沙田柚花柱S-糖蛋白的纯化和N-端序列测定

以人工自花授粉3d后的沙田柚（Citrus grandis var.Shatinyu Hort.）花柱为材料，切取1/2部位处花柱组织，匀浆后，进行抽提和硫酸铵盐析，得到35%级分的蛋白质粗提液，此液经聚丙烯酰胺凝胶电泳检测，显示出9条蛋白质带；经ConA-Sepharose4B亲和柱层析，特异峰（S^#）仅显示1条蛋白质带，恰好是35%级分中近正极端的2种蛋白质中的一种最优势蛋白质；部分生化性质测定结果表明，该蛋白质为碱性糖蛋白，糖含量为9.2%，由2个亚基组成，相对分子质量分别为38.0ku,32.0ku,等电点分别约为7.5,7.2；生物活性测定结果表明，该蛋白质能抑制离体（in vitro)萌发自花花粉花管的生长；氨其酸序列分析表明，32.0ku组分N-端15个氨基酸序列与矮牵牛，花烟草等的N-端相应序列极相似。

PURIFICATION AND AMINO-TERMINAL SEQUENCING OF STYLE S-GLYCOPROTEINS IN CITRUS GRANDIS VAR.S HATINYU HORT.

Styles of Citrus grandis var.shatinyu Hort.were chosen asexperimental material,which grew in only three days through artifica l pollination of their own.About 1/2 style tissue was cut,and triturated as homo geneity.35% protenin solution was gained by use of abstraction and salting out.T he solution showed nine protein brands through PAGE.The solution showed only one protein brand (S＃ peak) through ConA-Sepharose 4B affinitive chromatography column which was one of the two exceptional puoteins.The experiments was done i n order to determine the S＃ peak protein's part biochemical natures.The results are:S＃ peak protein was basic glycoprotein,sugar accounting for 9.2%,and it was made up of two subunits through SDS-PAGE,whose molecular weight was 38.0ku,32 .0 ku and iso-electric point 7.5,7.2.The search in protein seguence databa se reveals that the amino-terminal sequence of this 32.0 ku glycopoly pept ide is similar with that of P.hybrida,N.alata,and L.peruvianum.In additi on,S＃ peak protein's biochemical activity was experimented.S＃ protein could restra in the growth of pollen tubes which germinated in vitro.