摘要
以小麦品种中国春（Triticum aestivum）为材料，分析了颗粒结合淀粉合成酶（GBSS）与淀粉颗粒结合的影响因素及作用力。通过SDS-PAGE及测定GBSS溶液浓度，证实小麦GBSS与淀粉粒结合的紧密程度受温度影响，在50-80℃范围内，GBSS从淀粉颗粒上的解离量随温度的升高逐渐升高；而在85-95℃之间，解离量随温度的升高而降低；沸水浴处理15min的GBSS解离量较大，但超过35min时GBSS的量反而有所减少。Mg^2＋浓度也影响GBSS的解离，低于1．75mmol L^-1时，随Mg^2＋浓度降低解离量逐渐升高；高于2．5mmol L^-1时，随Mg^2＋浓度的升高解离量逐渐降低。表明GBSS与淀粉粒的结合力是非共价键。
The factors affecting the binding characteristics of GBSS with starch granule were studied using a wheat （Triticum aestivum ） cultivar Chinese Spring with different temperature treatments. Mter sodium dodecyl sulfate polyacrylamide gel electrophoresis （SDS-PAGE） analysis, we got GBSS concentration by coomassie brilliant blue G-250 （CBB G-250） method. The results showed that the temperature affected the binding of GBSS and starch granule. In 50-80℃, the concentration of GBSS unbound from starch increased with the temperature rising, which the maximal concentration was 11.361 μg mL^-1 at 80℃, while that was reduced when the temperature was 85-95℃. Furthermore, Mg^2＋ could also affect the quantity of GBSS unbound from starch. When Mg^2＋ concentration was lower than 1.75 mmol L^- 1, the concentration of GBSS unbound increased. The lower Mg^2 ＋ concentration, the higher the concentration of GBSS unbound. However, when Mg^2＋ concentration was higher than 2.5 mmol L^-1, it could restrain GBSS unbinding. These results showed that GBSS bound starch granule by non-covalent bonds. The best GBSS extracting conditions were 55 mmol L^-1 Tris-HCl （pH 6.8）, 0.75 mmol L^-1 MgCl2, 2.3% SDS, 5% 2-ME and 10% glycerol, 15 min in boiling water, or 55 mmol L^-1Tris-HCl （pH6.8）, 0.75 mmol L^-1 MgCl2, 2.3% SDS, 5% 2-ME and 10% glycerol, 80℃ 30 min. The results are helpful to investigate 3-D structure of biological activated GBSS and mechanism of GBSS binding with starch granule.
出处
《作物学报》
CAS
CSCD
北大核心
2007年第2期322-326,共5页
Acta Agronomica Sinica
基金
山东省"三○"工程项目(2003-108)
