Scheme 2. (A) Production of paCOSs with a Defined N-Acetylation Pattern (DDA and DDDA) Using PpChi (R = NH₂ or NHAc). (B) Subsite Binding and Catalysis at the Active Sites of Various Chitinases, including ChiA, ChiB, ChiC, and ChiG, and Likely Subsite Binding of PpChi. The Arrow Indicates the Glycosidic Linkage Hydrolyzed.