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O-methylation of L-dopa in melanin metabolism and the presence of catechol-O-methyltransferase in melanocytes.

Smit, N.; Tilgmann, C. LU ; Karhunen, T.; Slingerland, R.; Ulmanen, I.; Westerhof, W. and Pavel, S. (1994) In Pigment Cell Research1987-01-01+01:002008-01-01+01:00 7(6). p.403-408
Abstract

O-Methylation of L-dopa was investigated as a possible regulatory mechanism in melanin metabolism. The methylation product of L-dopa, 3-O-methoxytyrosine was detected in extracts of cultured human melanocytes. The enzyme catechol-O-methyltransferase is responsible for this O-methylation and that of the dihydroxyindolic intermediates of melanogenesis. The enzyme is present in melanocytes in its soluble and membrane-bound isoforms. Immuno-electron microscopy suggests the presence of the membrane-bound enzyme in the endoplasmic reticulum. This localization may indicate a role of catechol-O-methyltransferase in protecting the melanocyte against reactive dihydroxyphenolic intermediates of melanogenesis leaking from the melanogenic... (More)

O-Methylation of L-dopa was investigated as a possible regulatory mechanism in melanin metabolism. The methylation product of L-dopa, 3-O-methoxytyrosine was detected in extracts of cultured human melanocytes. The enzyme catechol-O-methyltransferase is responsible for this O-methylation and that of the dihydroxyindolic intermediates of melanogenesis. The enzyme is present in melanocytes in its soluble and membrane-bound isoforms. Immuno-electron microscopy suggests the presence of the membrane-bound enzyme in the endoplasmic reticulum. This localization may indicate a role of catechol-O-methyltransferase in protecting the melanocyte against reactive dihydroxyphenolic intermediates of melanogenesis leaking from the melanogenic compartments. On the other hand, the O-methylation of L-dopa may serve as a regulatory point in melanogenesis during early stage of tyrosinase processing in the endoplasmic reticulum.

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author
publishing date
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Contribution to journal
publication status
published
in
Pigment Cell Research1987-01-01+01:002008-01-01+01:00
volume
7
issue
6
pages
6 pages
publisher
Wiley-Blackwell
external identifiers
  • Scopus:0028724964
ISSN
0893-5785
language
English
LU publication?
no
id
a79be7c8-057f-426c-a7e2-1b9a675898cc
date added to LUP
2016-04-11 13:21:46
date last changed
2016-11-27 04:39:16
@misc{a79be7c8-057f-426c-a7e2-1b9a675898cc,
  abstract     = {<p>O-Methylation of L-dopa was investigated as a possible regulatory mechanism in melanin metabolism. The methylation product of L-dopa, 3-O-methoxytyrosine was detected in extracts of cultured human melanocytes. The enzyme catechol-O-methyltransferase is responsible for this O-methylation and that of the dihydroxyindolic intermediates of melanogenesis. The enzyme is present in melanocytes in its soluble and membrane-bound isoforms. Immuno-electron microscopy suggests the presence of the membrane-bound enzyme in the endoplasmic reticulum. This localization may indicate a role of catechol-O-methyltransferase in protecting the melanocyte against reactive dihydroxyphenolic intermediates of melanogenesis leaking from the melanogenic compartments. On the other hand, the O-methylation of L-dopa may serve as a regulatory point in melanogenesis during early stage of tyrosinase processing in the endoplasmic reticulum.</p>},
  author       = {Smit, N. and Tilgmann, C. and Karhunen, T. and Slingerland, R. and Ulmanen, I. and Westerhof, W. and Pavel, S.},
  issn         = {0893-5785},
  language     = {eng},
  number       = {6},
  pages        = {403--408},
  publisher    = {ARRAY(0xb101e10)},
  series       = {Pigment Cell Research1987-01-01+01:002008-01-01+01:00},
  title        = {O-methylation of L-dopa in melanin metabolism and the presence of catechol-O-methyltransferase in melanocytes.},
  volume       = {7},
  year         = {1994},
}