Mnatsakanyan Nelli, Poladian Anna, Bagramyan Karine, Trchounian Armen
Department of Biophysics of the Biological Faculty, Yerevan State University, Armenia.
Biochem Biophys Res Commun. 2003 Aug 29;308(3):655-9. doi: 10.1016/s0006-291x(03)01460-8.
The number of accessible SH-groups was determined in membrane vesicles prepared from Escherichia coli growing in fermentation conditions at slightly alkaline pH on glucose with or without added formate. Addition of ATP or formate to the vesicles caused a approximately 1.4-fold increase in the number of accessible SH-groups. The increase was inhibited by treatment with N-ethylmaleimide or the presence of the F(0)F(1)-ATPase inhibitors N,N(')-dicyclohexylcarbodiimide or sodium azide. The increase in accessible SH-groups was also absent in strains with the ATP synthase operon deleted or with the single F(0) domain cysteine Cysb21 changed to Ala. Using hyc and hyf mutants, it was shown that the increase was also largely dependent on hydrogenase 4 or hydrogenase 3, main components of formate hydrogen lyase, when bacteria were grown in the absence or presence of added formate. These results suggest a relationship between the F(0)F(1)-ATP synthase and hydrogenase 4 or hydrogenase 3 under fermentation conditions.
在由在微碱性pH值下于葡萄糖上进行发酵培养的大肠杆菌制备的膜囊泡中，测定了可及巯基的数量，培养条件为添加或不添加甲酸盐。向囊泡中添加ATP或甲酸盐会使可及巯基的数量增加约1.4倍。用N-乙基马来酰亚胺处理或存在F(0)F(1)-ATP酶抑制剂N,N'-二环己基碳二亚胺或叠氮化钠会抑制这种增加。在ATP合酶操纵子缺失的菌株或单个F(0)结构域半胱氨酸Cysb21突变为丙氨酸的菌株中，可及巯基也不会增加。利用hyc和hyf突变体表明，当细菌在添加或不添加甲酸盐的情况下生长时，这种增加在很大程度上也依赖于甲酸氢裂解酶的主要成分氢化酶4或氢化酶3。这些结果表明在发酵条件下F(0)F(1)-ATP合酶与氢化酶4或氢化酶3之间存在关联。
