A polymorphism of the human tyrosinase gene is associated with temperature-sensitive enzymatic activity.
A polymorphism of the human tyrosinase gene is associated with temperature-sensitive enzymatic activity.
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发表时间：
1991-05
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通讯作者：
R. K. Tripathi;L. B. Giebel;K. Strunk;R. Spritz
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作者：
R. K. Tripathi;L. B. Giebel;K. Strunk;R. Spritz
我们已经确定了人类酪氨酸酶基因的一个共同的非病理多态性。在高加索人中，密码子402可以是CGA（精氨酸）[p = .85]或CAA（谷氨酰胺）[p = .15]。在美国黑人中也存在这种多态性，但在东方人群中未检测到密码子402 CAA（Gln）等位基因。在密码子402处谷氨酰胺取代精氨酸导致相应酪氨酸酶多肽的中度热不稳定性。与31 ℃相比，当细胞在37 ℃培养时，在用密码子402Gln酪氨酸酶cDNA转染的HeLa细胞中表达的酪氨酸酶酶活性降低约75%，而密码子402Arg酪氨酸酶的酶活性对温度不敏感。然而，酪氨酸酶密码子402的基因型与正常白种人的表观色素沉着表型无关。
We have identified a common nonpathological polymorphism of the human tyrosinase gene. In Caucasians codon 402 can be either CGA (arginine) [p = .85] or CAA (glutamine) [p = .15]. This polymorphism also occurs in American Blacks, but the codon 402CAA (Gln) allele was not detected in Oriental populations. The substitution of glutamine for arginine at codon 402 results in moderate thermoinstability of the corresponding tyrosinase polypeptide. Tyrosinase enzymatic activity expressed in HeLa cells transfected with a codon 402Gln tyrosinase cDNA is reduced by approximately 75 percent when cells are cultured at 37 degrees C as compared to 31 degrees C, whereas enzymatic activity of codon 402Arg tyrosinase is not temperature-sensitive. However, the genotype at codon 402 of tryosinase is not correlated with the apparent pigmentation phenotype in normal Caucasians.