Structural and biochemical analysis reveals how ferulic acid improves catalytic efficiency of Humicola grisea xylanase.

ABSTRACT: Humicola grisea var. thermoidea is an aerobic and thermophilic fungus that secretes the GH11 xylanase HXYN2 in the presence of sugarcane bagasse. In this study, HXYN2 was expressed in Pichia pastoris and characterized biochemically and structurally in the presence of beechwood xylan substrate and ferulic acid (FA). HXYN2 is a thermally stable protein, as indicated by circular dichroism, with greater activity in the range of 40-50 °C and pH 5.0-9.0, with optimal temperature and pH of 50 °C and 6.0, respectively. FA resulted in a 75% increase in enzyme activity and a 2.5-fold increase in catalytic velocity, catalytic efficiency, and catalytic rate constant (k_cat), with no alteration in enzyme affinity for the substrate. Fluorescence quenching indicated that FA forms a complex with

SUBMITTER: Oliveira ICM 

PROVIDER: S-EPMC9259647 | biostudies-literature | 2022 Jul

REPOSITORIES: biostudies-literature