Site-specific DOTA/europium-labeling of recombinant human relaxin-3 for receptor-ligand interaction studies

Abstract

Relaxin-3 (also known as INSL7) is a recently identified neuropeptide belonging to the insulin/relaxin superfamily. It has putative roles in the regulation of stress responses, food intake, and reproduction by activation of its cognate G-protein-coupled receptor RXFP3. It also binds and activates the relaxin family peptide receptors RXFP1 and RXFP4 in vitro. To obtain a europium-labeled relaxin-3 as tracer for studying the interaction of these receptors with various ligands, in the present work we propose a novel site-specific labeling strategy for the recombinant human relaxin-3 that has been previously prepared in our laboratory. First, the N-terminal 69His-tag of the single-chain relaxin-..