Pronase (type XXV serine protease fromStreptomyces griseus) efficiently depolymerizes chitosan, a linearbfi1,4-linked polysaccharide of 2-amino-deoxyglucose and 2-amino-2-N-acetylamino-D-glucose, to low-molecular weight chitosans (LMWC), chito-oligomers (degree of poly-merization, 2–6) andmonomer. The maximumdepolymeri-zationoccurredatpH C,andthereactionobeyed Michaelis–Menten kinetics with aKmof mgÆmL )1 and Vmaxof nmolesÆmin )1 Æmg )1 .