Novel angiotensin I-converting enzyme inhibitory peptides from enzymatic hydrolysates of goby (Zosterisessor ophiocephalus) muscle proteins.

UNLABELLED: In recent years, food protein-derived bioactive peptides have received considerable attention because of their numerous health benefits. Amongst bioactive peptides, those with antihypertensive activity are receiving special attention due to their role in cardiovascular diseases. Goby protein hydrolysates (GPHs) prepared by treatment with five different crude bacterial proteases were found to exhibit varying degrees of angiotensin I-converting enzyme (ACE) inhibitory activity. The hydrolysate generated by the crude protease from Bacillus mojavensis A21, which displayed the highest ACE inhibitory activity, was further fractionated by size exclusion chromatography on a Sephadex G-25 and reversed-phase high performance liquid chromatography (RP-HPLC). The molecular masses and amino acid sequences of five peptides, in sub-fraction F5-2, which exhibited the highest ACE inhibitory activity, were determined using ESI-MS and ESI-MS/MS, respectively. The structures of these peptides were identified as Ala-Arg-Ser, Val-Val-Ala-Pro-Phe-Ala-His-Gly-Thr, Arg-Ser-Thr-Ala, Phe-Tyr-Pro-Pro, Arg-Cys-Ser-Ala-Gly-Val. Further, the sequences of fifteen peptides in the F5-4 sub-fraction, which exhibited high activity, were determined. Therefore, GPHs have a potential as hypotensive nutraceutical ingredients.

BIOLOGICAL SIGNIFICANCE: Peptides find many outlets of application in the biotechnological field, amongst which are pharmaceutical applications. Progression amongst new small molecules deposited like substance medicamentous blows itself. In this context, large pharmaceutical companies invest in peptide research to open therapeutic new prospects. Even if they are used as therapeutic agents for nearly one century in their natural form, the use of peptides remains parsimonious although we experienced a significant development since a few tens of years, in particular thanks to the clarification of the methods of production, chemical in solid or biological phase such as in phage display. Peptides present many advantages compared to traditional drugs that have small molecules, Generation of bioactive peptides by proteolysis of food proteins, using exogenous proteases, is a new and interesting approach for the production and identification of new and potent specific hypotensive agents. From another side, compared with natural peptides isolated from different sources, there is more diversity in structure and mode of action of the derived bioactive peptides. In fact, proteolysis of protein substrates, having different amino acid composition and sequences, by proteases having different specificities may generate numerous specific peptide inhibitors, with different lengths and amino acid sequences. These bioactive peptides have received considerable attention for their effectiveness in both the prevention and the treatment of hypertension.