Engineering Protease-Resistant and Highly Active Phytases.
Phytases can catalyze the hydrolysis of indigestible phytate and releases the usable phosphorus. Protease resistance and high activity of enzymes facilitate their biotechnological and medical application. Here we described a genetic manipulation method to improve enzyme tolerance to pepsin, trypsin, and low pH by optimizing the residual side chain of trypsin- and pepsin-sensitive HAP phytase YeAPPA from Yersinia enterocolitica.