Serum paraoxonase-1 (PON1) is the most studied member of the group of paraoxonases (PONs). This enzyme possesses three enzymatic activities: lactonase, arylesterase, and paraoxonase activity. PON1 and its isoforms play an important role in drug metabolism as well as in the prevention of cardiovascular and neurodegenerative diseases. Although all three members of the PON family have the same origin and very similar amino acid sequences, they have different functions and are found in different locations. PONs exhibit substrate promiscuity, and their true physiological substrates are still not known. However, possible substrates include homocysteine thiolactone, an analogue of natural quorum-sensing molecules, and the recently discovered derivatives of arachidonic acid-bioactive δ-lactones. Directed evolution, site-directed mutagenesis, and kinetic studies provide comprehensive insights into the active site and catalytic mechanism of PON1. However, there is still a whole world of mystery waiting to be discovered, which would elucidate the substrate promiscuity of a group of enzymes that are so similar in their evolution and sequence yet so distinct in their function.
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http://dx.doi.org/10.3390/molecules25245980 | DOI Listing |
ACS Environ Au
January 2025
Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland.
Organic micropollutants, including pharmaceuticals, personal care products, pesticides, and food additives, are widespread in the environment, causing potentially toxic effects. Human waste is a direct source of micropollutants, with the majority of pharmaceuticals being excreted through urine. Urine contains its own microbiota with the potential to catalyze micropollutant biotransformations.
View Article and Find Full Text PDFWater Res
January 2025
MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China. Electronic address:
Anaerobic digestion (AD) viruses have gained recognition as significant regulators of microbial interactions within AD communities, yet their ecological roles remain largely unexplored. In this study, we investigated the ecological roles of AD viruses in regulating microbial interactions among syntrophic hosts. We recovered 3921 diverse viral sequences from four full-scale anaerobic digesters and confirmed their widespread presence across 127 global metagenomic sampling sites (with >95 % sequence similarity), underscoring the ubiquity of prokaryotic viruses in AD-related systems.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
The structural groups of 2-oxindole and tricyclic 3a-hydroxy-hexahydropyrrolo-[2,3-]indole (HO-HPI) are important pharmacophores. Chemical synthesis of complex alkaloids containing a 2-oxindole or HO-HPI moiety, especially the latter one, has been a long-standing challenge. Herein, we characterized the P450 enzyme AfnD, and its homologue proteins, HmtT, ClpD, KtzM, and LtzR, as cyclopeptide 2-oxindole and HO-HPI monooxygenases (cpOPMOs) that could introduce a 2-oxindole or HO-HPI moiety into the tryptophan-containing cyclopeptides in a pH-dependent manner.
View Article and Find Full Text PDFiScience
January 2025
State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
Lignin valorization is crucial for achieving economic and sustainable biorefinery processes. However, the enzyme substrate preferences involved in lignin degradation remain poorly understood, and low activity toward specific substrates presents a significant challenge to the efficient utilization of lignin. In this study, we investigated the substrate promiscuity of Ado, a key enzyme involved in lignin valorization.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
National Resource Center for Chinese Meteria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China; State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, Beijing 100700, China.
Glycosylation is an effective means to alter the structure and properties of plant compounds, influencing the pharmacological activity of natural products (NPs) to obtain highly active NPs. In nature, glucosides are the most widely distributed, while other glycosides such as xylosides are less common and present in lower quantities. This is due to the scarcity of xylosyltransferases with substrate promiscuity in nature, and the modification of their catalytic function is also quite challenging.
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