Mallory bodies: isolation of hepatocellular hyalin and electrophoretic resolution of polypeptide components

Abstract

Mallory bodies (MBs) were obtained in purified form from human liver obtained at autopsy using a new procedure consisting of sedimentation through a Ficoll viscosity barrier. Preparations from six livers ranged in purity from 95 to 99 per cent. MB preparations were autofluorescent. MBs were strongly agglutinated by Concanavalin A. The presence of carbohydrate was also indicated by the fact that MBs bound fluorescently labeled Concanavalin A; no binding was observed in the presence of appropriate inhibitor monosaccharides. Direct analysis indicated that MBs contained variable amounts of neutral hexose (0.65 to 2.4 mumoles of glucose-equivalents per milligram of protein) but no sialic acid. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that purified MBs contain five major polypeptides possessing apparent molecular weights of 56,000, 48,500 to 45,000 (triplet), and 32,500. Periodic acid-Schiff-positive components were not detected. Scanning electron microscopy of isolated MBs revealed the presence of a rough, fibrous surface, whereas conventional transmission electron microscopy indicated the filamentous nature of MBs.