DynaPro used in protein freezing studies
(DLS) instruments can be used to determine whether freezing alters
a protein's homogeneity, according to researchers in France.
The team, from the IBMC-CNRS in Strasbourg, say the approach could be used for protein characterization applications and to see how proteins may behave when formulated into therapeutics.
Protein drugs are routinely formulated in a freeze-dried (lyophilized) format, and reconstituted just prior to use using water. But with certain proteins the biological activity disappears after being stored in a frozen state, possibly due to aggregation or clumping of the molecules. The IBMC-CBRS study suggests this tendency could be explored for new protein molecules early on in the development process.
The team said they used the DynaPro system as it is the industry standard in the protein crystallization market, and it enabled verification of the protein quality before reproducible investigations were undertaken on the sample.
For this particular application, two samples - one never subjected tofreezing and one kept frozen for two weeks - were available for comparison.The samples were transferred into two 12µL cuvettes and spun for threeminutes at 4,000 rpm in a small, tabletop centrifuge to remove dustparticles as well as the largest aggregates.
Altogether, the results, which are available in an application note that can be downloaded from the Wyatt website, demonstrated that this protein tends to aggregate upon freezing.
Wyatt says the DynaPro DLS system offers the most direct and least invasive method to answer the question of whether freezing actually alters the macromolecule's homogeneity or not within just a few minutes.
Wyatt acquired the DynaPro range along with US company Proterion Corp last year.
DynaPro is claimd to have made biomolecular characterisation by dynamic light scattering easier and affordable compared to earlier costly, complex, and cumbersome instrumentation used to measure parameters such as the hydrodynamic radius and polydispersity of macromolecules. It is also said to have the most sensitive commercially available DLS instrument with the smallest sample volume (2 microliters).
