Binding of 1,2(N)-dimethyl-6,7-dihydroxy-isoquinolinium ion to melanin: effects of ferrous and ferric ion on the binding.
1,2(N)-Dimethyl-6,7-dihydroxy-isoquinolinium ion (N-methylsalsolinium ion) was found to bind to melanin, while N-methyl(R)salsolinol and (R)salsolinol did not. Two components with different affinity to melanin were found; the dissociation constant and maximal binding capacity were obtained as 2.1 and 79.4 nM, and 103 and 1336 pmol/mg melanin, respectively. The binding was enhanced by ferrous ion markedly and inhibited by 1-methyl-4-phenylpyridinium ion and ferric ion. N-Methylsalsolinium ion may be accumulated in dopamine neurons as melanin conjugate, which is regulated by ferric and ferrous ions.
Naoi
M
M
Department of Biosciences, Nagoya Institute of Technology, Japan.
Maruyama
W
W
Dostert
P
P
D005290:Ferric Compounds / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry*; D007546:Isoquinolines / Q000737:chemistry*; D007700:Kinetics; D008543:Melanins / Q000737:chemistry*
D005290:Ferric Compounds; D005296:Ferrous Compounds; D007546:Isoquinolines; D008543:Melanins; C089303:N-methylsalsolinium; C036617:salsolinol