The effects of autolysis on the structure of chicken calpain II

Publisher Website
Google Scholar
Abstract
When chicken calpain II autolysed in the presence of Ca2+, it underwent limited porteolysis to give peptides of M4 54000 and 37000, and several of M4 approx. 30000 and 18000. The autolytic peptides were purified and their N-terminal amino acid sequences determined. By comparison of these sequences with the known sequence of the complete calpain molecule, the autolytic cleavage sites were identified. The structural integrity of the molecule during autolysis was investigated by gel-permeation chromatography. Experiments were also done to test the reversibility of adding EDTA to calpain during autolysis, measured as recoverable enzyme activity assayed in the presence of Ca2+. The results are presented in terms of a model for the structural changes occurring in calpain during autolysis. It was concluded that the loss of enzymic activity, which is a consequence of autolysis, was due to dissociation of the autolytic peptides after cleavage of the calpain large subunit within the third domain.

This publication has 34 references indexed in Scilit: