High-pressure studies on the calcium-ion-sensitive fluorophore Fluo-4

ORAL

Abstract

Fluorescence-based methods for intracellular calcium ion sensing are well established at ambient pressure. Because calcium ions play a ubiquitous role in cellular signaling, extending techniques of intracellular calcium-sensing to high pressures would play an important role in understanding the large variety of piezophysiologic effects. Here, we characterize the intracellular calcium-ion-sensitive fluorophore Fluo-4 under hydrostatic pressures up to 500 atm (50 MPa). Using an EGTA/MOPS solution as a calcium-buffer reference, we investigate the pressure dependence of the reaction \textit{pK} and determine the thermodynamic volume change associated with the Fluo-4 calcium-binding reaction.

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Authors

  • William H. Rauckhorst

    Gothenburg University, Denison University, Bowling Green State University, NASA Glenn Research Center, Ohio Wesleyan University, Nitronex Corporation, 2305 Presidential Drive, Durham, NC, AFRL/MLPS, Wright-Patterson AFB, OH, Miami University, Ursinus College, Purdue University Calumet, GSI, Florida State University, Carnegie Mellon University, Dept. of Health Sciences, Cleveland State University, Physics Dept., Cleveland State University, University of Rochester, OMI College of Applied Science, University of Cincinnati, Davis and Elkins College, WV, Schlumberger-Doll, Korea Institute of Science and Technology, University of Cincinnati, Lock Haven University of Pennsylvania, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6372, Albion College, Albion, MI 49224, University of Toledo, Toledo, OH 43606, Youngstown State University, Joint Institute for Nuclear Research (Dubna), Naval Research Laboratory, ManTech SRS Technologies, Inc., Ecopulse, Inc., Army Research Laboratory, University of Surrey, The Ohio State University, Univ. Akron, Owens Community College, Toledo, OH

  • Paul Urayama

    Miami University