Action of rat liver cathepsin B on bradykinin and on the oxidized insulin A‐chain

Abstract

Rat liver cathepsin B was tested for its peptide-bond specificity against bradykinin and the oxidized insulin A-chain. Bradykinin was shown to be resistant to the action of cathepsin B. One possible reason for this resistance is the proline content of the peptide and the discrimination against proline residues at three or four subsites of cathepsin B. Oxidized insulin A-chain was degraded by a peptidyl dipeptidase activity. Three dipeptides were cleaved from the C-terminal part of the insulin A-chain after having been incubated for 2 h (molar ration E:S = 1:2800) and six dipeptides were released after a longer digestion (10 h, E:S = 1575). Cathepsin B; Peptidyl dipeptidase; Substrate specificity; Bradykinin; Oxidized insulin A-chain

Prolonged signalling and trafficking of the bradykinin B2 receptor stimulated with the amphibian peptide maximakinin: Insight into the endosomal inactivation of kinins

“…Cathepsin K has been previously shown to degrade BK, but has a very limited distribution (mostly osteoclasts) [23]. BK is reportedly not inactivated by cathepsins B, C, L and S [23][24][25], while conflicting evidence has been produced for cathepsin H [23,26].…”