Biosynthesis of two lysosomal enzymes in macrophages. Evidence for a precursor of beta-galactosidase.

摘要: We have purified beta-galactosidase and beta-glucuronidase from macrophages of thioglycollate-treated mice using concanavalin A chromatography immunoprecipitation. The apparent molecular weight the subunit, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, changed during a long term pulse-chase experiment. Following 1-h pulse with [3H]leucine, radiolabel was present exclusively in an Mr = 82,000 form. However, after 3-h chase medium containing unlabeled leucine, most label migrated at 63,000, 24 h, all 63,000 Electrophoresis peptides produced cyanogen bromide cleavage immunoprecipitates demonstrated structural similarities between precursor mature forms. mutation mouse, which is known to depress rate synthesis many cell types, proportionately decreased incorporation [3H]leucine into both Therefore, kinetic, structural, genetic evidence, large macrophage enzyme. No 75,000 subunit detected.