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Biomedical subjects

V A Trapkov

Publications and source records attributed to V A Trapkov.

4 recordsLinked to original sources
PubMed1992

[Zinc metabolism in duodenal ulcer].

Zinc concentrations were measured in blood and gastroduodenal mucosa of patients with duodenal ulcer in remission and exacerbation. These were found reduced in plasma but elevated in gastroduodenal mucosa. Healing of the ulcer lesion was associated with positive shifts in zinc metabolism which recovered normal values in ulcer remission. It is concluded that plasma and gastroduodenal levels of zinc reflect the stage of the pathological process in peptic ulcer.

Adult↗
PubMedDate not supplied

[Stages in the thermal denaturation of spiral fragments of myosin].

Scanning microcalorimetry is used to study heat denaturation of myosin "tail" helical fragments, light meromyosin and the LF-3 subfragment. It has been shown that all the data obtained were well explained by the existence of a set of quasi-independent cooperative regions. Probable location sites of separate cooperative regions in the helical part of the molecule are indicated. The obtained places of cooperative "breaks" are in a good agreement with the places of predominant cleavage of the myosin tail by proteolytic enzymes at its limited hydrolysis. The total denaturation enthalpy for each of the helical fragments per hydrogen bond at 100 degrees C is slightly less (5.4 +/- 0.8 kJ . mol-1) than the corresponding value for globular proteins.

Animals↗
PubMedDate not supplied

Investigation of the interaction of trypsin with heparin.

The reversible inhibition of the enzymatic activity of trypsin by heparin was investigated. On the basis of an analysis of the Lineweaver-Burk and Dixon graphs, a noncompetitive nature of the inhibition of the BAPA amidase activity of trypsin by heparin was detected, and the values of Km and Ki were determined, equal to 3.1 . 10(-4) and 3.7-3.9 . 10(-7) M, respectively. A comparison of these values indicates a great affinity of heparin for the enzyme. It was shown that heparin inhibits the BAEE esterase activity of trypsin and at the same time has no inhibiting effect on acetyltrypsin. Considering that the acetylation of trypsin leads to selective blocking of the epsilon-amino groups, it was concluded that the epsilon-amino groups of the lysine residues of the trypsin molecule participate in the interaction with heparin.

Catalysis↗