甘蔗中的糖分积累：载体介导的葡萄糖主动运输。
Sugar Accumulation in Sugarcane: Carrier-mediated Active Transport of Glucose.
作者信息
Gayler K R, Glasziou K T
机构信息
David North Plant Research Centre, C. S. R. Research Laboratories, Indooroopilly, Queensland, Australia 406.
出版信息
Plant Physiol. 1972 Apr;49(4):563-8. doi: 10.1104/pp.49.4.563.
The rate-limiting reaction for glucose uptake in storage tissue of sugarcane, Saccharum officinarum L., appears to be the movement of glucose across the boundary between the free space and the metabolic compartments. The mechanism for uptake of glucose across this boundary has been studied using 3-O-methyl glucose, an analogue of glucose which is not metabolized by sugar-cane tissue.This analogue is taken up by sugarcane storage tissue at a similar rate to glucose. Its rate of uptake follows Michaelis-Menten kinetics, Km = 1.9 mm, and it is competitively inhibited by glucose, Ki = 2 to 3 mm. Glucose uptake is similarly inhibited by 3-O-methyl glucose. Uptake of 3-O-methyl glucose is energy-dependent and does not appear to be the result of counterflow of glucose.It is concluded that glucose and 3-O-methyl glucose uptake across the boundary between the free space and the metabolic compartment in this tissue is mediated by an energy-dependent carrier system capable of accumulating the sugars against a concentration gradient.
甘蔗（Saccharum officinarum L.）贮藏组织中葡萄糖摄取的限速反应，似乎是葡萄糖跨越自由空间与代谢区室之间边界的移动。利用3 - O - 甲基葡萄糖研究了葡萄糖跨越该边界的摄取机制，3 - O - 甲基葡萄糖是一种葡萄糖类似物，甘蔗组织不能对其进行代谢。这种类似物被甘蔗贮藏组织摄取的速率与葡萄糖相似。其摄取速率符合米氏动力学，Km = 1.9 mM，并且它受到葡萄糖的竞争性抑制，Ki = 2至3 mM。葡萄糖摄取同样受到3 - O - 甲基葡萄糖的抑制。3 - O - 甲基葡萄糖的摄取是能量依赖性的，似乎不是葡萄糖逆流的结果。得出的结论是，该组织中葡萄糖和3 - O - 甲基葡萄糖跨越自由空间与代谢区室之间的边界是由一个能量依赖性载体系统介导的，该系统能够逆浓度梯度积累糖类。
Zotero 插件