Improved purification and further characterization of Clostridium perfringens type A enterotoxin

1973 ◽  
Vol 19 (11) ◽  
pp. 1379-1382 ◽  
Author(s):  
A. H. W. Hauschild ◽  
R. Hilsheimer ◽  
W. G. Martin
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Clostridium Perfringens ◽  
Amino Acid Analysis ◽  
Sedimentation Coefficient ◽  
Type A ◽  
Sedimentation Equilibrium ◽  
Molecular Weights ◽  
Hydrolysis Of

The procedure for the purification of Clostridium perfringens type A enterotoxin was simplified, and the purity of the toxin was improved. Hydrolysis of the toxin by the p-toluenesulfonic acid procedure yielded 18 common amino acids. Among these, aspartic acid, serine, leucine, and glutamic acid were the predominant components. The sedimentation coefficient (s°20, w) was 2.8 Svedberg units. The molecular weights determined by the Archibald technique, sedimentation equilibrium, and amino acid analysis were 40 000, 36 000, and 33 000, respectively.

scholarly journals Bakerian lecture - Amino-acid analysis and the structure of proteins

1942 ◽  
Vol 131 (863) ◽  
pp. 136-160 ◽  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Analysis ◽  
Nutritive Value ◽  
Analytical Data ◽  
Seed Proteins ◽  
Decomposition Products ◽  
First Time ◽  
Structure Of Proteins

In recent years the X-ray crystallographers have made remarkable advances in the interpretation of protein structure, and it is becoming more and more evident that a stage has been reached when their views need to be reconciled with data obtained from accurate amino-acid analysis of the proteins concerned. In all too many cases these data are, unfortunately, not yet available, and the reason why the analyst cannot supply them at short notice is due not so much to the com­plexity of the problem—which he has never sought to minimize—but to the fact that many of the more important methods of analysis in current use are an inheritance from an earlier period when such accuracy as is now demanded would have been considered almost impossible of achievement. From about 1840 until 1900, following the lead given by Liebig and later by Ritthausen, the attention of protein chemists was centred chiefly on the prepara­tion and characterization of various animal and seed proteins; as substances of physiological interest their enzymic digestion products were studied in elaborate detail by Kühne, but little attention was paid to the ultimate decomposition products, the amino-acids, in spite of the fact that Ritthausen as early as 1872 had pointed out that the proportions in which these occur might be characteristic of the protein concerned. The enunciation by Hofmeister and Fischer of the peptide hypothesis in 1901 emphasized for the first time the fundamental importance of the amino-acids, and a most fruitful period followed in which attention became almost exclusively focused on these products. Under the inspiring leadership of Fischer himself great improvements were effected in the separation and identification of the amino-acids, so that by about 1915 reasonably good analyses were available for most of the better-known proteins. Though far from complete, the analytical data showed quite clearly that proteins could differ widely in composition, and in many cases it was possible to correlate composition with nutritive value. Such an aim was, indeed, the incentive behind much of the work of this period.

scholarly journals Hydrolysis of the Peptide Bond and Amino Acid Modification with Hydriodic Acid

1971 ◽  
Vol 24 (4) ◽  
pp. 1235 ◽  
Author(s):  
AS Inglis ◽  
PW Nicholls ◽  
CM Roxburgh
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Boiling Point ◽  
Amino Acid Analysis ◽  
Peptide Bond ◽  
Hydriodic Acid ◽  
Acid Modification ◽  
Amino Acid Modification ◽  
Hydrolysis Of

Reaction of hydriodic acid with peptides and proteins has been studied. At the boiling point, hydrolysis of the peptide bond, particularly stable bonds linking valine and isoleucine residues, is facile. Several amino acids react with constantboiling hydriodic acid but the only reactions detrimental to the amino acid analysis are the reduction of serine with concomitant formation of alanine, and the destruction of tryptophan. Gentler conditions of hydrolysis with diluted hydriodic acid are required for analysis of serine. Good results for analysis of proteins for amino acids may be obtained after a 6-hr hydrolysis period.

A comparison of methods for determining the concentration of extracellular peptides in rumen fluid of sheep

1990 ◽  
Vol 114 (1) ◽  
pp. 101-105 ◽  
Author(s):  
R. J. Wallace ◽  
N. McKain
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Analysis ◽  
Rumen Fluid ◽  
Amino Acid Content ◽  
Reliable Estimate ◽  
Precipitate Protein ◽  
Micro Organisms ◽  
Hydrolysis Of ◽  
Amino Acid Concentrations

