Changes in the major intrinsic polypeptide (MIP26K) during opacification of the Emory mouse lens.

Antisera against synthetic peptides corresponding to various regions of the Main Intrinsic Polypeptide (MIP26K) of fiber lens membranes have been used to probe Western blots of Emory mouse lens proteins resolved by SDS-polyacrylamide gel electrophresis. When compared with clear lenses from control animals of approximately the same age, the MIP26K component from Emory mouse lenses demonstrated no quantitative changes in the binding of anti-MIP26K256-263 and anti-MIP26Kwhole sera. In contrast, the MIP26K component from Emory mouse lenses bound significantly better to two other antisera directly against other parts of the molecule (antiMIP26K229-237 and anti-MIP26K252-259). Furthermore, this increase in binding was approximately proportional to the degree of lens opacification. Together, these results demonstrate that during the opacification process of the Emory mouse lens, there occur covalent changes in the MIP26K molecule that, in part, may mimic those occurring in the human senile cataract.