Saeki Y, Sakakibara Y, Araki Y, Yanagisawa K, Suiko M, Nakajima H, Liu M C
Department of Biochemistry, The University of Texas Health Center, Tyler, TX 75710, USA.
J Biochem. 1998 Jul;124(1):55-64. doi: 10.1093/oxfordjournals.jbchem.a022097.
A mouse liver homogenate was shown to contain enzymatic activities catalyzing the sulfation of 3,4-dihydroxyphenylalanine (Dopa) and tyrosine isomers with a pH optimum of 8.25. Western blot analysis revealed a 34 kDa protein exhibiting immunologic cross-reactivity to antiserum against rat liver SULT1B1 sulfotransferase. By employing the reverse transcriptase-polymerase chain reaction (RT-PCR) technique, a 910-base pair product encoding the putative mouse liver SULT1B1 sulfotransferase was obtained. Using this PCR product as a probe, a cDNA containing the entire open reading frame of the mouse liver SULT1B1 sulfotransferase was cloned from a mouse liver Lambda ZAP cDNA library. The nucleotide sequence indicated it is a new enzyme. The deduced amino acid sequence exhibited 87.6, 72.3, 55.9, 54.2, 52.8, 51.1, and 49.4% identity to the amino acid sequences of the rat liver SULT1B1 sulfotransferase, human thyroid hormone sulfotransferase, mouse phenol sulfotransferase, rat liver phenol sulfotransferase, rat liver hydroxyarylamine sulfotransferase, mouse estrogen sulfotransferase, and rat estrogen sulfotransferase. Upon transfection of COS-7 cells with an expression vector (pcDNA3) harboring the cDNA encoding this new enzyme, a 34 kDa protein exhibiting immunologic cross-reactivity to antiserum against the rat liver SULT1B1 sulfotransferase was expressed. The recombinant sulfotransferase exhibited enzymatic activities toward Dopa and tyrosine isomers, as well as dopamine and 3,3',5-triiodo-L-thyronine. Northern blot analyses indicated the SULT1B1 sulfotransferase was predominantly expressed in liver, but not in the other ten mouse organs examined. Furthermore, the enzyme was found to be expressed in a developmental stage-dependent manner, being at a very low level in liver samples from 1-day-old mice and then gradually increasing to the maximum level in liver samples from 4-week-old mice.
已证明小鼠肝脏匀浆含有催化3,4 - 二羟基苯丙氨酸（多巴）和酪氨酸异构体硫酸化的酶活性，最适pH为8.25。蛋白质免疫印迹分析显示，一种34 kDa的蛋白质与抗大鼠肝脏SULT1B1磺基转移酶的抗血清具有免疫交叉反应性。通过采用逆转录聚合酶链反应（RT-PCR）技术，获得了一个编码假定的小鼠肝脏SULT1B1磺基转移酶的910个碱基对的产物。使用该PCR产物作为探针，从小鼠肝脏Lambda ZAP cDNA文库中克隆出一个包含小鼠肝脏SULT1B1磺基转移酶完整开放阅读框的cDNA。核苷酸序列表明它是一种新酶。推导的氨基酸序列与大鼠肝脏SULT1B1磺基转移酶、人甲状腺激素磺基转移酶、小鼠酚磺基转移酶、大鼠肝脏酚磺基转移酶、大鼠肝脏羟基芳胺磺基转移酶、小鼠雌激素磺基转移酶和大鼠雌激素磺基转移酶的氨基酸序列具有87.6%、72.3%、55.9%、54.2%、52.8%、51.1%和49.4%的同一性。用携带编码这种新酶的cDNA的表达载体（pcDNA3）转染COS-7细胞后，表达出一种与抗大鼠肝脏SULT1B1磺基转移酶的抗血清具有免疫交叉反应性的34 kDa蛋白质。重组磺基转移酶对多巴和酪氨酸异构体以及多巴胺和3,3',5 - 三碘-L - 甲状腺原氨酸表现出酶活性。Northern印迹分析表明，SULT1B1磺基转移酶主要在肝脏中表达，而在所检测的其他十个小鼠器官中不表达。此外，发现该酶以发育阶段依赖性方式表达，在1日龄小鼠的肝脏样本中水平非常低，然后在4周龄小鼠的肝脏样本中逐渐增加到最高水平。
