Styrene monooxygenase (SMO) from Pseudomonas putida S12 is a two-component flavoenzyme composed of the NADH-specific flavin reductase, SMOB, and FAD-specific styrene epoxidase, SMOA. Here, we report the cloning, and expression of native and histidine-tagged versions of SMOA and SMOB and studies of the flavin transfer and styrene oxygenation reactions. In the reductive half-reaction, SMOB catalyzes the two-electron reduction of FAD with a turnover number of 3200 s(-1). Single turnover studies of the reaction of reduced SMOA with substrates indicate the formation of a stable oxygen intermediate with the absorbance characteristics of a flavin hydroperoxide. Based on the results of numerical simulations of the steady-state mechanism of SMO, we find that the observed coupling of NADH and styrene oxidation can be best explained by a model, which includes both the direct transfer and passive diffusion of reduced FAD from SMOB to SMOA.
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http://dx.doi.org/10.1016/j.abb.2005.07.020 | DOI Listing |
Mater Horiz
January 2025
Department of Material Sciences, Institute of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennodai, Ibaraki 305-5358, Japan.
The efficient immobilization of redox mediators remains a major challenge in the design of mediated enzyme electrode platforms. In addition to stability, the ability of the redox-active material to mediate electron transfer from the active-site buried enzymes, such as flavin adenine dinucleotide-dependent glucose dehydrogenase (FADGDH) and lactate oxidase (LOx), is also crucial. Conventional immobilization techniques can be synthetically challenging, and immobilized mediators often exhibit limited durability, particularly in continuous operation.
View Article and Find Full Text PDFJ Mol Model
January 2025
Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI, 48128, USA.
Context: Riboflavin (RF), also known as B2 vitamin, is the precursor to flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), two co-enzymes involved in many electron transport processes. Interactions of the isoalloxazine ring, common to all three compounds, are of great interest due to their biological function in flavoproteins and relevance in the transport by the carrier protein leading to development of drug delivery strategies and non-invasive diagnostics techniques. Based on protein crystallographic data, a computational investigation of the interactions in the complexes between lumiflavin, a model compound, and aromatic amino acids, tyrosine and tryptophan, was pursued with the goal of characterizing noncovalent interactions.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Zhang Jiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China.
Class II photolyases (PLs) are a distant subclade in the photolyase/cryptochrome superfamily, displaying a unique Trp-Tyr tetrad for photoreduction and exhibiting a lower quantum yield (QY) of DNA repair (49%) than class I photolyases (82%) [M. Zhang, L. Wang, S.
View Article and Find Full Text PDFJ Funct Biomater
December 2024
Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Russia.
X-ray-induced photodynamic therapy (X-PDT) represents a promising new method of cancer treatment. A novel type of nanoscintillator based on cerium fluoride (CeF) nanoparticles (NPs) modified with flavin mononucleotide (FMN) has been proposed. A method for synthesizing CeF-FMN NPs has been developed, enabling the production of colloidal, spherical NPs with an approximate diameter of 100 nm, low polydispersity, and a high fluorescence quantum yield of 0.
View Article and Find Full Text PDFJ Biol Chem
December 2024
Structural Biochemistry, Department of Chemistry, Bielefeld University, Bielefeld, Germany. Electronic address:
Two-component flavin-dependent monooxygenases are of great interest as biocatalysts for the production of pharmaceuticals and other relevant molecules, as they catalyze chemically important reactions such as hydroxylation, epoxidation, and halogenation. The monooxygenase components require a separate flavin reductase which provides the necessary reduced flavin cofactor. The tryptophan halogenase Thal from Streptomyces albogriseolus is a well-characterized two-component flavin-dependent halogenase.
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