Effect of Proline, Betaine and Some Other Solutes on the Heat Stability of Mitochondrial Enzymes

1982 ◽  
Vol 9 (1) ◽  
pp. 47 ◽  
Author(s):  
D Nash ◽  
LG Paleg ◽  
JJ Wiskich
Keyword(s):  
Malate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Plant Mitochondria ◽  
Heat Stability ◽  
Heat Inactivation ◽  
Mitochondrial Enzymes

When isolated plant mitochondria are heated, isocitrate dehydrogenase, malate dehydrogenase and fumarase lose activity at different rates. The rate of loss of activity of each enzyme is reduced if the mitochondria are heated in the presence of proline, betaine or some other solutes; protection by proline or betaine against heat inactivation is also evident with these enzymes when they are solubilized. NAD-isocitrate dehydrogenase in pea mitochondria and NADP-dependent isocitrate dehydrogenase of pea chloroplasts are also protected by proline and betaine against inactivation when the isolated organelles are heated.

Effects of Various Solutes on the Thermostability of Isocitrate Dehydrogenase and Malate Dehydrogenase of Isolated Plant Mitochondria.

1982 ◽  
Vol 9 (6) ◽  
pp. 715 ◽  
Author(s):  
D Nash ◽  
JT Wiskich
Keyword(s):  
Malate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Choline Chloride ◽  
Plant Mitochondria ◽  
Membrane Integrity ◽  
Triticum Aestivum L ◽  
Osmotic Effect ◽  
Pisum Sativum L ◽  
Wheat Leaves ◽  
Brassica Oleracea L

Proline and betaine increased the thermostability of NAD-isocitrate dehydrogenase (EC 1.1.1.41) and of NAD-malate dehydrogenase (EC 1.1.1.37) when mitochondria isolated from pea leaves (Pisum sativum L.), wheat leaves (Triticum aestivum L.) and cauliflower buds (Brassica oleracea L.) were heated. Potassium chloride and choline chloride also increased the thermostability of isocitrate dehydrogenase in the three species, but their effects on malate dehydrogenase varied. Protection was found with both intact and disrupted mitochondria, indicating that it was not dependent on an osmotic effect. Proline and KCl also prolonged membrane integrity, as measured by impermeability to NAD+, during heating of pea leaf and cauliflower bud mitochondria. Phenylalanine reduced the thermostability of isocitrate dehydrogenase, indicating that protection is not a general solute effect.

scholarly journals THE INHERITANCE OF ENZYME VARIANTS FOR TYROSINE AMINOTRANSFERASE, NADP-DEPENDENT MALATE DEHYDROGENASE, NADP-DEPENDENT ISOCITRATE DEHYDROGENASE, AND TETRAZOLIUM OXIDASE IN TETRAHYMENA PYRIFORMIS, SYNGEN 1

Genetics ◽  
1973 ◽  
Vol 74 (4) ◽  
pp. 595-603
Author(s):  
D Borden ◽  
E T Miller ◽  
D L Nanney ◽  
G S Whitt
Keyword(s):  
Detailed Analysis ◽  
Malate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Gel Electrophoresis ◽  
Tetrahymena Pyriformis ◽  
Tyrosine Aminotransferase ◽  
Breeding Program ◽  
Starch Gel Electrophoresis ◽  
Enzyme Locus ◽  
Starch Gel

ABSTRACT The isozymic patterns of tyrosine aminotransferase, NADP malate dehydrogenase, NADP isocitrate dehydrogenase, and tetrazolium oxidase were examined by starch-gel electrophoresis in Tetrahymena pyriformis, syngen 1. The genetics of the alleles controlling these enzymes was studied through a breeding program. Each enzyme locus was shown to assort vegetatively, as do other loci in this organism. A detailed analysis of the assortment process for the tyrosine aminotransferase locus indicated that the rate of stabilization of heterozygotes into pure types was essentially identical to previously-reported rates for other loci.

scholarly journals DNA Genome Size Affects the Stability of the Adenovirus Virion

