Strieder G, Sperk G
Department of Pharmacology, University of Innsbruck, Austria.
J Neurochem. 1989 Aug;53(2):346-53. doi: 10.1111/j.1471-4159.1989.tb07341.x.
A high molecular weight somatostatin-immunoreactive polypeptide, presumably prosomatostatin, was purified from rat brain and characterized. Purification steps included extraction with 2 M acetic acid, precipitation of contaminating proteins at pH 6.5, Sephadex G-50 chromatography, immunoaffinity chromatography, and HPLC steps (size exclusion and reversed-phase HPLC). The protein was purified more than 30,000-fold. It is heat stable. Sodium dodecyl sulfate-gel electrophoresis and immunoblotting revealed one major immunoreactive band of approximately 13,000 molecular weight which roughly corresponds to the size of prosomatostatin as derived from its DNA sequence. Isoelectric focusing and two-dimensional sodium dodecyl sulfate-gel electrophoresis gave a single immunoreactive spot at a pI of 5.4. The polypeptide did not bind to concanavalin A or to wheat germ lectin columns, suggesting lack of N-glycosylation in the molecule. Regional distribution of prosomatostatin varied between 6%, 10%, and 18% of total immunoreactivity in the brainstem, cortical areas, and striatum, respectively.
从大鼠脑中纯化并鉴定了一种高分子量的生长抑素免疫反应性多肽，推测为前生长抑素。纯化步骤包括用2M乙酸提取、在pH 6.5下沉淀污染蛋白、Sephadex G - 50柱色谱、免疫亲和色谱以及HPLC步骤（尺寸排阻和反相HPLC）。该蛋白被纯化了30000多倍。它具有热稳定性。十二烷基硫酸钠 - 凝胶电泳和免疫印迹显示一条约13000分子量的主要免疫反应带，这大致与从其DNA序列推导的前生长抑素大小相对应。等电聚焦和二维十二烷基硫酸钠 - 凝胶电泳在pI为5.4处给出一个单一的免疫反应点。该多肽不与伴刀豆球蛋白A或麦胚凝集素柱结合，表明分子中缺乏N - 糖基化。前生长抑素在脑干、皮质区域和纹状体中的区域分布分别占总免疫反应性的6%、10%和18%。
