We investigated the dissociation of tetradecameric @entity11217 by high hydrostatic pressure in the range of 1-2.5 kbar. Kinetics of the dissociation of @entity11217 in the absence and presence of @entity1025 and/or @entity4338 were monitored using light scattering. All of the kinetics were biphasic in nature. At any given pressure, only monomers and 14mers were produced, and below 2.5 kbar, the 14mers only partially dissociated to monomers, which did not significantly reassemble on depressurization. Under identical reaction conditions, the observed dissociation rates decreased by only 2-fold when the concentration of @entity11217 was increased by 20-fold. At 2.5 kbar the observed rates decreased exponentially with the increase in @entity4338 and reached a minimum at approximately 75mM. Similarly, the rates decreased with the increase in [ @entity1025 ] and reached a minimum at approximately 3 mM @entity1025 . In the presence of saturating amounts of @entity1025 (10 mM) and @entity4338 (100 mM), the rates were much faster than with 10 mM @entity1025 alone. The results could be rationalized in terms of the presence of @entity11217 heterogeneity, which could not be assessed easily by common techniques such as sedimentation velocity, HPLC, gel electrophoresis, and dissociation by chaotropes. This heterogeneity is evidence of subpopulations of @entity11217 that dissociate at different pressures. At low pressures, the oligomer without added @entity1025 only partially dissociates to monomers, leading to an apparent plateau in the kinetics, whereas in the presence of @entity1025 the species are converted to a tighter @entity1025 -bound species, leading to a much slower dissociation process. The presence of @entity4338 in the sample also leads to similar heterogeneity.

Conformational heterogeneity is revealed in the dissociation of the oligomeric chaperonin XXXX by high hydrostatic pressure.

@entity4338 :: ('CHEBI:32588', 'Chemical') :: ['[KCl]', 'KCl'] @entity11217 :: ('3329', 'Gene') :: ['GroEL'] @entity1025 :: ('CHEBI:18420', 'Chemical') :: ['Mg(2+)']
@entity11217 :: (3329,Gene) :: ['GroEL']
