Mukherjee Madhumita, Zhu Xianchun, Ogawa Michael Y
Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, OH 43403, USA.
Inorg Chem. 2008 Jun 2;47(11):4430-2. doi: 10.1021/ic702370k. Epub 2008 Apr 29.
A two-stranded alpha-helical coiled coil was prepared having a Cys 4 metal-binding site within its hydrophobic interior. The addition of Cd2+ results in the incorporation of 2 equiv of metal ion, which is accompanied by a conformational change of the peptide, as observed by circular dichroism (CD) spectroscopy. Isothermal titration calorimetry (ITC) shows that the addition of Cd2+ is accompanied by two thermodynamic events. A comparison of the time dependence of the ITC behavior with those of the UV absorption and CD behavior allows the assignment of these events to a preliminary endothermic metal-binding step followed by a slower exothermic conformational change.
制备了一种双链α-螺旋卷曲螺旋,其疏水内部含有一个半胱氨酸4金属结合位点。加入Cd2+会导致2当量金属离子的掺入,同时肽发生构象变化,这可通过圆二色性(CD)光谱观察到。等温滴定量热法(ITC)表明,加入Cd2+伴随着两个热力学事件。将ITC行为的时间依赖性与紫外吸收和CD行为的时间依赖性进行比较,可以将这些事件归因于一个初步的吸热金属结合步骤,随后是一个较慢的放热构象变化。