Identification of Bioactive Peptides with α-Amylase Inhibitory Potential from Enzymatic Protein Hydrolysates of Red Seaweed (Porphyra spp)

Inhibition of alpha-amylase enzyme is one therapeutic approach in lowering glucose level in the blood to manage diabetes mellitus. In this study alpha-amylase inhibitory peptides were identified from proteolytic enzymes hydrolysates of red seaweed laver (Porphyra species) using consecutive chromatographic techniques. In the resultant fractions from RP-HPLC (D-1-(10)), D-2 inhibited alpha-amylase activity (88.67 +/- 1.05%) significantly (p <= 0.5) at 1 mg/mL protein concentration. A mass spectrometry (ESI-Q-TOF- MS) analysis was used to identify peptides from this fraction. Two novel peptides were identified as Gly-Gly-Ser-Lys and Glu-Leu-Ser. To validate their alpha-amylase inhibitory activity, these peptides were synthesized chemically. The peptides were demonstrated inhibitory activity at IC50 value: 2.58 +/- 0 08 mM (Gly-Gly-Ser-Lys) and 2.62 +/- 0.05 mM (Glu-Leu-Ser) The inhibitory kinetics revealed that these peptides exhibited noncompetitive binding mode. Thus, laver can be a potential source of novel ingredients in food and pharmaceuticals in diabetes mellitus management.