P450 peroxidase activities are valued for their ability to catalyze complex chemical transformations using economical HO; however, they have been largely underexplored compared to their monooxygenase and peroxygenase activities. In this study, we identified an unconventional P450 enzyme, PtmB, which catalyzes the dimerization of purine nucleobases and tryptophan-containing diketopiperazines (TDKPs), yielding C3-nucleobase pyrroloindolines and nucleobase-TDKP dimers. Unlike typical TDKP P450 enzymes reliant on NAD(P)H cofactors and electron transfer systems, PtmB, and its analogs exhibit remarkable peroxidase activity in synthesizing adenine and other modified 6-aminopurine nucleobase-TDKP dimers. Structural analysis of the PtmB-substrate complex, mutation assays, and computational investigations reveal adenine's dual role as both substrate and acid-base catalyst in activating HO to generate Compound I (Cpd I). This initiates a specific radical cascade reaction, facilitating the formation of precise C─C and C─N bonds. Biochemical assays and molecular dynamics simulations demonstrate that adenine's 6-NH hydrogen-bonding networks induce necessary conformational changes for HO activation, thereby driving peroxidase activity. This study unveils an unusual catalytic mechanism for the P450 peroxidase system and underscores the pivotal role of nucleobases in enzyme-mediated reactions, which offers different prospects for developing P450 peroxidases and nucleobase-based biocatalysts.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11573659 | PMC |
http://dx.doi.org/10.1073/pnas.2412890121 | DOI Listing |
Free Radic Biol Med
January 2025
Graduate School of Life and Medical Sciences, Doshisha University, 1-3 Miyakodani, Tatara, Kyotanabe, Kyoto 610-0394, Japan. Electronic address:
Enzymatically formed side-chain oxysterols function as signaling molecules regulating cholesterol homeostasis and act as intermediates in the biosynthesis of bile acids. In addition to these physiological functions, an imbalance in oxysterol homeostasis has been implicated in pathophysiology. Cholesterol 25-hydroxylase (CH25H) and its product 25-hydroxycholesterol (25-OHC), also formed by autoxidation, are associated with amyotrophic lateral sclerosis.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, School of Environment, South China Normal University, University Town, Guangzhou 510006, China.
Co-metabolism with appropriate carbon sources has been demonstrated to effectively enhance the removal of ubiquitous recalcitrant micropollutant by microalgae. However, the specific impacts of carbon sources on the co-metabolism of antibiotics by microalgae remain insufficiently explored. In this study, transcriptomics, gene network analysis, extracellular polymeric substances (EPS), and enzymatic activity involved in co-metabolic pathways of norfloxacin (NFX), were systematically evaluated to investigate the underlying biological mechanisms involved in NFX co-metabolism by Chlorella pyrenoidosa.
View Article and Find Full Text PDFJ Genet Genomics
December 2024
Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Key Lab of Plant factory for Plant Factory Generation-Adding Breeding of Ministry of Agriculture and Rural Affairs, the Advanced Seed Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China; Hainan Institute of Zhejiang University, Sanya, Hainan 572025, China. Electronic address:
Adv Sci (Weinh)
December 2024
Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao New Energy Shandong Laboratory, CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
Amine oxidation is an important organic reaction for the production of high-value N-containing compounds. However, it is still challenging to control the reactivity of active N-centered radicals to selectively access N-oxidation products. Herein, this study reports the engineering of cytochrome P450BM3 into multifunctional N-oxidizing enzymes with the assistance of dual-functional small molecules (DFSM) to selectively produce N-oxygenation (i.
View Article and Find Full Text PDFEcotoxicol Environ Saf
December 2024
Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China; Sanya Research Academy, Chinese Academy of Tropical Agriculture Science, Sanya 572000, China. Electronic address:
Cyanogenic plants can release toxic hydrogen cyanide (HCN) to defend against herbivory by hydrolyzing the cyanogenic glycosides (CNGs) with its β-glucosidases (β-GLUs). Numerous studies have speculated this CNG-mediated toxicity by a plant-pest interaction manner. However, the specific toxic effect of HCN was not well-demonstrated because of the interference of other ingested metabolites.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!