Stability and catalytic properties of chemically modified pig trypsin

Abstract

Pig trypsin was chemically modified with the bifunctional compound ethylene glycol-bis(succinic acid N-hydroxysuccinimide ester) to yield EG-trypsin. EG-trypsin showed greater thermal stability (100% active beyond 100 min at 55°C; native only 53% active at 100 min) together with slightly increased tolerance toward some organic solvents. Arg/Lys hydrolysis ratio changed little. Esterase/amidase activity ratio of EG-trypsin in buffer was 11-fold greater than that of native pig trypsin, but 5-fold less in 30% v/v acetonitrile. In buffer, EG-trypsin synthesized the dipeptide benzoyl-Arg-Leu-NH₂ at a 3-fold higher rate than native trypsin, but native trypsin outperformed EG-trypsin in 30% v/v acetonitrile.

• trypsin
• stabilization
• bis-succinimide
• esterase/amidase ratio
• peptide synthesis

Notes

^*A search in the ISI Web of Knowledge database during July 2009 for ‘trypsin NOT inhibit*’ in the publication Title, and ‘chemical* modif*’ or ‘peptide synth*’ in the publication Topic, yielded 180 publications for the years 1969–2009. Within these 180 publications, only five scored for ‘pig OR hog OR porcine’ while 40 featured ‘beef OR bovine’.