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Cited by 126melanin and skin pigmentationMelanoma and MAPK PathwaysDermatologic Treatments and Research

The DOI matches its Crossref record; 40 of the 40 references it cites were found in a registry or an index.

The Relationship Between Tyrosinase Activity and Skin Color in Human Foreskins

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Iwata, Mitsuru, Corn, Todd, Iwata, Shoko, Everett, Mark A, Fuller, Bryan B·1990·Journal of Investigative Dermatology
DOI 10.1111/1523-1747.ep12872677
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Abstract

Tyrosinase activity was assayed in black and white human foreskin samples by measuring both the hydroxylation of tyrosine to dopa (tyrosine hydroxylase activity) and the conversion of [14C]tyrosine to [14C]melanin (melanin synthesis assay). Enzyme activity was found both in the particulate (75%) and soluble (25%) fractions of the cell. Membrane-bound tyrosinase was readily solubilized by either zwitter-ionic or nonionic detergents. The anionic detergent, sodium cholate, inhibited enzyme activity. Tyrosinase activity in black foreskin homogenates averaged almost three times that in white skin samples (33.8 pmols 3H2O/h/mg skin in black and 12.71 pmoles 3H2O/h/mg skin in white skin), although considerable overlap in activities existed among the two groups. Tyrosinase activities measured with two separate assays, tyrosine hydroxylase and [14C]melanin assays, were similar, suggesting that tyrosine hydroxylase activity is tightly coupled to melanin synthesis. Tyrosinase activity determined by either assay method generally correlated with skin melanin content. Kinetic analysis of tyrosinase from black and white foreskin revealed a Km for tyrosine of 2.5 X 10(-4) M in both skin types. Immunotitration experiments suggested that the difference in tyrosinase activities between white and black skin may be due, not only to different amounts of enzyme present in the melanocytes, but also possibly to differences in the catalytic activities of the enzyme found in melanocytes of black and white skin.

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Crossref · 10.1111/1523-1747.ep12872677

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Metadata

Authors
Iwata, M., Corn, T., Iwata, S., Everett, M. A., & Fuller, B. B.
Affiliations
University of Oklahoma Health Sciences Center (US)
Venue
Journal of Investigative Dermatology
Publisher
Elsevier BV
Published
1990-07
Volume
95
Issue
1
Pages
9-15
ISSN
0022-202X (ISSN-L)
DOI
10.1111/1523-1747.ep12872677
OpenAlex
W1979456082
Cited by
125
References
40
Citations by year
2025: 3 · 2024: 5 · 2023: 4 · 2022: 5 · 2021: 5 · 2020: 5 · 2019: 2 · 2018: 7 · 2017: 6 · 2016: 6 · 2015: 8 · 2014: 3 · 2013: 4 · 2012: 7
FWCI
1.56
Type
journal article
Language
en
Open access
Licence
Locations
  • Journal of Investigative Dermatology (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › melanin and skin pigmentation
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Melanoma and MAPK Pathways
  • Health Sciences › Medicine › Dermatology › Dermatologic Treatments and Research
Keywords
tyrosinase, skin color, melanogenesis, melanocytes, prepuce, tyrosine hydroxylase, enzyme kinetics, enzyme solubilization, detergent solubilization, skin pigmentation
MeSH terms
Catechol Oxidase, Humans, Immunochemistry, Infant, Newborn, Male, Melanins, Penis, Skin, Skin Pigmentation, Monophenol Monooxygenase, Tyrosine 3-Monooxygenase, Black People, White People

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