β-Crystallin association

Abstract

β-Crystallins are major protein constituents of the mammalian lens, where their stability and association into higher order complexes are critical for lens clarity and refraction. Dimerization is an initial step in formation of β-crystallin complexes. β-crystallin association into dimers is energetically highly favoured, but rapidly reversible under physiological conditions. β-Crystallin dimers can exchange monomers, probably through a transient and energetically unfavoured monomer intermediate state. As predicted by molecular modelling, the fraction of β-Crystallin present as dimers increases with increasing temperature, implying that β-crystallin association is entropically driven.