Bagramyan K A, Martirosov S M
Orbeli Institute of Physiology, Armenian Academy of Sciences, Yerevan, USSR.
FEBS Lett. 1989 Mar 27;246(1-2):149-52. doi: 10.1016/0014-5793(89)80272-8.
Hydrogen gas production was observed to occur during ATP-driven H+/K+ exchange in anaerobically grown E. coli. Neither process was found in aerobically grown cells or anaerobic cells grown on nitrate medium or when the osmotic pressure was decreased or K+ removed, or finally when DCCD, arsenate or CCCP was applied. Dithiothreitol restored the process even in the presence of CCCP but not in other cases of inhibition. A model of a multienzyme transport super-complex is proposed. The supercomplex consists of three genetically independent mechanisms: F0F1 H+-ATPase to provide energy, the K+-transporting Trk system as energy sink and formate-hydrogen lyase as donor of reducing equivalents. Within this supercomplex direct transduction of energy is accomplished via oxidation of 2 SH to S-S.
在厌氧生长的大肠杆菌中，观察到在ATP驱动的H⁺/K⁺交换过程中会产生氢气。在需氧生长的细胞、在硝酸盐培养基上生长的厌氧细胞中，或者当渗透压降低、K⁺被去除时，或者最后当应用二环己基碳二亚胺（DCCD）、砷酸盐或羰基氰化物间氯苯腙（CCCP）时，均未发现这两个过程。即使在存在CCCP的情况下，二硫苏糖醇也能恢复该过程，但在其他抑制情况下则不能。提出了一种多酶转运超复合物模型。该超复合物由三种遗传上独立的机制组成：提供能量的F₀F₁ H⁺-ATP酶、作为能量汇的K⁺转运Trk系统以及作为还原当量供体的甲酸-氢裂解酶。在这个超复合物中，能量的直接转导是通过将2个SH氧化为S-S来完成的。
