Open AccessMechanism of substrate inhibition in cellulose synergistic degradation
Author(s) -
Väljamäe Priit,
Pettersson Göran,
Johansson Gunnar
Publication year - 2001
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.2001.02377.x
Subject(s) - trichoderma reesei , cellulose , substrate (aquarium) , chemistry , cellulase , hydrolysis , diffusion , degradation (telecommunications) , biophysics , chemical engineering , product inhibition , enzyme , combinatorial chemistry , stereochemistry , biochemistry , non competitive inhibition , biology , computer science , thermodynamics , physics , ecology , telecommunications , engineering
A comprehensive experimental study of substrate inhibition in cellulose hydrolysis based on a well defined system is presented. The hydrolysis of bacterial cellulose by synergistically operating binary mixtures of cellobiohydrolase I from Trichoderma reesei and five different endoglucanases as well as their catalytic domains displays a characteristic substrate inhibition. This inhibition phenomenon is shown to require the two‐domain structure of an intact cellobiohydrolase. The experimental data were in accordance with a mechanism where cellobiohydrolases previously bound to the cellulose by means of their cellulose binding domains are able to find chain ends by lateral diffusion. An increased substrate concentration at a fixed enzyme load will also increase the average diffusion distance/time needed for cellobiohydrolases to reach new chain ends created by endoglucanases, resulting in an apparent substrate inhibition of the synergistic action. The connection between the binding properties and the substrate inhibition is encouraging with respect to molecular engineering of the binding domain for optimal performance in biotechnological processes.