The Sequence Analysis and Expression of cDNA of Human Cardiac Myosin Light Chain 1 and the Preparation of Monoclonal Antibody to the Expressed Product.

The nucleotide sequence of cDNA of ventricular myosin light chain 1 of Chinese patients was analyzed. Two remarkable differences in deduced amino acid sequence were found by comparison with amino acid sequence reported previously by Jackowski. The cDNA was expressed in E.coli and the expressed product was used for production of specific polyclonal and monoclonal antibodies. Using both of the poly- and monoclonal antibodies, as well as the expressed product, diagnosis kits for Acute Myocardial infarction was constructed (China patent application number 98 122066.5). Detailed studies on physiological function of cardiac myosin light chain 1 is under way in our lab.

Binding of Human Cardiac Myosin Light Chain 1 to Heavy Chain and Actin.

The cloning and sequence analysis of Chinese human cardiac myosin light chain 1 (CCMLC1) was previously reported. In this paper the cDNA of CCMLC1 was used as template and both of cDNAs of N and C terminal fragments of CCMLC1, each containing 98 amino acid residues, were obtained by PCR. Using the expressed products of both fragments, the binding experiments of two fragments to cardiacmyosin heavy chain of rat, human cardiac actin and to monoclonal antibody raised against CCMLC1, have been performed, respectively, by means of precipitation with GST-Sepharose beads. The results showed that all the heavy chain, actin and monoclonal antibody bound the N terminal fragment of CCMLC1 at different sites. Under experimental conditions, the binding of CCMLC1 with actin could affect the subsequent binding of CCMLC1 to heavy chain in topologically.