STUDIES ON LIPASE .13. INCREASE IN THE ACTIVITY OF RHIZOPUS C-LIPASE ON LIPOPROTEIN BY ITS INTERACTION WITH PHOSPHOLIPID

The present study is concerned in the interconversion of B-lipase and C-lipase which are found in the culture filtrate of Rhizopus (Rh.) delemar. Lipoprotein lipase (LPL) activity of C- lipase was originally much less than that of B-lipase. The phospholipid (PL)-treatment on C- lipase remarkably enhanced its LPL activity as well as the change in its isoelectric point. The enhancement depended on the treatment conditions such as PL concentration, time or temperature of treatment and a variety of PL. Various forms of modified C-lipase were indicated by the PL treatment in vitro and in terms of cultivation of Rh. delemar. Phospholipids from Rh. mycelia participated in the enhancement of LPL activity of C-lipase. These facts suggest that some transient forms exist in process of change of C-lipase into B-lipase which is performed in Rh. mycelia. © 1979 Taylor & Francis Group, LLC.