O-methylation of L-dopa in melanin metabolism and the presence of catechol-O-methyltransferase in melanocytes.
(1994) In Pigment Cell Research 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
- Smit, N. ; Tilgmann, C. LU ; Karhunen, T. ; Slingerland, R. ; Ulmanen, I. ; Westerhof, W. and Pavel, S.
- publishing date
- 1994-12
- type
- Contribution to journal
- publication status
- published
- in
- Pigment Cell Research
- volume
- 7
- issue
- 6
- pages
- 6 pages
- publisher
- Wiley-Blackwell
- external identifiers
-
- pmid:7539130
- 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
- 2024-01-04 01:04:49
@article{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 = {{Wiley-Blackwell}}, series = {{Pigment Cell Research}}, title = {{O-methylation of L-dopa in melanin metabolism and the presence of catechol-O-methyltransferase in melanocytes.}}, volume = {{7}}, year = {{1994}}, }