A recombinant GST-EMBP440 fusion protein from sea urchin embryos that has myosin binding capabilities

Abstract

A 53 kDal. (53K) native protein was isolated from sea urchin egg extract. The properties of this protein suggests that it may be a titin-like protein. Previous studies have shown that this protein has myosin light chain kinase activity. The antibody to native 53 kDal. was used to select recombinant GST-EMBP440 protein from a cDNA library. GST-EMBP440 protein was used in this study. This study confirms the myosin binding activity of GST-EMBP440 protein. Two binding assays were utilized to demonstrate myosin binding by GST-EMBP440 protein. A blot binding assay utilizing immunodetection suggested a lack of 53 kDal. binding. Results from a glutathione-agarose affinity precipitation assay indicated binding of the GST-EMBP440 fusion protein to myosin. The findings therefore suggest GST-EMBP440 protein may indeed be a myosin binding protein.