FEBS Letters | |
Binding of TNP‐ATP and TNP‐ADP to the non‐catalytic sites of Escherichia coli F1‐ATPase | |
Senior, Alan E1  Weber, Joachim1  | |
[1] University of Rochester Medical Center, Department of Biochemistry and Biophysics, Box 712, Rochester, NY 14642, USA | |
关键词: Oxidative phosphorylation; F1-ATPase; Nucleotide binding site; TNP-ATP or TNP-ADP; 2′; 3′-O-(2; 4; 6-trinitrophenyl)adenosine 5′-triphosphate or -diphosphate; respectively; | |
DOI : 10.1016/S0014-5793(97)00773-4 | |
学科分类:生物化学/生物物理 | |
来源: John Wiley & Sons Ltd. | |
【 摘 要 】
Using site-directed-tryptophan fluorescence, parameters for equilibrium binding of (Mg)TNP-ATP and (Mg)TNP-ADP to non-catalytic sites of Escherichia coli F1-ATPase were determined. All three non-catalytic sites showed the same affinity for MgTNP-ATP (K d=0.2 μM) or MgTNP-ADP (K d=6.5 μM) whereas even at concentrations of 100 μM no binding of uncomplexed TNP-ATP or TNP-ADP was observed. The results demonstrate that the three non-catalytic sites bind TNP-nucleotides non-cooperatively, and emphasize the importance of Mg2+ for non-catalytic-site nucleotide binding. Parameters for binding of (Mg)TNP-ADP to the three catalytic sites were also determined, and showed marked cooperativity. This work completes the set of thermodynamic parameters for equilibrium binding of (Mg)TNP-ATP and (Mg)TNP-ADP to all six nucleotide sites of F1, providing essential information to fully exploit the potential of these nucleotide analogs in studies of F1-ATPase.
【 授权许可】
Unknown
【 预 览 】
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RO201912020304658ZK.pdf | 476KB | download |