scholarly journals The Amino Acid Composition of Keratins II. The Amino Acid Composition of a Keratin Derivative Extracted From Wool With Alkaline Thioglycollate Solution

1955 ◽  
Vol 8 (1) ◽  
pp. 114 ◽  
Author(s):  
DH Simmonds

The amino acid composition of a protein component of Merino 64's quality wool, which moves as a single peak on electrophoresis in alkaline thioglycollate solutions, has been determined. The results, which are summarized in Table 1, show that the purified protein fraction contains more aspartic acid, glutamic acid, leucine, lysine, and amide nitrogen, and less cystine, proline, serine, and tryptophan, than the parent wool from which it was extracted.

Author(s):  
A. I. Fedosov ◽  
V. S. Kyslychenko ◽  
O. M. Novosel

Introduction. Plant amino acids have an important impact on functioning of various systems and organs of human body. In addition, they possess a wide range of pharmacotherapeutic properties, improve the digestion and potentiate the activity of biologically active compounds present in plants. Thus, the search of plant species that contain a large complex of plant amino acids and are used as food is of current interest. Garlic (Allium sativum L.) from Alliaceae family is one of such plants, and has been used since ancient times for the treatment of various disorders.The aim of the study – to determine the composition and quantitative content of free and bound amino acids of garlic bulbs and leaves.Research methods. The amino acid composition was determined using the high-performance liquid chromatography (HPLC) method.Results and Discussion. 16 amino acids were detected in garlic bulbs as a result of the experiment. Arginine (3.04 %) and proline (1.56 %) were found to be accumulated infree state, while glutamic acid (10.59 %), aspartic acid (6.06 %) and arginine (5.94 %) prevailed in bound state. 15 free and 16 bound amino acids were identified and quantified in garlic leaves. Glutamic acid (2.11 %), leucine (1.79 %), valine (1.77 %), isoleucine (1.52 %), treonine and phenylalanine (1.44 %) dominated infree state, and glutamic acid (28.49 %), aspartic acid (12.90 %) and leucine (7.61 %) prevailed in bound state. Methionine was found only in bound state in garlic leaves.Conclusions. The amino acid composition of garlic bulbs and leaves was studied using the HPLC method. 16 amino acids in both free and bound state were detected and their content was determined in garlic bulbs, while in garlic leaves – 15 free and 16 bound amino acids. The results of the experiment showed that methionine is present only in bound state in garlic leaves.


1972 ◽  
Vol 78 (2) ◽  
pp. 265-273 ◽  
Author(s):  
D. B. Smith

SUMMARYThe amino acid composition of barley grain was studied during the maturation of the grain and during germination of the mature grain. Samples of the variety Proctor, grown at two nitrogen levels in each of the years 1969 and 1970, were analysed together with one sample of Sultan grown in 1970. It was found that during maturation the proportions of glutamic acid and proline increased and that the levels of these amino acids were highest in those samples with the highest total protein content. During ripening the proportions of lysine, alanine, aspartic acid, threonine and glycine decreased. On germination the proportions of glutamic acid and proline rapidly decreased whilst aspartic acid, lysine, alanine and glycine increased.The nutritive value of ripe barley grain is limited by its low lysine content. Whilst the germination process increases the level of lysine it is suggested that this does not increase the nutritional value of the grain due to the low level of cystine in the germinated grain.


1968 ◽  
Vol 110 (2) ◽  
pp. 193-200 ◽  
Author(s):  
J. M. Gillespie ◽  
T. Haylett ◽  
H. Lindley

Fractions corresponding to the S-carboxymethylated high-sulphur protein component SCMK–B2 isolated by Gillespie (1963) from Merino wool were prepared from five different wool samples and also from bovine hair. The six fractions showed great similarities in amino acid composition, and also gave very similar peptide ‘maps’ after tryptic and chymotryptic digestion. Some of the peptides were isolated from the different samples, and evidence is given that suggests that a sequence of at least 21 amino acids is common to all the fraction SCMK–B2 preparations. Further, all the fractions derived from the wool samples have the same acetylated heptapeptide for the N-terminal sequence, but one extra residue may be present in this N-terminal sequence in the protein from bovine hair. The general significance of these findings is discussed.


1980 ◽  
Vol 60 (4) ◽  
pp. 1327-1331 ◽  
Author(s):  
F. W. SOSULSKI ◽  
N. W. HOLT

Eleven grain legumes were analyzed for amino acids (AA), AA scores and essential AA indexes (EAAI). Nitrogen-to-protein (N:P) factors were determined from these data. Concentrations of AA per gram of nitrogen were relatively constant among species with the exception of the AA arginine, methionine, tryptophan and cystine which had coefficients of variation of 23–30%. On average, arginine, leucine, lysine, aspartic acid and glutamic acid accounted for 50% of the total of all AA. These grain legumes met adult human requirements for essential AA except for methionine and cystine which were deficient in all species. This resulted in an average AA score and EAAI of 56 and 89, respectively. The N:P factor was 5.6 for the 11 species but this value was 5.0 if corrected for nonprotein nitrogen.


