Why mass spectrometry of virus-like particles (VLP) and adeno-associated viruses (AAV)?

VLP’s are becoming more and more important as biologics due to their ability to dock onto cell surfaces and release their payload into the cells. They are used for vaccinations, gene therapies and other applications. However, their characterzation is not so easy because of the size of these particles.

Common ways of analysis are the characterization of their individual components and their size. But a number of questions are not answered by this:

  • is the composition correct?
  • is the correct payload present?
  • is the correct amount of payload present?

The direct determination of the mass of the intact particle by native MS can adress these questions whereas e.g. SEC-MALS only provides size information. The size change of the particle however is only in the range of a few percent whereas the mass changes dramatically upon inclusion of the API.

Technilogies for intact VLP and AAV characterization

How can native mass spectrometry help in this task?

Native mass spectrometry has been successfully applied to characterize AAV’s and other VLP’s (see literature list below). Native MS allows for directly determining the ration between unloaded and loaded particles, purity of the product, correct composition (otherwise the mass would not match) and even for decomposing the particle for in-depth composition characterization.

3MDa intact virus capsid
Mass spectrum of empty and loaded adeno-associated virus particles

You can further increase instrument perfomance by adding an electron-capture dissociation (ECD) cell upgrade to the system as well. By adding ECD, it is also possible to pursue top-down characterization of the individual VLP constituents, characterize compounds with identical mass but different mobility e.g. for different locations of PTM, run collision-induced unfloding experiments to analyze structural stability and many more.

Enabling an existing Waters Synapt system with native MS capability to characterize VLP’s is cheaper than you think and will provide you with a great ROI.

VLP characterzation by native mass spectrometry – Literature:

Learn more about the application of MS Vision’s dedicated high mass QTOF and Synapt systems for VLP characterization: