Ultrasonic monitoring of enzymatic hydrolysis of proteins. 1. Effects of ionisation

Abstract

The paper describes the fundamentals of the application of high-resolution ultrasonic spectroscopy for precision, real-time, non-destructive monitoring of enzymatic hydrolysis of proteins in aqueous mixtures and the incorporation of characteristics of ionisation processes accompanying the hydrolysis into the algorithms of calculations of the concentration of peptide bonds hydrolysed, degree of hydrolysis, the average degree of polymerisation, and molar mass. The real-time ultrasonic profiles of protein hydrolysis, adjusted for the ionisation effects, agree well with those obtained with complementary techniques. The limiting resolution of the technique in the concentration of peptide bonds hydrolysed is on the level of 1.5 × 10−6 mol kg−1. Overall, our results demonstrate the versatility of high-resolution ultrasonic spectroscopy in monitoring enzyme hydrolysis of proteins in a broad range of environmental conditions.