SUMMARYSamples of rumen fluid were removed from pairs of sheep on four grass-hay-based diets 7 h after feeding. Micro-organisms were sedimented by centrifugation and the cell-free supernatant was treated with perchloric acid (PCA) to precipitate protein. The remaining fluid was analysed for peptides by several methods to determine how much peptide escaped degradation. Ammonia interfered with analysis by amino group reagents, especially ninhydrin. In this respect,o-phthalaldehyde and trinitrobenzene sulphonic acid were more specific and more useful than ninhydrin. Use of all these reagents showed that significant quantities of amino groups (equivalent to up to 153 mg amino acid N/1 of rumen fluid) were released by hydrolysis of the PCA extract with 6 M-HCI for 24 h. However, fluorescamine analysis indicated that the peptide content of the unhydrolysed PCA extract was < 3 mg N/1. The true amino acid content of different extracts was resolved by chromatographic amino acid analysis: the sum of individual amino acid concentrations in acid-hydrolysed PCA extracts of extracellular rumen fluid ranged from 7·8 to 14·5 mg N/1. Thus most of the free amino N released by hydrolysis of the PCA extract was not from amino acids, and most of the amino acids that were released were originally present in a form that did not react with fluorescamine. Although none of the methods gave a reliable estimate of peptide concentrations, amino acid analysis provided an upper limit. It was therefore concluded that peptide concentrations in extracellular rumen fluid are much lower than indicated by previous ninhydrin estimations, and that little dietary peptide escapes degradation for a prolonged period in the rumen.

D-Mannitol Interferes with Amino Acid Analysis of Marine Organisms

1979 ◽  
Vol 36 (9) ◽  
pp. 1134-1137 ◽  
Author(s):  
W. Fong ◽  
R. K. O'dor
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Hydrolysis ◽  
Key Words ◽  
Amino Acid Analysis ◽  
Chromatographic Analysis ◽  
Marine Algae ◽  
Protein S ◽  
New Compounds ◽  
Hydrolysis Of

Acid hydrolysis of a protein in the presence of D-mannitol, a common constituent of marine algae, can cause significant reductions in the recovery of a number of amino acids. The new compounds formed by the interactions of D-mannitol and these amino acids may interfere in the chromatographic analysis of other amino acids. The recoveries of most of the amino acids appear to be either directly or inversely proportional to the amount of D-mannitol added to a protein sample before acid hydrolysis. These results suggest that it is necessary to determine the effects of contaminants in a sample of protein(s) on the recoveries of amino acids during routine acid hydrolysis. Key words: kelp, amino acids, carbohydrates, D-mannitol

scholarly journals Comparison of the biliproteins from two strains of the thermophilic cyanophyte Synechococcus lividus

1974 ◽  
Vol 141 (2) ◽  
pp. 419-425 ◽  
Author(s):  
Robert MacColl ◽  
Mercedes R. Edwards ◽  
Martha H. Mulks ◽  
Donald S. Berns
Keyword(s):  
Amino Acid ◽  
Fluorescence Polarization ◽  
Amino Acid Analysis ◽  
Sedimentation Coefficient ◽  
Sedimentation Velocity ◽  
The Other ◽  
Sedimentation Equilibrium ◽  
Temperature Ranges ◽  
Synechococcus Lividus ◽  
Very High

C-Phycocyanins from two thermophilic strains of Synechococcus lividus that grow within different temperature ranges have been shown to be unalike. The aggregation ability of these two C-phycocyanins in sedimentation-velocity experiments varied dramatically. Surprisingly, the aggregation properties of mesophilic C-phycocyanins were found to lie between those of the two thermophilic proteins. Under identical conditions at pH7.0, one thermophilic protein (Sy I) was composed of 17S and larger aggregates, whereas the other (Sy III) was an almost homogeneous 6S aggregate. Mesophilic C-phycocyanins have a mixture of 6S, 11S and less stable 17S aggregates under these conditions. Amino acid analysis, absorption spectra, immunochemistry and fluorescence polarization all indicated differences in the composition and properties of the thermophilic proteins, which suggest that they have different modes of adaptation to very high temperatures. Allophycocyanins from the two strains of S. lividus were also purified and studied, but unlike the C-phycocyanins no major differences were found between them. Allophycocyanin was homogeneous at pH6.0, with a sedimentation coefficient of 5.54S and mol.wt. 1.03×105, as determined by sedimentation-equilibrium measurements.

Characterization of SNP, a Novel Tissue- and Phase-Specific Nuclear Protein Expressed during the Proliferative Phase in the Oviduct of the Lizard Podarcis sicula Raf.

2000 ◽  
Vol 381 (7) ◽  
pp. 615-618
Author(s):  
Piera Quesada ◽  
Luigia Atorino ◽  
Augusto Parente ◽  
Francesca Del Vecchio Blanco ◽  
Antimo Di Maro ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nuclear Protein ◽  
Reproductive Period ◽  
Amino Acid Residues ◽  
Seasonal Growth ◽  
Podarcis Sicula ◽  
Molecular Weights ◽  
Specific Nuclear Protein

Abstract The amino acid sequence of a novel tissueand phasespecific nuclear protein (SNP) has been determined, after purification from the nuclei of the oviduct of the lizard Podarcis sicula Raf. during the reproductive period of the seasonal growth. SNP has a pI of 9.0 and contains 81 amino acid residues with a molecular weight of 9211.88 ± 0.09. It shows a bipartite organization as the first 40 amino acids contain all 8 cysteinyl residues, while the last 41 amino acids contain 16 prolyl residues. Two more components have also been identified and characterized, with the first 79 amino acids matching SNP and missing one or two residues at the Cterminus. They have thus been named [des(Ala[81]) SNP1] and [des(Lys[80]Ala[81]) SNP2], respectively. The molecular weights are 9140.21 ± 0.83 for [des(Ala[81]) SNP1] and 9011 ± 0.09 for [des(Lys[80]Ala[81]) SNP2].

