in relation to the aromatase enzyme.


Subject(s)
Aromatase/metabolism , Steroids/chemistry , Steroids/metabolism , Aromatase Inhibitors , Computer Simulation , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/metabolism , Magnetic Resonance Spectroscopy , Quantitative Structure-Activity Relationship , Regression Analysis , Software Design
8.
J Ind Microbiol Biotechnol ; 26(3): 140-4, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11420653

ABSTRACT

To investigate the microbial biotransformation of veterinary fluoroquinolones, Mucor ramannianus was grown in sucrose/peptone broth with sarafloxacin for 18 days. Cultures were extracted with ethyl acetate and extracts were analyzed by liquid chromatography. The two metabolites (26% and 15% of the A280, respectively) were identified by mass and 1H nuclear magnetic resonance spectra as N-acetylsarafloxacin and desethylene-N-acetylsarafloxacin. The biological formation of desethylene-N-acetylsarafloxacin has not been previously observed.


Subject(s)
Anti-Infective Agents/metabolism , Ciprofloxacin/analogs & derivatives , Ciprofloxacin/metabolism , Fluoroquinolones , Mucor/metabolism , Animals , Biodegradation, Environmental , Soil Pollutants/metabolism , Veterinary Medicine/methods
9.
J Chem Inf Comput Sci ; 41(1): 219-24, 2001.
Article in English | MEDLINE | ID: mdl-11206376

ABSTRACT

We have developed a spectroscopic data-activity relationship (SDAR) model based on 13C NMR spectral data for 30 estrogenic chemicals whose relative binding affinities (RBA) are available for the alpha (ERalpha) and beta (ERbeta) estrogen receptors. The SDAR models segregated the 30 compounds into strong and medium binding affinities. The SDAR model gave a leave-one-out (LOO) cross-validation of 90%. Two compounds that were classified incorrectly in the SDAR model were in the transition zone between classifications. Real and predicted 13C NMR chemical shifts were used with test compounds to evaluate the predictive behavior of the SDAR model. The 13C NMR SDAR model using predicted 13C NMR data for the test compounds provides a rapid, reliable, and simple way to screen whether a compound binds to the estrogen receptors.


Subject(s)
Models, Chemical , Receptors, Estrogen/metabolism , Carbon Isotopes , Estradiol/metabolism , Nuclear Magnetic Resonance, Biomolecular , Quantitative Structure-Activity Relationship , Receptors, Estrogen/chemistry
11.
Mass Spectrom Rev ; 20(4): 172-94, 2001.
Article in English | MEDLINE | ID: mdl-11835305

ABSTRACT

The development of MALDI-TOF mass spectrometry methods for the characterization of bacteria is reviewed and discussed. The general use of MALDI for the characterization of large biomolecules led directly to obvious applications involving the analysis of isolated bacterial proteins. More surprising was the observation that MALDI-TOF mass spectrometry could be applied directly to crude cellular fractions or cellular suspensions and that the resulting data from such complex mixtures could provide evidence for chemotaxonomic classification. Versatility and the rapidity of analysis led to the rapid development of a number of MALDI-TOF methods involving bacteria. Examples of some of the applications covered in this review are the analysis of bacterial RNA and DNA, the detection of recombinant proteins, the characterization of targeted or unknown proteins, bacterial proteomics, the detection of virulence markers, and the very rapid characterization of bacteria at the genus, species, and strain level. The demonstrated capability of taxonomic classification at the strain level, using unprocessed cells, opens the possibility that MALDI-TOF and similar mass spectrometry approaches may contribute significantly to fulfilling emerging needs for the development of near real-time methods for the characterization of bacteria.


Subject(s)
Bacteria/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Bacteria/pathogenicity , Bacterial Proteins/chemistry , Biomarkers , DNA, Bacterial/chemistry , Humans , Proteome , RNA, Bacterial/chemistry
12.
J Chem Inf Comput Sci ; 40(6): 1449-55, 2000.
Article in English | MEDLINE | ID: mdl-11128104

ABSTRACT

We have developed four spectroscopic data-activity relationship (SDAR) models of monodechlorination of 32 chlorinated benzene compounds in anaerobic estuarine sediment. The SDAR models were based on combinations of 13C nuclear magnetic resonance (NMR), infrared absorption (IR), and electron ionization mass spectrometric (EI MS) data. The SDAR models segregated the 32 compounds into 17 readily monodechlorinated compounds and 15 not readily monodechlorinated compounds. The SDAR model based on 13C NMR, IR, and EI MS data gave a leave-one-out cross-validation of 93.8%. The SDAR model based on a composite of 13C NMR and IR data gave a leave-one-out cross-validation of 90.6%. The SDAR model based on a composite of IR and EI MS data gave a leave-one-out cross-validation of 84.4%. The SDAR model based on a composite of 13C NMR and EI MS data gave a leave-one-out cross-validation of 84.4%. These reliable SDAR models provide a rapid and simple way to predict whether a chlorinated benzene compound will readily go through monodechlorination. The FDA has filed a patent application on methods of using any combination of spectral data (NMR, MS, UV-vis, IR, and fluorescence, phosphorescence) to model a chemical, physical, or biological endpoint.


