An autolysis chitinase was purified from the cultural medium of the an
aerobic fungus Piromyces communis OTS I by ammonium sulfate precipitat
ion, affinity chromatography with regenerated chitin, chromate-focusin
g, gel filtration, and chromato-focusing again. The optimal pH and tem
perature were 6.0 and 50 degrees C, respectively, for a 20-min assay.
The chitinase was stable from pH 6.0 to 8.0, but was unstable at 70 de
grees C for 20 min, The molecular mass of chitinase was estimated by S
DS-PAGE to be 44.9 kDa, and its pi was 4.4. The enzyme activity, which
was of the 'endo' type, was inhibited by Hg2+ and allosamidin. The ch
itinase hydrolyzes chitin powder and fungal cell walls at a higher rat
e than an artificial chitin substrate. It can be concluded that extrac
ellular chitinase is similar to cytosolic chitinase, but they are not
the same protein.