scholarly journals Increased thermal stability of proteins in the presence of amino acids

1994 ◽  
Vol 303 (1) ◽  
pp. 147-153 ◽  
Author(s):  
S Taneja ◽  
F Ahmad
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cytochrome C ◽  
Thermal Denaturation ◽  
Thermal Transition ◽  
Native Protein ◽  
Guanidinium Chloride ◽  
Isoleucine Leucine ◽  
Hydrophobic Amino Acids ◽  
Thermal Stability Of

This study is a systematic attempt to understand the roles of osmolytes in protecting proteins against denaturing stress. Thermal denaturation of cytochrome c has been studied in the presence of various concentrations of all L-amino acids that are more hydrophobic than glycine and have a solubility of 0.1 M or higher in water at 25 degrees C. The basic observations are as follows. (1) Arginine and histidine destabilize the native protein; both Tm (the midpoint of thermal transition) and delta GDH2O (25 degrees C) (the Gibbs energy of stabilization) decrease with increasing amino acid concentration. (2) Isoleucine, leucine and phenylalanine have no effect on Tm and deltaGDH2O (25 degrees C). (3) Valine and less hydrophobic amino acids stabilize the protein in terms of Tm but deltaGDH2O (25 degrees C) is unchanged. This observation was confirmed by the study of isothermal denaturation of cytochrome c by guanidinium chloride which suggested that delta GDH2O is independent of osmolyte concentration, but Cm (the midpoint of transition) is increased in their presence. (4) In the case of stabilizers, change in Tm/mol of amino acid decreases with increasing hydrophobicity of these osmolytes.

scholarly journals The amino acid sequence of cytochromes c-551 from three species of Pseudomonas

1973 ◽  
Vol 131 (3) ◽  
pp. 485-498 ◽  
Author(s):  
R. P. Ambler ◽  
Margaret Wynn
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Cytochrome C ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Mitochondrial Cytochrome ◽  
Cytochromes C ◽  
Lending Library ◽  
Single Peptide

The amino acid sequences of the cytochromes c-551 from three species of Pseudomonas have been determined. Each resembles the protein from Pseudomonas strain P6009 (now known to be Pseudomonas aeruginosa, not Pseudomonas fluorescens) in containing 82 amino acids in a single peptide chain, with a haem group covalently attached to cysteine residues 12 and 15. In all four sequences 43 residues are identical. Although by bacteriological criteria the organisms are closely related, the differences between pairs of sequences range from 22% to 39%. These values should be compared with the differences in the sequence of mitochondrial cytochrome c between mammals and amphibians (about 18%) or between mammals and insects (about 33%). Detailed evidence for the amino acid sequences of the proteins has been deposited as Supplementary Publication SUP 50015 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973), 131, 5.

scholarly journals AMINO ACID COMPOSITION AND ELECTROPHORETIC PROPERTIES OF HYPERTENSIN I

1955 ◽  
Vol 102 (4) ◽  
pp. 435-440 ◽  
Author(s):  
Leonard T. Skeggs ◽  
Walton H. Marsh ◽  
Joseph R. Kahn ◽  
Norman P. Shumway
Keyword(s):  
Amino Acids ◽  
Quantitative Analysis ◽  
Amino Acid ◽  
Ion Exchange ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Isoelectric Point ◽  
Column Chromatography ◽  
Isoleucine Leucine ◽  
Ion Exchange Column

A preparation of hypertensin I was purified by countercurrent distribution and was shown to migrate as a single component in starch blocks at pH 9.3 and 4.2. It had an isoelectric point of 7.7. Quantitative analysis by ion exchange column chromatography showed eight amino acids in approximately unimolar proportion: aspartic, proline, valine, isoleucine, leucine, tyrosine, phenylalanine, and arginine. There were in addition two moles of histidine.

scholarly journals AMINO ACID PROFILE OF A BASIDIOMYCETOUS EDIBLE MUSHROOM-LENTINUS SAJOR-CAJU

2017 ◽  
Vol 9 (9) ◽  
pp. 252
Author(s):  
Lata . ◽  
Narender Singh Atri
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Content ◽  
Standard Technique ◽  
Edible Mushroom ◽  
Amino Acid Profile ◽  
Total Amino Acid ◽  
Isoleucine Leucine ◽  
Total Amino Acid Content ◽  
Basidiomycetous Mushroom

Objective: In this paper amino acid profile of Lentinus sajor-caju (Fr.) Fr., a basidiomycetous mushroom has been investigated.Methods: During the evaluation 15 amino acids (lysine, aspartic acid, serine, threonine, glutamic acid, cysteine, glycine, alanine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine and histidine) were determined from the dried sample of Lentinus sajor-caju by following the standard technique of biochemistry using ion-exchange chromatography.Results: The total amino acid content has been evaluated at 18.82 g/100g. Amongst the evaluated amino acids, exogenous amino acid lysine (6.66 g/100g) is preponderantly present in comparison to all other amino acids. The essential amino acid (EAA) index (44.64%) and biological value (BV=36.93%) has also been determined for the examined sample.Conclusion: Lentinus sajor-caju (Fr.) Fr. is a potential source of quality protein with a substantial proportion of exogenous and endogenous amino acids.

