Purification and Some Properties of Two Types of Penicillium Lipase,I and II,and Conversion of Types I and II under Various Modification Conditions

The lipase produced by a strain of Penicillium crustosum Thom was fractionated into three lipase components, I～III by DEAE cellulose column chromatography, and two of them, I and II were purified and obtained in crystalline form respectively, which proved homogeneous by electrophoresis and ultracentrifugal analysis. Lipase I was an ordinary lipase with molecular weight about 29,000 hydrolyzing olive oil and tributyrin favourably in almost the same degree, while II, rather, a so-called tributyrinase with M. W. about 32,000 hydrolyzing tributyrin more efficiently than olive oil. The site of the activity on olive oil in these lipase was generally sensitive to sodium desoxycholate, ethylenediamine-tetraacetate (EDTA), and p-chloromercuribenzoate (PCMB), and lipase I was converted to a lipase II by a treatment with these reagents. Also, partial degradation of I by proteinase (‘pronase’) yielded the enzyme fragment of type II. On the other hand, treatment of the enzymes with hydrogen peroxide or sodium borohydride caused the conversion of type II into I. From the observation of UV difference spectrum during incubation with sodium desoxycholate it was indicated that the situation of tryptophane residue in enzyme molecule may have a significance in the activity of lipase I on olive oil.