Jordan D B, Ogren W L
Arch Biochem Biophys. 1983 Dec;227(2):425-33. doi: 10.1016/0003-9861(83)90472-1.
Several kinetic parameters of ribulose-1,5-bisphosphate (RuBP) carboxylase/oxygenase from different species were measured and compared. The CO2/O2 specificity (VcKo/VoKc) was found to be about 80 in the enzymes from several C3 species and two C4 species. Specificity values of 58 and 70, respectively, were found in enzymes from the C4 plants Setaria italica and Sorghum bicolor. Two enzymes from cyanobacteria had values of about 50. Substitution of Mn2+ for Mg2+ reduced the CO2/O2 specificity by a factor of about 20 for all enzymes except that of Rhodospirillum rubrum, which was reduced by a factor of 10. Values for KMg2+(apparent) measured at 102 microM CO2 were found to vary by a factor of 8 between different RuBP carboxylase/oxygenase enzymes. Enzymes with high KMg2+(apparent) values generally had high Michaelis constants for CO2. The rate of CO2/Mg2+ activation was inhibited by RuBP in all enzymes, although the concentration of RuBP required to inhibit activation in the enzyme from the cyanobacterium Aphanizomenon flos-aquae was increased by an order of magnitude compared to other higher plant structural-type enzymes. The wide variation found in the kinetic properties of RuBP carboxylase/oxygenase isolated from diverse species appears to be determined in part by past evolutionary pressures and the present physicochemical environment in which the enzyme functions.
对来自不同物种的1,5 - 二磷酸核酮糖羧化酶/加氧酶（RuBP羧化酶/加氧酶）的几个动力学参数进行了测量和比较。发现几种C3物种和两种C4物种的酶中，CO2/O2特异性（VcKo/VoKc）约为80。在C4植物粟和高粱的酶中，特异性值分别为58和70。来自蓝细菌的两种酶的值约为50。除红螺菌外，用Mn2+替代Mg2+会使所有酶的CO2/O2特异性降低约20倍，红螺菌的特异性降低10倍。在102 microM CO2下测得的KMg2+(表观)值在不同的RuBP羧化酶/加氧酶之间相差8倍。KMg2+(表观)值高的酶通常对CO2具有高米氏常数。在所有酶中，RuBP均抑制CO2/Mg2+的活化速率，尽管与其他高等植物结构型酶相比，抑制蓝藻水华鱼腥藻中酶活化所需的RuBP浓度增加了一个数量级。从不同物种分离得到的RuBP羧化酶/加氧酶的动力学性质存在广泛差异，这似乎部分是由过去的进化压力和该酶发挥作用的当前物理化学环境所决定的。
