Investigation of tyrosinase activity and phospholipid composition in Harding-Passey melanoma microsomal fraction
Shtol'ko, V.N.; Bogdanov, G.N.; Vasil'eva, L.S.; Burlakova, E.B.
Biokhimiia 43(1): 121-126
1978
ISSN/ISBN: 0320-9725 PMID: 414789 Document Number: 128652
Alteration in DOPA-oxidase activity of Harding-Passey melanoma microsomal fraction tyrosinase, activation of tyrosinase after partial delipidization of the microsome, phospholipid composition of both native microsomes and the ones after delipidization have been studied. In the course of tumor growth (starting on the 14th day after tumor transplantation) the tyrosinase activity has been shown to decrease monotonously both in native microsomes and in the ones after delipidization. The phospholipid composition alters both in the process of tumor growth and after delipidization. Alteration in the tyrosinase activity in native microsomes as well as after their delipidization has been found to depend on the relative composition of certain phospholipids. In those cases a linear correlation between the enzyme activity and the phosphatydylethanolamine of phosphatydylcholine ratio has been found. This interrelationship may be accounted for by either simultenous presence of inhibitors and activators of the enzyme activity in the lipids or by changes in the membrane structure depending on the relative phospholipid composition.