INTERNATIONAL INSTITUTE
OF BIOPHYSICS
Conference
on Biophotons 1999
Abstracts of the Conference Reports in
alphabetic Order
THE LOW FREQUENCY COHERENT ACTIVITY IN LIVING CELLS
V.P.Tychinsky*, T. Vyshenskaja, and D. G. Weiss+
*Moscow State Institute for Radioengineering, Electronics and Automation,
Vernadskii Pr. 78, Moscow 117454, Russia, Moscow State University, Phys.
Dpt.
+Institute of Cell Physiology and Cellular Biosystems, and Light Microscopy
Centre, University of Rostock, Universitatsplatz 2, D-18051 Rostock, Germany
Co-operative processes have been suggested to be the physical grounds
that profoundly influence space-temporal organization of cellular function.
The degree of its general occurrence and the characteristics of such cooperativity
are however poorly understood. Despite improvements in the resolution and
sensitivity of commonly used DIC and fluorescence microscopy direct measurements
of enzyme dynamics are not possible. Since ATPase function implicates conformational
changes it is to be expected that these are accompanied by the changes
of refractive index. Changes of refractive index when resulting from a
sufficiently large number of molecules lead to detectable and space-temporally
correlated changes of local Optical Path Difference (OPD). The OPD changes
are measured with a novel method, Dynamic Phase Microscopy (DPM), providing
spatial resolution up to 100 nm and temporal resolution of tens of milliseconds.
Using this technique the co-operative activity of F1F0 ATPase complexes
incorporated into liposomes was studied. The OPD fluctuations were measured
with DPM when liposome aggregate were exposed to 1 mM ATP. The conformational
transitions in ensembles of interacting ATPase molecules resulted in a
specific type of synchronization of their movement and yielded locally
restricted changes of refractive index and OPD. These and numerous measurements
on blood cells, fibroblasts, neurons and other cellular and subcellular
specimens showing similar co-operative effects led us to propose that the
coherent states and co-operative processes are a common feature of living
cells that can be adequately studied by DPM.
© International
Institute of Biophysics 2001 E-mail: iib@lifescientists.de
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