Calmodulin protein dynamics

Gibrat, G., Blouquit, Y., Craescu, C.T., and Bellissent-Funel, M-C. (2008) Biophysical studies of thermal denaturation of calmodulin protein Dynamics, Biophysical Journal 95, 5247-5256... 

A novel pump-damp-probe method (PDPM), which allows the characterization of solvation dynamics of a fluorescence probe not only in excited but also in the ground states has been recently developed (Changenet-Barret, 2000 and references therein). In PDPM, a pump produces a nonequilibrium population of the probe excited, which, after media relaxation, is simulated back to the ground states. The solvent relaxation of the nonequlibrium ground state is probed by monitoring with absorption technique. The inramolecular protein dynamics in a solvent-inaccessible region of calmodulin labeled with coumarin 343 peptide was examined by PDPM. In the pump-dump-probe experiments, part of a series of laser output pulses was frequency-doubled and softer beams were used as the probe. The delay of the probe with respect to the pump was fixed at 500 ps. 

Yao, Y Squier, T.C. Variable conformation and dynamics of calmodulin complexed with peptides derived from the autoinhibitory domains of target proteins. Biochemistry 1996, 35, 6815-6827. 

Microfilaments of F actin traverse the microvilli in ordered bundles. The microfila-ments are attached to each other by actin-as-sociated proteins, particularly fimbrin and vil-lin. Calmodulin and a myosin-like ATPase connect the microfilaments laterally to the plasma membrane. Fodrin, another microfila-ment-associated protein, anchors the actin fibers to each other at the base, as well as attaching them to the cytoplasmic membrane and to a network of intermediate filaments. In this example, the microfilaments have a mainly static function. In other cases, actin is also involved in dynamic processes. These include muscle contraction (see p. 332), cell movement, phagocytosis by immune cells, the formation of microspikes and lamellipo-dia (cellular extensions), and the acrosomal process during the fusion of sperm with the egg cell. 

Figure 12.22 HPLC trace of a disulfide dynamic combinatorial library (a) with and (b) without addition of calmodulin. Dots indicate the peaks enhanced by the protein (Copyright Wiley VCH Verlag GmbH Co. KGaA. Reproduced by permission) (c) the chemical structure of the amplified ligand.

Libich, D.S, Hill, C.M, Bates, I.R, Hallett, F.R, Armstrong, S, Siemiarczuk, A and Harauz, G, 2003, Interaction of the 18.5-kD isofomi of myelin basic protein with Ca2-i--calmodulin effects of deimination assessed by intrinsic Trp fluorescence spectroscopy, dynamic light scattering, and circular dichroism. Protein Science 12, 1507-1521. 

FRET imaging can monitor dynamic interactions between a FRET donor (ECFP) and an acceptor (EYFP), which are fused to the protein of interest, in live cell experiments. As an example, we show the FRET changes of a fluorescent biosensor for Ca +, came-leon, using the spectral detector of the Zeiss LSM 510 META in a time-lapse imaging experiment. Cameleon is a chimeric protein that consists of ECFP, the calmodulin-binding peptide M13... 

Changenet-Barret, P., Choma, C.T., Gooding, E.F., De Grado, W.F., Hochstrasser, R.M. Ultrafast dielectric response of proteins from dynamic Stokes shifting of coumarin in calmodulin. J. Phys. Chem. B 104, 9322-9329 (2000)... 

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