Dr Martin Muschol, Assistant Professor at the University of South Florida's
(USF) Department of Physics and his team are carrying out important research
to gain a better understanding of protein aggregation phenomena, including protein
crystallization and amyloid fibril growth. Using the Zetasizer Nano ZS, from
Malvern Instruments
(Malvern, UK), the USF researchers have been able to perform temperature
controlled static and dynamic light scattering (DLS) measurements of protein
hydration, protein interactions and aggregation kinetics in vitro.
"By enabling temperature controlled measurements, the Zetasizer Nano
ZS is particularly suited to our work here at USF," said Dr Muschol. "With
it we have been able to monitor the effect on the hydration of proteins by salt
ions in solution, measuring the hydrodynamic radius of proteins down to plus/minus
one tenth the diameter of a water molecule. Interestingly we found that neither
chaotropic or cosmotropic salt ions affected overall protein hydration up to
salt concentrations of 1M." (ref: 'Hydration and Hydrodynamic Interactions
of Lysozyme: Effects of Chaotropic versus Kosmotropic Ions', Biophysical Journal,
Volume 96, pp 3781-3790)
Having published several papers in the past year alone, data gathered by Dr
Muschol and his team will be used to develop models for protein fibril formation,
a behaviour thought to trigger degenerative diseases, such as Alzheimer's disease
or Parkinson's disease. "Despite intensive research efforts, we still
don't understand how proteins can stay in solution in a crowded cellular environment
and what triggers their aggregation and subsequent pathological changes. We
hope our research will contribute to resolving these basic puzzles." (ref:
'Amyloid Protofibrils of Lysozyme Nucleate and Grow Via Oligomer Fusion',
Biophysical Journal, Volume 97, pp 590-598)
Dr Muschol's team has also had noticeable success in using the Zetasizer Nano
ZS to study the nucleation of gold nanoparticles (ref: R. Jagannathan, et al.
J. Phys. Chem. C, 2009, 113, pp3478-3486). Unlike static light measurements
commonly used to detect nucleation events, DLS separates out the background
scattering from small molecular species in gold sols. Therefore, DLS was able
to detect nucleation at a significantly earlier stage than has been possible
with other approaches.
The Zetasizer Nano ZS is proving to be the ultimate sizing solution for biotechnology
and materials scientists, offering exceptional sensitivity down to sub-micron
and nanometre scales. The system's ability to control temperature is important
when following the behaviour of polymers and protein samples. Further information
can be found at www.malvern.com/zetasizer
Malvern, Malvern Instruments and Zetasizer are registered trademarks of Malvern
Instruments Ltd