Institute for Physical and Theoretical Chemistry, Cluster of Excellence Frankfurt Macromolecular Complexes, Centre for Membrane Proteomics, Goethe-Universität, Max-von-Laue Str. 7, 60438 Frankfurt am Main, Germany.
Phys Chem Chem Phys. 2010 Nov 7;12(41):13375-82. doi: 10.1039/c0cp00733a. Epub 2010 Aug 27.
Mass spectrometry of membrane protein complexes is still a methodological challenge due to hydrophobic and hydrophilic parts of the species and the fact that all subunits are bound non-covalently together. The present study with the novel laser induced liquid bead ion desorption mass spectrometry (LILBID-MS) reports on the determination of the subunit composition of the F(1)F(o)-ATP synthase from Bacillus pseudofirmus OF4, that of both bovine heart and, for the first time, of human heart mitochondrial F(1)F(o)-ATP synthases. Under selected buffer conditions the mass of the intact F(1)F(o)-ATP synthase of B. pseudofirmus OF4 could be measured, allowing the analysis of complex subunit stoichiometry. The agreement with theoretical masses derived from sequence databases is very good. A comparison of the ATP synthase subunit composition of 5 different ATPases reveals differences in the complexity of eukaryotic and bacterial ATP synthases. However, whereas the overall construction of eukaryotic enzymes is more complex than the bacterial ones, functionally important subunits are conserved among all ATPases.
由于膜蛋白复合物的疏水性和亲水性部分以及所有亚基都是非共价结合在一起的，因此其质谱分析仍然是一个方法学上的挑战。本研究采用新型激光诱导液珠离子解吸质谱（LILBID-MS）报告了来自芽孢杆菌属假丝酵母 OF4 的 F(1)F(o)-ATP 合酶的亚基组成，这是牛心和人心脏线粒体 F(1)F(o)-ATP 合酶的首次报道。在选择的缓冲条件下，可以测量完整的芽孢杆菌属假丝酵母 OF4 的 F(1)F(o)-ATP 合酶的质量，从而分析复合物亚基的比例。与序列数据库中理论质量的吻合度非常好。对 5 种不同 ATP 酶的 ATP 合酶亚基组成的比较揭示了真核生物和细菌 ATP 酶的复杂性差异。然而，尽管真核酶的整体结构比细菌酶更复杂，但所有 ATP 酶中都保守了功能重要的亚基。
