Purification and characterization of a nitric oxide inhibitory peptide from Ruditapes philippinarum

Ruditapes philippinarum (R. philippinarum) were hydrolyzed using 8 proteases to produce an anti-inflammatory peptide of the various hydrolysates produced, the Alcalase hydrolysate exhibited the highest nitric oxide (NO) inhibitory activity. The derived peptide was purified using high performance liquid chromatography (HPLC) and NO-inhibitory activity of the purified compound was evaluated. The sequence of the NO-inhibitory peptide obtained was composed of 10 amino acid residues, Gln-Cys-Gln-Gln-Ala-Val-Gln-Ser-Ala-Val at N-terminal position. In addition, we investigated the inhibitory effect of the purified peptide from R. philippinarum on NO production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. In this analysis the purified peptide from R. philippinarum was shown to inhibit LPS-induced NO production in RAW264.7 cells. The present results indicate that the purified peptide displayed potent anti-inflammation activity in RAW264.7 cells.