Intramolecular electrostatic interactions accelerate hydrogen exchange in diketopiperazine relative to 2-piperidone
Intramolecular electrostatic interactions accelerate hydrogen exchange in diketopiperazine relative to 2-piperidone
复制标题
DOI：
10.1021/ja952892m
复制
发表时间：
1996-03-20
影响因子：
15
通讯作者：
Robertson, AD
中科院分区：
文献类型：
--
作者：
Forsyth, WR;Robertson, AD
用1H-1 NMR饱和转移和T-1实验研究了2.5-哌嗪二酮的酰胺氢交换速率（二酮哌嗪，DKP）和2-哌啶酮δ-戊内酰胺和DKP的特定酸催化交换速率常数（k（H））非常相似，但DKP在25 ℃下表现出约740倍的比碱催化速率常数（k（OH）），其接近扩散极限。DKP的速率常数大于从简单诱导效应所预期的。DKP的速率常数增加归因于涉及第二肽基团的静电相互作用。一般来说，交换数据和蛋白质结构的检查表明，这种静电相互作用可能对蛋白质中的氢交换有显着影响。
H-1 NMR saturation transfer and T-1 experiments were used to monitor the amide hydrogen exchange rates of 2.5-piperazinedione (diketopiperazine, DKP) and 2-piperidone (delta-valerolactam) in water, Specific acid-catalyzed exchange rate constants (k(H)) for delta-valerolactam and DKP are quite similar, but DKP exhibits an approximately 740-fold larger specific base-catalyzed rate constant (k(OH)) at 25 degrees C, which approaches the diffusion limit, The rate constants for DKP are larger than expected from simple inductive effects. The enhanced rate constants for DKP an attributed to electrostatic interactions involving the second peptide group. In general, the exchange data and inspection of protein structures suggest that such electrostatic interactions may have significant effects on hydrogen exchange in proteins.