Johnson Carey K
Department of Chemistry, 1251 Wescoe Drive, University of Kansas, Lawrence, Kansas 66045-7582, USA.
Biochemistry. 2006 Dec 5;45(48):14233-46. doi: 10.1021/bi061058e.
Single-molecule fluorescence measurements can provide a new perspective on the conformations, dynamics, and interactions of proteins. Recent examples are described illustrating the application of single-molecule fluorescence spectroscopy to calcium signaling proteins with an emphasis on the new information available in single-molecule fluorescence burst measurements, resonance energy transfer, and polarization modulation methods. Calcium signaling pathways are crucial in many cellular processes. The calcium binding protein calmodulin (CaM) serves as a molecular switch to regulate a network of calcium signaling pathways. Single-molecule spectroscopic methods can yield insights into conformations and dynamics of CaM and CaM-regulated proteins. Examples include studies of the conformations and dynamics of CaM, binding of target peptides, and interaction with the plasma-membrane Ca2+ pump. Single-molecule resonance energy transfer measurements revealed conformational substates of CaM, and single-molecule polarization modulation spectroscopy was used to probe interactions between CaM and the plasma-membrane Ca2+-ATPase.
单分子荧光测量能够为蛋白质的构象、动力学及相互作用提供新的视角。本文描述了近期的一些实例，阐述了单分子荧光光谱在钙信号蛋白研究中的应用，重点介绍了单分子荧光猝发测量、共振能量转移和偏振调制方法所提供的新信息。钙信号通路在许多细胞过程中至关重要。钙结合蛋白钙调蛋白（CaM）作为分子开关，调控着一系列钙信号通路网络。单分子光谱方法能够深入了解CaM及受CaM调控的蛋白质的构象和动力学。实例包括对CaM的构象和动力学、靶肽结合以及与质膜Ca2+泵相互作用的研究。单分子共振能量转移测量揭示了CaM的构象亚态，单分子偏振调制光谱则用于探测CaM与质膜Ca2+-ATP酶之间的相互作用。
