Enzyme catalyzed hydrolysis of glycosidic bonds is undertaken by glycoside hydrolases (GHs) in nature. In addition to a catalytic domain (CD), GHs often have carbohydrate-binding modules (CBMs) attached to the CD through a linker. Allosamidin binding to full-length GH18 Serratia marcescens ChiB and the catalytic domain only yield equal changes in reaction free energy (Delta G(r)(o) = -38 kJ/mol), enthalpy (Delta H-r(o) = 18 kJ/mol), and entropy (-T Delta S-r(o) = -57 kJ/mol). Interestingly, the change in heat capacity (Delta C-p,C-r) was 3-fold smaller for full-length vs. the CD alone (-263 vs. -695 J/K mol). Allosamidin binding to the full-length isoform and the CD alone of the GH18 human chitotriosidase yielded different Delta G(r)(o) (-46.9 vs. -38.9 kJ/mol) due to differences in Delta H-r(o) (-58.2 vs. -50.2 kJ/mol), while -T Delta S-r(o) and (11.3 vs. 11.3 kJ/mol) and Delta C-p,C-r (-531 vs. -602 kJ/mol) are similar. The results combined show that the nature of the linker region and CBM affect the thermodynamic signatures of active site ligand binding. (C) 2018 Elsevier Ltd.