Wyatt Technology Corporation, the world leader in instrumentation for absolute macromolecular characterization and software, announces that its Möbius™ electrophoretic mobility instrument can measure precise protein charges.
The innovative optical design of the Möbius boosts the sensitivity of mobility measurements, enabling protein net charge characterization at much lower concentrations than previously possible. This unique capability is illustrated in a new application note, titled “Möbius Computation of Protein Net Charge from Electrophoretic Mobility”, which is available to download free-of-charge via http://www.wyatt.com/literature/application-notes/mobius.html.
Protein molecules carry charges that are influenced by their environment, amino acid sequence, ionic strength and the aqueous solvent pH in which they are dissolved. The net charge carried by protein molecules is of enormous scientific interest since it affects the behavior of the molecules. As the ionic strength of the solution increases, for example, more counter ions are present in the vicinity of the protein molecules and the mobility generally decreases due to the electrophoretic effect. However, measuring protein charge has been a challenging task for conventional phase analysis light scattering (PALS) instruments that can only provide measurements at high concentrations and at high voltages. In addition, undesirable interactions can often occur, such as that between the proteins and the capillary walls, which diminish the reliability of results.
This new application note demonstrates how the Möbius overcomes the limitations of traditional PALS methods, eliminates undesirable interactions and facilitates protein charge measurements at low concentrations—all without damaging the protein itself. The Möbius mobility instrument is capable of carrying out protein net charge measurements with a moderate antibody concentration of 1.0 mg/mL, which are not possible with conventional PALS instruments.
The Möbius incorporates several patent-pending innovations to realize fast and reliable measurements of electrophoretic mobilities. The key to the successful measurement of a proteins’ mobility lies in a much shortened measurement time and the availability of sufficient data to average away molecular diffusion. The Möbius achieves these goals through massive parallelism of its light scattering detection and extends the measurable molecular size range below 2 nm. A reduced measurement time of fewer than 60 seconds, in most cases, contributes to excellent preservation of precious and fragile protein samples. The instrument also features a temperature control capability, making it suitable for performing automated temperature studies.