Putting the Squeeze on
Biology:
Biomolecules Under
Pressure
Modest
pressures encountered in the biosphere (i.e., below a few kbar) have
extraordinary effects on biomembranes and proteins. These include pressure
denaturation of proteins, dramatic changes in protein-protein association,
substrate binding, membrane ion transport, DNA transcription, virus
infectivity, and enzyme kinetics. Yet all of the biomaterials involved are
highly incompressible. The challenge to the physicist is to understand the
structural coupling between these effects and pressure to elucidate the
relevant mechanisms. X-ray diffraction studies of membranes and proteins under
pressure will be described. It is seen that it is not so much the magnitude of
the changes, but rather the differential compressibilities of different parts
of the structure that are responsible for effects.