2008 ◽  
Vol 83 (4) ◽  
pp. 2025-2028 ◽  
Author(s):  
Adam C. Smith ◽  
Kathy L. Poulin ◽  
Robin J. Parks
Keyword(s):  
Genome Size ◽  
Critical Role ◽  
Heat Stability ◽  
Helper Virus ◽  
Heat Inactivation ◽  
Similar Relationship ◽  
Viral Dna ◽  
A Genome ◽  
The Stability ◽  
Replication Defective Adenovirus

ABSTRACT Replication-defective adenovirus (Ad) vectors can vary considerably in genome length, but whether this affects virion stability has not been investigated. Helper-dependent Ad vectors with a genome size of ∼30 kb were 100-fold more sensitive to heat inactivation than their parental helper virus (>36 kb), and increasing the genome size of the vector significantly improved heat stability. A similar relationship between genome size and stability existed for Ad with early region 1 deleted. Loss of infectivity was due to release of vertex proteins, followed by disintegration of the capsid. Thus, not only does the viral DNA encode all of the heritable information essential for virus replication, it also plays a critical role in maintaining capsid strength and integrity.

Heat Stability of the Bile Salt-Stimulated Lipase in Human Milk Fortified with Sodium Taurocholate1

1988 ◽  
Vol 51 (4) ◽  
pp. 310-313 ◽  
Author(s):  
H. L. PAN ◽  
C. W. DILL ◽  
E. S. ALFORD ◽  
S. L. DILL ◽  
C. A. BAILEY ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Human Milk ◽  
Bile Salt ◽  
Lipase Activity ◽  
Sodium Taurocholate ◽  
Heat Stability ◽  
Heat Inactivation ◽  
Temperature Differential ◽  
Heat Stable ◽  
Control Samples

Time-temperature relationships for heat-inactivation of the bile salt-stimulated lipase activity were compared in whole human milk and in the same product fortified to 9 mM/ml with sodium taurocholate. Heat treatments were varied from 45 to 70°C for times ranging from 15s to 40 min. Enzyme activity was more heat stable in human milk fortified with taurocholate than in control samples. The temperature required for the onset of heat inactivation at 30-min holding time was increased from 45°C for control samples to 60°C following addition of taurocholate. A temperature differential of approximately 12°C was required in the fortified milks to produce inactivation equivalent to that observed in the control milks over the heating range studied.

Confirmation of the Synteny of the Human Genes for Cytoplasmic Isocitrate Dehydrogenase and Cytoplasmic Malate Dehydrogenase and Assignment to Chromosome 2

1974 ◽  
Vol 13 (1-2) ◽  
pp. 79-82
Author(s):  
R.P. Creagan ◽  
B. Carritt ◽  
S. Chen ◽  
R. Kucherlapati ◽  
F.A. McMorris ◽  
...  
Keyword(s):  
Malate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Chromosome 2 ◽  
Human Genes

scholarly journals Decreased cardiac mitochondrial NADP+-isocitrate dehydrogenase activity and expression: a marker of oxidative stress in hypertrophy development

2004 ◽  
Vol 287 (5) ◽  
pp. H2122-H2131 ◽  
Author(s):  
Mohamed Benderdour ◽  
Guy Charron ◽  
Blandine Comte ◽  
Riwa Ayoub ◽  
Diane Beaudry ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Energy Metabolism ◽  
Mrna Expression ◽  
Isocitrate Dehydrogenase ◽  
Metabolic Enzyme ◽  
Mitochondrial Enzymes ◽  
Lipid Peroxidation Product ◽  
Sequence Of Events ◽  
Sd Rats ◽  
The Impact

