Saksela M, Raivio K O
Children's Hospital, University of Helsinki, Helsinki, Finland.
Biochem J. 1996 Apr 1;315 ( Pt 1)(Pt 1):235-9. doi: 10.1042/bj3150235.
To study the expression of human xanthine dehydrogenase/oxidase (hXDH/XO), we cloned the cDNA covering its complete coding sequence and characterized it by translation in vitro in rabbit reticulocyte lysates and by transient expression in COS-1 cells. Two specific protein products with approximate molecular masses of 150 and 130 kDa were detected in both expression systems. These products are compatible with the molecular sizes of XDH/XO, and these peptides also showed immunoreactivity with polyclonal anti-hXDH antibodies. Significant XDH/XO enzyme activity (277 +/- 54 pmol/min per mg of protein) was measured in lysates of transfected COS cells, whereas in control transfections the activities were below the detection limit of our assay (0.2 pmol/min per mg of protein). The COS cells expressed the enzyme predominantly (89.8 +/- 0.3%) in the dehydrogenase form.
为研究人黄嘌呤脱氢酶/氧化酶（hXDH/XO）的表达，我们克隆了覆盖其完整编码序列的cDNA，并通过在兔网织红细胞裂解物中进行体外翻译以及在COS-1细胞中进行瞬时表达来对其进行表征。在两种表达系统中均检测到两种分子量约为150 kDa和130 kDa的特异性蛋白质产物。这些产物与XDH/XO的分子大小相符，并且这些肽也显示出与多克隆抗hXDH抗体的免疫反应性。在转染的COS细胞裂解物中测得显著的XDH/XO酶活性（每毫克蛋白质277±54 pmol/分钟），而在对照转染中，活性低于我们测定的检测限（每毫克蛋白质0.2 pmol/分钟）。COS细胞主要以脱氢酶形式表达该酶（89.8±0.3%）。
