Construction of an efficient expression system for aspergillus isopullulanase in pichia pastoris, and a simple purification method

Abstract

Aspergillus niger ATCC 9642 isopullulanase (IPU) was heterologously expressed by Pichia pastoris GS115 under three different signal sequences of Saccharomyces cerevisiae acid phosphatase, S. cerevisiae α-factor prepro peptide, and A. niger isopullulanase. One-step purification using lectin Con A affinity chromatography yielded recombinant IPU (IPU-PP) with high purity. IPU-PP had a higher carbohydrate content than native IPU and IPU-AO expressed in A. oryzae M-2-3. IPU-PP hydrolyzed various substrates containing the structure of panose, which indicated a strict subsite recognition of the panose motif. © 1999 by Japan Society for Bioscience, Biotechnology, and Agrochemistry.