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1.
J Food Sci Technol ; 52(5): 2751-60, 2015 May.
Article in English | MEDLINE | ID: mdl-25892772

ABSTRACT

Seasonal variation in the proximate and mineral composition of Kappaphycus alvarezii were investigated in the present study, moreover, the relationship between the nutritive components of this seaweed and the environment were also established. Carbohydrates represented the major portion of the algae (i.e. average total carbohydrate content was 23.01 ± 1.64 g/100 g DW), while the lipid content was the lowest among the constituents investigated (0.39 ± 0.04 to 0.91 ± 0.51 g/100 g DW). The protein content of K. alvarezii varied from 12.69 ± 0.6 to 23.61 ± 0.02 g/100 g DW, and the fiber content varied between 9.68 ± 0.08 to 18.57 ± 0.15 g/100 g DW. Highest total mineral content (29939.61 ± 9340.38 mg/100 g DW) was observed in April 2005, while least values were recorded in January 2006 i.e. (10997.62 ± 1120.26 mg/100 g DW). The Na/K ratio during the study ranged from 0.34 to 0.87. All the samples showed remarkable semi-refined carrageenan (SRC) yield ranging from 42.70 ± 1.07 to 63.73 ± 1.73 % (average 53.90 ± 1.37 %), and, the samples collected during December 2004 and January 2006 demonstrated maximum gel strengths i.e. 743 ± 15.28 and 783.33 ± 15.28 g·cm(-2) respectively. Various environmental parameters influenced the chemical composition of K. alvarezii, and these parameters demonstrated seasonal fluctuations. Moreover, based on the nutritional composition obtained, it could be stated that this seaweed has great scope to be incorporated into several food products as an excellent nutritional supplement, or as a value additive in animal or pet food.

2.
Food Chem ; 153: 353-60, 2014 Jun 15.
Article in English | MEDLINE | ID: mdl-24491740

ABSTRACT

Protein concentrate (PC) of Kappaphycus alvarezii (cultivated on the West coast of India), was extracted and its functional properties were evaluated. The K. alvarezii PC contained 62.3 ± 1.62% proteins. At pH 12, the nitrogen solubility of this PC was 58.72 ± 1.68% in the presence of 0.5M NaCl. The emulsifying and foaming properties of this PC varied with time and pH. However, it formed remarkably stable emulsions with Jatropha oil after 720 min (i.e. E720=53.67 ± 1.59). On the other hand, maximum foaming ability (53.33 ± 2.31%) of the PC was recorded at pH 4.0. This PC had high oil (1.29 ± 0.20 ml oil/g PC) and water absorption capacity (2.22 0.04 ml H2O/g PC). DSC analysis revealed thermal transitions at about 109.25°C at neutral pH. The results obtained in this investigation suggest the suitability of K. alvarezii PC as an inexpensive source of protein; thus this PC could be incorporated into several value-added food products.


Subject(s)
Plant Proteins/chemistry , Rhodophyta/chemistry , Seaweed/chemistry , Vegetables/chemistry , Plants, Edible/chemistry , Protein Stability , Solubility
3.
Toxicon ; 50(7): 893-900, 2007 Dec 01.
Article in English | MEDLINE | ID: mdl-17681579

ABSTRACT

High titer antibodies (IgY) were raised in egg yolk of white leghorn chicken (Gallus gallus domesticus) by immunizing with the venom of Echis carinatus (Saw scaled viper or carpet viper), an Indian venomous snake belonging to the family Viperidae. The anti-snake venom antibodies (antivenom) were isolated from egg yolk by the water dilution method, enriched by 19% sodium sulfate precipitation and purified by immunoaffinity chromatography. A single, electrophoretically pure IgY band of 180-200 kDa was obtained on SDS-PAGE. Immunoblot analysis revealed not only the specific binding of the antivenom but also dose-dependent blocking of antivenom by venom proteins. In neutralization studies, a preincubated mixture of both affinity-purified (50 mg/kg body weight) as well as partially purified (210 mg/kg body weight) anti-E. carinatus IgY with 2 LD(50) dose of E. carinatus venom (2 x 6.65 mg/kg body weight) gave 100% protection in mice when administered subcutaneously.


