Assessing the Efficacy of Protease Inactivation for the Preservation of Bioactive Amphibian Skin Peptides

• Published in: International journal of molecular sciences Vol. 25; no. 16; p. 8759
• Main Authors: Samgina, Tatiana Yu, Mazur, Dmitrii M, Lebedev, Albert T
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12.08.2024; MDPI
• Subjects: Amino Acid Sequence; Amino acids; Amphibian Proteins - chemistry; Amphibian Proteins - metabolism; Amphibian Proteins - pharmacology; Amphibians - metabolism; Animals; Antimicrobial agents; bioactive peptides; Enzymes; Frogs; frogs’ proteases; Mass spectrometry; Methanol - chemistry; Peptide Hydrolases - chemistry; Peptide Hydrolases - metabolism; Peptides; Peptides - chemistry; Peptides - pharmacology; peptides degradation; Phenylmethylsulfonyl Fluoride - pharmacology; Protease Inhibitors - chemistry; Protease Inhibitors - pharmacology; proteolysis inhibitors; Reagents; Reptiles & amphibians; Scientific imaging; Skin; Skin - drug effects; Skin - metabolism; skin secretions of ranid frogs; frogs’ proteases; peptides degradation; bioactive peptides; mass spectrometry; proteolysis inhibitors; skin secretions of ranid frogs
• ISSN: 1661-6596; 1422-0067; 1422-0067
• DOI: 10.3390/ijms25168759

The skin of amphibians is a rich source of peptides with a wide range of biological activities. They are stored in secretory granules in an inactive form. Upon stimulation, they are secreted together with proteases into the skin. Once activated, they rapidly exert their biological effects, including fighting microorganisms and predators, while their excess is immediately destroyed by the released proteases. To keep bioactive peptides in their initial form, it is necessary to inhibit these enzymes. Several inhibitors for this purpose have previously been mentioned; however, there has not been any reliable comparison of their efficiency so far. Here, we studied the efficiency of methanol and hydrochloric and formic acids, as well as phenylmethylsulfonyl fluoride, in the inhibition of nine frog peptides with the known sequence, belonging to five families in the secretion of . The results demonstrated that methanol had the highest inhibitory efficiency, while phenylmethylsulfonyl fluoride was the least efficient, probably due to its instability in aqueous media. Possible cleavages between certain amino acid residues in the sequence were established for each of the inhibitors. These results may be helpful for future studies on the nature of proteases and on prediction of the possible cleavage sites in novel peptides.