Two-dimensional 1H NMR spectroscopy of bovine eye lens α-crystallin and its isolated αA and αB subunits reveals that these aggregates have short and very flexible C-terminal extensions of eight (αA) and ten (αB) amino acids which adopt little preferred conformation in solution. Total α-crystallin forms a tighter aggregate than the isolated αA and αB subunit aggregates. Our results are consistent with a micelle model for α-crystallin quaternary structure. The presence of terminal extensions is a general feature of those crystallins, α and β, which form aggregates.
