Identification and characterization of Chromobacterium viscosum lipase

Separation of a commercial preparation of Chromobacterium viscosum by hydrophobic interaction chromatography yields two active fractions, one corresponding to a lipase of 33.0 ± 1.0 kDa by SDS-PAGE and the other to a high molecular weight aggregate (> 250 kDa) of the lipase with some impurities absorbing at 436 nm. Partial disaggregation of this complex occurs on gel filtration chromatography in the presence of 1% (w/v) CHAPS. On gel filtration under non reducing conditions the lipase behaves like a 17 kDa protein; in the presence of a strong denaturant and of a reducing agent a molecular size of 36 kDa is obtained, in accordance with SDS-PAGE results.