Natural anionic polymer acts as highly efficient trypsin inhibitor based on an electrostatic interaction mechanism.

Abstract

Sodium alginate (SA), acting as a trypsin inhibitor by means of electrostatic interaction, is studied. The half-maximal inhibitory concentration (IC50 = 0.05 μg mL(-1) ) of this natural anionic polymer is about 400 times lower than that of commercial soybean trypsin inhibitor (STI). Unlike the Ca(2+) -deprivation mechanisms, its inhibition may be attributed to preventing the trypsin active site (TAS) from accessing the macromolecular substrates instead of denaturing it. SA is an efficient, innocuous, and cost-effective inhibitory excipient that can be conveniently used in many peptide and protein dosage formulations.