desArgbradykinin

desArgbradykinin is a peptide fragment derived from bradykinin, produced when the C-terminal arginine is removed from bradykinin by extracellular carboxypeptidases. It is commonly referred to as des-Arg-bradykinin or des-Arg9-bradykinin, and is considered part of the kallikrein–kinin system.

Biological activity and receptor binding: desArgbradykinin preferentially activates the bradykinin B1 receptor (B1R), a G protein–coupled receptor that is inducible and upregulated during inflammation. It generally has lower affinity for the B2 receptor, which is the primary target of bradykinin itself.

Physiological effects: Activation of B1R by desArgbradykinin contributes to components of the inflammatory response, including vasodilation, increased vascular permeability, edema, pain signaling, and leukocyte recruitment. Its effects are typically more prominent in inflamed or injured tissues where B1R expression is elevated, and the peptide can sustain inflammatory signaling relative to bradykinin.

Synthesis and metabolism: desArgbradykinin is formed from bradykinin through enzymatic cleavage by carboxypeptidases that remove the C-terminal arginine. This metabolic pathway links bradykinin activity to B1R-mediated responses, particularly under conditions of tissue injury or inflammation.

Clinical relevance: Inflammatory diseases, sepsis, and certain types of angioedema can involve desArgbradykinin signaling. Therapeutic approaches that target the B1 receptor or modulate kinin metabolism are areas of ongoing research for reducing inflammation and edema.

See also: bradykinin, des-Arg9-bradykinin, bradykinin B1 receptor, bradykinin B2 receptor, kallikrein–kinin system.