title: Identification and optimization of a novel inhibitor of mitochondrial calpain 10.
abstract: Calpain 10 has been localized to the mitochondria and is a key mediator of Ca(2+) induced mitochondrial dysfunction. A peptide screen followed by a series of modifications identified the homodisulfide form of CYGAK (CYGAK)(2) as an inhibitor of calpain 10 while showing no inhibitory activity against calpain 1. Methylation or truncation of the N-terminal cysteine significantly reduced the inhibitory activity of (CYGAK)(2) and inhibition was reversed by reducing agents, suggesting that CYGAK forms a disulfide with a cysteine near the active site. Data suggests CYGAK may be a P' calpain inhibitor and may achieve its specificity through this mechanism. CYGAK inhibited calpain activity in intact mitochondria, renal cells, and hepatocytes, prevented Ca(2+) induced cleavage of NDUFV2, and blocked Ca(2+) induced state III dysfunction. (CYGAK)(2) is the first P' specific calpain inhibitor and will be a valuable tool to prevent Ca(2+) induced mitochondrial dysfunction and explore the function of calpain 10.
authors.affiliation: Department of Biomedical and Pharmaceutical Sciences, Center for Cell Death, Injury, and Regeneration, South Carolina College of Pharmacy, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
authors.forename: Kyle A
authors.initials: KA
authors.lastname: Rasbach
authors.forename: David D
authors.initials: DD
authors.lastname: Arrington
authors.forename: Sina
authors.initials: S
authors.lastname: Odejinmi
authors.forename: Chris
authors.initials: C
authors.lastname: Giguere
authors.forename: Craig C
authors.initials: CC
authors.lastname: Beeson
authors.forename: Rick G
authors.initials: RG
authors.lastname: Schnellmann
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002154:Calpain / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D011817:Rabbits
chemical_list: D004791:Enzyme Inhibitors; D010455:Peptides; D002154:Calpain; C415197:calpain 10