Behne D, Kyriakopoulos A, Kalcklösch M, Weiss-Nowak C, Pfeifer H, Gessner H, Hammel C
Hahn-Meitner-Institut Berlin, Department Trace Elements in Health and Nutrition, Germany.
Biomed Environ Sci. 1997 Sep;10(2-3):340-5.
After labeling of rats in vivo with 75Se and protein separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis more than 25 Se-containing bands could be distinguished. Of those proteins which were detected only in certain compartments and might therefore have tissue-specific functions, two were chosen for detailed investigation. A 15 kDa-protein was found in the prostatic epithelium where it accounted for about two thirds of the protein-bound 75Se. It was mainly present in the cytosol but was not released into the prostatic secretion. After gel chromatography it was found in the fraction which contained proteins with molecular masses of about 300 kDa. Using two-dimensional electrophoresis a pI-value of about 4.5 was determined. In the testis a specific Se-containing 34 kDa-protein was observed which appeared after the onset of puberty. It was localized in the spermatid nuclei where it contained about 80% of the Se tracer present and was found to be bound to the DNA. After extraction it partly disintegrated into a 20 kDa-protein. Both compounds contain Se in the form of selenocysteine. The fact that their formation had priority over that of glutathione peroxidase during insufficient Se intake is an indication of their biological significance. Special interest in the prostatic epithelial selenoprotein derives from a possible inverse relationship between the Se status and the incidence of prostate cancer observed in epidemiological studies, whereas with the 34 kDa-selenoprotein its appearance during the condensation phase of the spermatid nuclei might suggest its participation in some processes of sperm maturation.
用75Se对大鼠进行体内标记，并通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳进行蛋白质分离后，可区分出25条以上含硒条带。在仅在某些特定区域检测到的、可能具有组织特异性功能的蛋白质中，选择了两种进行详细研究。在前列腺上皮中发现了一种15 kDa的蛋白质，它约占蛋白质结合75Se的三分之二。它主要存在于细胞质中，但不会释放到前列腺分泌物中。凝胶过滤后，它出现在含有分子量约为300 kDa蛋白质的组分中。通过二维电泳测定其pI值约为4.5。在睾丸中观察到一种特定的含硒34 kDa蛋白质，它在青春期开始后出现。它定位于精子细胞核中，其中含有约80%的硒示踪剂，并且发现它与DNA结合。提取后，它部分分解为一种20 kDa的蛋白质。这两种化合物都以硒代半胱氨酸的形式含有硒。在硒摄入不足时，它们的形成优先于谷胱甘肽过氧化物酶的形成，这一事实表明了它们的生物学意义。对前列腺上皮硒蛋白的特别关注源于在流行病学研究中观察到的硒状态与前列腺癌发病率之间可能存在的反比关系，而对于34 kDa硒蛋白，它在精子细胞核浓缩阶段的出现可能表明它参与了精子成熟的某些过程。
