Proteolytic Activity of the MMGP1 Antifungal Peptide Derived from Marine Metagenome

An antifungal peptide, MMGP1 with direct cell penetrating property was recently reported from marine metagenome. The peptide showed efficient in vitro proteolytic activity, which could be associated with its antifungal activity. The proteolytic activity of MMGP1 was confirmed by tricine SDS-PAGE and gel filtration chromatography. Liquid chromatography-mass spectrometry analysis of MMGP1 treated bovine serum albumin (BSA), RNaseA and casein substrates revealed that the peptide does not have common cleavage position and it cleaves the substrates non-specifically at all peptide bonds. The proteolytic activity of MMGP1 was enhanced in the presence of Mn²⁺. Molecular docking studies revealed that the predicted active site residues of MMGP1 could interact with BSA, RNaseA and casein.