Study on cloning, expression and hydrolysis characteristics of Aspergillus niger protease (pepD) gene.

Study on cloning, expression and hydrolysis characteristics of Aspergillus niger protease (pepD) gene.

Protein Expr Purif. 2019 Jun 07;:

Authors: Ke Y, Wei MY, Fu YT, Zhu YM, Zhan XL

Abstract
The Aspergillus niger AS3.350 protease gene (pepD) was successfully cloned and expressed in Pichia pastoris KM71. The rPepD activity was 331.5 U/ml, and the optimum temperature and pH were 45 °C and 8-9 respectively. In addition, enzyme activity was significantly inhibited by PMSF, EDTA, Mg2+, Fe2+ and Zn2+ ions, and stimulated by Ca2+ which selectively bound to the T302 and D323 residues. Mutation in either or both of the residues inhibited rPepD expression, indicating that binding to Ca2+ is necessary for PepD expression and activity. The rPepD showed a wide substrate range, and was particularly selective to those with hydrophobic amino acids. The degree of rPepD-mediated hydrolysis of soy protein isolate, corn flour and gluten meal were 8.7%, 38.1% and 33.6% respectively, which was higher than that by Alcalase, indicating that rPepD has potential applications in the food processing industry.

PMID: 31181254 [PubMed – as supplied by publisher]

Source: Industry