scholarly journals Hydrolysis of Pork Muscle Sarcoplasmic Proteins byLactobacillus curvatus and Lactobacillus sake

1999 ◽  
Vol 65 (2) ◽  
pp. 578-584 ◽  
Author(s):  
Silvina Fadda ◽  
Yolanda Sanz ◽  
Graciela Vignolo ◽  
M.-Concepción Aristoy ◽  
Guillermo Oliver ◽  
...  
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Lactobacillus Curvatus ◽  
Whole Cells ◽  
Sarcoplasmic Proteins ◽  
Lactobacillus Sake ◽  
Cell Extracts

ABSTRACT Lactobacillus curvatus CECT 904 and Lactobacillus sake CECT 4808 were selected on the basis of their proteolytic activities against synthetic substrates. Further, the effects of whole cells, cell extracts, and a combination of both enzymatic sources on muscle sarcoplasmic proteins were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography analyses. Strains of both species displayed proteinase activities on five sarcoplasmic proteins. The inoculation of whole cells caused a degradation of peptides, whereas the addition of cell extracts resulted in the generation of both hydrophilic and hydrophobic peptides. This phenomenon was remarkably more pronounced when L. curvatus was involved. Whole cells also consumed a great amount of free amino acids, while the addition of intracellular enzymes contributed to their generation.L. sake accounted for a greater release of free amino acids. In general, cell viability and also proteolytic events were promoted when cell suspensions were provided with cell extracts as an extra source of enzymes.

Dipeptide utilization by starter streptococci

1977 ◽  
Vol 44 (2) ◽  
pp. 309-317 ◽  
Author(s):  
B. A. Law
Keyword(s):  
Amino Acids ◽  
Transport System ◽  
Free Amino Acids ◽  
Free Amino ◽  
Essential Amino Acids ◽  
Exponential Phase ◽  
Whole Cells ◽  
Streptococcus Cremoris ◽  
Defined Media ◽  
Hydrolysis Of

SummaryOf 8 strains ofStreptococcus cremoristested, 5 grew almost as well in defined media in which various essential amino acids were supplied in dipeptides as they did in media containing the equivalent free amino acids. The remainder grew poorly or not at all in the peptide-containing media. Growth of peptide-utilizing strains was inhibited by also including structurally-related dipeptides in the medium, presumably due to competition for uptake by transport system carriers. Both types of starters produced cell-free dipeptidases recoverable from the medium of exponential phase cultures. Addition of the partly-purified extracellular dipeptidases to dipeptidecontaining test media initiated growth in strains unable to use peptides.Str. lactisgrew in defined peptide media, but the further addition of structurally-related dipeptides did not inhibit growth, either bcause each dipeptide was transported by a specific carrier or because peptides were hydrolysed extracellularly. The presence of cell-bound extracellular dipeptidase was indicated by the hydrolysis of dipeptides with washed whole cells in buffer. This was not observed withStr. cremorisstrains.

scholarly journals Preparation of polyribosome aminoacyl-transfer ribonucleic acid from the muscle of chick embryos.

1975 ◽  
Vol 147 (3) ◽  
pp. 473-477 ◽  
Author(s):  
M Nwagwu
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sodium Dodecyl Sulphate ◽  
Ribonucleic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Sodium Dodecyl ◽  
Specific Radioactivity ◽  
Chick Embryos ◽  
Aminoacyl Transfer

A procedure for preparing polyribosome aminoacyl-tRNA free from contamination by supernatant aminoacyl-tRNA and free amino acids is described. Important features of the procedure are the use of acidic buffers to help protect the amino acid-tRNA linkage and the inclusion of sodium dodecyl sulphate, to inhibit ribonuclease activity. The specific radioactivity of polyribosome aminoacyl-tRNA is high within 30s and reaches a maximum in 2 1/2 min, well ahead of polyribosome peptides which, as described by Herrmann et al. (1971), attain maximum specific radioactivity in about 10 min.

scholarly journals FREE AMINO ACIDS AND NUCLEIC ACID CONTENT OF CELL NUCLEI ISOLATED BY A MODIFICATION OF BEHRENS' TECHNIQUE

1950 ◽  
Vol 33 (5) ◽  
pp. 629-642 ◽  
Author(s):  
Alexander L. Dounce ◽  
Garson H. Tishkoff ◽  
Shirley R. Barnett ◽  
Richard M. Freer
Keyword(s):  
Amino Acids ◽  
Nucleic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Essential Amino Acids ◽  
Nucleic Acid Content ◽  
Cell Nuclei ◽  
Whole Cells ◽  
Cell Fractions ◽  
Isolated Cell

