Seftor R E, Bahr J T, Jensen R G
Department of Biochemistry and Plant Sciences, University of Arizona, Tucson, Arizona 85721.
Plant Physiol. 1986 Feb;80(2):599-600. doi: 10.1104/pp.80.2.599.
When the amount of activation of ribulose 1,5-bisphosphate carboxylase has been measured, two forms of the enzyme, not one, are actually determined experimentally. Only the enzyme-activator CO(2)-Mg(2+) form can bind ribulose bisphosphate for reaction with substrate CO(2) or O(2). A method is presented which measures only this catalytically active form by stabilizing it with ribulose bisphosphate just before dilution and assay in Mg(2+)-free reaction medium.
当测量1,5-二磷酸核酮糖羧化酶的激活量时，实际上通过实验确定的是该酶的两种形式，而非一种。只有酶-激活剂CO₂-Mg²⁺形式能够结合二磷酸核酮糖，以便与底物CO₂或O₂发生反应。本文介绍了一种方法，该方法通过在无Mg²⁺的反应介质中稀释和测定之前用二磷酸核酮糖稳定这种催化活性形式，从而仅测量这种催化活性形式。
