Microfilarial chitinase, which may function to degrade chitin-containing structures in the micro-filaria or in its mosquito vector during parasite development and transmission. Random endo-hydrolysis of N-acetyl-beta-D-glucosaminide (1->4)-beta-linkages in chitin and chitodextrins. The appearance of the MF1 antigen correspond with the onset of the parasite's ability to infect the mosquito. O-glycosylated. Known to bind calcium. Belongs to the glycosyl hydrolase 18 family. Chitinase class II subfamily.