Biochemical characterization of two new Aspergillus niger aspartic proteases.

ABSTRACT: Two new aspartic proteases, PepAb and PepAc (encoded by pepAb and pepAc), were heterologously expressed and biochemically characterized from Aspergillus niger F0215. They possessed a typical structure of pepsin-type aspartic protease with the conserved active residues D (84, 115), Y (131, 168) and D (281, 326), while their identity in amino acid sequences was only 19.0%. PepAb had maximum activity at pH 2.5 and 50 °C and PepAc at 3.0 and 50 °C. The specific activities of PepAb and PepAc toward casein were 1368.1 and 2081.4 U/mg, respectively. Their activities were significantly promoted by Cu²⁺ and Mn²⁺ and completely inhibited by pepstatin. PepAb exhibited higher catalytic efficiency (k _cat/K _m) toward soy prot

SUBMITTER: Song P 

PROVIDER: S-EPMC7293714 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature