Improving thermal and detergent stability of Bacillus stearothermophilus neopullulanase by rational enzyme design
Articles > Article ยท 2015
Authors: Selin ECE, Serap EVRAN, Jan-Oliver JANDA, Rainer MERKL, Reinhard STERNER
Protein Engineering, Design and Selection, Journal Indexed in SCI Expanded, International, WoS, 2015, vol 28, pp 147-151
Summary
Neopullulanase, a glycosyl hydrolase from Bacillus stearothermophilus (bsNpl), is a potentially valuable enzyme for starch and detergent industries. However, as the protein is not active at elevated temperatures and high surfactant concentrations, we aimed to increase its stability by rational enzyme design. Nine potentially destabilizing cavities were identified in the crystal structure of the enzyme. Based on computational predictions, these cavities were filled by residues with bulkier side chains. The five Asp46Glu, Val239Leu, Val404Leu, Ser407Thr and Ala566Leu exchanges resulted in a drastic stabilization of bsNpl against inactivation by heat and detergents. The catalytic activity of the variants was identical to the wild-type enzyme.