Substrate specificity and reaction mechanism of purified alkane hydroxylase from the hydrocarbonoclastic bacterium Alcanivorax borkumensis (AbAlkB)
| Autor: | Marilla Pender-Cudlip, Rachel N. Austin, John T. Groves, Swe-Htet Naing, Saba Parvez |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Cyclopropanes
Models Molecular Free Radicals Stereochemistry AlkB Alcanivoraceae Hydroxylation Zea mays Biochemistry Article Substrate Specificity Inorganic Chemistry Bridged Bicyclo Compounds chemistry.chemical_compound Bacterial Proteins Cyclohexanes Radical clock Organic chemistry Plant Proteins biology Bicyclic molecule Terpenes Rubredoxins Substrate (chemistry) Active site biology.organism_classification Biodegradation Environmental chemistry biology.protein Cytochrome P-450 CYP4A Alcanivorax Oxidation-Reduction NADP Norcarane |
| Zdroj: | Journal of Inorganic Biochemistry. 121:46-52 |
| ISSN: | 0162-0134 |
| DOI: | 10.1016/j.jinorgbio.2012.12.012 |
| Popis: | An alkane hydroxylase from the marine organism Alcanivorax borkumensis ( Ab AlkB) was purified. The purified protein retained high activity in an assay with purified rubredoxin (AlkG), purified maize ferredoxin reductase, NADPH, and selected substrates. The reaction mechanism of the purified protein was probed using the radical clock substrates bicyclo[4.1.0]heptane (norcarane), bicyclo[3.1.0]hexane (bicyclohexane), methylphenylcyclopropane and deuterated and non-deuterated cyclohexane. The distribution of products from the radical clock substrates supports the hypothesis that purified Ab AlkB hydroxylates substrates by forming a substrate radical. Experiments with deuterated cyclohexane indicate that the rate-determining step has a significant C H bond breaking character. The products formed from a number of differently shaped and sized substrates were characterized to determine the active site constraints of this AlkB. Ab AlkB can catalyze the hydroxylation of a large number of aromatic compounds and linear and cyclic alkanes. It does not catalyze the hydroxylation of alkanes with a chain length longer than 15 carbons, nor does it hydroxylate sterically hindered C H bonds. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect