RESUMEN
Two major intrinsic membrane polypeptides of molecular weights 22K and 26K have been isolated and antisera for each prepared against highly purified preparations. The lack of reactivity of these antibodies in several other tissues suggests that they are unique to the lens. These antisera were used for localization of these polypeptides in adult human lenses by indirect immunofluorescent staining. Neither of the polypeptides is found in the epithelial cells; however those cells commencing differentiation show some fluorescent staining. The elongating fiber cells of the bow region show cytoplasmic staining for both 22K and 26K. This may reflect their sites of synthesis. In this region the species of 22K studies showed no localization in the membrane; however, 26K is concentrated at the membrane as evidenced by the intense band of fluorescent staining in this region. In the lens inner cortical region, there is a loss of cytoplasmic staining and both polypeptides appear to be membrane bound. This redistribution of the membrane polypeptides occurring in the inner cortex is at the site of considerable lens fiber contour alterations.
Asunto(s)
Cristalino/análisis , Péptidos/análisis , Adolescente , Adulto , Membrana Celular/ultraestructura , Niño , Citoplasma/inmunología , Citoplasma/ultraestructura , Técnica del Anticuerpo Fluorescente , Humanos , Cristalino/ultraestructura , Péptidos/aislamiento & purificaciónRESUMEN
A 43,000-dalton polypeptide has been isolated from the high-molecular-weight disulfide-rich fraction of the water-insoluble protein of human cataractous lenses. On the basis of immunochemical reactivity and fluorescent antibody binding, this polypeptide is localized in the membrane region of the lens cell. This observation suggests an interaction between the soluble lens proteins and membrane-associated polypeptides in the formation of large protein aggregates which may cause cataract.