4,5-, 7,8- and 9,10-dihydrodiols of benz(a)pyrene (BP) were separated by thin-layer chromatography and their influence on BP-hydroxylase activity was studied in liver microsomes isolated from rats treated with phenobarbital (PB-microsomes) and 3-methylcholanthrene (MC-microsomes). All diols studied inhibited hydroxylation of BP by the competitive type. Accumulation of BP-diols in the incubation media correlated with their affinity to cytochrome P-450 isoenzymes which catalyzed the secondary metabolism of these diols. This correspondence allowed to formulate the kinetic and temperature dependence of BP oxidation suggesting that two main groups of hemoprotein isoforms were contained which were dissimilar in the active site orientation. Treatment with 3-methylcholanthrene induced specifically those hemoproteins which had the active site directed inside the membrane lipids; treatment with phenobarbital involved induction of two groups of hemoproteins active site of which was directed both to lipid and to water. The primary metabolism of the hydrophobic BP involved cytochrome P-450 isoenzymes which had the active site directed inside the lipids; the secondary metabolism of more polar diols was realized using both groups of hemoprotein isoenzymes with active sites oriented into lipids and water.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Synthesis, biological evaluation and molecular docking studies of flavonol-3-O-β-D-glycoside as a potential inhibitor of SARS-CoV-2 main protease (3CLpro) in drug development for COVID-19.
Int J Biol Macromol
January 2025
Department of Basic Medical Sciences, Faculty of Medicine, Istanbul Medipol University, Istanbul 34815, Türkiye.
The COVID-19 pandemic began in March 2020 and has affected many countries and infected over a million people. It has had a serious impact on people's physical and mental health, daily life and the global economy. Today, many drugs show limited efficacy in the treatment of COVID-19 and studies to develop effective drugs continue.
View Article and Find Full Text PDFCrystal structure and functional characterization of a novel bacterial lignin-degrading dye-decolorizing peroxidase.
Int J Biol Macromol
January 2025
Department of Life Sciences and Systems Biology, University of Torino, Italy.
A new gene coding for an iron-containing enzyme was identified in the genome of Acinetobacter radioresistens. Bioinformatics analysis allowed the assignment of the protein to DyP peroxidases, due to the presence of conserved residues involved in heme binding and catalysis. Moreover, Ar-DyP is located in an operon coding also for other enzymes involved in iron uptake and regulation.
View Article and Find Full Text PDFStructure of E6AP in complex with HPV16-E6 and p53 reveals a novel ordered domain important for E3 ligase activation.
Structure
January 2025
Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA. Electronic address:
High-risk human papillomavirus E6 oncoprotein is a model system for the recognition and degradation of cellular p53 tumor suppressor protein. There remains a gap in the understanding of the ubiquitin transfer reaction, including placement of the E6AP catalytic HECT domain of the ligase concerning the p53 substrate and how E6 itself is protected from ubiquitination. We determined the cryoelectron microscopy (cryo-EM) structure of the E6AP/E6/p53 complex, related the structure to in vivo modeling of the tri-molecular complex, and identified structural interactions associated with activation of the ubiquitin ligase function.
View Article and Find Full Text PDFDirect Methane to Methanol Conversion: An Overview of Non-Syn Gas Catalytic Strategies.
Chem Rec
January 2025
Bioinspired & Biomimetic Inorganic Chemistry Laboratory, Department of Chemistry, National Institute of Technology Calicut, Kozhikode, Kerala, 673601, India.
Direct methane to methanol conversion is a dream reaction in industrial chemistry, which takes inspiration from the biological methanol production catalysed by methane monooxygenase enzymes (MMOs). Over the years, extensive studies have been conducted on this topic by bioengineering the MMOs, and tailoring methods to isolate the MMOs in the active form. Similarly, remarkable achievements have been noted in other methane activation strategies such as the use of heterogeneous catalysts or molecular catalysts.
View Article and Find Full Text PDFSupramolecularly Built Local Electric Field Microenvironment around Cobalt Phthalocyanine in Covalent Organic Frameworks for Enhanced Photocatalysis.
J Am Chem Soc
January 2025
Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
The local electric field (LEF) plays an important role in the catalytic process; however, the precise construction and manipulation of the electric field microenvironment around the active site remains a significant challenge. Here, we have developed a supramolecular strategy for the implementation of a LEF by introducing the host macrocycle 18-crown-6 (18C6) into a cobalt phthalocyanine (CoPc)-containing covalent organic framework (COF). Utilizing the supramolecular interaction between 18C6 and potassium ion (K), a locally enhanced K concentration around CoPc can be built to generate a LEF microenvironment around the catalytically active Co site.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!