Comparative biochemistry of GH3, GH20 and GH84 β-N-acetyl-Dhexosaminidases and recent progress in selective inhibitor discovery.

Glycosyl hydrolase family 3, 20 and 84 β-N-acetyl-D-hexosaminidases are widely distributed enzymes that function in energy metabolism, cell proliferation, signal transduction as well as in pathogen-related inflammation and autoimmune diseases. Sharing the same retaining catalytic mechanism, they are distinguished from each other in terms of structure rather than substrate-enzyme transition state. Selective inhibition of each of these enzymes that exploits the structural differences would appear promising in the regulation and investigation of their corresponding life functions within the organism. Thanks to molecular structural biology, detailed structures of GH3, 20 and 84 β-N-acetyl-Dhexosaminidases have become available at the atomic level. This review gives a panoramic description and comparison of the enzymes catalytic mechanisms, overall structures, active site architectures as well as structure-based analysis of inhibition, with the hope of exploiting novel targets for developing novel drugs and pesticides.