title: Transglycosylating and hydrolytic activities of the beta-mannosidase from Trichoderma reesei.
abstract: A purified beta-mannosidase (EC 3.2.1.25) from the fungus Trichoderma reesei has been identified as a member of glycoside hydrolase family 2 through mass spectrometry analysis of tryptic peptides. In addition to hydrolysis, the enzyme catalyzes substrate transglycosylation with p-nitrophenyl beta-mannopyranoside. Structures of the major and minor products of this reaction were identified by NMR analysis as p-nitrophenyl mannobiosides and p-nitrophenyl mannotriosides containing beta-(1-->4) and beta-(1-->3) linkages. The rate of donor substrate hydrolysis increased in presence of acetonitrile and dimethylformamide, while transglycosylation was weakly suppressed by these organic solvents. Differential ultraviolet spectra of the protein indicate that a rearrangement of the hydrophobic environment of the active site following the addition of the organic solvents may be responsible for this hydrolytic activation.
authors.affiliation: Petersburg Nuclear Physics Institute, Russian Academy of Science, Molecular and Radiation Biophysics Division, Gatchina, Leningrad District, Russia.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Eneyskaya
authors.forename: Gustav
authors.initials: G
authors.lastname: Sundqvist
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Golubev
authors.forename: Farid M
authors.initials: FM
authors.lastname: Ibatullin
authors.forename: Dina R
authors.initials: DR
authors.lastname: Ivanen
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Shabalin
authors.forename: Harry
authors.initials: H
authors.lastname: Brumer
authors.forename: Anna A
authors.initials: AA
authors.lastname: Kulminskaya