CLONING, EXPRESSION, CHARACTERIZATION AND ROLE OF THE LEADER SEQUENCEOF A LIPASE FROM RHIZOPUS-ORYZAE

A lipase from Rhizopus oryzae DSM 853 (ROL) was cloned from a chromoso mal gene bank, sequenced and overexpressed in Escherichia coli. ROL an d its precursors ProROL and PreProROL were purified and their pH and t emperature profile was determined. In contrast to ROL, ProROL and PreP roROL had considerably higher thermostability and a slightly higher pH optimum. Moreover, it could be demonstrated by in vitro experiments t hat the natural leader sequence of ROL is able to inhibit the folding supporting properties of the prosequence, resulting in a retardation o f folding. In addition, there is strong evidence that all different li pase forms derived from Rhizopus sp. described in the literature are a result of different proteolytic processing and originate from the sam e gene. (C) 1998 Elsevier Science B.V. All rights reserved.