Chemical synthesis and relaxin activity of analogues of ovine insulin 3 containing specific B-chain residue replacements

Abstract

Insulin 3 (INSL3, RLF) is a new member of the insulin/relaxin family of peptide hormones. It possesses all the structural features of this peptide family including a two chain structure (A and B chains) linked by two interchain and one intrachain disulfide bond in the A chain. Close examination of the INSL3 sequence indicates that it is more relaxin-like than insulin-like and circular dichroism (CD) spectroscopy measurements of the synthetic sheep peptide indicate a secondary structure similar to relaxin [1]. Furthermore, the INSL3 B-chain contains an Arg-XXX-Arg, a cassette that is also present in the relaxin B-chain (Fig. 1) where it is known to be essential for relaxin bioactivity [2]. Ho..