Polypeptide composition of extracellular enveloped vaccinia virus

Area of Science:

• Virology
• Molecular Biology
• Cell Biology

Background:

• Vaccinia virus exists in different forms, including extracellular enveloped vaccinia (EEV) and intracellular naked vaccinia (INV).
• Understanding the protein composition of these viral forms is crucial for comprehending viral assembly and infectivity.

Purpose of the Study:

• To compare the polypeptide composition of purified EEV and INV viruses.
• To identify viral proteins unique to EEV and those altered during its formation from INV.

Main Methods:

• Purification of EEV and INV using sucrose and cesium chloride density gradients.
• Analysis of viral polypeptides by polyacrylamide gel electrophoresis.
• Biochemical treatments (detergent, ether, Pronase, Brij-58) to characterize protein location and function.
• Separation of viral envelope components.

Main Results:

• EEV and INV differ in several protein components; some INV surface proteins are absent or reduced in EEV, while EEV contains unique proteins.
• These altered INV proteins are surface-located and not essential for infectivity.
• EEV possesses unique viral envelope proteins, seven of which are glycoproteins.

Conclusions:

• A processing of surface INV proteins occurs during the development of EEV.
• The EEV particle comprises an INV core with modified surface proteins, enclosed by a unique viral envelope containing EEV-specific proteins.