PRIMARY STRUCTURE OF A-CHAIN OF PORCINE RELAXIN

Relaxin, a peptide hormone previously purified from ovaries of pregnant hogs, was reduced, alkylated and separated into its component A and B chains. The A chain contains 22 residues and the B chain 30 residues. The sequence of the A chain of relaxin was Arg-Met-Thr-Leu-Ser-Glu-Lys-Cys-Cys-Glu-Val-Gly-Cys-Ile-Arg-Lys-Asp-Ile-Ala-Arg-Leu-Cys (2500 daltons). While no homology to the insulin A chain exists, the relative distribution of the cysteine residues is identical if the N-terminal glycine of the insulin A chain is aligned with the threonine residue of the A chain of relaxin.