Relaxin: Recent structure and activity studies

摘要

The peptide hormone relaxin is produced in, and acts upon, tissues of the reproductive tract in many mammalian species to facilitate parturition [1]. The primary structure of rat relaxin was determined by its isolation, sequencing and amino acid analysis [2]. It was shown to consist of a twenty four residue A-chain and a thirty five residue B-chain (Fig.1). Comparatively little is known about the structure and biology of this peptide. It was shown to be active in both the mouse public ligament assay and the rat uterine contraction assay. However, it produced a non-parallel dose-response curve to the porcine relaxin standard [2]. Binding sites for relaxin have been detected in the uterus and, more recently, in the brain and heart of both male and female rats [3,4]. Subsequent work has shown that relaxin possesses potent inotropic and chronotropic activity in the isolated rat heart assay [5]. This suggests that it may, in fact, have a broad physiological role. Given the convenience of the rat as a laboratory model for biological study and, as part of a study of hte role of rat relaxin in pregnancy, we undertook the solid phase synthesis of the peptide and compared it with the native product both chemically and biologically.