摘要
越来越多的证据表明,动物的甾类激素广泛存在于植物体内(Hewitt等1980,周永春和曹宗巽1982,王焕民和曹宗巽1986,Jones和Roddick 1988,Simons和Grinwich 1989,Zhang等1991a,b)。而这些激素对植物的生长发育也具有多方面的作用,如雌二醇可以促进多种植物开花,增加菠菜、女蒌菜等雌花比例;
Different fractions of extracts from etiolated mung bean hypocotyls were tested for estradiol binding. Among them, the 1000～10000×g fiaction was found to have stronger estradiol binding than other fractions (Table 1). The estradiol binding to 1000～10000×g fractions was saturated after incubation for 1h (Fig.1) The binding was temperature-dependent, showing a maximum at 4℃ (Fig. 2). In a relatively wide pH range of 5～8.5, the estradiol binding was stable and the optimal pH was 7.5 (Fig. 3). Trypsin treatment lowered the estradiol binding (Fig.4), indicating that estradiol binding sites were proteinousin nature. Some steroids other than estradiol could also bind to some extent to the estradiol binding sites (Table 2). By Scatehard analysis (Fig. 5 A, B), the number of estradiol binding sites was determined to be 29～108 fmol/mg protein and the dissociation constant (K_d) was 11～20 nmol/L (n=3)
基金
国家自然科学基金
关键词
雌二醇结合位点
绿豆下胚轴
estradiol binding sites
mung bean hypocotyl
