Specific alteration of Sendai virus glycoprotein subunits

Area of Science:

• Virology
• Biochemistry
• Structural Biology

Background:

• Sendai virus glycoproteins (HN and F) are crucial for viral entry and function.
• Understanding glycoprotein structure is vital for antiviral strategies.
• Neuraminidase activity is a key viral enzyme affected by glycoprotein conformation.

Purpose of the Study:

• To investigate the structural alterations in Sendai virus glycoproteins induced by chemical and physical agents.
• To determine the impact of these alterations on neuraminidase activity.
• To elucidate the role of free sulfhydryl groups in glycoprotein structure and function.

Main Methods:

• Treatment of glycoproteins with sodium dodecyl sulfate (SDS), beta-mercaptoethanol, and urea at varying concentrations and temperatures.
• Analysis of molecular weights of glycoprotein subunits using gel electrophoresis.
• Estimation of free sulfhydryl (-SH) group content.
• Assessment of residual neuraminidase activity after treatment and storage.

Main Results:

• Dissociation into known HN (60,000 Da) and F (53,000 Da) subunits was achieved with SDS, beta-mercaptoethanol, and urea.
• 1% SDS treatment resulted in higher molecular weight components (60,000 Da, 120,000 Da, and above).
• Treatment with 2% beta-mercaptoethanol and 0.1% SDS yielded a single 75,000 Da component.
• Free -SH groups, estimated at 6 per subunit, were implicated in structural alterations.
• Stored glycoproteins (4°C) showed conversion of 67,000 Da to 53,000 Da subunits, retaining 60% neuraminidase activity.

Conclusions:

• Chemical and physical agents significantly alter Sendai virus glycoprotein structure.
• Free sulfhydryl groups play a critical role in maintaining glycoprotein conformation and stability.
• Structural changes impact viral neuraminidase activity, with implications for viral infectivity.