Article

Characterization of a New Cold-adapted Lipase from Pseudomonas sp. TK-3.

Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, 930-8555, Japan, .
Applied biochemistry and biotechnology (Impact Factor: 1.94). 06/2012; 168(2):327-38. DOI: 10.1007/s12010-012-9776-7
Source: PubMed

ABSTRACT A psychrotrophic Pseudomonas sp. TK-3 was isolated from dirty and cool stream water in Toyama, Japan from which we cloned and characterized the bacterial lipase LipTK-3. The sequenced DNA fragment contains an open reading frame of 1,428 bp that encoded a protein of 476 amino acids with an estimated molecular mass of 50,132 Da. The lipase showed high sequence similarity to those of subfamily Ι.3 lipase and had a conserved GXSXG motif around the catalytic Ser residue. Its optimal temperature was 20-25 °C, lower than in most other subfamily Ι.3 lipases. The lipase exhibited about 30 % of maximal activity at 5 °C. The optimal pH value was 8.0. The activity was strongly inhibited by EDTA and was highly dependent on Ca(2+). Tricaprylin and p-nitrophenyl caprylate were the most favorable substrates among the triglycerides and p-nitrophenyl esters, respectively. LipTK-3 also showed high activity towards natural substrates including edible vegetable oils and animal fats. Furthermore, LipTK-3 was very active and stable in the presence of several detergents, metal ions, and organic solvents. This cold-adapted lipase may prove useful for future applications.

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