Continuous production of a peptidic fraction containing the intermediate opioid peptide LVV-haemorphin-7 (LVVh-7) by peptic hydrolysis of bovine haemoglobin in a continuous membrane reactor.

Peptic hydrolysis of native bovine haemoglobin at pH 3 yields the LVV-haemorphin-7 (Leu-Val-Val-Tyr-Pro-Trp-Thr-Gln-Arg-Phe; LVVh-7) opioid peptide corresponding to the residues-31-40 fragment of the beta-chain of haemoglobin. This peptide is intermediate in the course of batch hydrolysis and is rapidly degraded. Indeed, it shows an optimum at 3% degree of hydrolysis (i.e. 2 min of reaction time). The hydrolysis was carried out in a continuous membrane reactor with a space time (ratio of the flux to the reactor volume) set to 2 min (corresponding to optimum LVVh-7 production). This process allows the continuous production of a constant fraction of intermediate peptides containing LVVh-7 for 48 min.