<title>Nano-aerosol approach for characterization of proteins and viruses</title>

Abstract

This contribution presents the potential of an innovative approach for determination of molecular masses of high-mass biopolymers through the aerosol phase. Macromolecular ions were formed by means of a nano-electrospray ionisation. The multiply charged species were charge-reduced to yield neutral, or singly charged airborne particles. Subsequently the so obtained aerosols were size separated according to their electrophoretic mobility in air using a nano-differential mobility analyzer. The particles were then detected by means of a condensation particle counter. The mobility diameters of well-defined proteins were determined and linked with their molecular weights in the range from 3.5 - 2000 kDa showing a correlation coefficient of 0.999. This calibration relationship allowed then the determination of large biocomplexes with a mass accuracy of the order of 5% including supramolecular complexes such as viruses. We investigated the stability of various noncovalent protein complexes as a function of pH. The study on the human rhinoviruses demonstated the capability of the used experimental system to measure the size of the intact infectious virus (HRV2) and its partial thermal dissociation. This research can be viewed as a first documentation of observation of stability of non-covalent complexes and of a real-time virus characterization using nanoaerosol measuring technique.