P450 : A New, Robust and α-Selective Fatty Acid Hydroxylase Displaying Unexpected 1-Alkene Formation

Chemistry. 2020 Dec 4;26(68):15910-15921. doi: 10.1002/chem.201905511. Epub 2020 Oct 27.

Abstract

Oxyfunctionalization of fatty acids (FAs) is a key step in the design of novel synthetic pathways for biobased/biodegradable polymers, surfactants and fuels. Here, we show the isolation and characterization of a robust FA α-hydroxylase (P450 ) which catalyses the selective conversion of a broad range of FAs (C6:0-C16:0) and oleic acid (C18:1) with H2 O2 as oxidant. Under optimized reaction conditions P450 yields α-hydroxy acids all with >95 % regioselectivity, high specific activity (up to 15.2 U mg-1 ) and efficient coupling of oxidant to product (up to 85 %). Lauric acid (C12:0) turned out to be an excellent substrate with respect to productivity (TON=394 min-1 ). On preparative scale, conversion of C12:0 reached 83 % (0.9 g L-1 ) when supplementing H2 O2 in fed-batch mode. Under similar conditions P450 allowed further the first biocatalytic α-hydroxylation of oleic acid (88 % conversion on 100 mL scale) at high selectivity and in good yields (1.1 g L-1 ; 79 % isolated yield). Unexpectedly, P450 displayed also 1-alkene formation from shorter chain FAs (≤C10:0) showing that oxidative decarboxylation is more widely distributed across this enzyme family than reported previously.

Keywords: P450 peroxygenases; alpha-hydroxylation; biocatalysis; fatty acids; oleic acid.

MeSH terms

  • Alkenes* / metabolism
  • Cytochrome P-450 Enzyme System* / metabolism
  • Fatty Acids* / metabolism
  • Hydroxylation
  • Substrate Specificity

Substances

  • Alkenes
  • Fatty Acids
  • Cytochrome P-450 Enzyme System