Active-Site-Directed Chemical Tools for Profiling Mitochondrial Lon Protease

Document Type

Article

Publication Date

4-26-2011

Publication Title

ACS Chemical Biology

Abstract

Lon and ClpXP are the only soluble ATP-dependent proteases within the mammalian mitochondria matrix, which function in protein quality control by selectively degrading misfolded, misassembled, or damaged proteins. Chemical tools to study these proteases in biological samples have not been identified, thereby hindering a clear understanding of their respective functions in normal and disease states. In this study, we applied a proteolytic site-directed approach to identify a peptide reporter substrate and a peptide inhibitor that are selective for Lon but not ClpXP. These chemical tools permit quantitative measurements that distinguish Lon-mediated proteolysis from that of ClpXP in biochemical assays with purified proteases, as well as in intact mitochondria and mitochondrial lysates. This chemical biology approach provides needed tools to further our understanding of mitochondrial ATP-dependent proteolysis and contributes to the future development of diagnostic and pharmacological agents for treating diseases associated with defects in mitochondrial protein quality.

Comments

This work was supported by the National Institute of Health grants R01 GM067172 (I.L.) and R01 GM084039 and R21NS067668 (C.K.S.), the National Science Foundation grant MCB-0919631 (I.L.), and the Foundation of UMDNJ (C.K.S.).SNC was a recipient of a post-doctoral fellowship from the NIH/ NCI (CA059366-14).

DOI

10.1021/cb100408w

Volume

6

Issue

8

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