Amino Acid Composition of Fishery Products

1949 ◽  
Vol 7c (9) ◽  
pp. 513-521 ◽  
Author(s):  
Catherine P. Deas ◽  
H. L. A. Tarr
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Essential Amino Acids ◽  
Waste Materials ◽  
Small Peptides ◽  
Isoleucine Leucine ◽  
Fish Flesh ◽  
Microbiological Methods ◽  
Fishery Products ◽  
Muscle Myosin

Fish flesh and certain waste materials were hydrolysed by tryptic enzymes of fish pyloric caeca. Fractionation of the resulting hydrolysates showed that they contained largely peptone, sub-peptone and residual (small peptides and amino acids) nitrogen, and little or no protein or proteose nitrogen. Fish flesh, milts, roes, meal, stickwater and a muscle myosin preparation were extracted to remove the fat, then dried and hydrolysed with acid or alkali. The essential amino acids arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, valine, tryptophane and tyrosine were determined in these enzyme-, acid- and alkali-hydrolysed materials by microbiological methods. The results have been summarized.

Amino Acid Requirements for the Wheat Stem Sawfly Determined with Glucose-U-C14 after Vacuum-infiltration

1964 ◽  
Vol 96 (8) ◽  
pp. 1133-1137 ◽  
Author(s):  
R. Kasting ◽  
A. J. McGinnis
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Vacuum Infiltration ◽  
Artificial Diets ◽  
Isoleucine Leucine ◽  
Wheat Stem Sawfly ◽  
Carbon 14 ◽  
Amino Acid Requirements ◽  
Radioactive Substrate

AbstractGlucose-U-C14 was incorporated into immature larvae of the wheat stem sawfly, Cephus cinctus Nort., by vacuum-infiltration. These insects were too small to be conveniently injected and could not be easily fed on artificial diets. About half of them survived the infiltration treatment. C14O2 was produced by the organism showing that the radioactive substrate was metabolized. Of the amino acids isolated from the larvae, proline, alanine, glutamic acid, serine, aspartic acid, and glycine contained relatively large quantities of carbon-14 indicating biosynthesis, and are classed as nutritionally non-essential. In contrast, arginine, isoleucine, leucine, lysine, phenylalanine, threonine, tyrosine, and valine contained little, if any, radioactivity and are classed as nutritionally essential. The concentrations of some of the amino acids in the larval tissues are also presented.

Amino acid activity in the Nelson–Somogyi glucose assay

1990 ◽  
Vol 68 (7) ◽  
pp. 1479-1481 ◽  
Author(s):  
Mahesh K. Upadhyaya ◽  
David W. Konesky
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Key Words ◽  
Reducing Sugars ◽  
Reducing Sugar ◽  
Manganese Ions ◽  
Isoleucine Leucine ◽  
Glucose Assay ◽  
Color Development

The Nelson–Somogyi assay has been widely used to measure reducing sugars in plant research. We found that the L-amino acids cysteine, cystine, serine, tryptophan, and tyrosine (at 0.1 to 1 mM) react in the Nelson–Somogyi glucose assay, yielding high absorbance values. Alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, hydoxyproline, isoleucine, leucine, lysine, methionine, phenylalanine, proline, threonine, and valine showed little or no effect on color development. Manganese ions strongly inhibited color development in the presence of glucose, serine, cystine, and tryptophan. Investigators measuring glucose in biological materials using this assay must consider the activity of amino acids and (or) the effect of manganese ions in the reaction mixture when interpreting their results. Key words: Nelson–Somogyi assay, sugar analysis, glucose assay, reducing sugar assay.

Amino Acid Composition of Fishery Products (II)

1950 ◽  
Vol 7d (10) ◽  
pp. 563-566 ◽  
Author(s):  
Phyllis W. Ney ◽  
Catherine P. Deas ◽  
H. L. A. Tarr
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Essential Amino Acids ◽  
Microbiological Assay ◽  
Isoleucine Leucine ◽  
Fishery Products

The essential amino acids arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, valine, tryptophane and tyrosine were determined in the following fishery products using microbiological assay technique: fish meals, stickwaters (fish solubles), condensed fish solubles, liver, commercial liver hydrolysate, frozen pink salmon viscera, chum salmon fingerlings and herring scales.

scholarly journals Determination of three amino acids causing alteration of proteolytic activities of staphylococcal glutamyl endopeptidases

