pHpG family

The snake pHpG family groups unusual, short (18-30 residues) peptides mostly composed of histidine and glycine residues (poly-His-poly-Gly or pHpG), hence their name. Wagstaff and colleagues (2008) postulate that these peptides serve as inhibitors of venom metalloproteases during glandular storage and that their inhibition is instantly disengaged, by dilution or physiochemical change, when venom is injected into tissue of the victim.

pHpG peptides are encoded by different large precursor polypeptides that contain an open-reading frame encoding either several bradykinin-potentiating peptides, one pHpG peptide and one natriuretic peptide (Fig.1A, see entries ) or several pEKW tripeptides, several pHpG peptides and one natriuretic peptide (Fig.1B, see entry ).

Fig.1: Genes coding for pHpG peptides.