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Biochemistry - Biophysics - Chemistry - Ophthalmology


ßB1-Crystallin: Thermodynamic Profiles of Molecular Interactions
Published: Friday, January 06, 2012
Author: Monika B. Dolinska et al.

by Monika B. Dolinska, Paul T. Wingfield, Yuri V. Sergeev

Background

ß-Crystallins are structural proteins maintaining eye lens transparency and opacification. Previous work demonstrated that dimerization of both ßA3 and ßB2 crystallins (ßA3 and ßB2) involves endothermic enthalpy of association (~8 kcal/mol) mediated by hydrophobic interactions.

Methodology/Principal Findings

Thermodynamic profiles of the associations of dimeric ßA3 and ßB1 and tetrameric ßB1/ßA3 were measured using sedimentation equilibrium. The homo- and heteromolecular associations of ßB1 crystallin are dominated by exothermic enthalpy (-13.3 and -24.5 kcal/mol, respectively).

Conclusions/Significance

Global thermodynamics of ßB1 interactions suggest a role in the formation of stable protein complexes in the lens via specific van der Waals contacts, hydrogen bonds and salt bridges whereas those ß-crystallins which associate by predominately hydrophobic forces participate in a weaker protein associations.

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