Gaudet S J, Slominski A, Etminan M, Pruski D, Paus R, Namboodiri M A
Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892.
J Invest Dermatol. 1993 Nov;101(5):660-5. doi: 10.1111/1523-1747.ep12371672.
Arylamine N-acetyltransferase (EC 2.3.1.5) activity was examined using skin from Syrian hamster. Two isozymes of arylamine N-acetyltransferase, designated NAT-1 and NAT-2, were detected on anion-exchange high-performance liquid chromatography analysis. Both enzyme activities had indistinguishable molecular masses (30 kDa), but differed significantly in their specificity toward the aromatic amines including serotonin, dopamine, methoxytryptamine, tryptamine, para-phenetidine, para-aminobenzoic acid, and sulphamethazine. Specifically, NAT-2 but not NAT-1 catalyzed acetylation of dopamine to N-acetyldopamine and acetylation of serotonin to form N-acetylserotonin, a direct precursor of melatonin. The two isozymes were also distinguishable based upon their sensitivity toward methotrexate inhibition (50% inhibiting dose for NAT-1 = 380 microM; NAT-2 > 2 mM). The presence of these two activities in the skin raises new questions about the physiologic role of this enzyme in general and in the skin-specific functions in particular.
使用叙利亚仓鼠的皮肤检测芳胺N - 乙酰基转移酶（EC 2.3.1.5）活性。通过阴离子交换高效液相色谱分析检测到芳胺N - 乙酰基转移酶的两种同工酶，分别命名为NAT - 1和NAT - 2。两种酶活性的分子量无法区分（30 kDa），但它们对包括血清素、多巴胺、甲氧基色胺、色胺、对乙氧基苯胺、对氨基苯甲酸和磺胺二甲嘧啶在内的芳香胺的特异性有显著差异。具体而言，NAT - 2而非NAT - 1催化多巴胺乙酰化为N - 乙酰多巴胺，并催化血清素乙酰化形成N - 乙酰血清素，即褪黑素的直接前体。这两种同工酶对甲氨蝶呤抑制的敏感性也有所不同（NAT - 1的50%抑制剂量 = 380 microM；NAT - 2 > 2 mM）。皮肤中这两种活性的存在引发了关于该酶一般生理作用，尤其是皮肤特定功能方面生理作用的新问题。
