scholarly journals Complete amino acid analysis of peptides and proteins after hydrolysis by a mixture of Sepharose-bound peptidases

1972 ◽  
Vol 129 (3) ◽  
pp. 695-701 ◽  
Author(s):  
H. P. J. Bennett ◽  
D. F. Elliott ◽  
B. E. Evans ◽  
P. J. Lowry ◽  
C. McMartin
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Standard Deviation ◽  
Quantitative Determination ◽  
Edman Degradation ◽  
Amino Acid Residues ◽  
Peptide Fragments ◽  
Enzyme Mixture ◽  
Acid Labile

Incubation with a mixture of Sepharose-bound peptidases was shown to result in the quantitative release of amino acids from certain peptides and S-aminoethylated proteins. Subtraction of the low background values of amino acids generated by the enzymes enables amino acid ratios of corticotrophin-(1–24)-tetracosapeptide to be determined with a standard deviation on repeat digestions of 3–5%. Good values were obtained for amino acids that are completely or partially destroyed on acid hydrolysis, i.e. tryptophan, tyrosine, serine, asparagine and glutamine. Experiments with peptides containing d-amino acids showed that the enzyme mixture is stereospecific and could therefore be used to detect the presence of d-residues in peptides. The enzyme mixture completely hydrolyses peptide fragments obtained after Edman degradation and should therefore be useful for determining sequences of peptides containing acid-labile amino acid residues. The activities of the bound enzymes were unaltered over a period of 7 months and they provide a simple, reproducible procedure for the quantitative determination of amino acids in peptides and proteins containing l-amino acids.

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.

Quantitative determination of free amino acids with automatic amino acid analyser in liver cirrhosis blood plasma

1966 ◽  
Vol 1 (3) ◽  
pp. 75-75
Author(s):  
S. Tanaka ◽  
K. Hattori ◽  
Y. Katoo ◽  
S. Suga ◽  
A. Ishiwara ◽  
...  
Keyword(s):  
Amino Acids ◽  
Liver Cirrhosis ◽  
Amino Acid ◽  
Quantitative Determination ◽  
Blood Plasma ◽  
Free Amino Acids ◽  
Free Amino ◽  
Amino Acid Analyser

Comparison of procedures for extracting free amino acids from polymorphonuclear lekocytes.

1976 ◽  
Vol 22 (10) ◽  
pp. 1618-1622 ◽  
Author(s):  
Y Houpert ◽  
P Tarallo ◽  
G Siest
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Quantitative Determination ◽  
Free Amino Acids ◽  
Free Amino ◽  
Polymorphonuclear Leukocytes ◽  
Extraction Procedure ◽  
Intracellular Pool ◽  
Human Polymorphonuclear Leukocytes

Abstract We studies five methods for extracting amino acids from human polymorphonuclear leukocytes. Both the use of cell lysis and of a deproteinizing agent interfere with quantitative determination of the amino acids, basic amino acids being the most sensitive to the extraction procedure. Among the methods used, disruption of the cells by freezing-thawing is the best method for extracting all the amino acids. Taurine is the only amino acid extracted in the same amount by all the methods studied, and it represents half of the intracellular pool.

The nature of epidermidins, new antibiotics from staphylococci

1972 ◽  
Vol 18 (2) ◽  
pp. 121-125 ◽  
Author(s):  
Chun-yang Hsu ◽  
G. M. Wiseman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Staphylococcus Epidermidis ◽  
Cyclic Peptide ◽  
Average Molecular Weight ◽  
Partial Hydrolysis ◽  
Amino Acid Residues ◽  
Peptide Fragments ◽  
New Antibiotics ◽  
Hydrolysis Of

New antibiotics have been isolated from Staphylococcus epidermidis strains 29297 and 36534. These agents are designated epidermidins A1, A2, B1, B2 and are peptides with an average molecular weight of 1200–1400 based on three independent methods of estimation. Each fraction contained 11 amino acid residues, eight of which were shared in common. The ratio of L- to D-amino acids was 7:4 for epidermidins A2 and B1, while that for epidermidins A1 and B2 was 5:6.The appearance of the same amino acids at the beginning and end of many of the peptide fragments obtained by partial hydrolysis of epidermidin A1 suggested that this antibiotic was a cyclic peptide. The absence of N- and C-terminal residues supported this finding. The amino acid sequence of epidermidin A1 was also tentatively deduced and may be written as follows: cyclo-lys-ala-asp-glu-ser-leu-thr-gly-val-gly-arg.

