High impact information on L-dopachrome

• This dopachrome tautomerase binds to Concanavalin A-Sepharose, and the major product of its action on L-dopachrome is 5,6-dihydroxyindole-2-carboxylic acid [1].
• One of the functions assigned to MIF is that of a tautomerase that interconverts the enol and keto forms of phenylpyruvate and (p-hydroxyphenyl)pyruvate and converts D-dopachrome, a stereoisomer of naturally occurring L-dopachrome, to 5,6-dihydroxyindole-2-carboxylic acid [2].
• Of note, molecular modeling of the substrate L-dopachrome methyl ester into the active site of MIF suggests an acid-catalyzed enzymatic mechanism that is different from that deduced from studies of the enzymes 4-OT and CHMI [3].
• We have cloned and sequenced a chicken cDNA encoding an l-DOPAchrome tautomerase (DCT) from an embryonic melanocyte cDNA library [4].
• The action of dopachrome tautomerase on L-dopachrome yields DHICA, a stable dihydroxyindole with a low rate of spontaneous oxidation [5].

Biological context of L-dopachrome

• It had a high substrate specificity for L-dopachrome, methyl-L-dopachrome and L-dopachrome methyl ester but no activity on the corresponding D-isomers or on dopaminechrome [6].

Anatomical context of L-dopachrome

• The tyrosinase-expressing parent line does not have L-dopachrome tautomerase activity, but this enzyme is detectable in double transfectants as well as in fibroblasts expressing the b-protein alone [7].

Gene context of L-dopachrome

• Dopachrome tautomerase (DCT; EC 5.3.3.12) catalyses the conversion of L-dopachrome into 5,6-dihydroxyindole-2-carboxylic acid in the mammalian eumelanogenic biosynthetic pathway [8].
• Tyrosinase-related protein-2 (TYRP2) is a melanocyte-specific enzyme that catalyses the non-decarboxylative tautomerization of L-dopachrome to 5,6-dihydroxyindole-2-carboxylic acid (DHICA) in the melanin biosynthetic pathway [9].

References