Fragmentation of chloroplast coupling factor in dependence of bound nucleotides Preparation of a reconstitutionally active form of subunit δ

FEBS Letters

Engelbrecht, S.¹  Junge, W.¹ 

[1] Abt. Biophysik, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, D-4500 Osnabrück, FRG

关键词: CF1;    Nucleotide content;    Phosphorylation;    Photosynthesis;    H +-ATPase;    CF0CF1;    chloroplast ATP synthase;    CF1;    chloroplast ATPase;    CF0;    chloroplast ATP synthase;    proton-conducting part;    CF1(-δ);    CF1 lacking the δ-subunit;    CF1(-ϵ);    CF1 lacking the ϵ-subunit;    CF1(-δϵ);    CF1 lacking the δ- and ϵ- subunits;    Mega 9;    N-(D-gluco-2;    3;    4;    5;    6-pentahydroxylhexyl)-N-methylnonanamide;   

DOI  :  10.1016/0014-5793(87)80244-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Previous studies on the ability of CF₁, fragments to reconstitute photophosphorylation in CF₁,-depleted thylakoids have shown that the degree of reconstitution was correlated with the presence of subunit δ in the fragment. This was taken as evidence that subunit δ was necessary for plugging the active proton channel CF₀ [(1986) Eur. J. Biochem. 160, 635–643]. We questioned whether or not δ alone had this ability. In order to obtain δ we investigated the role of bound nucleotides in the stability of CF₁. Starting from ammonium sulfate-precipitated CF₁, we found that a low content of bound ADP (1 mol ADP/mol CF₁) seemed to stabilize the β—δ interaction, while loosening the interaction between α,β and γ. By elution from an anion-exchange column in the presence of the nonionic surfactant Mega 9 we obtained β₃δ and CF₁(—δ) (both containing one ADP) or, after washing with alcohol/glycerol mixtures, β (nucleotide-free) and CF₁/CF₁(—ϵ). On the other hand, with a further 2 ADP and 2 ATP bound to CF₁, (after incubation with excess ATP) the α-β-γ interaction was stabilized in such a way that subunit δ alone could be isolated from the complex. Subunit δ, when isolated by this procedure and added back to CF₁-depleted thylakoids, reconstituted a high rate of photophosphorylation.

【 授权许可】

Unknown