ADDITIONAL PEPTIDYL DIAZOMETHYL KETONES, INCLUDING BIOTINYL DERIVATIVES, WHICH AFFINITY-LABEL CALPAIN AND RELATED CYSTEINYL PROTEINASES

Calpain, the calcium-activated cysteinyl proteinase, can be irreversib ly inactivated by peptidyl diazomethyl ketones in which the peptide po rtion contains a penultimate leucine residue. Some new derivatives of this type have been synthesized and examined for their rates of inacti vation of chicken gizzard and human platelet calpain. Two derivatives containing a C-terminal biotin residue, Biot-Aca-Leu-TyrCHN2 and Biot- Aca-Leu-Leu-TyrCHN2, have also been prepared in the expectation that t heir application to the study of the function of calpain and related p roteases will prove fruitful.