O-linked and free exendin-1 and exendin-1b have vasoactive intestinal peptide(VIP)/secretin-like biological activities. They interact with rat and human VIP receptors 1 (VIPR1) and 2 (VIPR2), with the highest affinity for the human VIPR2. They induce hypotension that is mediated by relaxation of cardiac smooth muscle. Expressed by the venom gland. O-linked glycan consists of Hex-HexNAc saccharide. Glycosylation may be of interest for the biological stability of exendin-1 and exendin-1b. Exendin-1b. Exendin-1. O-glycosylated exendin-1b. O-glycosylated exendin-1. Belongs to the glucagon family.