Calmodulin, conformational states, and calcium signaling. A single-molecule perspective

Biochemistry. 2006 Dec 5;45(48):14233-46. doi: 10.1021/bi061058e.

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium / chemistry
  • Calcium / metabolism
  • Calcium Signaling*
  • Calcium-Transporting ATPases / metabolism
  • Calmodulin / chemistry*
  • Calmodulin / metabolism*
  • Molecular Conformation
  • Substrate Specificity

Substances

  • Calmodulin
  • Calcium-Transporting ATPases
  • Calcium