摘要
采用密度泛函理论B3LYP方法研究了蛋白质和水环境下2-磷酸甘油酸脱水生成磷酸烯醇式丙酮酸的反应机理.优化得到了反应物、过渡态及产物的几何构型并计算了反应势垒.研究结果表明:没有H2O参与时,反应需要通过四元环过渡态完成,反应势垒高达287.7kJ/mol,常温下难以进行;有H2O参与时,反应可以通过六元环过渡态完成,反应势垒大为降低;Mg2+的参与可使反应势垒进一步降低;蛋白质环境下两个Mg2+和一个H2O的共同作用可使反应势垒降低至91.2kJ/mol,从而使反应在常温下容易进行.
The dehydration reaction mechanism of 2-phospho-D-glycerate to form phosphoenolpyruvate in water and protein environments were studied by the density function theory B3LYP method.The optimal structures of reactants,transition states and products were located at the B3LYP/6-31G＊ level of theory.The reaction barriers were then predicted at the B3LYP/6-311＋＋G（3df,2p） level of theory.The calculation results show that a high reaction barrier （287.7 kJ/mol） exists for the pathway in which no water molecule is involved;whereas the reaction barrier is lowered obviously for the pathway in which a water molecule is involved because of the formation of a six-membered ring transition state structure.The participation of the Mg2＋ ion can further lower the reaction barrier.Including two Mg2＋ ions and one water molecule can reduce the reaction barrier to 91.2 kJ/mol,indicating that a water molecule as well as Mg2＋ ions plays a very important role in the dehydration reaction of 2-phospho-D-glycerate.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2010年第21期2186-2190,共5页
Acta Chimica Sinica
基金
国家自然科学基金(Nos.20973088
20633050)
辽宁省高校创新团队基金(No.2007T091)资助项目
