Structural polypeptides of adenovirus type 16 incomplete particles

Area of Science:

• Virology
• Molecular Biology
• Biochemistry

Background:

• Adenoviruses are common human pathogens.
• Incomplete viral particles can provide insights into viral assembly and protein processing.
• Previous studies have characterized polypeptides in adenovirus types 2 and 3.

Purpose of the Study:

• To compare the polypeptide composition of adenovirus type 16 incomplete particles with complete virions and late infected cell polypeptides.
• To identify and characterize novel polypeptides present in incomplete adenovirus type 16 particles.

Main Methods:

• Sodium dodecyl sulfate-gel electrophoresis was used to analyze viral polypeptides.
• Buoyant density centrifugation in cesium chloride (CsCl) was employed to separate particles.
• Radioactive labeling and chase experiments were performed to study protein processing and stability.

Main Results:

• Incomplete adenovirus type 16 particles lacked polypeptides V, VI, and VII, similar to other serotypes.
• Eight major polypeptides (59K, 46K, 31K, 30K, 28K, 27K, 26K, 19K) were identified in incomplete particles.
• Specific polypeptides were identified as precursors (27K, 19K) or chase products (31K, 30K, 26K), with 26K suggested as a processing intermediate.
• Polypeptides V and VII were associated with particles containing more than a quarter of the genome.
• A 46K polypeptide was a major constituent of incomplete particles and was rapidly labeled.

Conclusions:

• The polypeptide composition of adenovirus type 16 incomplete particles differs significantly from complete virions.
• Specific polypeptides play roles as precursors or intermediates in viral protein processing.
• The study provides a detailed characterization of polypeptides in adenovirus type 16 incomplete particles, contributing to understanding viral assembly.