食細胞の脂質分解酵素と結核菌
1982 年 57 巻 1 号 p. 1-7
詳細
1982 年 57 巻 1 号 p. 1-7
Phosphoiipase A (PLase) and cholesterol esterase (CEase) activities of guinea pig peritoneal leucocytes were examined using a post-unclear fraction as enzyme material. PLase reaction was performed with [14C] oleate-labeled phospholipids (mainly phosphatidylethanolamine) as substrate and 2.5mM of Ca2+, and the intensity was expressed by % degradation of the substrate as calculated by the released amount of labelled fatty acids. The reaction was inhibited by higher concentrations (e.g. 0.5mM) of lysolecithin or linoleic acid. CEase activity was measured with cholesteryl [1-14C] oleate as substrate at optimum pH of 4.6. This reaction was inhibited by increasing concentrations of lysolecithin but not of linoletic acid.
PLase reaction by the cell fraction was enhanced in the presence of added tubercle bacilli (virulent M. bovis), but the CEase reaction was apparently inhibited. Heat-killed mycobacteria did not stimulate the PLase reaction. When the mycobacteria were incubated with the cell fraction, the viable counts decreased during the course of time.
The relation between the enhancement of PLase activity and the mycobactericidal activity in the cell fraction was discussed in view of our previous findings that the artificial biomembrane (liposomes) and the cell fraction of phagocytic cells can kill mycobacteria in the presence of exogenous phospholipase A2.
