Sequence-based screening was carried out to find a type of cytosolic mandelate oxidase that converted l-mandelate to phenylglyoxylate using oxygen as the final electron acceptor. The sequence features of the cytosolic mandelate oxidase were summarized, and were used in the screening process. Mandelate oxidases from Streptomyces coelicolor (HmoSC) and Amycolatopsis orientalis (HmoAO) were screened and then they were heterologously expressed and characterized. At pH 7.3 40 °C, the HmoAO showed kcat and Km values of 140 min(-1) and 10.2 mM, the HmoSC showed kcat and Km values of 105.1 min(-1) and 2.06 mM. The HmoSC was thermal stable and retained its 90% activity at 60 °C for up to 5 h, while HmoAO lost most of its activity at this temperature. The HmoSC could effectively catalyze the conversion of l-mandelate to phenylglyoxylate at higher temperature using oxygen as the final electron acceptor.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.enzmictec.2014.11.001 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Sequence-based screening and characterization of cytosolic mandelate oxidase using oxygen as electron acceptor.
Enzyme Microb Technol
February 2015
National Engineering Laboratory for Cereal Fermentation Technology, The Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China. Electronic address:
Sequence-based screening was carried out to find a type of cytosolic mandelate oxidase that converted l-mandelate to phenylglyoxylate using oxygen as the final electron acceptor. The sequence features of the cytosolic mandelate oxidase were summarized, and were used in the screening process. Mandelate oxidases from Streptomyces coelicolor (HmoSC) and Amycolatopsis orientalis (HmoAO) were screened and then they were heterologously expressed and characterized.
View Article and Find Full Text PDFConclusive identification of the oxybutynin-hydrolyzing enzyme in human liver.
Drug Metab Dispos
May 2012
Drug Metabolism Research Laboratories, Drug Discovery Research, Astellas Pharma Inc., 2-1-6 Kashima, Yodogawa-ku, Osaka 532-8514, Japan.
The aim of this study was to conclusively determine the enzyme responsible for the hydrolysis of oxybutynin in human liver. Hydrolysis in human liver microsomes (HLMs) and human liver cytosol (HLC) followed Michaelis-Menten kinetics with similar K(m) values. In recombinant human carboxylesterase (CES)-expressing microsomes, CES1 was much more efficient than CES2 and yielded a K(m) value more comparable with that found in HLMs or HLC than did CES2.
View Article and Find Full Text PDFStudy on the metabolic mechanism of chiral inversion of S-mandelic acid in vitro.
Chirality
January 2012
Department of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.
Mandelic acid (MA) is generally used as a biological indicator of occupational exposure to styrene, which is classified as a class of hazardous environmental pollutants. It was found to undergo one-directional chiral inversion (S-MA to R-MA) in Wistar and Sprague-Dawley rats in vivo. This study was aimed to explore the metabolic mechanism of chiral inversion of S-MA in vitro.
View Article and Find Full Text PDFInvestigation on the enantioselectivity of the sulfation of the methylenedioxymethamphetamine metabolites 3,4-dihydroxymethamphetamine and 4-hydroxy-3-methoxymethamphetamine using the substrate-depletion approach.
Drug Metab Dispos
November 2011
Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Building 46, D-66421 Homburg (Saar), Germany.
Different pharmacokinetic properties are known for the two enantiomers of the entactogen 3,4-methylendioxy-methamphetamine (MDMA), most likely due to enantioselective metabolism. The aim of the present work was 1) the investigation of the main sulfotransferases (SULT) isoenzymes involved in the sulfation of the main MDMA phase I metabolites 3,4-dihydroxymethamphetamine (DHMA) and 4-hydroxy-3-methoxymethamphetamine (HMMA) and 2) the evaluation of a possible enantioselectivity of this phase II metabolic step. Therefore, racemic DHMA and HMMA were incubated with heterologously expressed SULTs, and quantification of the sulfates by liquid chromatography-high-resolution mass spectrometry was conducted.
View Article and Find Full Text PDFSulfation of the 3,4-methylenedioxymethamphetamine (MDMA) metabolites 3,4-dihydroxymethamphetamine (DHMA) and 4-hydroxy-3-methoxymethamphetamine (HMMA) and their capability to inhibit human sulfotransferases.
Toxicol Lett
April 2011
Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Kirrberger Strasse 1, D-66421 Homburg (Saar), Germany.
3,4-Methylenedioxymethamphetamine (MDMA, Ecstasy) is excreted in human urine mainly as conjugates of its metabolites 3,4-dihydroxymethamphetamine (DHMA) and 4-hydroxy-3-methoxymethamphetamine (HMMA). The glucuronidation kinetics of HMMA showed high capacities, but also high K(m) values, unlikely to be reached after recreational user's doses. Therefore, the aim of the present work was to investigate the sulfation of DHMA and HMMA by human sulfotransferases (SULTs) in pooled human liver cytosol (pHLC).
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!