Regioselective hydroxylation of norisoprenoids by CYP109D1 from Sorangium cellulosum So ce56

• Published in: Applied microbiology and biotechnology 2010-09, Vol.88 (2), p.485-495
• Main Authors: Khatri, Yogan, Girhard, Marco, Romankiewicz, Anna, Ringle, Michael, Hannemann, Frank, Urlacher, Vlada B, Hutter, Michael C, Bernhardt, Rita
• Format: Article
• Language: English
• Subjects: Analysis; Bacteria; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biochemistry; Biological and medical sciences; Biomedical and Life Sciences; Biotechnological Products and Process Engineering; Biotechnology; Chemical reactions; Chromatography; Cosmetics; CYP109D1; Cytochrome; Cytochrome P-450 Enzyme System - chemistry; Cytochrome P-450 Enzyme System - genetics; Cytochrome P-450 Enzyme System - metabolism; Cytochromes P450; Fundamental and applied biological sciences. Psychology; Hydroxylation; Life Sciences; Microbial Genetics and Genomics; Microbiology; Models, Molecular; Myxococcales - enzymology; Norisoprenoids; Norisoprenoids - metabolism; Organic chemistry; Pharmaceuticals; Proteins; Sorangium cellulosum; Sorangium cellulosum So ce56; Studies; terpenoids
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-010-2756-3

Sesquiterpenes are particularly interesting as flavorings and fragrances or as pharmaceuticals. Regio- or stereoselective functionalizations of terpenes are one of the main goals of synthetic organic chemistry, which are possible through radical reactions but are not selective enough to introduce the desired chiral alcohol function into those compounds. Cytochrome P450 monooxygenases are versatile biocatalysts and are capable of performing selective oxidations of organic molecules. We were able to demonstrate that CYP109D1 from Sorangium cellulosum So ce56 functions as a biocatalyst for the highly regioselective hydroxylation of norisoprenoids, α- and β-ionone, which are important aroma compounds of floral scents. The substrates α- and β-ionone were regioselectively hydroxylated to 3-hydroxy-α-ionone and 4-hydroxy-β-ionone, respectively, which was confirmed by ¹H NMR and ¹³C NMR. The results of docking α- and β-ionone into a homology model of CYP109D1 gave a rational explanation for the regio-selectivity of the hydroxylation. Kinetic studies revealed that α- and β-ionone can be hydroxylated with nearly identical V max and K m values. This is the first comprehensive investigation of the regioselective hydroxylation of norisoprenoids by CYP109D1.