Physical and chemical perturbations induce the formation of protein aggregates with different structural features.
The in vitro aggregation of the model GST-GFP fusion protein was induced by several effectors, including those mimicking variations occurring under cell stress conditions. In particular, we examined the effects of thermal treatments, redox state and pH variations, salt addition, and freezing and thawing cycles. The resulting aggregates displayed different morphologies as seen by electron microscopy, and different secondary and tertiary structures, as indicated by Fourier transform infrared spectroscopy and fluorescence. Therefore, proteins can be forced to undergo multiple aggregation pathways that lead to assemblies with different molecular structures and, possibly, specific physiological and pathological roles. In conclusion, great caution should be taken in inferring conclusions on protein aggregation and disaggregation in vivo from results obtained using aggregates produced under non-physiological perturbations.
Natalello
Antonino
A
Dipartimento di Biotecnologie e Bioscienze, Universita' degli Studi Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy.
Santarella
Rachel
R
Doglia
Silvia Maria
SM
de Marco
Ario
A
D005615:Freezing; D005982:Glutathione Transferase / Q000737:chemistry*; D049452:Green Fluorescent Proteins / Q000737:chemistry*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D018384:Oxidative Stress; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D005982:Glutathione Transferase