Activity and NMR structure of synthetic peptides of the bovine ATPase inhibitor protein, IF₁

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• 作者：de Chiara ; Cesira ; Nicastro ; Giuseppe ; Spisni ; Alberto ; Zanotti ; Franco ; Cocco ; Tiziana ; Papa ; Sergio
• 关键词：CD ; circular dichroism ; DQF-COSY ; double quantum filtered correlation spectroscopy ; ESMP ; submitochondrial particles prepared in the presence of EDTA ; F_o ; membrane integral sector of the H⁺-ATP synthase ; F₁ ; catalytic sect
• 刊名：Peptides
• 出版年：2002
• 出版时间：December, 2002
• 年：2002
• 卷：23
• 期：1
• 页码：2127-2141
• 全文大小：341 K

文摘

The protein IF₁ is a natural inhibitor of the mitochondrial F_oF₁-ATPase. Many investigators have been prompted to identify the shortest segment of IF₁, retaining its native activity, for use in biomedical applications. Here, the activity of the synthetic peptides IF₁-(42–58) and IF₁-(22–46) is correlated to their structure and conformational plasticity determined by CD and [¹H]-NMR spectroscopy. Among all the IF₁ segments tested, IF₁-(42–58) exerts the most potent, pH and temperature dependent activity on the F_oF₁ complex. The results suggest that, due to its flexible structure, it can fold in helical and/or β-spiral arrangements that favor the binding to the F_oF₁ complex, where the native IF₁ binds. IF₁-(22–46), instead, as it adopts a rigid α-helical conformation, it inhibits ATP hydrolysis only in the soluble F₁ moiety.