PubMed HealthSearch

Biomedical subjects

D A Chetverikov

Publications and source records attributed to D A Chetverikov.

17 recordsLinked to original sources

[Effect of hypobaric hypoxia on the acetate-1-14C incorporation rate in hydrophilic and hydrophobic brain phospholipid components].

Rats were kept in barochamber for 2 hours at the pressure of 240 mm Hg after subcutaneous administration of (1)14C-acetate. Hypobaric hypoxia caused depression in the incorporation of labeled acetate similar in both phospholipid (PL) components. But the dependence of depression in the metabolic rate upon hypothermia which accompanied hypoxia was more pronounced for hydrophobic portion of PB (carbon skeleton of fatty acids) than for hydrophilic one. Similarity in the degree of the hypoxia induced depression of incorporation of the precursors containing labeled phosphorus and carbon allows one to suggest that the carbon-containing parts of PL hydrophilic components (glycerol and nitrogen bases) and residues of ortho-phosphoric acid respond to hypoxia as a whole.

Acetates

[Properties of the high energy phosphate bonds of triphosphoinositide].

High heat of enzymatic hydrolysis of triphosphoinositide phosphate bonds and of high-energy phosphates is observed using microcalorimetry. Heats of hydrolysis of triphosphoinositide, ADP and ATP sharply increase with increasing pH values from 6.6 to 7.4. Heat of hydrolysis of diphosphoinositide correlates with that of low-energy phosphates, pK4 and pK5 values for triphosphoinositide are found to be 7.4 and 9.3 respectively by means of potentiometric titration deltaGo' values for diphosphoinositide and triphosphoinositide are -3.5 and -7.1 kcal/mole respectively, taking into consideration the correction for heat neutralization-ionization during hydrolysis. Rapid triphosphoinositide hydrolysis takes place in 1% aqueous pyridine solution at 100 degrees C. In contrast to diphosphoinositide and monophosphoinositide, infrared spectra of triphosphoinositide have an additional absorption band at 930 cm(-1). 31P NMR method has revealed the presence of one diester and two monoester groups in the molecule of triphosphoinositide. The differences described between triphosphoinositide and other compounds with phosphomonoester groups are suggested to be due to electrostatic nonbounded interaction of vicinal diequatorial phosphate groups.

Adenosine Diphosphate