1. Nuclei were prepared from frozen rat liver by a modification of the technique of Behrens, and were studied with regard to the content of free amino acids and nucleic acid. 2. Under rigorously controlled conditions, preparations of nuclei are obtained by the Behrens' method which form a gel in the presence of 5 or 10 per cent NaCl or of water plus a small amount of dilute alkali; whereas when conditions are less rigorously controlled, nuclei are obtained which form no such gel. The property of forming gels with alkali is probably characteristic of all cell nuclei which have not undergone autolysis. 3. Nuclei prepared by the Behrens' technique contain the enzymes arginase, catalase, and esterase in very appreciable concentrations. 4. The free amino acids of the isolated cell nuclei, as well as of other liver cell fractions, have been investigated using the technique of paper chromatography. 5. The chromatographic patterns of the free amino acids of whole cells, ground cytoplasm, and isolated cell nuclei were very similar or identical. A feature of interest in these chromatograms was the faintness or absence of the spots due to a number of the essential amino acids, as compared to the intensities of the spots due to glycine, alanine, and glutamic acid. Glutathione was present in the isolated nuclei as well as in the whole cells. 6. Chromatograms made from hydrolysates of nuclei showed high concentrations of the essential amino acids and were similar to chromatograms of hydrolysates of typical proteins.

Free active peptidases are detected in Emmental juice extracted before ripening in the warm room

1998 ◽  
Vol 65 (1) ◽  
pp. 119-128 ◽  
Author(s):  
VALERIE GAGNAIRE ◽  
SYLVIE LORTAL ◽  
JOELLE LEONIL
Keyword(s):  
Amino Acids ◽  
Gel Electrophoresis ◽  
Free Amino Acids ◽  
Free Amino ◽  
Polyacrylamide Gel Electrophoresis ◽  
Peptidase Activity ◽  
Continuous Increase ◽  
Cheese Ripening ◽  
Emmental Cheese ◽  
Warm Room

In Swiss-type cheese such as Emmental, proteolysis is one of the major phenomena occurring during ripening. Among the proteolytic agents involved in cheese ripening, the free enzymes originally present in milk and those arising from bacterial autolysis can act directly on the casein network. In order to understand the contribution of the bacterial enzymes and especially those arising from the thermophilic starters, the juice of an Emmental cheese entering the warm room was extracted by pressure, then sterilized by filtration and incubated at 24°C for 20 d under anaerobiosis. At different times, the peptides and free amino acids were determined in the sterile cheese juice. In parallel, in order to gather information about the nature of the enzymes present, the sterile juice was also incubated with β-naphthylamide derivatives as substrates. We have demonstrated a continuous increase in free NH2 groups and in free amino acids throughout the 20 d incubation time. The main peptidase activity was due to aminopeptidase(s) and X-prolyldipeptidyl aminopeptidase(s) whose activities were recovered after non-denaturing polyacrylamide gel electrophoresis. Most of the enzymes found in the juice would have their origin in thermophilic starters. As they are generally intracellularly located, their release could be explained by the autolysis of these starters. Finally, the main free amino acids released in the juice (Pro, Glu, Ala, Val, Leu and Lys) corresponded to those previously found in Emmental cheese, suggesting that the enzymes detected in this study participate significantly in peptide degradation during ripening.

Effect of Water Stress on Composition of Peanut Leaves

1998 ◽  
Vol 25 (1) ◽  
pp. 31-34 ◽  
Author(s):  
M. Ali-Ahmad ◽  
S. M. Basha
Keyword(s):  
Amino Acids ◽  
Water Stress ◽  
Protein Content ◽  
Free Amino Acids ◽  
Free Amino ◽  
Polyacrylamide Gel Electrophoresis ◽  
Soluble Sugars ◽  
Total Protein Content ◽  
Effect Of Water ◽  
Arachis Hypogaea L

Abstract Water stress was induced in peanut (Arachis hypogaea L. cv. Marc 1) plants by withholding water for 5 to 20 d. Leaves from the water-stressed plants were analyzed to determine the effect of water stress on amino acids, sugars, protein content, and polypeptide composition of peanut plants. The results showed that the total protein content of the leaves significantly increased when peanut plants were subjected to water stress for 5 to 20 d as compared to irrigated controls. Analysis of the leaf protein by SDS polyacrylamide gel electrophoresis showed higher levels of polypeptides in stressed leaves compared to the control leaves. Peanut leaves from water-stressed plants also showed higher amounts of free amino acids and soluble sugars as compared to the irrigated plants. Thus, water stress enhanced accumulation of proteins, free amino acids, and soluble sugars in the peanut plants.

Betaines and free amino acids in salt stressed vitroplants and winter resting buds of Populus trichocarpa x deltoides

1991 ◽  
Vol 83 (1) ◽  
pp. 136-143 ◽  
Author(s):  
L. Bray ◽  
D. Chriqui ◽  
K. Gloux ◽  
D. Le Rudulier ◽  
M. Meyer ◽  
...  
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Populus Trichocarpa

Plasma and skeletal muscle free amino acids in type I, insulin-treated diabetic subjects

Diabetes ◽  
1985 ◽  
Vol 34 (8) ◽  
pp. 812-815 ◽  
Author(s):  
L. Borghi ◽  
R. Lugari ◽  
A. Montanari ◽  
P. Dall'Argine ◽  
G. F. Elia ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Type I
Sign in / Sign up

Export Citation Format

Share Document