Matuz-Mares Deyamira, Flores-Herrera Oscar, Guerra-Sánchez Guadalupe, Romero-Aguilar Lucero, Vázquez-Meza Héctor, Matus-Ortega Genaro, Martínez Federico, Pardo Juan Pablo
Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Copilco, Cd. Universitaria, Coyoacán, Ciudad de México 04510, Mexico.
Laboratorio de Bioquímica y Biotecnología de Hongos, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Carpio y Plan de Ayala S/N, Miguel Hidalgo, Ciudad de México 11350, Mexico.
J Fungi (Basel). 2021 Jan 11;7(1):42. doi: 10.3390/jof7010042.
Respiratory supercomplexes are found in mitochondria of eukaryotic cells and some bacteria. A hypothetical role of these supercomplexes is electron channeling, which in principle should increase the respiratory chain efficiency and ATP synthesis. In addition to the four classic respiratory complexes and the ATP synthase, mitochondria contain three type II NADH dehydrogenases (NADH for reduced nicotinamide adenine dinucleotide) and the alternative oxidase. Changes in the composition of the respiratory supercomplexes due to energy requirements have been reported in certain organisms. In this study, we addressed the organization of the mitochondrial respiratory complexes in under diverse energy conditions. Supercomplexes were obtained by solubilization of mitochondria with digitonin and separated by blue native polyacrylamide gel electrophoresis (BN-PAGE). The molecular mass of supercomplexes and their probable stoichiometries were 1200 kDa (I:IV), 1400 kDa (I:III), 1600 kDa (I:III:IV), and 1800 kDa (I:III:IV). Concerning the ATP synthase, approximately half of the protein is present as a dimer and half as a monomer. The distribution of respiratory supercomplexes was the same in all growth conditions. We did not find evidence for the association of complex II and the alternative NADH dehydrogenases with other respiratory complexes.
呼吸超复合物存在于真核细胞和一些细菌的线粒体中。这些超复合物的一个假设作用是电子传递，原则上这应该会提高呼吸链效率和ATP合成。除了四种经典的呼吸复合物和ATP合酶外，线粒体还含有三种II型NADH脱氢酶（NADH即还原型烟酰胺腺嘌呤二核苷酸）和交替氧化酶。在某些生物体中，已经报道了由于能量需求导致的呼吸超复合物组成的变化。在本研究中，我们探讨了在不同能量条件下线粒体呼吸复合物的组织情况。通过用洋地黄皂苷溶解线粒体并通过蓝色天然聚丙烯酰胺凝胶电泳（BN-PAGE）进行分离来获得超复合物。超复合物的分子量及其可能的化学计量比分别为1200 kDa（I:IV）、1400 kDa（I:III）、1600 kDa（I:III:IV）和1800 kDa（I:III:IV）。关于ATP合酶，大约一半的蛋白质以二聚体形式存在，一半以单体形式存在。在所有生长条件下，呼吸超复合物的分布都是相同的。我们没有发现复合物II和交替NADH脱氢酶与其他呼吸复合物相关联的证据。