2009 ◽  
Vol 390 (3) ◽  
Author(s):  
Takayuki K. Nemoto ◽  
Toshio Ono ◽  
Yu Shimoyama ◽  
Shigenobu Kimura ◽  
Yuko Ohara-Nemoto
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protease Activity ◽  
Binding Pocket ◽  
Catalytic Triad ◽  
Amino Acid Residues ◽  
Proteolytic Activities ◽  
Hydrophobic Amino Acids ◽  
The Difference

Abstract Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus warneri secrete glutamyl endopeptidases, designated GluV8, GluSE, and GluSW, respectively. The order of their protease activities is GluSE<GluSW<<GluV8. In the present study, we investigated the mechanism that causes these differences. Expression of chimeric proteins between GluV8 and GluSE revealed that the difference is primarily attributed to amino acid residues 170–195, which define the intrinsic protease activity, and additionally to residues 119–169, which affect the proteolytic sensitivity. Among nine substitutions present in residues 170–195 of the three proteases, the substitutions at positions 185, 188, and 189 were responsible for the changes in their activities, and the combination of W185, V188, and P189, which naturally occurs in GluV8, exerts the highest protease activity. W185 and P189 were indispensable for full activity, but V188 could be replaced by hydrophobic amino acids. These three amino acid residues appear to create a substrate-binding pocket together with the catalytic triad and the N-terminal V1, and therefore define the K m values of the proteases. We also describe a method to produce a chimeric form of GluSE and GluV8 that is resistant to proteolysis, and therefore possesses 4-fold higher activity than the wild-type recombinant GluV8.

scholarly journals Changes in neurotransmitter levels associated with the deficiency of some essential amino acids in the diet

1992 ◽  
Vol 68 (2) ◽  
pp. 409-420 ◽  
Author(s):  
José L. Venero ◽  
Antonio J. Herrera ◽  
Alberto Machado ◽  
Josefina Cano
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Substantia Nigra ◽  
Corpus Striatum ◽  
Essential Amino Acids ◽  
Serotoninergic System ◽  
Main Metabolite ◽  
Isoleucine Leucine ◽  
Low Protein ◽  
The Brain

The contents of dopamine (DA) and serotonin (5-HT) and their metabolites were measured in rat substantia nigra and corpus striatum following dietary changes, including restriction of protein content (low-protein diet; LPD) and the contents of several large neutral amino acids (isoleucine, leucine, methionine, phenylalanine, tryptophan and valine) for 25 d. The LPD produced an increase in the concentration of tyrosine (TYR) in the two regions of the brain studied. This effect was also observed with all amino acid deficiencies studied except for valine in the substantia nigra, tryptophan in the striatum and phenylalanine in both regions. Likewise, the concentration of 5-hydroxyindolacetic acid (5-HIAA), the main metabolite of 5-HT, increased in the substantia nigra but not in the striatum after LPD, as well as with all the amino acid deficiencies studied, with the exception of tryptophan deficiency. In this case there was a dramatic effect on all components of the serotoninergic system, with decreases in the concentration of tryptophan (TRP; precursor), 5-HT and 5-HIAA. This behaviour clearly shows an interrelationship between precursor (TRP) availability and 5-HT synthesis and metabolism. With valine deficiency, dopaminergic and serotoninergic systems demonstrated opposite effects in the substantia nigra and the corpus striatum, and the behaviour of the two monoamines was also opposite within each structure. The significance of these changes is discussed.

scholarly journals Extraction and Characterization of “Batuan” [Garcinia binucao (Blco.) Choisy] Seed Protein

2014 ◽  
pp. 89-103 ◽  
Author(s):  
Elizabeth Quevedo ◽  
Marivic Lacsamana ◽  
Antonio Laurena
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Seed Protein ◽  
Seed Proteins ◽  
Essential Amino Acids ◽  
Food Supplement ◽  
Seed Meal ◽  
Molecular Weights ◽  
Hydrophobic Amino Acids ◽  
Amino Acid Score

“Batuan” [Garcinia binucao (Blco.) Choisy], an indigenous, lesser known member of the Gutifferae family with export potential is underutilized and understudied. The present study was carried out to extract and characterize the protein in “batuan” [Garcinia binucao (Blco.) Choisy] seeds for nutritional quality assessment. Protein content of “batuan” seed meal was 8.9 ± 0.59% dry basis. Solubility fractionation of “batuan” seed meal showed globulin and glutelin as the major seed proteins. SDS-PAGE resolved the globulin and glutelin into three groups of polypeptides with molecular weights of about 20 – 54 kDa. Amino acid analysis revealed that seed protein contained all the essential amino acids with leucine as the most abundant while tryptophan, the least. “Batuan” seed proteins were mostly made up of acidic and hydrophobic amino acids with glutamic acid (2.67%) as the highest. Nutritional assessments including E/T (38.4%), amino acid score (1.6%), predicted PER (3.2-3.7) and estimated BV (98.3%) suggested that the seed proteins are of good quality. Hence, “batuan” seeds has a promising potential as an important sources of valuable proteins and amino acids for use as food supplement/enhancing ingredient.

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