Subject(s)
Antibodies/immunology , Antibodies/isolation & purification , Antivenins/immunology , Chickens/immunology , Egg Yolk , Viper Venoms/immunology , Viperidae/immunology , Animals , Antivenins/isolation & purification , Dose-Response Relationship, Drug , Female , Immunoblotting , Immunoglobulins/immunology , Lethal Dose 50 , Mice
4.
J Hazard Mater ; 143(1-2): 590-2, 2007 May 08.
Article in English | MEDLINE | ID: mdl-17092641

ABSTRACT

In the present investigation, three living color forms (brown, green and pale yellow) of Kappaphycus alvarezii were examined for their biosorption ability in the laboratory. The brown color form proved to be an excellent metal biosorbent, i.e. it could adsorb good amount of cadmium 3.064 mg/100 gf.wt. and cobalt 3.365 mg/100 gf.wt. It also removed 2.799 mg/100 gf.wt. of chromium. The green color form absorbed 2.684, 3.43 and 2.692 mg/100 gf.wt. of cadmium, cobalt and chromium, respectively. In contrast, the pale yellow form removed almost equal proportion of cadmium 0.961 mg/100 gf.wt. and chromium 0.942 mg/100 gf.wt. It also removed 1.403 mg/100 gf.wt. cobalt. Thus, the living color forms of this seaweed could form an effective biosorbent material for removal of heavy metals.


Subject(s)
Metals, Heavy/chemistry , Rhodophyta/chemistry , Adsorption , Biodegradation, Environmental , Pigmentation
5.
Bioorg Med Chem Lett ; 13(4): 657-60, 2003 Feb 24.
Article in English | MEDLINE | ID: mdl-12639552

ABSTRACT

We have synthesised a series of 2-[[2-alkoxy-6-pentadecylphenyl)methyl]thio]-1H-benzimidazoles/benzothiazoles and benzoxazoles from anacardic acid and investigated their ability to inhibit human cyclooxygenase-2 enzyme (COX-2). The active compounds were screened for cyclooxygenase-1 (COX-1) inhibition. Compound 13 is 384-fold and 19 is more than 470-fold selective towards COX-2 compared to COX-1. Thus, this class of compounds may serve as excellent candidates for selective COX-2 inhibition.


Subject(s)
Cyclooxygenase Inhibitors/chemical synthesis , Heterocyclic Compounds/chemical synthesis , Heterocyclic Compounds/pharmacology , Benzimidazoles/chemical synthesis , Benzimidazoles/pharmacology , Benzothiazoles , Benzoxazoles/chemical synthesis , Benzoxazoles/pharmacology , Blood/metabolism , Cyclooxygenase 1 , Cyclooxygenase 2 , Cyclooxygenase 2 Inhibitors , Cyclooxygenase Inhibitors/pharmacology , Drug Evaluation, Preclinical , Humans , Inhibitory Concentration 50 , Isoenzymes/antagonists & inhibitors , Membrane Proteins , Prostaglandin-Endoperoxide Synthases , Structure-Activity Relationship , Thiazoles/chemical synthesis , Thiazoles/pharmacology
6.
J Agric Food Chem ; 50(26): 7709-13, 2002 Dec 18.
Article in English | MEDLINE | ID: mdl-12475293

ABSTRACT

Anacardic acid (6-pentadecylsalicylic acid), a major component of cashew nut shell liquid, consists of a heterogeneous mixture of monoenes, dienes, and trienes. The enes mixture of anacardic acid was hydrogenated to a saturated compound. Using saturated anacardic acid as a starting material, analogues of sildenafil [a potent phosphodiesterase-5 (PDE(5)) inhibitor and an orally active drug for the treatment of erectile dysfunction] were synthesized, to observe the effect of the pentadecyl side chain on PDE(5) inhibition. The synthesized compounds were characterized by spectral studies and tested for PDE(5) inhibition, and the results were compared with those obtained with sildenafil.


