Monoclonal antibody analysis of bovine epithelial keratins: specific pairs as defined by coexpression

We have characterized the keratin proteins of var-ious bovine epithelial tissues by one- and two-dimen-sional gel electrophoresis, coupled with the immuno-blot technique using AE1, AE2, AE3, AE5, CA20, BE14, and 6.1 1 monoclonal antikeratin antibodies. The results indicate that all known bovine keratins can be divided into two subfamilies. The ‘‘acidic ” (Type I) subfamily consists of 41-, 43-, 45-, 46-, 50-, 54-, 56-, and 56.5-kDa keratins, all of which have a PI of <5.6, and most of them are recognized by our AE 1 antibody, whereas the “neutral-to-basic ” (Type 11) subfamily consists of 55-, 57-, 58-, 62-65-, 66-, and 67-kDa keratins, all of which have a PI of>6.0 and are rec-ognized by our AE3 antibody. Tissue distribution data and cell culture studies show that, within the tw