IMMUNOLOCALIZATION OF THE C-TERMINAL AND N-TERMINAL REGIONS OF ALPHA-A AND ALPHA-B CRYSTALLINS

The C-terminal and possibly the N-terminal regions of the alpha crystallins are thought to be involved in the molecular chaperone properties of the protein. To localize these regions within the 13-15 nm aggregate of native alpha crystallin, antisera specific for the C-terminal and N-terminal regions were used together with immunogold and transmission electron microscopy. The results demonstrate that the C-terminal regions of the alpha-A and alpha-B molecules and the N-terminal regions of the alpha-A and/or alpha-B molecules are localized to a central region of the native alpha aggregate. These findings demonstrate that the C-terminal and N-terminal regions of alpha crystallin are localized to a region of the alpha aggregate that has previously been hypothesized to be the binding site for partially denatured proteins.