Direct comparison of chitinolytic properties and determination of combinatory effects of mouse chitotriosidase and acidic mammalian chitinase

Chitotriosidase (Chit1) and acidic mammalian chitinase (AMCase) have been implicated in food processing and various pathophysiological conditions such as chronic inflammatory diseases. By combination of the colorimetric analysis and fluorophore-assisted carbohydrate electrophoresis (FACE) method, we directly compared the chitinolytic properties of mouse Chitl and AMCase and determined their combinatory effects in artificial and natural chitin substrates processing. Chitl and AMCase display different dynamics of chitinolytic properties through acidic to neutral conditions. At pH 2.0, the activity of AMCase was higher than that of Chitl and stronger or comparable with that of Serratia marcescens chitinase B, a well-characterized bacterium chitinase. Changes of degradation products using different substrates indicate that AMCase and Chitl have diverse properties under various pH conditions. Exposure of the chitin substrates to both Chit1 and AMCase did not indicate any mutual interference of these enzymes and showed no synergistic effect, in contrast to observations regarding some bacterial chitinases. Our results suggest that Chitl and AMCase have no synergistic effect under physiological conditions. (C) 2019 The Authors. Published by Elsevier B.V.