Related Experiment Videos
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.
Insights
This study successfully purified Mallory bodies (MBs) from human liver, revealing their autofluorescent, carbohydrate-rich composition and fibrous structure. These findings advance understanding of liver disease pathology.
Area of Science:
- Hepatology
- Biochemistry
- Cell Biology
Background:
- Mallory bodies (MBs) are intracellular inclusions found in various liver diseases.
- Their precise biochemical composition and ultrastructure remain incompletely characterized.
Purpose of the Study:
- To develop a new method for purifying Mallory bodies (MBs) from human liver tissue.
- To characterize the biochemical and ultrastructural properties of purified MBs.
Main Methods:
- Purification of MBs using Ficoll density gradient centrifugation.
- Autofluorescence, Concanavalin A binding assays, carbohydrate analysis (neutral hexose, sialic acid).
- SDS-PAGE for protein analysis, electron microscopy (SEM, TEM) for ultrastructure.
Main Results:
- Achieved 95-99% purity of MB preparations from six human livers.
- MBs exhibited autofluorescence and strong agglutination with Concanavalin A, indicating carbohydrate presence.
- Analysis revealed variable neutral hexose content but no sialic acid.
- SDS-PAGE identified five major polypeptides (56,000, 48,500-45,000 triplet, 32,500 Da).
- SEM showed a rough, fibrous surface; TEM confirmed their filamentous nature.
Conclusions:
- The novel purification method yields highly pure MBs for detailed analysis.
- MBs are composed of specific polypeptides and contain carbohydrates, contributing to their fibrous, autofluorescent nature.
- These findings provide a foundation for further research into the pathogenesis of liver diseases associated with MBs.