Open AccessThe initial kinetics of hydrolysis by cellobiohydrolases I and II is consistent with a cellulose surface − erosion model
Author(s) -
Väljamäe Priit,
Sild Veljo,
Pettersson Göran,
Johansson Gunnar
Publication year - 1998
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.1998.2530469.x
Subject(s) - cellobiose , trichoderma reesei , chemistry , microcrystalline cellulose , hydrolysis , cellulose , biochemistry , kinetics , cellulase , chromatography , glucan , steric effects , stereochemistry , physics , quantum mechanics
of a novel method for the quantification of the cellobiose released made it possible to follow the initial stage of hydrolysis of bacterial microcrystalline cellulose (BMCC) by cellobiohydrolases 1,4‐β‐ D ‐glucan‐cellobiohydrolase I (CBH I) and 1,4‐β‐ D ‐glucan‐cellobiohydrolase II (CBH II) from Trichoderma reesei . A drastic retardation of the rate of the hydrolysis was observed already at a very low degree of conversion. Earlier‐suggested retardation factors, such as product inhibition by cellobiose or enzyme inactivation, could be discounted as primary causes for the pattern. A model including steric hindrance by non‐productive binding and erosion of the cellulose surface during the processive action of exoenzymes was proposed to describe the rate retardation observed. Simultaneous action of CBH I and CBH II on cellulose was not a prerequisite for synergy between them.