Tyrosinase activity in human skin. Influence of race and age in newborns.

Tyrosinase has been measured in homogenates of foreskins from newborn babies. The tyrosine hydroxylation reaction is dependent upon 3,4-dihydroxyphenylalanine as a cosubstrate, and the Km for tyrosine is 0.15 mM, similar to the value observed for other mammalian tyrosinases. The mean enzyme activity for black babies (n = 169) is about two and one-fourth times that for white babies (n = 82). For white babies there is a significant correlation between age at circumcision and tyrosinase activity. For black babies this correlation becomes significant when four individuals with extremely high tyrosinase activities are omitted from the series.

[1]  M. Okun,et al.  Peroxidatic oxidation of tyrosine to melanin in supernatant of crude mouse melanoma homogenates. , 1974, The Biochemical journal.

[2]  B. Barisas,et al.  A proteolytically activated tyrosinase from frog epidermis. , 1974, The Journal of biological chemistry.

[3]  W. Chavin,et al.  Tyrosinase Activity in a Highly Pigmented Human Melanoma and in Negro Skin 1 , 1974, Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine.

[4]  W. C. Quevedo,et al.  Peroxidase, "protyrosinase," and the multiple forms of tyrosinase in mice. , 1973, The Yale journal of biology and medicine.

[5]  S. Pomerantz,et al.  Purification and properties of tyrosinase isoenzymes from hamster melanoma. , 1973, The Yale journal of biology and medicine.

[6]  V. Hearing.  Mammalian melanogenesis: tyrosinase versus peroxidase involvement, and activation mechanisms. , 1973, Archives of biochemistry and biophysics.

[7]  M. A. Everett,et al.  Skin color, melanin, and erythema. , 1973, Archives of dermatology.

[8]  W. C. Quevedo,et al.  Multiple forms of tyrosinase in rodents and lagomorphs with special reference to their genetic control in mice. , 1971, The Journal of experimental zoology.

[9]  J. Burnett.  The tyrosinases of mouse melanoma. Isolation and molecular properties. , 1971, The Journal of biological chemistry.

[10]  S. Pomerantz,et al.  Effects of beta-MSH, cortisol and ACTH on tyrosinase in the skin of newborn hamsters and mice. , 1970, Endocrinology.

[11]  S. Pomerantz.  L-Tyrosine-3, 5-3H Assay for Tyrosinase Development in Skin of Newborn Hamsters , 1969, Science.

[12]  H. Seiler,et al.  Multiple forms of tyrosinase from human melanoma. , 1969, The Journal of investigative dermatology.

[13]  E. Rittenhouse.  Genetic effects on fine structure and development of pigment granules in mouse hair bulb melanocytes: II. Thec andp loci, andddpp interaction , 1968 .

[14]  E. Rittenhouse.  Genetic effects on fine structure and development of pigment granules in mouse hair bulb melanocytes: II. Thec andp loci, andddpp interaction , 1968 .

[15]  S. Pomerantz.  The tyrosine hydroxylase activity of mammalian tyrosinase. , 1966, The Journal of biological chemistry.

[16]  S. Udenfriend,et al.  TYROSINE HYDROXYLASE. THE INITIAL STEP IN NOREPINEPHRINE BIOSYNTHESIS. , 1964, The Journal of biological chemistry.

[17]  G. Atfield,et al.  Analytical separations by highvoltage paper electrophoresis. Amino acids in protein hydrolysates. , 1961, The Biochemical journal.