Characterization of an extracellular lipase in Burkholderia sp. HY-10 isolated from a longicorn beetle.

摘要: Burkholderia sp. HY-10 isolated from the digestive tracts of longicorn beetle, Prionus insularis, produced an extracellular lipase with a molecular weight 33.5 kDa estimated by SDS-PAGE. The was purified culture supernatant to near electrophoretic homogenity one-step adsorption-desorption procedure using polypropylene matrix followed concentration step. exhibited highest activities at pH 8.5 and 60 degrees . A broad range substrates, C4 C18 rho-nitrophenyl esters, were hydrolyzed efficiently lipase. most efficient substrate caproate (C6). 2485 bp DNA fragment PCR amplification chromosomal walking which encoded two polypeptides 364 346 amino acids, identified as foldase, respectively. N-terminal acid sequence nucleotide analysis predicted that precursor proteolytically modified through secretion step catalytically active protein. deduced for shared extensive similarity those family I.2 lipases other bacteria. contained Cystein residues forming disulfide bond in molecule three, well-conserved residues, Ser131, His330, Asp308, composed catalytic triad enzyme.