Carmien Tolmie

• PhD Biochemistry
• Lecturer at University of the Free State

The rising global burden of infectious fungal disease and the steady increase of resistance by fungal pathogens to available treatments necessitate a concerted effort to develop new antifungal medicines. Squalene synthase is a critical enzyme in the synthesis of ergosterol, a fungal-specific sterol, and has not yet been exploited as an antifungal d...

Candida albicans is a critical priority fungal pathogen causing invasive fungal infections with high mortality rates in immunocompromised patients. The increasing fungal infection rate and resistance of fungal pathogens to existing antifungal treatments have emphasized the need for the development of novel antifungal medicine. The ergosterol biosyn...

Selective oxyfunctionalization of non-activated C–H bonds remains a major challenge in synthetic chemistry. The biocatalytic hydroxylation of non-activated C–H bonds by cytochrome P450 monooxygenases (CYPs), however, offers catalysis with high regio- and stereoselectivity using molecular oxygen. CYP153s are a class of CYPs known for their selective...

We report the crystal structure of the copper‐containing nitrite reductase (NirK) from the Gram‐negative bacterium Sinorhizobium meliloti 2011 (Sm), together with complex structural alignment and docking studies with both non‐cognate and the physiologically related pseudoazurins, SmPaz1 and SmPaz2, respectively. S. meliloti is a rhizobacterium used...

CYP505A30 is a fungal, self-sufficient cytochrome P450 monooxygenase that can selectively oxyfunctionalise n-alkanes, fatty alcohols, and fatty acids. From alkanes, it produces a mixture of non-vicinal diols by two sequential...

Baeyer-Villiger monooxygenases (BVMOs) are flavin-dependent enzymes that primarily convert ketones to esters, but can also catalyze heteroatom oxidation. Several structural studies have highlighted the importance of the ‘control loop’ in BVMOs, which adopts different conformations during catalysis. Central to the ‘control loop’ is a conserved trypt...

Aflatoxins are carcinogenic mycotoxins that are produced by the filamentous fungus Aspergillus flavus, a contaminant of numerous food crops. Aflatoxins are synthesised via the aflatoxin biosynthesis pathway, with the enzymes involved encoded by the aflatoxin biosynthesis gene cluster. MoxY is a type I Baeyer–Villiger monooxygenase (BVMO), responsib...

Covering: up to end of June 2018 Baeyer–Villiger monooxygenases (BVMOs) are flavin-dependent enzymes that catalyse the oxidation of ketones and cyclic ketones to esters and lactones, respectively, by using molecular oxygen and NAD(P)H. BVMOs also catalyse sulfoxidations and N-oxidations. BVMOs are widely studied as attractive biocatalysts, but also...

The inside cover picture shows the bioconversion of octanal to heptyl formate by a fungal Baeyer–Villiger monooxygenase (BVMO). Alkyl formate esters such as heptyl formate and octyl formate are used as fruity and floral aromas in the flavour and fragrance industry. Previously, BVMOs tested with aliphatic aldehydes yielded the corresponding carboxyl...

Baeyer-Villiger monooxygenase (BVMO) mediated synthesis of alkyl formate esters, important flavour and fragrance products, was investigated. A recombinant fungal BVMO from Aspergillus flavus was found to transform a selection of aliphatic aldehydes to alkyl formates with high regioselectivity. Near complete conversion of 10 mM octanal was achieved...

Baeyer-Villiger monooxygenases (BVMOs) are biocatalysts that convert ketones to esters. Due to their high regio-, stereo- and enantioselectivity and ability to catalyse these reactions under mild conditions, they have gained interest as alternatives to chemical Baeyer-Villiger catalysts. Despite their widespread occurrence within the fungal kingdom...