Subject(s)
Anacardic Acids , Phosphodiesterase Inhibitors/chemical synthesis , Phosphodiesterase Inhibitors/pharmacology , Piperazines/chemistry , Salicylates/chemistry , 3',5'-Cyclic-GMP Phosphodiesterases , Cyclic Nucleotide Phosphodiesterases, Type 5 , Magnetic Resonance Spectroscopy , Mass Spectrometry , Phosphoric Diester Hydrolases/metabolism , Piperazines/pharmacology , Purines , Sildenafil Citrate , Structure-Activity Relationship , Sulfones
7.
J Agric Food Chem ; 50(16): 4705-8, 2002 Jul 31.
Article in English | MEDLINE | ID: mdl-12137500

ABSTRACT

Commercially available technical cashew (Anacardium occidentale L.) nut shell liquid (CNSL) contains mainly cardanol (decarboxylated anacardic acid) and cardol. Cardanol, the monophenolic component of technical CNSL, is widely used as a synthon for the preparation of a number of polymers and agricultural products. This paper describes the separation of cardanol from toxic cardol. Technical CNSL was dissolved in a mixture of methanol and ammonium hydroxide (8:5) and extracted with hexane to obtain cardanol. The resultant methanolic ammonia layer was extracted with a mixture of ethyl acetate and hexane to yield cardol. This is the first industrially feasible process based on solvent extractions for the isolation of cardanol from technical CNSL.


Subject(s)
Anacardiaceae/chemistry , Nuts/chemistry , Phenols/isolation & purification , Acetates , Ammonium Hydroxide , Chromatography, High Pressure Liquid , Hexanes , Hydroxides , Magnetic Resonance Spectroscopy , Methanol , Resorcinols/isolation & purification , Solvents
8.
Int Arch Allergy Immunol ; 121(4): 308-16, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10828721

ABSTRACT

BACKGROUND: Tropomyosin from shrimp is the major cross-reacting crustacean food allergen. Earlier studies have led to the purification and immunochemical characterization of the major IgE binding epitopes of the allergen. Maleylated proteins are known to be specifically targeted to scavenger receptors on macrophage. Since antigens processed and presented by macrophages are known to elicit Th1 type of responses and allergic responses are characterized by polarization towards Th2 phenotype, the possibility of modulation of allergen-specific immune responses by targeting of tropomyosin to macrophage via scavenger receptor was explored. METHODS: The IgG and IgE binding potential of the native maleylated form of tropomyosin was carried out by ELISA and immunoblot. The ability of the native and maleylated form of allergen to induce in vitro proliferation of splenocytes from BALB/C mice immunized with both forms of allergen was tested. The in vitro production of IL-4 and IFN-gamma by splenocytes from mice immunized with the two forms of allergen was determined from culture supernatants. The in vivo production of serum IgG1 and IgG2a antibodies following immunization with native and modified allergens was monitored by ELISA. RESULTS: The maleylated form of tropomyosin was found to have reduced antigenicity and allergenicity as compared to its native counterpart. The modified allergen was, however, found to elicit a cellular response similar to native tropomyosin in vitro. Analysis of the cytokine profiles showed a modulation from an IL-4-dominant, proallergic, Th2 phenotype to an IFN-gamma-dominant, antiallergic, Th1 phenotype that could also be correlated to a modulation in the in vivo antibody isotype. CONCLUSION: The results suggest the possible potential for modulating allergic responses in vivo by selective targeting to macrophages.


Subject(s)
Allergens/immunology , Decapoda/immunology , Macrophages/immunology , Receptors, Immunologic/immunology , Tropomyosin/immunology , Allergens/chemistry , Amino Acid Sequence , Animals , Cytokines/metabolism , Decapoda/chemistry , Electrophoresis, Polyacrylamide Gel , Enzyme-Linked Immunosorbent Assay , Female , Food Hypersensitivity , Gene Expression Regulation/immunology , Immunization , Immunoblotting , Immunoglobulin G/immunology , Immunoglobulin Isotypes , Lymphocyte Activation , Maleates/metabolism , Mice , Mice, Inbred BALB C , Molecular Sequence Data , Receptors, Immunologic/chemistry , Receptors, Immunologic/metabolism , T-Lymphocytes/immunology , Tropomyosin/chemistry
9.
Allergy ; 53(46 Suppl): 44-7, 1998.
Article in English | MEDLINE | ID: mdl-9825997

