Abstract
The amino acid sequence of an atrial peptide, AAP, that improves the rhythmicity of cultured myocardial cell clusters, was established as Gly-Pro-4Hyp-Gly-Ala-Gly. This was accomplished by the sequence analyses with dansyl-Edman degradation and carboxypeptidase Y digestion on the isolated native peptide. The hexapeptide and its several constituent peptides were synthesized by using dicyclohexylcarbodiimide as a condensing agent. Synthetic AAP was found to be chemically and biologically indistinguishable from the native one. In a structure-activity correlation of AAP, it was recognized that the whole molecule of this peptide was essential for its antiarrhythmic activity and its promoting effect on spreading phenomenon of myocardial cells in culture.
