| AVS 65th International Symposium & Exhibition | |
| Plasma Science and Technology Division | Tuesday Sessions |
| Session PS+PB-TuM |
| Session: | Plasma Medicine |
| Presenter: | Joshua Blatz, University of Wisconsin-Madison |
| Authors: | J. Blatz, University of Wisconsin-Madison B.B. Minkoff, University of Wisconsin-Madison F.A. Choudhury, University of Wisconsin-Madison D.I. Benjamin, University of Wisconsin-Madison J.L. Shohet, University of Wisconsin-Madison M.R. Sussman, University of Wisconsin-Madison |
| Correspondent: | Click to Email |
Atmospheric-pressure plasma discharges are well-known to generate OH radicals when interacting with water. However, the use of radicals created in this way for protein footprinting is virtually non-existent. Here, we describe a novel technique which utilizes a dielectric-barrier plasma discharge to oxidize proteins in solution. These oxidation events are quantified using mass spectrometry and allows us to determine the exterior domain and solvent accessibility of a protein.
To generate the plasma a high-voltage A.C. signal is applied to a needle electrode in close proximity to the surface of the liquid sample. This causes the gas to breakdown and form the plasma. These plasma discharges have been measured to be on the order of microseconds which prevents the protein from cleaving. During plasma exposure the sample is cooled to maintain temperature and prevent denaturation.
Protein bovine serum albumin was exposed to plasma. Labeling of the exterior domain was found in a manner consistent with other protein structural analysis techniques. Additionally, initial measurements have been collected which indicate that by changing various electrical, physical, and chemical parameters the technique may still be optimized. This could lead to greater OH-radical generation, reduced sample heating, and reduced pH change.
In addition to the consistent initial results and optimization potential there are many advantages it holds over competing techniques. It can be built inexpensively and on a space-limited benchtop. There are no necessary chemical additives which may interfere with the results and there seems to be no limit to the size of the protein which can be treated. All the samples are treated in liquid solution so they are free to move as they would in vivo.