Suo S, Koike H, Sorimachi H, Ishiura S, Suzuki K
Institute of Molecular and Cellular Bioscience, University of Tokyo, Tokyo, 113-0032, Japan.
Biochem Biophys Res Commun. 1999 Apr 2;257(1):63-6. doi: 10.1006/bbrc.1999.0407.
The calmodulin-like domain of calpain is important for the association of the calpain large and small subunits. We expressed the calmodulin-like domains of the large subunits of rabbit mu- and m-calpains and their small subunits in E. coli and purified them to homogeneity. Unlike the full-length subunits, the calmodulin-like domains are soluble in buffer containing Ca2+. We performed gel filtration chromatography of the purified proteins and found that all three calmodulin-like domains exist as homodimers in the absence of Ca2+ and dissociate into monomers upon the addition of Ca2+.
