Investigation of inhibition angiotensin-converting enzyme (ACE) activity and opioid activity of two hemorphins, LVV-hemorphin-5 and VV-hemorphin-5, isolated from a defined peptic hydrolysate of bovine hemoglobin.

Two peptides, LVV-hemorphin-5 and VV-hemorphin-5, were isolated from a defined peptic bovine hemoglobin hydrolysate by reversed-phase HPLC. These peptides were identified as 31-38 and 32-38 fragments of beta chain of bovine hemoglobin. Their inhibitory activity towards angiotensin-converting enzyme and opioid potency were determined. Since their amino acid sequences show close homology with spinorphin, which is found in human cerebrospinal fluid and in the bovine spinal cord, the possible physiological role in vivo of these peptides was discussed.