Subject(s)
Hydrocarbons, Chlorinated/chemistry , Mass Spectrometry/methods , Water Pollutants, Chemical , Carbon Isotopes , Models, Chemical , Spectrophotometry, Infrared
13.
Toxicol Appl Pharmacol ; 169(1): 17-25, 2000 Nov 15.
Article in English | MEDLINE | ID: mdl-11076692

ABSTRACT

Two Spectroscopic Data-Activity Relationship (SDAR) models based on (13)C nuclear magnetic resonance (NMR) and electron ionization mass spectra (EI MS) data were developed for 108 compounds whose relative binding affinities (RBA) to the estrogen receptor are known. The (13)C NMR and EI MS data were used as spectrometric digital fingerprints to reflect the electronic and structural characteristics of the compounds. Both SDAR models segregated the 108 compounds into 20 strong, 15 medium, and 73 weak relative binding classifications. The first SDAR model, based on (13)C NMR data alone, gave a leave-one-out (LOO) cross-validation of 75.0%. The second SDAR model, based on a composite of (13)C NMR and EI MS data, gave a LOO cross-validation of 82.4%. Many of the misidentifications from the cross-validations were between medium and weak classifications, where there were fewer specific spectrometric characteristics to identify the relationship of spectra to estrogen receptor binding. Real and predicted (13)C NMR chemical shifts were used to test the predictive behavior of both SDAR models. The ease of use and speed of SDAR modeling may facilitate their use with other toxicological endpoints.


Subject(s)
Magnetic Resonance Spectroscopy/methods , Models, Molecular , Quantitative Structure-Activity Relationship , Receptors, Estrogen/metabolism , Spectrometry, Mass, Electrospray Ionization/methods , Carbon Radioisotopes , Discriminant Analysis , Estrogens, Non-Steroidal/chemistry , Estrogens, Non-Steroidal/metabolism , Receptors, Estrogen/chemistry
14.
J Chromatogr A ; 888(1-2): 85-92, 2000 Aug 04.
Article in English | MEDLINE | ID: mdl-10949475

ABSTRACT

A RP-HPLC method with photodiode array detection and LC-electrospray ionization (ESI) MS confirmation was established for the determination of major active components in St. John's Wort dietary supplement capsules. The samples alternatively were extracted with ethanol-acetone (2:3) using a 55 degrees C water-bath shaker or an ambient temperature ultrasonic bath. Extracts were separated by RP-C18 chromatography using a 95-min water-methanol-acetonitrile-trifluoroacetic acid gradient. The major components were identified by photodiode array detection and then confirmed by LC-ESI-MS. The quantification of components was performed using an internal standard (luteolin). This method may serve as a valuable tool for the quality evaluation of St. John's Wort dietary supplement products.


Subject(s)
Chromatography, High Pressure Liquid/methods , Dietary Supplements/analysis , Hypericum/chemistry , Plants, Medicinal , Calibration , Reproducibility of Results , Spectrometry, Mass, Electrospray Ionization , Spectrophotometry, Ultraviolet
16.
Appl Environ Microbiol ; 66(6): 2664-7, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10831454

ABSTRACT

Enrofloxacin metabolism by Mucor ramannianus was investigated as a model for the biotransformation of veterinary fluoroquinolones. Cultures grown in sucrose-peptone broth were dosed with enrofloxacin. After 21 days, 22% of the enrofloxacin remained. Three metabolites were identified: enrofloxacin N-oxide (62% of the total absorbance), N-acetylciprofloxacin (8.0%), and desethylene-enrofloxacin (3.5%).


Subject(s)
Anti-Infective Agents/metabolism , Fluoroquinolones , Mucor/metabolism , Quinolones/metabolism , Anti-Infective Agents/chemistry , Biotransformation , Chromatography, High Pressure Liquid , Enrofloxacin , Magnetic Resonance Spectroscopy , Mucor/growth & development , Quinolones/chemistry
17.
Rapid Commun Mass Spectrom ; 14(10): 911-7, 2000.
Article in English | MEDLINE | ID: mdl-10825256

ABSTRACT

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectra of bacterial proteins were obtained from water, lettuce and cloth samples contaminated with Shigella flexneri, Escherichia coli, and Aeromonas hydrophila. Spectra were obtained using proteins directly isolated from water (or water used for rinsing samples) without culturing the bacteria. For S. flexneri and E. coli, two marker ions for specific proteins associated with a virulence-related property (acid resistance) were easily detected. For A. hydrophila, ions from two specifically selected marker proteins, as well as ions from the larger group of proteins isolated from pure cultures, all matched spectra from a contaminated water sample, providing strong evidence that A. hydrophila was the bacterial contaminant. Rinse water from contaminated lettuce and cloth samples showed the same marker ions as the contaminated water samples.


