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Mammalian microsomal and soluble Ras‐processing peptidase activities are distinct
Author(s) -
Hitz Anna M.,
Georgopapadakou Nafsika H.
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00766-1
Subject(s) - microsome , biochemistry , chemistry , peptide , chelation , cysteine , substrate (aquarium) , enzyme , hydrolysis , biology , ecology , organic chemistry
Microsomal and soluble peptidases from bovine liver and pig brain hydrolyze the farnesylated, Ras‐based CAAX peptide [ 3 H]Ac‐fCVIM‐ OH . However, they differ in their sensitivity to substrate‐based inhibitors, sulfhydryl and chelating agents, pH and ionic strength optima, and stability. The microsomal activity was exquisitely sensitive to the substrate‐based inhibitor Boc‐fC[CH 2 ]VIM‐ OH , moderately sensitive to the sulfhydryl agent p CMB, but insensitive to NEM and the metal‐chelating agent o ‐phenanthroline. The soluble activity was insensitive to Boc‐fC[CH 2 ]VIM‐ OH , but very sensitive to p CMB, NEM and o ‐phenanthroline, suggesting it to be the previously reported (Biochem. Biophys. Res. Commun. 198, 787–794 (1994)) zinc metallopeptidase. The microsomal activity is most likely to be a cysteine peptidase involved in the post‐translational processing of Ras proteins.