Boyce Thompson Institute for Plant Research, Inc., 1086 North Broadway, Yonkers, New York 19701.
Plant Physiol. 1978 Nov;62(5):718-22. doi: 10.1104/pp.62.5.718.
The development of methods of preparation of long wavelength ultraviolet light capable of activating ribulose bisphosphate carboxylase is reported. This preparation was obtained from tobacco (Nicotiana tabacum) leaves which had reached about one-half maximum leaf weight. It was prepared at low ionic strength by use of mixed anion and cation exchange resins and buffers containing dimethylsulfoxide. The preparation is greatly enriched in fraction I protein to the point of apparent homogeneity. When assayed in the presence of saturating ribulose bisphosphate and sodium bicarbonate, the rate of carbon fixation is a linear function of long wavelength ultraviolet irradiation in the range of 20,000 to 30,000 ergs per square centimeter per second. Glutathione (5 mm) inhibits light activation without affecting activity in the dark. Copper sulfate inhibits both light and dark activity, but is slightly less effective in the presence of ultraviolet light. Sucrose inhibition of carboxylation is only readily apparent in the absence of ultraviolet light. Ammonium sulfate precipitation followed by solubilization in buffers containing dimethylsulfoxide plus heat treatment promotes ultraviolet light activation.
本文报道了一种能激活核酮糖二磷酸羧化酶的长波紫外光制备方法的研究进展。该制备物是从达到半叶重一半的烟草（Nicotiana tabacum）叶片中提取的。它是在低盐离子强度下，使用混合阴离子和阳离子交换树脂以及含二甲基亚砜的缓冲液制备的。该制备物在 I 型蛋白方面得到了极大的富集，达到了明显的均一性。当在饱和核酮糖二磷酸和碳酸氢钠存在下进行测定时，在 20,000 至 30,000 埃每平方厘米每秒的长波紫外辐照范围内，碳固定的速率是线性的。谷胱甘肽（5 毫米）抑制光激活而不影响暗活性。硫酸铜抑制光和暗活性，但在紫外光存在下效果稍差。蔗糖对羧化作用的抑制作用只有在没有紫外光的情况下才容易显现。硫酸铵沉淀后，用含有二甲基亚砜的缓冲液溶解并进行热处理可促进紫外光激活。
