Considerations in predicting phenotypic modifications in amino acid profiles of total cell protein of microorganisms

1977 ◽  
Vol 19 (8) ◽  
pp. 1145-1153 ◽  
Author(s):  
Yair Alroy ◽  
Steven R. Tannenbaum
Keyword(s):  
Amino Acid ◽  
Total Cell ◽  
Cell Protein ◽  
Total Cell Protein ◽  
Amino Acid Profiles

The Effect of Dilution Rate upon Protein Content and Cellular Amino Acid Profiles in Chemostat Cultures of Saccharomyces Cerevisiae CABI 039916

2010 ◽  
Vol 6 (4) ◽  
Author(s):  
Beverley Finn ◽  
Linda M Harvey ◽  
Brian McNeil
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Protein Content ◽  
Dilution Rate ◽  
Specific Growth ◽  
Cellular Protein ◽  
Cell Protein ◽  
Protein Pool ◽  
Cellular Protein Content ◽  
Amino Acid Profiles

In the present study we examined the use of a chemostat system to investigate the impact of changes in the specific growth rate of Saccharomyces cerevisiae CABI 039916 on cellular amino acid profiles and total protein content. This experimental system allowed the unambiguous examination of the link between changes in dilution rate and the culture response, which would have been difficult in batch or fed-batch cultures. Alteration of the specific growth rate (via manipulation of the dilution rate) within a carbon and energy-limited chemostat has a significant impact on the physiology of Saccharomyces cerevisiae. Low dilution rates (<0.1h-1) led to predominantly respiratory metabolism and the maximisation of cellular protein content within the cell (58%), by contrast high dilution rates (>0.2h-1) led to respirofermentative metabolism, where the cellular protein content was minimal (~40%). The content of nearly all amino acids in the yeast protein pool fell significantly as dilution rate increased in parallel with the decline in cell protein content. By contrast, the concentration of two related key food/feed amino acids in the cell protein pool—glutamic acid and arginine could be increased within the cellular protein by 5% (increasing the dilution rate from 0.05h-1 to 0.25h-1) and 1.5% respectively (decreasing the dilution rate from 0.05h-1 to 0.2h-1). Despite previous studies showing that metabolic change was associated with major changes in free amino acid levels, the present study indicates that the total cellular yeast protein amino acid composition is largely invariant despite profound metabolic changes, with one or two key exceptions.

Contraction regulates myosin synthesis and myosin content of cultured heart cells

1985 ◽  
Vol 249 (4) ◽  
pp. H763-H769
Author(s):  
P. McDermott ◽  
M. Daood ◽  
I. Klein
Keyword(s):  
Protein Synthesis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Total Cell ◽  
Neonatal Rat ◽  
Cell Protein ◽  
Heart Cells ◽  
Culture Dish ◽  
Total Cell Protein ◽  
Cultured Heart Cells

Cultured neonatal rat heart cells are a useful model for studying the regulation of myocyte growth. The myosin content of heart cells increases between days 1 and 4 in culture. To determine if contraction per se can regulate myocyte growth, myosin content and protein synthesis were compared in spontaneously contracting and noncontracting cultured heart cells. Myosin content, assayed as the total myosin ATPase activity per culture dish, was significantly increased in contracting cells after 3, 4, and 5 days in culture. Protein synthesis was measured by incorporation of [14C]lysine into total cell protein and into sodium dodecyl sulfate-polyacrylamide gel electrophoresis resolved myosin. Contraction stimulated both total cell protein content and protein synthesis by day 3 in culture. Compared with heart cells arrested with 50 mM KCl, myosin synthesis was significantly increased by 96, 112, and 46% at days 2, 3, and 4, respectively. Similar results were observed when myosin content and protein synthesis in contracting myocytes were compared with cells arrested with either 25 mM KCl or 10(-5) M verapamil. The present studies suggest that contraction increases the myosin content in cultured heart cells and that this increase is mediated via a stimulation of myosin synthesis in association with cell growth.

Sub-cellular fractionation ofTrypanosoma brucei. Isolation and characterization of plasma membranes

Parasitology ◽  
1980 ◽  
Vol 80 (3) ◽  
pp. 507-524 ◽  
Author(s):  
Luciana Rovis ◽  
Steinunn Baekkeskov
Keyword(s):  
High Speed ◽  
Plasma Membranes ◽  
Specific Activity ◽  
Total Cell ◽  
Molar Ratio ◽  
Cell Protein ◽  
Phospholipid Content ◽  
Total Cell Protein ◽  
Isolation And Characterization ◽  
Enzymatic Markers

SummaryA procedure is described for the isolation of sub-cellular fractions from bloodstream forms ofTrypanosoma brucei. The method leaves intact most of the nuclei, mitochondria and microbodies. All the fractions have been chemically characterized and tested for 10 enzymatic markers. About 5% of total cell protein was isolated as a microsomal fraction containing mostly plasma membranes and endoplasmic reticulum vesicles. Plasma membranes were purified by high-speed centrifugation on magnesium-containing Dextran, and on linear sucrose-density gradients. The yield of membranes was approximately 0·3% of the total cell protein. The purified material had a sucrose density of 1·14 g/cm3and consisted of smooth vesicles. Specific activity of the membrane markers Na+, K+, ouabain-sensitive ATPase and adenylate cyclase were 26-and 20-fold higher, respectively, than in total cells. Neither DNA nor RNA was detected. The sum of the cholesterol and phospholipid content was 0·99 mg/mg protein. The cholesterol/phospholipid molar ratio was 1 : 2.

Cytophotometric assessment of Feulgen-DNA and coomassie-total cell protein in adrenocortical fasciculata cells of noise-exposed wister rats

1991 ◽  
Vol 9 (4) ◽  
pp. 287-292
Author(s):  
D. U. Ballough ◽  
G. P. Ballough ◽  
J. A. Strauss ◽  
M. J. Durkot ◽  
A. Anthony
Keyword(s):  
Total Cell ◽  
Cell Protein ◽  
Total Cell Protein

Skeletal muscle growth is stimulated by intermittent stretch-relaxation in tissue culture

1989 ◽  
Vol 256 (3) ◽  
pp. C674-C682 ◽  
Author(s):  
H. H. Vandenburgh ◽  
S. Hatfaludy ◽  
P. Karlisch ◽  
J. Shansky
Keyword(s):  
Creatine Kinase ◽  
Protein Synthesis ◽  
Cell Growth ◽  
Mechanical Stimulation ◽  
Basal Medium ◽  
Total Cell ◽  
Mechanical Activity ◽  
Cell Protein ◽  
Cell Hyperplasia ◽  
Total Cell Protein

Avian pectoralis muscle cells differentiated in vitro are mechanically stimulated by repetitive stretch-relaxation of the cell's substratum using a computerized mechanical cell stimulator device. Initiation of mechanical stimulation increases the efflux of creatine kinase from the cells during the first 8-10 h of activity, but the efflux rate returns to control levels after this time period. Decreased total cell protein content accompanies the temporary elevation of creatine kinase efflux. With continued mechanical stimulation for 48-72 h, total cell protein loss recovers and significantly increases in medium supplemented with serum and embryo extract. Myotube diameters increase and cell hyperplasia occurs in the stimulated cultures. In basal medium without supplements, mechanical activity prevents myotube atrophy but does not lead to cell growth. Mechanically induced growth is accompanied by significant increases in protein synthesis rates. The increases in protein synthesis and accumulation induced by mechanical stimulation are not inhibited by tetrodotoxin but are significantly reduced in basal medium without supplements. Mechanically stimulated cell growth is thus dependent on medium growth factors but independent of electrical activity.

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