Synthesis, Structure, and Properties of MeSer1-Tentoxin, a New Cyclic Tetrapeptide Which Interacts Specifically with Chloroplast F1 H+-ATPase Differentiation of Inhibi

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• 作者：Eric Pinet ; Florine Cavelier ; Jean Verducci ; Guy Girault ; Laurence Dubart ; Francis Haraux ; Claude Sigalat ; and Franç ; ois André
• 刊名：Biochemistry
• 出版年：1996
• 出版时间：October 1, 1996
• 年：1996
• 卷：35
• 期：39
• 页码：12804 - 12811
• 全文大小：555K
• 年卷期：v.35,no.39(October 1, 1996)
• ISSN：1520-4995

文摘

A new tentoxin analogue, in which the L-methyl alanineresidue is substituted by L-methylserine,has been prepared following the synthetic pathway recently describedfor the synthesis of tentoxin [Cavelier,F., & Verducci, J. (1995) Tetrahedron Lett. 36,4425-4428]. Using two-dimensional homonuclearprotonnuclear magnetic resonance and structural analysis, we observed thatMeSer¹-tentoxin, like tentoxin, adoptsseveral conformations in aqueous solution and presents self-aggregativeproperties. This analogue wasfound to be conformationally similar to the natural toxin. Itshowed the same efficiency as tentoxin ininhibition of ATPase activity of the isolated chloroplastF₁ proton ATPase (CF₁) as well as ininhibitionof the ATP synthase activity of the membrane-bound enzyme(CF₀CF₁) in thylakoids andproteoliposomes.At concentrations above 10 mages/entities/mgr.gif">M, MeSer¹-tentoxin didnot reactivate CF₁ to a high extent, contrarytotentoxin. It appeared, however, to bind in the same way, since thereactivating effect of tentoxin wasinhibited by MeSer¹-tentoxin. These results show thatit is possible, using tentoxin analogues, to separateinhibitory and activating effects on the chloroplast ATPase, despitethe limited chemical difference betweenthe two toxins.