E. Montero et al., NMR-STUDIES OF THE CONFORMATION OF THIOCELLOBIOSE BOUND TO A BETA-GLUCOSIDASE FROM STREPTOMYCES SP, FEBS letters, 421(3), 1998, pp. 243-248
The conformation of 4-thiocellobiose bound to beta-glucosidase from St
reptomyces sp. has been studied by H-1-NMR transferred nuclear Overhau
ser effect spectroscopy (TR-NOE), Thiocellobiose behaves as an inhibit
or of this glucosidase when cellobiose is used as substrate. NOE measu
rements and molecular mechanics calculations have also been performed
to estimate the probability distribution of conformers of thiocellobio
se when free in solution. Experimental data show that, in contrast wit
h the natural O-analogue, thiocellobiose presents three conformational
families in the free state, namely syn, anti-Psi and anti-Phi, whilst
only one of them (syn) is recognized by the enzyme. (C) 1998 Federati
on of European Biochemical Societies.