Abstract
Physical and chemical properties of the two kinds of lipases (lipase A and lipase B) from Chromobacterium viscosum were investigated. The results were as follows : Sedimentatation constants were 5.35×10-13 cm·g/sec·dyne ; Molecular weights were 1.2×105 and 2.7×104 ; Intrinsic viscosities were 0.060 and 0.051 dl/g ; Partial specific volumes were 0.816 and 0.663 cm3/g ; Isoelectric points were 4.7 and 6.9 for the lipase A and B respectively. From the study of ORD, the α-helix content of the lipase A was calculated to be less than 10% and of the lipase B was to be about 20%. The amino acid compositions of the lipases were different from each other and the lipase B did not contain the half-cystine. Lipid was not detected in the both enzymes and carbohydrate was contained only in the lipase A (14%). By the modification with diazonium-1-H-tetrazole, the enzymic activities were decreased with increase of the modification of histidine residue in the both lipases, and it was assumed that one mole of the histidine residue in the lipase B was related with the catalytic action of the enzyme. Some properties of the lipases which will be concerned with the affinity of the enzymes on their hydrophobic substrates were also discussed.
