The use of 4‐methylumbelliferyl and other chromophoric glycosides in the study of cellulolytic enzymes

[摘要]

HPLC-analysis of the reaction products of a series of 4-methylumbelliferyl glycosides from cello-oligosaccharides, used as substrates of a cellobiohydrolase from Trichoderma reesei, proves the lack of specificity for terminal cellobiosyl groups. Also, different reaction patterns are observed for this CBHI and for an endocellulase, when acting on these same substrates. 4-Methylumbelliferyl β-D-lactoside is an unexpected substrate for CBHI, yielding only lactose and phenol as reaction products. The binding characteristics of p-nitrobenzyl 1-thio-β-D-lactoside for this enzyme are determined by a dia-filtration technique, yielding 1 binding site and an association constant of 4.0 × 10⁴ M⁻¹.

[学科分类] 生物化学/生物物理

[关键词] Cellulase;4-Methylumbelliferyl glycoside;Exo-cellobiohydrolase;Endocellulase;Specificity;Binding;MeUmb β-Glcp;4-methylumbelliferyl β-D-glucopyranoside;MeUmb β-(Glcp) n(n=2–6);4-methylumbelliferyl β-D-glycosides from cellobiose to cellohexaose);MeUmb β-Galp β (1 → 4)Glcp;4-methylumbelliferyl β-D-lactoside;CBH;1;4-β-glucan cellobiohydrolase (EC 3.2.1.91);endocellulase;1;4-β-glucan glucanohydrolase (EC 3.2.1.4);HPLC;high-pressure liquid chromatography