Expression in Pichia pastoris and characterization of Rhizomucor miehei lipases containing a new propeptide region.

A large number of propeptide regions from various proteins have been identified which function as intramolecular chaperones and assist the folding of the respective functional domains. The same polypeptide can fold into an altered conformation because of a mutated intramolecular chaperone and can maintain the "memory" of the folding process (new physicochemical properties). Two new kinds of Rhizomucor miehei lipase (RML) were constructed by replacing its propeptide region with that from either Rhizopus chinensis lipase (RCL) or Rhizopus oryzae lipase (ROL). The enzymatic properties were also analyzed and compared between wild-type RML and the mutants. The results indicated that the same polypeptide can fold into different conformations because of changes in the propeptide region.