Related Experiment Videos
Incorporation of branched-chain fatty acids into myxoviruses
Abstract:
The incorporation of free fatty acids into myxoviruses was shown, using branched-chain fatty acids as molecular markers. The presence of isostearic or phytanic acid was detected by gas-liquid chromatography in the phospholipid fraction of the A(0)/PR8/34 strain of influenza virus. Uptake of free fatty acids into the virus varied from 8 to 11 per cent and was accompanied by a shift in the fatty acid profile. Infected allantoic fluids from eggs treated with branched-chain acids possessed higher hemagglutinin activity when compared to fluids infected under normal conditions. Attempts to detect branched-chain acids in Sendai virus were unsuccessful. Shifts in acyl chain composition persisted after three passages of modified viruses in the absence of branched-chain acids. Force-area curves at an air-water interface revealed the cross-sectional area of branched-chain acids to be greater than their straight-chain homologs. It is suggested that hydrophobic interactions can alter the configuration of envelope proteins. Such changes may have an important role in the selection of fragments of influenza viral genome and can conceivably alter viral genotype.
Insights
This study demonstrates that branched-chain fatty acids can be incorporated into influenza viruses, altering their hemagglutinin activity and potentially their genetic makeup. These modifications suggest a role for fatty acid interactions in viral evolution.
Area of Science:
- Virology
- Biochemistry
- Molecular Biology
Background:
- Myxoviruses, including influenza virus, have lipid envelopes derived from host cell membranes.
- The role of specific lipid compositions in viral function and evolution is not fully understood.
Purpose of the Study:
- To investigate the incorporation of free fatty acids (FFAs) into influenza virus.
- To determine the effect of FFAs on viral hemagglutinin activity and envelope protein configuration.
- To explore the potential impact of altered lipid composition on viral genome selection and genotype.
Main Methods:
- Utilized branched-chain fatty acids (isostearic and phytanic acid) as molecular markers.
- Employed gas-liquid chromatography to detect FFAs in the viral phospholipid fraction.
- Measured hemagglutinin activity in infected allantoic fluids.
- Performed force-area measurements at an air-water interface to assess fatty acid molecular dimensions.
Main Results:
- Successfully detected branched-chain FFAs in the influenza A(0)/PR8/34 strain, with uptake ranging from 8-11%.
- Observed increased hemagglutinin activity in viruses grown in the presence of branched-chain FFAs.
- Demonstrated that altered acyl chain composition persisted through viral passages.
- Found branched-chain fatty acids to have a larger cross-sectional area than straight-chain homologs.
Conclusions:
- Incorporation of FFAs alters influenza virus lipid composition and hemagglutinin activity.
- Hydrophobic interactions involving altered lipid profiles may influence viral envelope protein configuration.
- These changes could play a role in viral genome selection and potentially alter viral genotype, offering insights into viral evolution mechanisms.