Elucidating Ligand Interactions and Small-Molecule Activation in the Pyrrolnitrin Biosynthetic Enzyme PrnB.

Pyrrolnitrin, a potent antifungal compound originally discovered in Pseudomonas strains, is biosynthesized through a secondary metabolic pathway involving four key enzymes. Central to this process is PrnB, a heme enzyme that catalyzes the complex transformation of 7-Cl-L-tryptophan. Despite its structural similarity to indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) and its classification within the histidine-ligated heme-dependent aromatic oxygenase (HDAO) superfamily, PrnB has remained relatively unexplored due to challenges in reconstituting its in vitro activity.

Cryoradiolysis of oxygenated cytochrome P450 17A1 with lyase substrates generates expected products.

When subjected to γ-irradiation at cryogenic temperatures the oxygenated complexes of Cytochrome P450 CYP17A1 (CYP17A1) bound with either of the lyase substrates, 17α-Hydroxypregnenolone (17-OH PREG) or 17α-Hydroxyprogesterone (17-OH PROG) are shown to generate the corresponding lyase products, dehydroepiandrosterone (DHEA) and androstenedione (AD) respectively. The current study uses gas chromatography-mass spectrometry (GC/MS) to document the presence of the initial substrates and products in extracts of the processed samples. A rapid and efficient method for the simultaneous determination of residual substrate and products by GC/MS is described without derivatization of the products.

Structural and spectroscopic characterization of RufO indicates a new biological role in rufomycin biosynthesis.

Rufomycins constitute a class of cyclic heptapeptides isolated from actinomycetes. They are secondary metabolites that show promising treatment against Mycobacterium tuberculosis infections by inhibiting a novel drug target. Several nonproteinogenic amino acids are integrated into rufomycins, including a conserved 3-nitro-tyrosine.

Revealing substrate-induced structural changes in active site of human CYP51 in the presence of its physiological substrates.

The human sterol 14α-demethylases (CYP51, CYP is an abbreviation for cytochrome P450) catalyze three-step oxidative removal of 14α-methyl group of lanosterol by first forming an alcohol, then an aldehyde, and finally conducting a CC bond cleavage reaction. This present study utilizes a combination of Resonance Raman spectroscopy and Nanodisc technology to probe the active site structure of CYP51 in the presence of its hydroxylase and lyase substrates. Ligand-binding induced partial low-to-high-spin conversion is observed by applying electronic absorption spectroscopy and Resonance Raman (RR) spectroscopy.

Solution phase refinement of active site structure using 2D NMR and judiciously C-labeled cytochrome P450.

The Cytochrome P450 (CYP450) superfamily has been the subject of intense research for over six decades. Here the HU227 strain of E. coli, lacking the δ-aminolevulinic acid (δ-ALA) synthase gene, was employed, along with [5-C] δ-ALA, in the heterologous expression of P450cam harboring a prosthetic group labeled with C at the four methine carbons (C) and pyrrole C positions.

Natural products for the treatment and management of diabetes mellitus in Zimbabwe-a review.

Use of medicinal plants and herbs in the treatment and management of diseases, including diabetes mellitus and its complications remains an integral part of African tradition. In Zimbabwe, nearly one million people are living with diabetes mellitus. The prevalence of diabetes mellitus in Zimbabwe is increasing every year due to lifestyle changes, and has accelerated the use of traditional medicines for its treatment and management in urban areas.

Resonance Raman spectroscopic studies of peroxo and hydroperoxo intermediates in lauric acid (LA)-bound cytochrome P450 119.

Cytochromes P450 bind and cleave dioxygen to generate a potent intermediate compound I, capable of hydroxylating inert hydrocarbon substrates. Cytochrome P450 119, a bacterial cytochrome P450 that serves as a good model system for the study of the intermediate states in the P450 catalytic cycle. CYP119 is found in high temperature and sulfur rich environments.