Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: CAS:5461-93-8 (cyclohexanecarboxylic acid)
 147 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

4-Hydroxycyclohexanecarboxylate dehydrogenase, which requires NAD as a cofactor, was detected in crude soluble extracts of Corynebacterium cyclohexanicum grown on cyclohexanecarboxylic acid as the sole carbon source. The dehydrogenase was purified from extracts to an electrophoretically homogenous state by ammonium sulfate precipitation and chromatography on DEAE-650s, agarose-NAD and hydroxyapatite. The enzyme consisted of two identical subunits and had a native relative molecular mass of 53,600. There were two residues each of cysteine and tryptophan in the enzyme molecule. Oxo acid rather than hydroxy acid was routinely used as substrate for assay of the enzyme. The enzyme is highly specific for 4-oxocyclohexanecarboxylic acid: the carboxyl group is essential and the position of carbonyl group is important; neither the 2-oxo nor the 3-oxo homologue was used as substrate. A methyl substitution on the ring of 4-oxocyclohexanecarboxylate resulted in an almost complete loss of its activity. The reduction product was identified as trans-4-hydroxycyclohexanecarboxylic acid by gas-liquid chromatography and mass spectrometry. It was used as a substrate for the reverse reaction in the presence of NAD but not its cis-isomer. The enzyme was specific for the B-side (pro-S) hydrogen of NADH in the hydrogen transfer from NADH to 4-oxocyclohexanecarboxylate. The Km values for 4-oxocyclohexanecarboxylate and NADH in the reduction reaction at pH 6.8 were 0.50 mM and 0.28 mM, respectively, whereas those for trans-4-hydroxycyclohexanecarboxylate and NAD in the oxidation reaction at pH 8.8 were 0.51 mM and 0.23 mM, respectively. The equilibrium constant of the reaction was 1.79 x 10(-10) M. The enzyme was strongly inhibited by N-bromosuccinimide.
 ...
PMID:Purification and properties of 4-hydroxycyclohexanecarboxylate dehydrogenase from Corynebacterium cyclohexanicum. 329 36

Crude soluble extracts of Corynebacterium cyclohexanicum, grown on cyclohexanecarboxylic acid, were found to contain 4-hydroxybenzoate 3-hydroxylase which functions with NADH as well as NADPH. The purified enzyme preparation was electrophoretically homogeneous and contained FAD as prosthetic group. The relative molecular mass of the enzyme was estimated to be about 47000 by native and denaturated acrylamide gel electrophoresis, indicating that it is monomeric. The enzyme was stable at 60 degrees C for 10 min. The enzyme was highly specific for p-hydroxybenzoate. The activity was inhibited by several aromatic analogues of p-hydroxybenzoate such as p-aminobenzoate, p-fluorobenzoate, o-hydroxybenzoate, m-hydroxybenzoate, 2,4-dihydroxygenzoate, and 2,5-dihydroxybenzoate. The Km value for NADH was fairly constant, about 45 microM, in the pH range 7.0-8.4, whereas the Km value for NADPH increased from 63 microM to 170 microM as the pH rose from 7.0 to 8.4. V values in the same pH range, however, were approximately constant in both cases; about 30 mumol min-1 mg-1 for NADH, and 26 mumol min-1 mg-1 for NADPH. Mg2+ was required for full activity of the enzyme in low concentrations of phosphate buffer. The enzyme was inhibited by C1- which was non-competitive with respect to NADH, NADPH and p-hydroxybenzoate.
 ...
PMID:Purification and properties of NADH/NADPH-dependent p-hydroxybenzoate hydroxylase from Corynebacterium cyclohexanicum. 397 79