ABSTRACT

The major crustacean allergen characterized from different species of shrimp is the muscle protein tropomyosin. Two shared epitopes corresponding to 47-63 and 150-158 of the deduced amino-acid sequence of the brown shrimp, M. ensis, were identified as IgE-binding B-cell epitopes. A 21-mer peptide spanning the amino-acid residues 261-281 was identified as a putative T-cell epitope capable of reducing ongoing tropomyosin-specific IgG and IgE responses in a mouse model. These observations suggest that peptide immunotherapy may also be effective in the treatment of food hypersensitivity.


Subject(s)
Allergens/immunology , Decapoda/immunology , Epitopes, B-Lymphocyte , Epitopes, T-Lymphocyte , Tropomyosin/immunology , Amino Acid Sequence , Animals , Humans , Mice , Molecular Sequence Data
10.
J Immunol ; 142(10): 3411-5, 1989 May 15.
Article in English | MEDLINE | ID: mdl-2785554

ABSTRACT

In order to explore idiotypic, anti-idiotypic, and anti-anti-idiotypic responses to allergens, BALB/c mice were immunized with affinity-purified human idiotypic antibodies directed against a highly purified shrimp allergen. This resulted in the production of anti-idiotypic antibodies which were quantitated by using rabbit idiotypic antibodies raised against the same purified allergen. The mouse anti-idiotypic antibodies recognized shrimp-specific human idiotypic antibodies of the IgE isotype from 18 of 20 individuals, and IgG antibodies from 14 of 20 shrimp-sensitive patients. Immunization of BALB/c mice with affinity-purified, allergen-specific anti-idiotypic antibodies induced anti-allergen IgE and IgG responses in the absence of the allergen. This paper thus presents evidence that anti-idiotypic antibodies raised against allergen-specific idiotypic antibodies may substitute for the original allergen in the induction of allergen-specific idiotypic antibodies. The demonstration of shared idiotopes on IgG and IgE antibodies in the sera of shrimp-sensitive patients supports the use of allergen-specific anti-idiotypic antibodies as surrogate allergens.


Subject(s)
Allergens/immunology , Antibodies, Anti-Idiotypic/administration & dosage , Antibody Specificity , Immunoglobulin E/biosynthesis , Immunoglobulin G/biosynthesis , Immunoglobulin Idiotypes/immunology , Adult , Animals , Antibodies, Anti-Idiotypic/biosynthesis , Antibodies, Anti-Idiotypic/immunology , Decapoda/immunology , Food Hypersensitivity/blood , Food Hypersensitivity/immunology , Humans , Immunoglobulin E/immunology , Immunoglobulin G/immunology , Male , Mice , Mice, Inbred BALB C
11.
Article in English | MEDLINE | ID: mdl-28134170

ABSTRACT

Seventy five female workers employed in the cashew nut industry in Karnataka to slice off the outer hard shells from the nuts and thus exposed to the chashew nut shell oil had a characteristic cauterization type of reaction manifesting as brownish-black, thickened sheets of dead skin covering the dorsal as well as the palmar aspects of hands including the fingers and feet. Smaller but similer lesions were also seen on these parts of the forearms, abdomen, neck and face which were not covered with clothes. The fingers were thinned and tapering and several nails of the hands and feet were thickened, discolored and eaten away. The other changes included loss of the dermatoglyphic patterns, maceration of the hands, small pits on the finger tips and pitted keratolysis seen in some cases only. Similar changes were also seen on the feet of both the male workers exposed to the same oil, in the section which extracts the oil from the sliced shells. In contrast 29, feamle wokers engaged to peel off the thin reddish covering on the cashew nut had normal hands and feet, except for the two callosities on the flexural aspect of the proximal phalanx of the right middle finger and proximal interphalangeal joint of the right index finger respectively, caused by the friction of the peeling knife. An open patch test with the cashew nut shell oil used as such in 17 workers produced a cauterization type of reaction in 32 workers irrespective of the nature of their duties, while the standard occluded patch test with 10% cashew nut shell oil in polyethylene glycol showed a mild cauterization type of reaction in only 6 workers. Patch tests with 1% and 0.1% concentrations of the shell oil were negative in all the workers. Two barrier creams tested to protect the workers from the cashew nut shell oil produced reasonably effective results within a week.

