Molecular characterization of a proteolysis-resistant lipase from Bacillus pumilus SG2

Proteolysis-resistant lipases can be well exploited by industrial processes which employ both lipase
and protease as biocatalysts. A proteolysis resistant lipase from Bacillus pumilus SG2 was isolated,
purified and characterized earlier. The lipase was resistant to native and commercial proteases. In the
present work, we have characterized the lip gene which encodes the proteolysis-resistant lipase from
Bacillus pumilus SG2. The parameters and structural details of lipase were analysed. The lip gene
consisted of 650 bp. The experimental molecular weight of SG2 lipase was nearly double that of its
theoretical molecular weight, thus suggesting the existence of the functional lipase as a covalent
dimer. The proteolytic cleavage sites of the lipase would have been made inaccessible by dimerisation, thus rendering the lipase resistant to protease.