Ledgerwood E C, Brennan S O, Birch N P, George P M
Molecular Pathology Laboratory, Christchurch Hospital, New Zealand.
Biochem Mol Biol Int. 1996 Aug;39(6):1167-76. doi: 10.1080/15216549600201352.
The Kex2-like convertase PC3 (PC1) has been implicated in the processing of a number of prohormones and proneuropeptides. In order to be able to more accurately predict substrates for PC3 its specificity was defined using recombinant proalbumins and synthetic peptide substrates. P2P1 and P4P1 dibasic sites were cleaved with similar efficiencies however there were specific restrictions on amino acids NH2- and COOH-terminal to the cleavage site. His was disallowed at P2 and basic residues were forbidden at P1. The presence of a charged residue at P2 either completely prevented (Arg) or seriously impaired (Glu) cleavage by PC3 and the presence of a P4 Arg did not significantly increase its activity.