Related Experiment Video
Updated: May 21, 2026
A Liquid Phase Affinity Capture Assay Using Magnetic Beads to Study Protein-Protein Interaction: The Poliovirus-Nanobody Example
Published on: May 29, 2012
Characterization of rhinovirus subviral A particles via capillary electrophoresis, electron microscopy and gas-phase
Victor U Weiss1, Xavier Subirats, Angela Pickl-Herk
1Max F. Perutz Laboratories, Department of Medical Biochemistry, Medical University of Vienna, Vienna Biocenter (VBC), Vienna, Austria.
Abstract:
During infection, enteroviruses, such as human rhinoviruses (HRVs), convert from the native, infective form with a sedimentation coefficient of 150S to empty subviral particles sedimenting at 80S (B particles). B particles lack viral capsid protein 4 (VP4) and the single-stranded RNA genome. On the way to this end stage, a metastable intermediate particle is observed in the cell early after infection. This subviral A particle still contains the RNA but lacks VP4 and sediments at 135S. Native (150S) HRV serotype 2 (HRV2) as well as its empty (80S) capsid have been well characterized by capillary electrophoresis. In the present paper, we demonstrate separation of at least two forms of subviral A particles on the midway between native virions and empty 80S capsids by CE. For one of these intermediates, we established a reproducible way for its preparation and characterized this particle in terms of its electrophoretic mobility and its appearance in transmission electron microscopy (TEM). Furthermore, the conversion of this intermediate to 80S particles was investigated. Gas-phase electrophoretic mobility molecular analysis (GEMMA) yielded additional insights into sample composition. More data on particle characterization including its protein composition and RNA content (for unambiguous identification of the detected intermediate as subviral A particle) will be presented in the second part of the publication.
Insights
Human rhinoviruses (HRVs) convert to empty particles during infection. This study identifies and characterizes intermediate A particles, crucial for understanding HRV uncoating and B particle formation.
Area of Science:
- Virology
- Structural Biology
- Biochemistry
Background:
- Enteroviruses, including human rhinoviruses (HRVs), undergo significant structural changes during infection.
- Native, infectious 150S HRVs transform into empty 80S B particles, lacking VP4 and genomic RNA.
- A metastable intermediate, the 135S A particle, containing RNA but lacking VP4, is observed early in infection.
Purpose of the Study:
- To separate and characterize intermediate subviral A particles of HRV2.
- To investigate the conversion pathway from A particles to empty 80S capsids.
- To provide a foundation for further detailed analysis of HRV uncoating intermediates.
Main Methods:
- Capillary electrophoresis (CE) for separating HRV particles.
- Transmission electron microscopy (TEM) for visualizing particle structure.
- Gas-phase electrophoretic mobility molecular analysis (GEMMA) for compositional insights.
Main Results:
- Separation of at least two distinct forms of HRV2 subviral A particles by CE.
- Reproducible preparation and characterization of one A particle intermediate.
- Electrophoretic mobility and TEM analysis of the isolated A particle intermediate.
- Investigation into the conversion process of this intermediate to 80S particles.
Conclusions:
- Subviral A particles represent distinct intermediates in the HRV lifecycle.
- CE is a powerful tool for resolving HRV structural heterogeneity.
- Further characterization, including protein and RNA content, will confirm the identity and role of these A particles.