12.
Ann Allergy ; 55(3): 511-5, 1985 Sep.
Article in English | MEDLINE | ID: mdl-4037438

ABSTRACT

A clinical survey in two silk filatures revealed that 36.2% of the persons engaged in the processing of natural silk were suffering from bronchial asthma, while 16.9% of the total subjects had asthma of occupational origin. Skin prick tests using crude silkworm cocoon and pupal allergen extracts revealed that 28.8% of the subjects were sensitive to the silkworm-derived allergens. IgE antibodies specific to both cocoon and pupal allergens were demonstrable by RAST in the sera of patients with positive skin reactions and occupational asthma.


Subject(s)
Asthma/etiology , Bombyx , Occupational Diseases , Textile Industry , Antibody Specificity , Humans , Immunoglobulin E/analysis , India , Skin Tests , Tissue Extracts
13.
Clin Allergy ; 15(5): 449-54, 1985 Sep.
Article in English | MEDLINE | ID: mdl-4053335

ABSTRACT

The pollen of Parthenium hysterophorus, an alien weed growing wild in India was found to be a potential source of allergic rhinitis. A clinical survey showed that 34% of the patients suffering from rhinitis and 12% suffering from bronchial asthma gave positive skin-prick test reactions to Parthenium pollen antigen extracts. Parthenium-specific IgE was detected in the sera of sixteen out of twenty-four patients suffering from seasonal rhinitis. There was 66% correlation between skin test and RAST.


Subject(s)
Asthma/etiology , Rhinitis, Allergic, Seasonal/etiology , Asthma/immunology , Humans , Pollen , Radioallergosorbent Test , Rhinitis, Allergic, Seasonal/immunology , Skin Tests
14.
Int Arch Allergy Appl Immunol ; 77(1-2): 96-102, 1985.
Article in English | MEDLINE | ID: mdl-3891632

ABSTRACT

It has long been recognized that mast cells occur throughout connective tissues. Histologic studies have revealed that such cells release their granules into the surrounding environment upon exposure to both immunologic and nonimmunologic stimuli. By microscopy these extracellular granules appeared to be phagocytosed by fibroblasts and by blood-borne phagocytic cells as they entered the site of mast cell degranulation. Such in vivo observations led to the suggestion that mast cells both altered connective tissue components and influenced fibroblast function through these discharged granules. Recent in vitro studies using cultured fibroblasts and isolated mast cells and mast cell granules have confirmed both these hypotheses. In addition, such studies have also documented that fibroblasts degrade ingested mast cell granules. Such studies document that a number of critical interactions may occur between mast cells and connective tissue components.


Subject(s)
Connective Tissue/physiology , Mast Cells/physiology , Animals , Cell Communication , Cells, Cultured , Connective Tissue Cells , Cytoplasmic Granules/metabolism , Extracellular Matrix/metabolism , Fibroblasts/physiology , Fibronectins/metabolism , Humans , Hyaluronic Acid/metabolism , Intercellular Junctions , Microscopy, Electron , Phagocytosis , Proteoglycans/metabolism
15.
J Immunol Methods ; 57(1-3): 71-85, 1983 Feb 25.
Article in English | MEDLINE | ID: mdl-6827114