1985 ◽  
Vol 54 (2) ◽  
pp. 483-492 ◽  
Author(s):  
H. A. Greife ◽  
J. A. Rooke ◽  
D. G. Armstrong

1. In a 4 x 4 Latin square experiment four cows were given, twice daily, diets consisting of (g/kg dry matter (DM)) 500 barley, 400 grass silage and 100 soya-bean meal. The diets were given at either 1.15 (L) or 2.3 (H) times maintenance energy requirements and the soya-bean meal was either untreated (U) or formaldehyde (HCH0)-treated (T).2. The passage of digesta to the duodenum was estimated using chromic oxide as a flow marker;35S was used to estimate the amount of microbial protein entering the small intestine. A microbial fraction was prepared by differential centrifugation from duodenal digesta. Samples of bacteria and of protozoa from rumen digesta were also prepared.3. The total amino acid contents of feedingstuffs, duodenal digesta, duodenal microbial material, rumen bacteria and rumen protozoa were determined by ion-exchange chromatography. The D-alanine and D-glutamic acid contents of the samples were determined by gas–liquid chromatography.4. The quantity of each amino acid entering the small intestine was significantly (P < 0,001) increased by increasing DM intake and tended to be increased by formaldehyde-treatment of the soya-bean meal. There were net losses of all amino acids across the forestomachs except for lysine, methione, o-alanine and D-glutamic acid for which there were net gains.5. There were significant (P < 0.05) differences in amino acid composition between rumen bacteria and duodenal microbial material; differences in amino acid composition between rumen bacteria and rumen protozoa were also observed.6. D-Alanine and D-glutamic acid were present in the silage but not in the barley or either of the soya-bean meals. All samples of microbes and digesta contained D-alanine and D-glutamic acid.7. The use of D-ahine and D-glUtamiC acid as markers for microbial nitrogen entering the small intestine was assessed. Estimates of the quantities of microbial N entering the small intestine based on the D-alanine or D-glutamic acid contents of rumen bacteria or duodenal microbes were significantly higher than those determined using 35S as a marker.


2019 ◽  
Vol 17 (1) ◽  
pp. 313-324 ◽  
Author(s):  
Marta Pikosz ◽  
Joanna Czerwik-Marcinkowska ◽  
Beata Messyasz

AbstractFilamentous green algae (FGA) frequently forms dense mats which can be either mono- or polyspecies. While various defense mechanisms of competition in algae are known, little is known about the interactions between different species of FGA. An experiment in controlled laboratory conditions was conducted to gather data on the changes in amino acids (AA) concentrations in FGA species in the presence of exudates from different other species. The aim of the present study was to identify the AA whose concentrations showed significant changes and to assess if the changes could be adaptation to stress conditions. The major constituents of the AA pool in Cladophora glomerata, C. fracta and Rhizoclonium sp. were Glutamic acid (Glu), Aspartic acid (Asp) and Leucine (Leu). In response to chemical stress, that is the increasing presence of exudates, a significant increase in the concentrations Proline (Pro) and Tryptophan (Trp) was noted. The increase in Proline levels was observed in C. fracta and Rhizoclonium in response to chemical stress induced by C. glomerata exudates. As the concentration of exudates increased in the medium, there was a progressive shift in the pattern of AA group in FGA.


2004 ◽  
Vol 61 (6) ◽  
pp. 1012-1020 ◽  
Author(s):  
K Hüssy ◽  
H Mosegaard ◽  
F Jessen

The purpose of this study was to analyse the amino acid composition of otolith matrix protein, estimate the proportion of the water-soluble protein fraction, and analyse the effect of matrix composition on otolith visual appearance. Juvenile Atlantic cod (Gadus morhua) were reared under constant temperature and feeding conditions and sampled at the beginning and the end of the experiment. The amino acid composition was dominated by asparagine, glutamic acid, leucine, serine, and proline. A change in amino acid composition was observed with increasing temperature and time, caused by changing proportions of the water-soluble and -insoluble protein fractions. Feeding level had no effect. The relative content of water-soluble protein was linearly related to fish dry weight and temperature. Otolith opacity, defined as the percentage of incident light absorbed by an otolith section, did not differ significantly between experimental treatments. The soluble protein fraction had a positive, albeit insignificant, correlation with opacity. Using opacity and otolith volume, deposited total otolith protein content was estimated with an R2 of 0.91, where otolith volume alone explained 83% of the observed variation.


1975 ◽  
Author(s):  
A.D. Muller ◽  
B. M. Bas ◽  
H. C. Hemker

Staphylocoagulase, an exoprotein of coagulase positive staphylocoagulase, has been purified to a state in which only trace amounts of contaminating proteins are detectable.Purification was more than 35,000 fold, which is 7 times more than the highest value reported in the literature. The yield was about 15%.Aspartic acid was found as a single N-terminal amino acid in this preparation. The molecular weight is 61,000 and the isoelectric point lies at pH 4.53.The amino acid composition was determined.


1983 ◽  
Vol 49 (3) ◽  
pp. 395-399 ◽  
Author(s):  
Rachel Bielorai ◽  
Z. Harduf ◽  
B. Iosif ◽  
Eugenia Alumot

1. The apparent absorption values of individual amino acids from two samples of feather meal (FM) were determined in the lower ileum of chicks fed on diets containing magnesium ferrite as a marker.2. The average absorption values for FM amino acids were low, approximately 0.50, as compared with approximately 0.85 for soya bean, used as a control. Values for individual amino acids from FM differed distinctly, ranging from 0.20 to 0.70. Low values were obtained for aspartic acid, histidine, lysine, glutamic acid and cystine.3. An indication of the low absorption of the previously-mentioned amino acids was obtained by analysing the amino acid composition of the FM residues undigested by pepsin or pancreatin.4. The reasons for testing the apparent rather than the true absorption are discussed.


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