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Updated: Feb 4, 2026

Sigma's Non-specific Protease Activity Assay - Casein as a Substrate
Published on: September 17, 2008
Functional characterization of purified pear protease and its proteolytic activities with casein and myofibrillar
Seung-Hee Nam1, Young-Min Kim2,3, Marie K Walsh4
11Institute of Agricultural Science and Technology and Department of Food Science & Technology, Chonnam National University, Gwangju, 61186 Korea.
Abstract:
This study was performed to characterize pear protease proteolytic activity and investigate the use of pear protease as a meat tenderizer. Pear protease was purified and stabilized by 5% dextrin during lyophilization (dry) or concentration (liquid). Pear protease was further characterized with respect to pH, thermodynamics, and enzyme kinetics. Pear protease was stable at a pH range of 5-8 with an optimum pH of 6.5. From Arrhenius plots, liquid protease showed higher temperature dependency (23.49 kJ/mol) than dry protease (18.62 kJ/mol) due to its higher activation energy. The kcat/Km, catalytic efficiency of enzyme, was similar with 2.9 and 2.7 µM/min with dry and liquid proteases. Pear protease was evaluated for its proteolytic activities with casein and beef myofibrillar proteins by individually and combination with fig and kiwifruit proteases. These result indicated that pear and kiwifruit proteases could be complementary to be a desirable product for meat tenderization.
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