title: Tyrosinase activity in human skin. Influence of race and age in newborns.
abstract: 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.
mesh_terms: D000367:Age Factors; D044383:Black People; D002374:Catalase; D002384:Catalysis; D004156:Catechol Oxidase / Q000032:analysis*; D006801:Humans; D006861:Hydrogen Peroxide; D007231:Infant, Newborn; D007700:Kinetics; D008297:Male; D012867:Skin / Q000201:enzymology*; D044465:White People
chemical_list: D006861:Hydrogen Peroxide; D004156:Catechol Oxidase; D002374:Catalase