Subject(s)
Bacterial Proteins/analysis , Food Microbiology , Gossypium/microbiology , Lactuca/microbiology , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Water Microbiology , Aeromonas hydrophila/isolation & purification , Biomarkers/analysis , Escherichia coli/isolation & purification , Ions , Lasers , Shigella flexneri/isolation & purification
18.
J Agric Food Chem ; 48(5): 1673-7, 2000 May.
Article in English | MEDLINE | ID: mdl-10820077

ABSTRACT

Improper application of antibiotic chemicals to livestock and aquaculture species may lead to the occurrence of residues in food supplies. An appropriate depletion period is needed after the administration of drugs to animals for ensuring that residues in edible tissues are below established tolerance levels. This study was conducted to determine incurred amoxicillin residues in catfish muscle following oral administration. Dosed fish were harvested after four depletion periods, and muscle fillets were analyzed for amoxicillin residues using an HPLC method with precolumn derivatization and fluorescence detection. The residue levels in fish after a 6-h depletion ranged from 40 to 64 ng/g with one exception at 297 ng/g. Average residue levels decreased to 5.4 and 2. 8 ng/g after 24- and 48-h depletions, respectively. Residue levels after a 72-h depletion decreased to below the method's limit of quantitation (1.2 ng/g). An LC-MS/MS confirmatory method was developed. Confirmation of the presence of amoxicillin was demonstrated in incurred fish samples containing residues at approximately 50-300 ng/g.


Subject(s)
Amoxicillin/analysis , Chromatography, High Pressure Liquid/methods , Drug Residues/analysis , Muscles/chemistry , Penicillins/analysis , Administration, Oral , Amoxicillin/administration & dosage , Animals , Ictaluridae , Penicillins/administration & dosage , Spectrometry, Fluorescence
19.
Arch Microbiol ; 174(6): 422-8, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11195098

ABSTRACT

Fecal bacteria from a healthy individual were screened for the specific bacteria involved in the metabolism of dietary isoflavonoids. Two strains of bacteria capable of producing primary and secondary metabolites from the natural isoflavone glycosides daidzin and genistin were detected. The metabolites were identified by comparison of their HPLC/mass, 1H NMR and UV spectra with those of standard and synthetic compounds. Both Escherichia coli HGH21 and the gram-positive strain HGH6 converted daidzin and genistin to the their respective aglycones daidzein and genistein. Under anoxic conditions, strain HGH6 further metabolized the isoflavones daidzein and genistein to dihydrodaidzein and dihydrogenistein, respectively. The reduction of a double bond between C-2 and C-3 to a single bond was isoflavonoid-specific by strain HGH6, which did not reduce a similar bond in the flavonoids apigenin and chrysin. Strain HGH6 did not further metabolize dihydrodaidzein and dihydrogenistein. This is the first study in which specific colonic bacteria that are involved in the metabolism of daidzin and genistin have been detected.


Subject(s)
Escherichia coli/metabolism , Feces/microbiology , Gram-Positive Bacteria/metabolism , Intestines/microbiology , Isoflavones/metabolism , Anaerobiosis , Biotransformation , Chromatography, High Pressure Liquid , Genistein/metabolism , Humans , Magnetic Resonance Spectroscopy , Mass Spectrometry , Oxidation-Reduction , Spectrophotometry, Ultraviolet , beta-Glucosidase/metabolism
20.
Anal Chem ; 71(15): 3226-30, 1999 Aug 01.
Article in English | MEDLINE | ID: mdl-10450164

ABSTRACT

Characteristic ions in the MALDI TOF mass spectra from bacterial cells have been associated with four known proteins. The proteins, observed both from cells and in filtered cellular suspensions, were isolated by HPLC and identified on the basis of their mass spectra and their partial amino acid sequence, determined using the Edman method (10-15 residues). The acid resistance proteins HdeA and HdeB give rise to ions near m/z 9735 and 9060 in MALDI TOF mass spectra from cells and from extracts of both Escherichia coli 1090 and Shigella flexneri PHS-1059. However, the proteins associated with proteolytic cleavage by the peptidase Lep, rather than the precursor proteins, were observed, both using cells and from cellular extracts. A cold-shock protein, CspA, was associated with the ion near m/z 7643 from Pseudomonas aeruginosa. Similarly, a cold-acclimation protein, CapB, was identified as the source of the ion near m/z 7684 in P. putida. This last protein was homologous with a known CapB from P. fragi. While these experiments involved the detection of known or homologous proteins from typical bacteria, this same approach could also be applied to the detection of unique proteins or biomarker proteins associated with other bacteria of public health significance.


Subject(s)
Bacterial Proteins/analysis , Escherichia coli Proteins , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Amino Acid Sequence , Bacterial Proteins/isolation & purification , Carrier Proteins/analysis , Carrier Proteins/isolation & purification , Chromatography, High Pressure Liquid , Cold Temperature , Escherichia coli/chemistry , Heat-Shock Proteins/analysis , Heat-Shock Proteins/isolation & purification , Molecular Sequence Data , Pseudomonas aeruginosa/chemistry , Sequence Homology, Amino Acid , Shigella flexneri/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL
...