Antigenic activity of angiotensin II and its fragments

The antigenic activity of angiotensin and its seven fragments has been studied in cross-reaction with specific antibodies, elicited to angiotensin and its fragments: C-terminal hexapeptide and middle tetrapeptide. It has been found that all the fragments studied possess certain affinity for antibodies elicited to angiotensin, C-terminal hexapeptide and middle tetrapeptide. The middle tetrapeptide was identified to be the immunologically active centre of the angiotensin molecule.