A new technique combining two forms of spectrometry could help biopharmaceutical companies improve their choice of formulation buffer for antibody manufacturing by revealing how molecular forms and three-dimensional shapes of complex biologics respond to their environment. That’s the view of Christian Bleiholder, PhD, a professor at Florida State University who helped develop the technique.
According to Bleiholder, what happens structurally when a complex biological molecule, such as an antibody or viral spike protein, binds to its target is currently poorly understood.
“This is where [this approach] can help with the bioprocessing and formulation,” he says, as structural changes “can affect the lifespan [of the product] and lead to issues, such as aggregation.”
Because antibodies are complex, existing techniques tend to be powerful at different levels of complexity, he explains. Mass spectrometry is particularly powerful for distinguishing molecular composition, while structural approaches such as X-ray crystallography and cryo-electron microscopy can provide high-resolution structural information.
The challenge is understanding the link between these things within a heterogeneous sample, he says.
To overcome this, Bleiholder and his team worked with Bruker Daltonics to develop Tandem-Trapped Ion Mobility Spectrometry (Tandem-TIMS). This combines tandem ion mobility spectrometry with tandem mass spectrometry to disentangle three overlapping layers of molecular complexity: molecular form, three-dimensional shape, and binding or assembly state, he says.
He explains that, if the proteins have different structures, they can be characterized with tandem ion mobility spectrometry, and then mass spectrometry can be used to look at their molecular forms and binding states.
Going forward, Bleiholder hopes the technique can be used for formulation development but also earlier, during drug discovery of new products, such as multi-specific antibodies, to determine which molecular states are important and how those change when a biologic engages its target. He also plans to look at automating the technique.
Bleiholder spoke about using Tandem-TIMS at the Bioprocessing Summit in Boston earlier this year.
