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Updated: Jul 18, 2026

Pull-down of Calmodulin-binding Proteins
Published on: January 23, 2012
Calmodulin, conformational states, and calcium signaling. A single-molecule perspective
1Department of Chemistry, 1251 Wescoe Drive, University of Kansas, Lawrence, Kansas 66045-7582, USA. ckjohnson@ku.edu
Abstract:
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.
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