Biochim. Biophys. Acta, 1256, 396-402 (1995)

Lipase from Chromobacterium viscosum: Biochemical characterization indicating homology to the lipase from Pseudomonas glumae

Taipa, M. A., Liebeton, K., Costa, J. V., Cabral, J. M. S., Jaeger, K.- E.

Abstract

Previous purification of a commercial lipolytic preparation from Chromobacterium viscosum using gel filtration chromatography yielded two enzymatically active fractions, named lipases A and B. Characterization of these fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that lipase A consisted of a high molecular weight aggregate of lipase protein with lipopolysaccharides. This complex could be dissociated by treatment with EDTA-Tris buffer containing the non-ionic detergent n-octyl-b-D-glucopyranoside and subsequent isoelectric focusing in an agarose gel containing the same detergent. Both lipases A and B revealed a major peak corresponding to an isoelectric point of 7.1. SDS-PAGE analysis of lipases A and B after purification by gel filtration or by IEF revealed one major protein band of Mr of 33 K. Determination of N-terminal amino acid sequences confirmed that both fractions A and B contained the same lipase protein. Furthermore, the N-terminal amino acid sequence of the C. viscosum lipase was identical to the one of Pseudomonas glumae lipase.

Keywords: lipase; C. viscosum; P. glumae; isoelectric focusing; lipopolysaccharide

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