Influence of the protonation degree on the self-association properties of adenosine 5'-triphosphate (ATP).
Influence of the protonation degree on the self-association properties of adenosine 5'-triphosphate (ATP).
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质子化程度对 5-三磷酸腺苷 (ATP) 自缔合特性的影响。
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
H. Sigel
中科院分区：
文献类型：
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作者：
R. Tribolet;H. Sigel
ATP 质子 H-2、H-8 和 H-1' 的化学位移的浓度依赖性已在 27°C 的 D2O 中测量，在 pD 范围为 1.5 至 8.4 的多个质子化度下进行测量。 pD 大于 4.5 时的结果与无限期非合作堆叠的等线模型一致，而 pD 小于 4.5 时的结果表明倾向于形成二聚体堆叠。堆积趋势遵循该系列，ATP4- (K = 1.3 M-1) 小于 D(ATP)3- (2.1 M-1) 小于 D(ATP)3-/D2(ATP)-2- (6.0 M-1) 的 1:1 比率，远小于 D2(ATP)2-（约 200 M-1） 远大于 D3(ATP)-（K 约小于 17 M-1）（对于比较的原因所有常数均在等脉模型中表达）。这些结果与腺苷 [Ado (K = 15 M-1) 大于 1:1 比率 Ado/D(Ado)+ (6.0 M-1) 大于 D(Ado)+ (0.9 M-1)] 和 AMP [AMP2- (K = 2.1 M-1) 小于 D(AMP)- (3.4 M-1) 小于 1:1 比率的数据进行比较D(AMP)-/D2(AMP) +/- (5.6 M-1) 大于 D2(AMP) +/-（约等于 2 M-1）大于 D3(AMP)+（K 小于或等于 1 M-1）] 以便于解释 ATP 系统的结果。额外的离子相互作用显然有利于 H2(ATP)2- 的堆叠形成；通过电位 pH 滴定测量含有不同浓度 ATP 的溶液中 H2(ATP)2- 的酸度常数，可以证实这一点。建议在[H2(ATP)]4-(2)二聚体中，一个H2(ATP)2-的H+(N-1)位点和另一个H2(OH)(O)-2基团之间形成分子间离子对(和氢键)；通过这种方式，（a）堆栈进一步稳定，（b）腺嘌呤残基处的正电荷得到补偿（否则会发生排斥，从腺苷系统可以明显看出）。提出了 [H2(ATP)4-(2) 二聚体的详细结构，并指出了所描述的 ATP 堆积特性对生物系统的一些影响。
The concentration dependence of the chemical shifts for the protons H-2, H-8 and H-1' of ATP has been measured in D2O at 27 degrees C under several degrees of protonation in the pD range from 1.5 to 8.4. The results at pD greater than 4.5 are consistent with the isodesmic model of indefinite noncooperative stacking, while those at pD less than 4.5 indicate a preference for the formation of dimeric stacks. The stacking tendency follows the series, ATP4- (K = 1.3 M-1) less than D(ATP)3- (2.1 M-1) less than 1:1 ratio of D(ATP)3-/D2(ATP)-2- (6.0 M-1) much less than D2(ATP)2- (approximately 200 M-1) much greater than D3(ATP)- (K approximately less than 17 M-1) (for reasons of comparison all constants are expressed in the isodesmic model). These results are compared with previous data for adenosine [Ado (K = 15 M-1) greater than 1:1 ratio of Ado/D(Ado)+ (6.0 M-1) greater than D(Ado)+ (0.9 M-1)] and AMP [AMP2- (K = 2.1 M-1) less than D(AMP)- (3.4 M-1) less than 1:1 ratio of D(AMP)-/D2(AMP) +/- (5.6 M-1) greater than D2(AMP) +/- (approximately equal to 2 M-1) greater than D3(AMP)+ (K less than or equal to 1 M-1)] to facilitate the interpretation of the results for the ATP systems. Stack formation of H2(ATP)2- is clearly favored by additional ionic interactions; this is confirmed by measuring via potentiometric pH titrations the acidity constants of H2(ATP)2- in solutions containing different concentrations of ATP. It is suggested that in the [H2(ATP)]4-(2) dimer intermolecular ion pairs (and hydrogen bonds) are formed between the H+(N-1) site of one H2(ATP)2- and the gamma-P(OH)(O)-2 group of the other; in this way (a) the stack is further stabilized, and (b) the positive charges at the adenine residues are compensated (otherwise repulsion would occur as is evident from the adenosine systems). A detailed structure for the [H2(ATP)4-(2) dimer is proposed and some implications of the described stacking properties of ATP for biological systems are indicated.
影响因子：
5.6
作者：
D. Rees
通讯作者：
D. Rees