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Research has been conducted on cellulose binding and hydrolysis by cellulases. The cellulase steady-state and pre-steady-state kinetics have been investigated via the study of the prepared 4-methyl-7-thioumbelliferyl-beta-D-cellobioside and the results demonstrate that it is a ground-state substrate analogue for 4-methylumbelliferyl-beta-D-cellobioside.

X-ray crystallography has been used to determine the three-dimensional structures of many cellulose-degradable cellulases including the bacterial endocellulase Thermomonospora fusca E2. Fluorescence titration is used to study E2 interaction with a series of 4-methylumbelliferyl glycosides while displacement titration is used to study E2 binding to several non-fluorescent glycosides. Results indicate that E2 binds glycosides with high affinity and specificity.

Cellulose hydrolysis in the E4 enzyme of Thermomonospora fusca is accomplished through two cellulose binding domains and a catalytic domain. Structural studies of various domain combination revealed the mechanics of enzymatic cellulose degradation in Thermomonospora. E4 is postulated to act in synergy with exocellulases and endocellulases. The activity of E4 using various substrates revealed the function of the various domains.

Ion-spray mass spectrometry of labeled cellopentaose subjected to enzyme hydrolysis was conducted to examine the substrate specificities of two Trichoderma reesei and three Thermomonospora fusca exocellulases. The goal was to elucidate the phenomenon of cellulase synergism. The results show that one class of exocellulases cleaves cellulose at the reducing end while another class of exocellulases cleaves cellulose at the non-reducing end. This explains exocellulase synergism and disproves models of exocellulases that cleave cellulose only from the non-reducing end.

E1 and E4 genes of Thermomonospora fusca were sequenced and injected into Streptomyces lividans and Escherchia coli. The measurement of the expression of the genes in these two organisms was carried out. The role of gene orientation in relation to the lac promoter of the pBluescript was also computed. The catalytic domains of the E1 and E4 are different from those of T. fusca E2 or E5. However, all four enzymes have parallel cellulose-binding domains and 14-bp inverted repeat upstream of the initiation codons.