Catalytic Conversion of Lipophilic Substrates by Phase constrained Enzymes in the Aqueous or in the Membrane Phase
| Autor: | Jerker Widengren, Madhuranayaki Thulasingam, Bengt Mannervik, Hiroshi Abe, Ralf Morgenstern, Marcus Cebula, Joseph Brock, Birgitta Sjödin, Agnes Rinaldo-Matthis, Ilke Simsek Turan, Engin U. Akkaya, Jesper Z. Haeggström, Volodymyr Chmyrov |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Boron Compounds Models Molecular Octoxynol Article Catalysis Substrate Specificity Xenobiotics 03 medical and health sciences Cytosol Phase (matter) Microsomes Animals Humans Glucuronosyltransferase Fluorescent Dyes Glutathione Transferase chemistry.chemical_classification Epoxide Hydrolases Membranes Multidisciplinary 030102 biochemistry & molecular biology Chemistry Substrate (chemistry) Enzymes Immobilized Combinatorial chemistry Kinetics 030104 developmental biology Membrane Enzyme Eukaryotic Cells Biocatalysis Enzyme mechanisms Inactivation Metabolic Sulfotransferases Hydrophobic and Hydrophilic Interactions Chemical modification |
| Zdroj: | Scientific Reports |
| ISSN: | 2045-2322 |
| Popis: | Both soluble and membrane-bound enzymes can catalyze the conversion of lipophilic substrates. The precise substrate access path, with regard to phase, has however, until now relied on conjecture from enzyme structural data only (certainly giving credible and valuable hypotheses). Alternative methods have been missing. To obtain the first experimental evidence directly determining the access paths (of lipophilic substrates) to phase constrained enzymes we here describe the application of a BODIPY-derived substrate (PS1). Using this tool, which is not accessible to cytosolic enzymes in the presence of detergent and, by contrast, not accessible to membrane embedded enzymes in the absence of detergent, we demonstrate that cytosolic and microsomal glutathione transferases (GSTs), both catalyzing the activation of PS1, do so only within their respective phases. This approach can serve as a guideline to experimentally validate substrate access paths, a fundamental property of phase restricted enzymes. Examples of other enzyme classes with members in both phases are xenobiotic-metabolizing sulphotransferases/UDP-glucuronosyl transferases or epoxide hydrolases. Since specific GSTs have been suggested to contribute to tumor drug resistance, PS1 can also be utilized as a tool to discriminate between phase constrained members of these enzymes by analyzing samples in the absence and presence of Triton X-100. |
| Databáze: | OpenAIRE |
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