ABSTRACT

This paper describes an improved microtiter solid-phase enzyme immunoassay for the determination of total and allergen-specific human IgE. This assay technique is unique in its use of the avidin-biotin interaction to increase sensitivity. The avidin-biotin microtiter enzyme-linked immunosorbant assay (AB-microELISA) was performed in polyvinyl chloride microtiter plates using biotinylated anti-IgE and horseradish peroxidase (HRP)-avidin conjugate. This AB-microELISA technique enabled the quantitation of human serum IgE in the range of 0.1-5 ng/ml (10-500 pg/test) in less than 3 h. Total serum IgE, whether measured by the AB-microELISA or the paper radioimmunosorbant test (PRIST) was similar (correlation coefficient, r = 0.92). Further, the presence or absence of positive skin tests to 7 specific allergens determined in serum donors generally agreed with the presence or absence of allergen-specific IgE in their sera as measured by the AB-microELISA. The quantity of short ragweed allergen-specific IgE as determined by the AB-microELISA agreed with values obtained by the radioimmunosorbant test (RAST) (correlation coefficient, r = 0.89). No significant interference by ragweed-specific IgG (blocking antibody) was observed in the quantitation of allergen-specific IgE. The AB-microELISA is not only rapid and inexpensive, but also more sensitive than other published ELISA procedures and comparable to solid-phase radioimmunoassays in the quantitation of total and allergen-specific IgE.


Subject(s)
Allergens , Immunoglobulin E/analysis , Antibody Specificity , Avidin , Biotin , Dose-Response Relationship, Immunologic , Enzyme-Linked Immunosorbent Assay , Horseradish Peroxidase , Humans
16.
J Immunol ; 130(1): 341-9, 1983 Jan.
Article in English | MEDLINE | ID: mdl-6847886

ABSTRACT

Cultured rat embryonic skin fibroblasts phagocytosed rat mast cell granules added to the medium or released from co-cultured mast cells by rabbit anti-rat IgE or Compound 48/80. Electron microscopy of fibroblasts incubated with mast cell granules revealed that granules adjacent to the plasmalemma were engulfed by long, thin cytoplasmic processes. Internalization proceeded to fusion of encircling processes and formation of phagosomes. Microtubules and 60 A microfilaments became closely associated with the phagosomal membrane to which small vesicles and cisternae of endoplasmic reticulum fused. The rate of uptake of mast cell granules by fibroblasts was dependent upon temperature and granule concentration. Cytochalasin B inhibited granule uptake whereas colchicine and nocodazole had little effect. Phagocytosis was not influenced by actinomycin D and cycloheximide, was partially inhibited by fluoride, and was markedly inhibited by cyanide, azide, and 2,4-dinitrophenol. Supernatants from fibroblast cultures incubated with mast cell granules for 24 and 48 hr, during which period phagocytosis occurred, contained elevated levels of collagenase and beta-hexosaminidase, but normal levels of lactate dehydrogenase and superoxide dismutase. These results support the concept that immediate hypersensitivity reactions are in part terminated by phagocytosis of biologically active discharged mast cell granules by resident connective tissue fibroblasts. Further, it is suggested that a consequence of this process is an alteration in fibroblast behavior, providing a unique link between immediate hypersensitivity reactions and connective tissue responses to inflammation.


Subject(s)
Fibroblasts/physiology , Mast Cells/physiology , Animals , Cells, Cultured , Connective Tissue/immunology , Cytoplasmic Granules/physiology , Lysosomes/enzymology , Mast Cells/ultrastructure , Microscopy, Electron , Phagocytosis/drug effects , Rats , Temperature
17.
Biochem J ; 193(2): 379-87, 1981 Feb 01.
Article in English | MEDLINE | ID: mdl-6796044

ABSTRACT

Glucoamylase (1,4-alpha-D-glucan glucohydrolase, EC 3.2.1.3) was purified from the culture filtrates of the thermophilic fungus Thermomyces lanuginosus and was established to be homogeneous by a number of criteria. The enzyme was a glycoprotein with an average molecular weight of about 57 000 and a carbohydrate content of 10-12%. The enzyme hydrolysed successive glucose residues from the non-reducing ends of the starch molecule. It did not exhibit any glucosyltransferase activity. The enzyme appeared to hydrolyse maltotriose by the multi-chain mechanism. The enzyme was unable to hydrolyse 1,6-alpha-D-glucosidic linkages of isomaltose and dextran. It was optimally active at 70 degrees C. The enzyme exhibited increase in the Vmax. and decreased in Km values with increasing chain length of the substrate molecule. The enzyme was inhibited by the substrate analogue D-glucono-delta-lactone in a non-competitive manner. The enzyme inhibited remarkable resistance towards chemical and thermal denaturation.


