The short form of the recombinant CAL-A-type lipase UM03410 from the smut fungus Ustilago maydis exhibits an inherent trans-fatty acid selectivity

Appl Microbiol Biotechnol. 2012 Apr;94(1):141-50. doi: 10.1007/s00253-012-3903-9. Epub 2012 Feb 1.

Abstract

The Ustilago maydis lipase UM03410 belongs to the mostly unexplored Candida antarctica lipase (CAL-A) subfamily. The two lipases with [corrected] the highest identity are a lipase from Sporisorium reilianum and the prototypic CAL-A. In contrast to the other CAL-A-type lipases, this hypothetical U. maydis lipase is annotated to possess a prolonged N-terminus of unknown function. Here, we show for the first time the recombinant expression of two versions of lipase UM03410: the full-length form (lipUMf) and an Nterminally truncated form (lipUMs). For comparison to the prototype, the expression of recombinant CAL-A in E. coli was investigated. Although both forms of lipase UM03410 could be expressed functionally in E. coli, the N-terminally truncated form (lipUMs) demonstrated significantly higher activities towards p-nitrophenyl esters. The functional expression of the N-terminally truncated lipase was further optimized by the appropriate choice of the E. coli strain, lowering the cultivation temperature to 20 °C and enrichment of the cultivation medium with glucose. Primary characteristics of the recombinant lipase are its pH optimum in the range of 6.5-7.0 and its temperature optimum at 55 °C. As is typical for lipases, lipUM03410 shows preference for long chain fatty acid esters with myristic acid ester (C14:0 ester) being the most preferred one.More importantly, lipUMs exhibits an inherent preference for C18:1Δ9 trans and C18:1Δ11 trans-fatty acid esters similar to CAL-A. Therefore, the short form of this U. maydis lipase is the only other currently known lipase with a distinct trans-fatty acid selectivity.

MeSH terms

  • Enzyme Stability
  • Fungal Proteins / chemistry*
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Hydrogen-Ion Concentration
  • Kinetics
  • Lipase / chemistry*
  • Lipase / genetics
  • Lipase / metabolism
  • Plant Diseases / microbiology*
  • Protein Structure, Tertiary
  • Substrate Specificity
  • Trans Fatty Acids / chemistry
  • Trans Fatty Acids / metabolism*
  • Ustilago / chemistry
  • Ustilago / enzymology*
  • Ustilago / metabolism

Substances

  • Fungal Proteins
  • Trans Fatty Acids
  • Lipase