Noncovalent binding of thioxylo-oligosaccharide inhibitors, methyl 4-thio-a-xylobioside (S-Xyl2-Me), methyl 4,4 II -dithio-a-xylotrioside (S-Xyl3-Me), methyl 4,4 II ,4 III -trithio-a-xylotetroside (S-Xyl4-Me), and methyl 4,4 II , 4 III ,4 IV -tetrathio-a-xylopentoside (S-Xyl5-Me), to three family 11 endo-1,4-b-xylanases from Trichoderma reesei(TRX I and TRX II) and Chaetomium thermophilum (CTX) was characterized using electrospray ionization Fourier transform ion cyclotron resonance (FT-ICR) MS and X-ray crys-tallography. .