Subject(s)
Glucan 1,4-alpha-Glucosidase/isolation & purification , Glucosidases/isolation & purification , Mitosporic Fungi/enzymology , Chemical Phenomena , Chemistry , Electrophoresis, Polyacrylamide Gel , Glucan 1,4-alpha-Glucosidase/metabolism , Hydrolysis , Kinetics , Protein Denaturation , Substrate Specificity , Temperature
18.
Biochem J ; 193(2): 389-94, 1981 Feb 01.
Article in English | MEDLINE | ID: mdl-6796045

ABSTRACT

Physical entrapment was used as an approach to achieve thermal stabilization of enzymes. The t 1/2 values for the thermoinactivation of glucose oxidase and glucoamylase were increased several-fold by their entrapment in polyacrylamide gels. In polyacrylate gels the individual enzymes behaved differently, probably owing to microenvironmental effects arising by the polyelectrolyte nature of the carrier.


Subject(s)
Glucan 1,4-alpha-Glucosidase/metabolism , Glucose Oxidase/metabolism , Glucosidases/metabolism , Hot Temperature , Acrylic Resins , Aspergillus niger/metabolism , Enzyme Activation , Gels , Half-Life , Kinetics , Mitosporic Fungi/metabolism , Protein Denaturation , Rhizopus/metabolism
20.
J Bacteriol ; 126(2): 568-78, 1976 May.
Article in English | MEDLINE | ID: mdl-1262311

ABSTRACT

Maximal levels of L-henylalanine ammonia-lyase activity were observed when the mycelial felts of Rhizoctonia solani were grown for 4.5 days on Byrde synthetic medium containing 3.5% glucose and 0.3% L-phenylalanine, Differential centrifugation studies have indicated that the enzyme is localized in the soluble fraction. The time course of induction of L-phenylalanine ammonia-lyase activity by L-phenylalanine showed a lag period of 1 to 1.5 h and reached a maximum around 4 to 6 h after the addition of the inducer to the medium. L-Phenylalanine, L-tyrosine, and L-tryptophan were nearly equally efficient inducers of the enzyme. D-Phenylalanine was as efficient as the L-isomer, whereas D-tyrosine was a poor inducer. Light, gibberellic acid, indole 3-acetic acid, and kinetin had no effect on the induction of L-phenylalanine ammonia-lyase activity. Cycloheximide did not inhibit the uptake of amino acids by the mycelia but completely blocked the incorporation of radioactive amino acids into soluble proteins and the development of L-phenylalanine ammonia-lyase activity. Actinomycin D inhibited both the incorporation of 32P into ribonucleic acid and the enzyme activity. Conclusive evidence for de novo synthesis of L-phenylalanine ammonia-lyase was obtained by the incorporation of radioactive amino acids into the enzyme. Electrophoretic analysis of the purified preparation showed a single protein band that coincided with radioactivity and L-phenylalanine ammonia-lyase activity. Glucose and intermediates of the tricarboxylic acid cycle, like citric acid, alpha-ketoglutaric acid, and succinic acid, and the metabolites of L-phenylalanine, like o-coumaric acid, o-hydroxyphenylacetic acid, and protocatechuic acid, significantly repressed L-phenylalanine ammonia-lyase activity. The observed repression was not relieved by cyclic adenosine 5'-triphosphate.


Subject(s)
Ammonia-Lyases/metabolism , Mitosporic Fungi/enzymology , Phenylalanine Ammonia-Lyase/metabolism , Rhizoctonia/enzymology , Cell-Free System , Cycloheximide/pharmacology , Dactinomycin/pharmacology , Enzyme Induction , Enzyme Repression , Glucose/metabolism , Light , Phenylalanine/metabolism , Plant Growth Regulators/pharmacology , Rhizoctonia/growth & development , Rhizoctonia/metabolism , Stereoisomerism , Temperature , Tryptophan/metabolism , Tyrosine/metabolism
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