title: Degradation of (+/-)-synephrine by Arthrobacter synephrinum. Oxidation of 3,4-dihydroxyphenylacetate to 2-hydroxy-5-carboxymethyl-muconate semialdehyde.
abstract: 1. Cell-free extracts of Arthrobacter synephrinum catalyse the oxidation of 3,4-dihydroxy-phenylacetate. 2. The product of oxidation was characterized as 2-hydroxy-5-carboxymethylmuconate semialdehyde from its chemical behaviour as well as from nuclear-magnetic-resonance spectra. 3. A 3,4-dihydroxyphenylacetate 2,3-dioxygenase (EC 1.13.11.15) was partially purified from A. synephrinum. 4. The enzyme had a Km of 25 micrometer towards its substrate and exhibited typical Michaelis-Menten kinetics. 5. The enzyme also catalysed the oxidation of 3,4-dihydroxymandelate and 3,4-dihydroxyphenylpropionate, at reaction rates of 0.5 and 0.04 respectively of that for 3,4-dihydroxyphenylacetate. 6. The enzyme was sensitive to treatment with thiol-specific reagents. 7. The molecular weight of the enzyme as determined by Sephadex G-200 chromatography was approx. 282000.
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000031:analogs & derivatives / Q000378:metabolism*; D000447:Aldehydes; D001173:Arthrobacter / Q000378:metabolism*; D049308:Dioxygenases; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000302:isolation & purification; D010648:Phenylacetates / Q000378:metabolism*; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds / Q000494:pharmacology; D013578:Synephrine / Q000378:metabolism*
chemical_list: D000447:Aldehydes; D010648:Phenylacetates; D013438:Sulfhydryl Compounds; D015102:3,4-Dihydroxyphenylacetic Acid; C015930:2-hydroxy-5-carboxymethylmuconate semialdehyde; D010105:Oxygenases; D049308:Dioxygenases; C020055:3,4-dihydroxyphenylacetate 2,3-dioxygenase; D013578:Synephrine