Open AccessA constitutive, plasma‐membrane bound β‐glucosidase in Trichoderma reesei
Author(s) -
Umile Claudio,
Kubicek Christian P.
Publication year - 1986
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1986.tb01423.x
Subject(s) - membrane , digitonin , isoelectric point , chromatofocusing , trichoderma reesei , enzyme , chemistry , biochemistry , concanavalin a , cellulase , glucosidases , chromatography , glucoside , in vitro , medicine , alternative medicine , pathology
Plasma membranes of Trichoderma reesei QM 9414, isolated from protoplasts by means of the concanavalin A procedure, contained β‐glucosidase activity, which appeared constitutively upon growth on glucose. The enzyme had a pH optimum around 6, and was active on p ‐nitrophenyl‐β‐ d ‐glucoside, cellobiose and sophorose ( K m 0.7, 3.9 and 3.1 mM, respectively). Glucose was only weakly inhibitory ( K i 7 mM). Treatment of the plasma membranes with Triton X‐100, Tween 80 or digitonin solubilized more than 60% of the membrane‐bound β‐glucosidase activity. The enzyme so solubilized exhibited an M r of 70 000 ± 5000 and an isoelectric point at pH 8.2 ± 0.3.