Analysis of glycoprotein deposits on disposable soft contact lenses

By using gel electrophoresis, as well as Western blotting with specific antibodies or with the lectin concanavalin A, we characterized the types and amounts of proteins that are deposited on 58% ionic and 38% nonionic water-content disposable soft contact lenses (DSCLs) worn for 1 to 21 days by asymptomatic subjects with mild to moderate myopic refractive errors. The total amounts of protein eluted from the lenses ranged from 0.1 to 80 micrograms/lens. The amount of protein deposited on 58% water-content lenses was greater than that on 38% water-content DSCLs. We did not find a strict correlation between the amount of protein deposited and the duration of wear for either type of lens. The major polypeptide fractions detected had apparent molecular weights of 14, 17, 21, 30, and 60 kD. The fractions at 14 kD-bound antibodies specific for human lysozyme, and those at 17 kD corresponded to prealbumin. The 60 kD fraction included IgG heavy chains. The identity of the fractions at 21 kD and 30 kD is unknown. Because oligosaccharide side chains on the proteins attract microbes and facilitate their adherence, knowledge about the types of carbohydrate moieties in lens deposits can provide a rational approach to inhibiting or reversing microbial infection.