Analysis of productive binding modes in the human chitotriosidase.

Human chitotriosidase (HCHT) is a family 18 chitinase that is an innate part of the immune system. We have mapped preferred productive binding modes of chito-oligosaccharide substrates to HCHT and the data show that HCHT has strong binding affinity in the +3 subsite. Moreover, HCHT shows anomer-specific binding affinities in subsites +2 and +3. These features could endorse HCHT with higher endo-activity and a higher transglycosylation potential.