小麦叶绿体中细胞分裂素结合蛋白的特性  

Properties of a CTK-binding Protein from Wheat Chloroplasts

作　　者：张华敏 刘愚[1] 沈允钢[1] 

机构地区：[1]中国科学院上海植物生理研究所

出　　处：《植物生理学报（0257-4829)》1996年第1期27-32,共6页Acta Phytophysiologica Sinica

基　　金：国家自然科学重点基金;中国科学院重点基金

摘　　要：小麦叶绿体中的ＣＴＫ结合蛋白属热敏感蛋白，它与６－ＢＡ结合的最适温度约为２５℃；最适ｐＨ为８左右；在其蛋白分子上存在两类ＣＴＫ结合位点，高亲和力位点与６－ＢＡ结合的Ｋα值为１．１×１０－９ｍｏｌ／Ｌ，低亲和力位点的Ｋα值为９×１０－７ｍｏｌ／Ｌ；激动素、玉米素对６－ＢＡ的结合只有部分抑制作用，而ＡＢＡ、ＧＡ３、ＩＡＡ及腺嘌呤则无竞争作用。ＣＴＫ结合蛋白分子中的中性氨基酸含量很高，在中性介质中带弱负电。A CTK-binding protein from wheat chloroplasts was shown to be heat-labile (Fig. 1 ). It showed high binding activity to 6-BA by sedimentation method at 25℃ (Fig. 2) and pH 7￣ 8 (Fig. 3). Scatchard plot (Fig. 4 )showed two classes of binding sites in this CTK-binding protein, with Kαvalues of 1.1× 10-9 mol/L and 9 ×10-7 mol/L. Fig. 5 showed that the binding of 6-BA to this protein was partially inhibited by kinetin and zeatin, but not inhibited by ABA,GA, IAA and adenine. The amino acid composition of the CTK-binding protein indicated that it is rich in neutral amino acids and to have negative charge in a neutral medium.

关 键 词：小麦 叶绿体 细胞分裂素 结合蛋白 

分 类 号：S512.101[农业科学—作物学]