Mitochondrial dysfunction subsequent to increased oxidative stress and alterations in energy metabolism is considered to play a role in the development of cardiac hypertrophy and its progression to failure, although the sequence of events remains to be elucidated. This study aimed at characterizing the impact of hypertrophy development on the activity and expression of mitochondrial NADP+-isocitrate dehydrogenase (mNADP+-ICDH), a metabolic enzyme that controls redox and energy status. We expanded on our previous finding of its inactivation through posttranslational modification by the lipid peroxidation product 4-hydroxynonenal (HNE) in 7-wk-old spontaneously hypertensive rat (SHR) hearts before hypertrophy development (Benderdour et al. J Biol Chem 278: 45154–45159, 2003). In this study, we used 7-, 15-, and 30-wk-old SHR and Sprague-Dawley (SD) rats with abdominal aortic coarctation. Compared with age-matched control Wistar-Kyoto (WKY) rats, SHR hearts showed a significant 25% decrease of mNADP+-ICDH activity, which preceded in time 1) the decline in its protein and mRNA expression levels (between 10% and 35%) and 2) the increase in hypertrophy markers. The chronic and persistent loss of mNADP+-ICDH activity in SHR was associated with enhanced tissue accumulation of HNE-mNADP+-ICDH and total HNE-protein adducts at all ages and contrasted with the profile of changes in the activity of other mitochondrial enzymes involved in antioxidant or energy metabolism. Two-way ANOVA of the data also revealed a significant effect of age on most parameters measured in SHR and WKY hearts. The mNADP+-ICDH activity, protein, and mRNA expression were reduced between 25% and 35% in coarctated SD rats and were normalized by treatment of SHR or coarctated SD rats with renin-angiotensin system inhibitors, which prevented or attenuated hypertrophy. Altogether, our data show that cardiac mNADP+-ICDH activity and expression are differentially and sequentially affected in hypertrophy development and, to a lesser extent, with aging. Decreased cardiac mNADP+-ICDH activity, which is attributed at least in part to HNE adduct formation, appears to be a relevant early and persistent marker of mitochondrial oxidative stress-related alterations in hypertrophy development. Potentially, this could also contribute to the aetiology of cardiomyopathy.

scholarly journals FURTHER OBSERVATIONS ON THE BEHAVIOR OF STAPHYLOCOCCI WITHIN HUMAN LEUKOCYTES

1960 ◽  
Vol 111 (4) ◽  
pp. 533-558 ◽  
Author(s):  
David E. Rogers ◽  
Marian Ann Melly
Keyword(s):  
Heat Stability ◽  
Test System ◽  
Rabbit Serum ◽  
Heat Inactivation ◽  
Coagulase Negative Staphylococci ◽  
Opsonic Activity ◽  
Fresh Serum ◽  
Large Populations ◽  
Two Factors ◽  
Homologous Strain

A specific serum factor was required for rapid phagocytosis of pathogenic staphylococci by human polymorphonuclear leukocytes when the ingestion process was studied in siliconed glass systems and the concentrations of staphylococci were maintained at low levels. In contrast to certain other microbes, the resistance to phagocytosis which characterized pathogenic staphylococci was relative, and phagocytosis was readily accomplished when large populations of staphylococci were present in the test system. A factor promoting phagocytosis was present in eight of eight normal adult sera. In contrast, the sera of twenty-eight of thirty normal rabbits did not promote phagocytosis. Serum obtained from 2 rabbits maintained in the rabbit colony for several months acquired the ability to opsonize pathogenic staphylococci. The phagocytosis-promoting factor was almost completely removed by prior absorption of test sera with the homologous strain. The factor was incompletely removed by absorption with heterologous strains of pathogenic staphylococci and was not significantly reduced by absorption with coagulase-negative staphylococci or unrelated microorganisms. Present evidence suggests that the factor promoting phagocytosis is a thermostable opsonin. While the activity of heated serum could not be restored by the addition of small amounts of fresh serum or complement, the addition of large amounts of complement partially restored opsonic activity. Incubation of staphylococci in fresh serum prior to heat inactivation did not reduce subsequent phagocytosis, further suggesting the heat stability of the phagocytosis-promoting factor. Preliminary studies correlating the presence of antistaphylococcal hemagglutinins and phagocytosis-promoting factor in certain sera suggest that the two factors were not necessarily related. The phagocytosis of staphylococci in fresh human serum was inhibited by the addition of fresh or inactivated rabbit serum. Further studies on the nature of such inhibition are in progress. Once ingestion was accomplished, coagulase-positive staphylococci consistently survived in significant numbers within the cytoplasm of human granulocytes. Coagulase-negative staphylococci appeared to be destroyed within the leukocyte and could not be recultured from the cytoplasm following 3 to 4 hours of intracellular residence.

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