Abstract
Purpose: :
Recent studies using microequilibrium dialysis have demonstrated significant, noncovalent interactions between alpha crystallins and gamma crystallins from the fetal bovine lens, when measured under true equilibrium conditions. Since changes in these interactions may play a role in the loss of transparent properties of the aging lens, microequilibrium dialysis was used to quantitate protein–protein interactions of alpha and gamma crystallins purified from young versus old bovine lenses.
Methods: :
Native alpha and gamma crystallins were purified from fetal and aged (i.e. greater than 30 months of age) bovine lenses using a TSK–3000SWXL gel filtration column. Alpha and gamma crystallins were loaded into 50 µl microequilibrium chambers separated by a 100,000 MW cut–off membranes, then allowed to equilibrate for 5 days at 37 degrees C., followed by quantitation of free versus bound gamma crystallin species using HPLC, reverse phase chromatography.
Results: :
Four out of seven species of gamma crystallin from fetal lenses showed decreased binding to aged alpha crystallins when compared to alpha crystallins from fetal lenses.
Conclusions: :
Under true equilibrium conditions, fetal gamma crystallins show decreased interactions with alpha crystallins from older lenses, consistent with the possible role of these interactions in the decreased transparent properties of the aged lens.
Keywords: crystalline lens