Isolation and characterization of a genetic variant of bovine proinsulin

Abstract
A genetic variant of bovine proinsulin was isolated using preparative reverse-phase HPLC [high performance liquid chromatography]. The new proinsulin (bovine proinsulin II) differs from the known proinsulin (bovine proinsulin I) by a single amino acid residue at position C-48 in the connecting peptide. The amino acid replacement is a Leu substitution for Pro. The 2 proinsulins were found in a ratio of .apprx. 9:1, proinsulin I: proinsulin II. No chemical or biological differences were observed for the 2 proinsulins other than their different elution times on reverse-phase HPLC.