MSU-DOE Plant Research Laboratory and Biochemistry Department, Michigan State University, East Lansing, Michigan 48824.
Plant Physiol. 1989 Apr;89(4):1311-7. doi: 10.1104/pp.89.4.1311.
The higher plant mitochondrial electron transport chain contains, in addition to the cytochrome chain which terminates with cytochrome oxidase, an alternative pathway that terminates with an alternative oxidase. The alternative oxidase of Sauromatum guttatum Schott has recently been identified as a cluster of proteins with apparent M(r) of 37, 36, and 35 kilodaltons (kD). Monoclonal antibodies have now been prepared to these proteins and designated as AOA (binding all three proteins of the alternative oxidase cluster), AOU (binding the upper or 37 kD protein), and AOL (binding the lower or 36 and 35 kD proteins). All three antibodies bind to their respective alternative oxidase proteins whether the proteins are in their native or denatured states (as on protein blots). AOA and AOU inhibit alternative oxidase activity around 49%, whereas AOL inhibits activity only 14%. When coupled individually to Sepharose 4B, all three monoclonal resins were capable of retaining the entire cluster of alternative oxidase proteins, suggesting that these proteins are physically associated in some manner. The monoclonals were capable of binding similar mitochondrial proteins in a number of thermogenic and nonthermogenic species, indicating that they will be useful in characterizing and purifying the alternative oxidase of different systems. The ability of the monoclonal-Sepharose 4B resins to retain the cluster of previously identified alternative oxidase proteins, along with the inhibition of alternative oxidase activity by these monoclonals, supports the role of these proteins in constituting the alternative oxidase.
高等植物线粒体电子传递链除了含有细胞色素链，其末端为细胞色素氧化酶外，还有另一种末端为交替氧化酶的替代途径。最近已经确定 Sauromatum guttatum Schott 的交替氧化酶为一组具有明显 M(r) 37、36 和 35 千道尔顿 (kD) 的蛋白质。现在已经制备了针对这些蛋白质的单克隆抗体，并将其命名为 AOA（结合交替氧化酶簇的所有三种蛋白质）、AOU（结合上或 37 kD 蛋白质）和 AOL（结合下或 36 和 35 kD 蛋白质）。无论蛋白质处于天然状态还是变性状态（如在蛋白质印迹上），所有三种抗体都与各自的交替氧化酶蛋白结合。AOA 和 AOU 抑制交替氧化酶活性约 49%，而 AOL 仅抑制活性 14%。当单独偶联到 Sepharose 4B 上时，这三种单克隆树脂都能够保留整个交替氧化酶蛋白簇，表明这些蛋白质以某种方式在物理上相关。这些单克隆抗体能够结合许多产热和非产热物种中的类似线粒体蛋白，表明它们将在表征和纯化不同系统的交替氧化酶方面非常有用。单克隆-Sepharose 4B 树脂保留先前鉴定的交替氧化酶蛋白簇的能力，以及这些单克隆体对交替氧化酶活性的抑制作用，支持这些蛋白质构成交替氧化酶的作用。
