光声量热法测定辅酶B_(12)光解的焓变和体积变化  

Determination of Enthalpy and Volume Changes in Photolysis of Coenzyme B_(12) Using Photoacoustic Calorimetry

作　　者：李刚[1] 罗来斌[1] 陈慧兰[1] 傅少伟[2] 张淑仪[2] 

机构地区：[1]南京大学化学系配位化学国家重点实验室,南京210093 [2]南京大学声学研究所近代声学国家实验室,南京210093

出　　处：《物理化学学报》1998年第7期615-619,共5页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金

摘　　要：用时间分辨的光声量热法研究了浦防B12的光解反应，首次测定了脉冲激光诱导输酶B12光解反应的治变和反应体积变化，其值分别为131±12kJ·mol-1和6±1mL·mol-1，推测该反应体积变化可能与Co－C健断裂引起的柔性咕啉环构象变化有关．The photolysis of coenzyme B12 (5'-deoxyadenosylcobalamin, AdoCbl) at 355nm inaqueous solution is investigated by Photoacoustic Calorimetry (PAC). Both enthalpy and reactionvolume change for this photoinitiat,ed reaction have been determined to be 131±12 kJ.mol-1 and61 mL.mol-1 , respectively. It can be suggested that the reaction volume change is related tothe conformational change of corrin ring which accompanies the homolytic cleavage of the cobalt-carbon(Co-C) bond.

关 键 词：辅酶B12 光声量热 光解 脱氧腺苷钴胺素 

分 类 号：Q552.02[生物学—生物化学]