Determination of the Complete Absolute Configuration of Petriellin A

2006 ◽  
Vol 59 (6) ◽  
pp. 407 ◽  
Author(s):  
Luigi Aurelio ◽  
Robert T. C. Brownlee ◽  
Jason Dang ◽  
Andrew B. Hughes ◽  
Gideon M. Polya
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Natural Product ◽  
Absolute Configuration ◽  
Structural Determination ◽  
Amino Acid Residues ◽  
The Common ◽  
The Absolute ◽  
Derivatives Of

We report the full structural determination of the depsipeptide petriellin A. The absolute configuration of the amino acid residues, N-methyl isoleucine and N-methyl threonine, have been determined by a combination of HPLC and TLC comparison of synthetic Marfey’s derivatives and Marfey’s derivatives of the natural product hydrolysate. The configuration of the chiral centres in these two N-methylated residues was found to be the same as those of the common unmethylated l-amino acids.

scholarly journals Amino Acid Sequence of Cyanogen Bromide Fragment CN2 From a Hong Kong Influenza Haemagglutinin Heavy Chain

1980 ◽  
Vol 33 (2) ◽  
pp. 137 ◽  
Author(s):  
Colin W Ward ◽  
Theo AA Dopheide ◽  
Adam S Inglis
Keyword(s):  
Hong Kong ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Heavy Chain ◽  
Cyanogen Bromide ◽  
Edman Degradation ◽  
Amino Acid Residues ◽  
Core Peptide ◽  
Cyanogen Bromide Fragment

The amino acid sequence of cyanogen bromide peptide CN2 from the heavy chain (HAl) of the haemagglutinin of the Hong Kong variant A/Memphis/l02/72 has been obtained by direct, automated sequence analysis on the whole fragment and by manual dansyl-Edman degradation of tryptic, peptic and chymotryptic peptides. It was found to contain 92 amino acid residues, including a large, insoluble, tryptic core peptide (residues 62-87). It did not contain any half-cystine residues or carbohydrate. The determination of its structure was complicated by the presence of an Asn-Ile bond at positions 48-49 which was readily cleaved by both trypsin and chymotrypsin.

scholarly journals Determination of amino acids in human biological fluids by high-performance liquid chromatography: critical review

Amino Acids ◽  
2021 ◽  
Author(s):  
Grażyna Gałęzowska ◽  
Joanna Ratajczyk ◽  
Lidia Wolska
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
High Performance ◽  
Hplc Analysis ◽  
Limit Of Detection ◽  
Biological Fluids ◽  
Analytical Techniques ◽  
Epidemiological Studies ◽  
Preparation Conditions

AbstractThe quantitation and qualification of amino acids are most commonly used in clinical and epidemiological studies, and provide an excellent way of monitoring compounds in human fluids which have not been monitored previously, to prevent some diseases. Because of this, it is not surprising that scientific interest in evaluating these compounds has resurfaced in recent years and has precipitated the development of a multitude of new analytical techniques. This review considers recent developments in HPLC analytics on the basis of publications from the last few years. It helps to update and systematize knowledge in this area. Particular attention is paid to the progress of analytical methods, pointing out the advantages and drawbacks of the various techniques used for the preparation, separation and determination of amino acids. Depending on the type of sample, the preparation conditions for HPLC analysis change. For this reason, the review has focused on three types of samples, namely urine, blood and cerebrospinal fluid. Despite time-consuming sample preparation before HPLC analysis, an additional derivatization technique should be used, depending on the detection technique used. There are proposals for columns that are specially modified for amino acid separation without derivatization, but the limit of detection of the substance is less beneficial. In view of the fact that amino acid analyses have been performed for years and new solutions may generate increased costs, it may turn out that older proposals are much more advantageous.

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