Production of melanins by ceruloplasmin.
It was shown that ceruloplasmin, apart from the known oxidative conversion of dopamine into melanin, can also produce (DHI)-melanin from 5,6-dihydroxyindole and THP-melanin from tetrahydropapaveroline. Ceruloplasmin acts as an oxidase and the kinetic parameters for these oxidative reactions are reported. Since these ceruloplasmin-catalyzed reactions occur also at pH 7.4, they could have a significant physiological impact. This ceruloplasmin-oxidasic activity is enhanced by copper ions and inhibited by chelators, such as ethylenediaminetetraacetic acid (EDTA) and desferoxamine (DEF). Some possible implication of melanin production in blood are discussed.
Rosei
M A
MA
Department of Biochemical Sciences, University La Sapienza of Rome, Italy. rosei@axcasp.caspur.it
Foppoli
C
C
Wang
X T
XT
Coccia
R
R
Mateescu
M A
MA
D002570:Ceruloplasmin / Q000378:metabolism*; D002614:Chelating Agents; D003300:Copper; D006863:Hydrogen-Ion Concentration; D008543:Melanins / Q000378:metabolism*; D010084:Oxidation-Reduction; D013765:Tetrahydropapaveroline / Q000378:metabolism
D002614:Chelating Agents; D008543:Melanins; D013765:Tetrahydropapaveroline; D003300:Copper; D002570:Ceruloplasmin