Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.10.3.1 (tyrosinase)
 9,065 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Grixazone contains a phenoxazinone chromophore and is a secondary metabolite produced by Streptomyces griseus. In the grixazone biosynthesis gene cluster, griF (encoding a tyrosinase homolog) and griE (encoding a protein similar to copper chaperons for tyrosinases) are encoded. An expression study of GriE and GriF in Escherichia coli showed that GriE activated GriF by transferring copper ions to GriF, as has been observed for a Streptomyces melanogenesis system in which the MelC1 copper chaperon transfers copper ions to MelC2 tyrosinase. In contrast with tyrosinases, GriF showed no monophenolase activity, although it oxidized various o-aminophenols as preferable substrates rather than catechol-type substrates. Deletion of the griEF locus on the chromosome resulted in accumulation of 3-amino-4-hydroxybenzaldehyde (3,4-AHBAL) and its acetylated compound, 3-acetylamino-4-hydroxybenzaldehyde. GriF oxidized 3,4-AHBAL to yield an o-quinone imine derivative, which was then non-enzymatically coupled with another molecule of the o-quinone imine to form a phenoxazinone. The coexistence of N-acetylcysteine in the in vitro oxidation of 3,4-AH-BAL by GriF resulted in the formation of grixazone A, suggesting that the -SH group of N-acetylcysteine is conjugated to the o-quinone imine formed from 3,4-AHBAL and that the conjugate is presumably coupled with another molecule of the o-quinone imine. GriF is thus a novel o-aminophenol oxidase that is responsible for the formation of the phenoxazinone chromophore in the grixazone biosynthetic pathway.
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PMID:A novel o-aminophenol oxidase responsible for formation of the phenoxazinone chromophore of grixazone. 1628 22

The influence of endogenous root nodules phenolic acids on indoleacetic acid (IAA) production by its symbiont (Rhizobium) was examined. The root nodules contain higher amount of IAA and phenolic acids than non-nodulated roots. Presence of IAA metabolizing enzymes, IAA oxidase, peroxidase, and polyphenol oxidase indicate the metabolism of IAA in the nodules and roots. Three most abundant endogenous root nodule phenolic acids (protocatechuic acid, 4-hydroxybenzaldehyde and p-coumaric acid) have been identified and their effects on IAA production by the symbiont have been studied in L-tryptophan supplemented yeast extract basal medium. Protocatechuic acid (1.5 microg ml(-1)) showed maximum stimulation (2.15-fold over control) of IAA production in rhizobial culture. These results indicate that the phenolic acids present in the nodule might serve as a stimulator for IAA production by the symbiont (Rhizobium).
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PMID:Stimulation of indoleacetic acid production in a Rhizobium isolate of Vigna mungo by root nodule phenolic acids. 1915 66

A series of novel 5-benzylidene barbiturate and thiobarbiturate derivatives were synthesized and evaluated as tyrosinase inhibitors and antibacterial agents. The results demonstrated that some compounds had more potent inhibitory activities than the parent compound 4-hydroxybenzaldehyde (IC(50)=1.22 mM). Particularly, compounds 1a and 2a were found to be the most potent inhibitors with IC(50) value of 13.98 microM and 14.49 microM, respectively. The inhibition mechanism study revealed that these compounds were irreversible inhibitors. The circular dichroism spectra indicated that these compounds induced conformational changes of mushroom tyrosinase upon binding. In addition, these compounds exhibited selectively antibacterial activity against Staphylococcus aureus. All these results suggested that further development of such compounds may be of interest.
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PMID:Inhibitory effects of 5-benzylidene barbiturate derivatives on mushroom tyrosinase and their antibacterial activities. 1955 84

A series of novel 4-hydroxybenzaldehyde derivatives were synthesized and their inhibitory effects on the diphenolase activity of mushroom tyrosinase were investigated. Most of target compounds had more potent inhibitory activities than the parent compound 4-hydroxybenzaldehyde (IC(50)=1.22 mM). Interestingly, compound 3c bearing a dimethoxyl phosphate was found to be the most potent inhibitor with IC(50) value of 0.059 mM. The inhibition kinetics analyzed by Lineweaver-Burk plots revealed that compound 3c was a non-competitive inhibitor (K(I)=0.0368 mM). In particular, compound 3c showed no side effects at dose of 1600 mg/kg in mice. These results suggested that such compounds might be served as lead compounds for further designing new potential tyrosinase inhibitors.
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PMID:Synthesis and biological evaluation of novel 4-hydroxybenzaldehyde derivatives as tyrosinase inhibitors. 1993 28

A range of phenolic acids, viz., p-coumaric acid, 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid, protocatechuic acid, caffeic acid, ferulic acid, and cinnamic acid have been isolated and identified by LC-MS analysis in the roots and root nodules of Mimosa pudica. The effects of identified phenolic acids on the regulation of nodulation (nod) genes have been evaluated in a betarhizobium isolate of M. pudica root nodule. Protocatechuic acid and p-hydroxybenzoic acid were most effective in inducing nod gene, whereas caffeic acid had no significant effect. Phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase activities were estimated, indicating regulation and metabolism of phenolic acids in root nodules. These results showed that nodD gene expression of betarhizobium is regulated by simple phenolic acids such as protocatechuic acid and p-hydroxybenzoic acid present in host root nodule and sustains nodule organogenesis.
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PMID:Induction of nodD Gene in a Betarhizobium Isolate, Cupriavidus sp. of Mimosa pudica, by Root Nodule Phenolic Acids. 2689 26