Related Experiment Videos
pH-dependent aggregation and secretion of soluble monomeric influenza hemagglutinin
P Vanlandschoot1, E Beirnaert, J Grooten
1Laboratory of Molecular Biology, Flanders Interuniversity Institute of Biotechnology, University of Ghent, Belgium.
Abstract:
We previously reported the expression of soluble A/Victoria/3/75 (H3N2) hemagglutinin in insect cells and the molecular and immunological structure of an aggregated fraction, only observed in cell supernatant when expression was performed at low pH [23]. Here we report that besides this aggregated a monomeric and possibly a trimeric structure is detected in cell supernatant, irrespective of the pH of the medium. Evidence is presented that the aggregated fraction is generated out of monomeric HAOs molecules due to a low intracellular pH encountered during secretion.
Insights
Researchers found that soluble hemagglutinin (HA) from A/Victoria/3/75 (H3N2) exists in monomeric and trimeric forms in cell culture supernatant. Aggregation into larger structures is linked to low intracellular pH during secretion.
Area of Science:
- Virology
- Protein Biochemistry
- Cell Biology
Background:
- Previous work reported expression of soluble A/Victoria/3/75 (H3N2) hemagglutinin (HA) in insect cells.
- An aggregated HA fraction was observed in cell supernatant specifically at low pH during expression.
Purpose of the Study:
- To investigate the different structural forms of soluble H3N2 hemagglutinin in cell supernatant.
- To determine the factors influencing the formation of aggregated HA structures.
Main Methods:
- Expression of soluble A/Victoria/3/75 (H3N2) hemagglutinin in insect cells.
- Analysis of cell supernatant using biochemical and biophysical techniques to identify different HA structures.
- Investigation of the role of pH in HA aggregation during secretion.
Main Results:
- Monomeric and possibly trimeric forms of soluble H3N2 hemagglutinin are detected in cell supernatant.
- These monomeric and trimeric structures are present irrespective of the culture medium pH.
- Evidence suggests that the aggregated HA fraction arises from monomeric HA molecules due to low intracellular pH during secretion.
Conclusions:
- Soluble H3N2 hemagglutinin exists in multiple structural forms (monomeric, trimeric, aggregated) in the cell supernatant.
- Intracellular pH is a critical factor controlling the aggregation state of secreted H3N2 hemagglutinin.
- Understanding these structural variations is important for influenza virus research and vaccine development.