Abstract
Functional compatibility between the F1 and F0 parts of ATP synthases from Escherichia coli (EF1F0) and the thermophilic bacterium PS3 (TF1F0) was analyzed. F1-stripped everted membrane vesicles from both organisms bound the homologous or heterologous F1 part to the same extent. Titration of the reconstituted membrane vesicles with dicyclohexylcarbodiimide revealed a similar sensitivity of the homologous and hybrid F1F0 complexes towards the inhibitor. Furthermore, the heterologous enzymes exhibited ATP-dependent H+ translocation comparable to that of homologous F1F0. Antisera raised against EF1 or subunits a, b, and c of EF0 were analyzed for cross-reactivity with TF1 and TF0. Common antigenic sites have been detected with immunoblot analysis for subunit beta and subunit c of EF1F0 and the corresponding subunits from TF1F0. A weak binding of the anti-a and anti-b antisera with the TF0 part has been observed in an enzyme-linked immunosorbent assay. Based on these findings the structural and functional relationship between the mesophilic and thermophilic ATP synthase complexes is discussed.
Highlights
Ganisms bound the homologous or heterologousF, part TheATPsynthase of thethermophilicbacteriumPS3 to the same extent
Immunological studies with tural and functional relationship between the meso- antisera raised against componentsof the ATP synthasferom philic and thermophilic ATP synthase complexes is E. coli were carried out to detectpossible structural homolodiscussed
Preparative Procedures-Everted membrane vesicleswere prepared from E. coli K12 (30 g) as described in Ref. 7
Summary
Preparative Procedures-Everted membrane vesicleswere prepared from E. coli K12 (30 g) as described in Ref. 7. For removal of F, the membranes were washed in 30 ml of 10 mM Tris/SO4, pH 7.5, 10 mM EDTA, 10% (v/v) glycerol, and incubated overnight a t 4 “C (EFIFo) ( 5 ). It is composed of eight different subunits, the in 30 ml of 1mM Tris/Cl, pH 8.0,0.5 mM EDTA, 10% (v/v) glycerol. The phosphate liberated was determined by the continuous flow procedure described by Arnold et al [29].One unit of ATPase activity is defined as the release of 1 pmol of Pi X min" at 37 "C for EF, and 60 "C for TF,.
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