Has endochitinase activity (PubMed:15725197). Hydrolyzes chitin oligosaccharides, GlcNAc(n), with different degrees of polymerization (n=2-6), a soluble substrate glycol chitin, and an insoluble substrate beta-chitin nanofiber in vitro. GlcNAc(6) is hydrolyzed at the second glycosidic linkage from the reducing end in addition to the middle linkage. GlcNAc(4) is further hydrolyzed to GlcNAc(2). Has antifungal activity against hyphal growth of H.rufa (PubMed:29756783). Random endo-hydrolysis of N-acetyl-beta-D-glucosaminide (1->4)-beta-linkages in chitin and chitodextrins. Expressed in pollen (at protein level). Contains an N-terminal substrate-binding domain (CBM18) and a GH19 catalytic domain (PubMed:29756783). The CBM18 domain is involved in binding of the insoluble substrate chitin nanofiber (PubMed:29459179). The CBM18 domain is not required for catalytic activity, but possesses antifungal activity (PubMed:29756783). The N-terminus is blocked. Causes an allergic reaction in human. The native protein binds to IgE in all 31 patients tested allergic to Japanese cedar pollen. Belongs to the glycosyl hydrolase 19 family. Chitinase class IV subfamily.