IDENTIFICATION AND ISOLATION OF A CYTOSOLIC PROTEOLYTIC COMPLEX CONTAINING INSULIN DEGRADING ENZYME AND THE MULTICATALYTIC PROTEINASE

The insulin degrading enzyme (IDE) is the first recognized member of a new class of metalloproteinases. Studies on the purification and the properties of this enzyme have led to divergent results and conclusion s from different laboratories. The present manuscript suggests that ma ny of the divergent results may be due to the interaction of this enzy me with other proteins as part of a proteolytic complex. IDE co-isolat es with the multicatalytic proteinase (MCP) during a wide variety of p urification approaches including affinity chromatography and conventio nal purification approaches. Ion exchange chromatography will partiall y or completely separate IDE and MCP. The SDS-PAGE protein bands at va rious purification steps suggest the presence of a cytosolic proteolyt ic complex containing IDE, MCP and other unidentified components and r aise the possibility of a functional interaction among these proteins. (C) 1994 Academic Press, Inc.