Functional, Biochemical and Molecular Analyses of the *Cold Stable Eye Lens Crystallins From the Antarctic Toothfish Dissostichus Mawsoni
Isolation, cloning and sequencing of the cDNAs encoding for the toothfish crystallins revealed a total of 21 isoforms (2 alphas, 6 betas, and 13 gammas). Phylogenetic analyses suggest that toothfish alpha and beta crystallins are orthologues of mammalian counterparts, while gammas do not. Further separation, partial purification (ion-exchange chromatography) and analyses (isoelectric focussing and 2D SDS-PAGE) of the gamma crystallins has generated eleven sub-fractions, although they are not homogeneous for a single gamma isoform. Cross-species chaperone-like assays with these eleven toothfish gamma fractions show that those containing acidic gammas are protected by cow alpha crystallin, while those which are largely composed of basic isoforms cannot. Solubility of toothfish lens alpha, beta and gamma crystallins are similar to which has been previously reported for cow and humans. Thus, the long-lived, cold-adapted Antarctic toothfish lens is an attractive model system for further investigations into lens crystallin stability.
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign