Purification and properties of a novel extra-cellular thermotolerant metallolipase of Bacillus coagulans MTCC-6375 isolate

Protein Expr Purif. 2006 Apr;46(2):421-8. doi: 10.1016/j.pep.2005.10.007. Epub 2005 Oct 27.

Abstract

A novel extra-cellular lipase from Bacillus coagulans MTCC-6375 was purified 76.4-fold by DEAE anion exchange and Octyl Sepharose chromatography. The purified enzyme was found to be electrophoretically pure by denaturing gel electrophoresis and possessed a molecular mass of approximately 103 kDa. The lipase was optimally active at 45 degrees C and retained approximately 50% of its original activity after 20 min of incubation at 55 degrees C. The enzyme was optimally active at pH 8.5. Mg2+, Cu2+, Ca2+, Hg2+, Al3+, and Fe3+ at 1mM enhanced hydrolytic activity of the lipase. Interestingly, Hg2+ ions resulted in a maximal increase in lipase activity but Zn2+ and Co2+ ions showed an antagonistic effect on this enzyme. EDTA at 150 mM concentration inhibited the activity of lipase but Hg2+ or Al3+ (10mM) restored most of the activity of EDTA-quenched lipase. Phenyl methyl sulfonyl fluoride (PMSF, 15 mM) decreased 98% of original activity of lipase. The lipase was more specific to p-nitrophenyl esters of 8 (pNPC) and 16 (pNPP) carbon chain length esters. The lipase had a Vmax and Km of 0.44 mmol mg(-1)min(-1) and 28 mM for hydrolysis of pNPP, and 0.7 mmol mg(-1)min(-1) and 32 mM for hydrolysis of pNPC, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus / chemistry
  • Bacillus / enzymology*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / isolation & purification*
  • Edetic Acid / chemistry
  • Enzyme Activation / drug effects
  • Hot Temperature
  • Hydrolysis / drug effects
  • Lipase / chemistry
  • Lipase / isolation & purification*
  • Metalloproteins / chemistry
  • Metalloproteins / isolation & purification*
  • Metals / chemistry

Substances

  • Bacterial Proteins
  • Metalloproteins
  • Metals
  • Edetic Acid
  • Lipase