Hydrolysis of Proteins for Amino Acid Analysis. II. Acid Hydrolysis in Sealed Tubes of Mixtures of β-Lactoglobulin and Starch

1964 ◽  
Vol 47 (4) ◽  
pp. 745-747 ◽  
Author(s):  
William G Gordon ◽  
Jay J Basch
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Hydrolysis ◽  
Amino Acid Analysis ◽  
Special Method ◽  
Large Excess ◽  
Β Lactoglobulin ◽  
Hydrolysis Of

Abstract Experiments with a mixture of β-Iactoglobulin and starch, simulating the composition of carbohydrate-rich foods and feeds, have been carried out to determine conditions for acid hydrolysis that will permit maximal recovery of amino acids in hydrolysates of such materials. When a large excess of 6N HC1 is used for hydrolysis, good recoveries of most amino acids are obtained. However, about one-quarter of the tyrosine present is destroyed under the conditions investigated. Some destruction of methionine and cystine may also be attributed to the presence of carbohydrate, but a special method for the determination of these amino acids is available.

The characterization of the 12 S "globulin" from rapeseed and its glycoprotein component

1970 ◽  
Vol 48 (10) ◽  
pp. 1096-1103 ◽  
Author(s):  
L. A. Goding ◽  
R. S. Bhatty ◽  
A. J. Finlayson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Sedimentation Coefficient ◽  
Carbohydrate Content ◽  
Amino Terminal ◽  
Terminal Amino

A 12 S globulin was isolated from each of the two species of rapeseed (B. napus L. and B. campestris L.) and they have been shown to be similar in terms of amino acid composition, amino terminal amino acids, number of subfractions, and carbohydrate content. One of the major proteins, a glycoprotein, present in each of the 12 S aggregates, was isolated and purified. Its amino acid composition, carbohydrate content, N-terminal amino acids, and sedimentation coefficient are reported herein.

scholarly journals Isolation and characterization of sheep pepsin

1977 ◽  
Vol 161 (2) ◽  
pp. 389-398 ◽  
Author(s):  
P F Fox ◽  
J R Whitaker
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Ethyl Ester ◽  
Gel Filtration ◽  
Ph Optimum ◽  
Isolation And Characterization ◽  
Sepharose 4B ◽  
Hydrolysis Of

Sheep pepsin was isolated (approx. 120-fold purification) from aqueous abomasal homogenates by (1) pH fractionation, (2) chromatography on Sepharose 4B-poly-L-lysine columns and (3) gel filtration on Sephadex G-100. The enzyme had mol.wt. approx. 34000, N-terminal valine and C-terminal alanine. The amino acid composition of sheep pepsin was generally similar to that of pig and ox pepsins, with a very low content of basic residues and a high content of acidic and hydroxy-amino acids. The pH optimum for NN-dimethyl-casein and NN-dimethyl-haemoglobin as substrates was approx. 1.8. The Km and kcat. for NN-dimethyl-haemoglobin were 46micronM and 1100min-1 respectively, and for NN-dimethyl-casein the corresponding parameters were 50micronM and 420min-1. These values were generally similar to those for pig and ox pepsins. At the pH optimum of 4.6, the sheep pepsin was about 50% as active on benzyloxycarbonyl-L-histidyl-L-phenyl-alanyl-L-tryptophan ethyl ester as was pig pepsin. The pH optimum for the hydrolysis of N-acetyl-L-phenylalanyl-L-di-iodotyrosine by sheep, ox and pig pepsins was approx. 1.85.

scholarly journals Avoided motifs: short amino acid strings missing from protein datasets

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Pablo Mier ◽  
Miguel A. Andrade-Navarro
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Function ◽  
Large Protein ◽  
New Approach ◽  
Cellular Context ◽  
Human Proteins ◽  
Context Specific ◽  
Protein Datasets

Abstract According to the amino acid composition of natural proteins, it could be expected that all possible sequences of three or four amino acids will occur at least once in large protein datasets purely by chance. However, in some species or cellular context, specific short amino acid motifs are missing due to unknown reasons. We describe these as Avoided Motifs, short amino acid combinations missing from biological sequences. Here we identify 209 human and 154 bacterial Avoided Motifs of length four amino acids, and discuss their possible functionality according to their presence in other species. Furthermore, we determine two Avoided Motifs of length three amino acids in human proteins specifically located in the cytoplasm, and two more in secreted proteins. Our results support the hypothesis that the characterization of Avoided Motifs in particular contexts can provide us with information about functional motifs, pointing to a new approach in the use of molecular sequences for the discovery of protein function.

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