Solvent-induced collapse of alpha-synuclein and acid-denatured cytochrome c.
The effects of solution conditions on protein collapse were studied by measuring the hydrodynamic radii of two unfolded proteins, alpha-synuclein and acid-denatured ferricytochrome c, in dilute solution and in 1 M glucose. The radius of alpha-synuclein in dilute solution is less than that predicted for a highly denatured state, and adding 1 M glucose causes further collapse. Circular dichroic data show that alpha-synuclein lacks organized structure in both dilute solution and 1 M glucose. On the other hand, the radius of acid-denatured cytochrome c in dilute solution is consistent with that of a highly denatured state, and 1 M glucose induces collapse to the size and structure of native cytochrome c. Taken together, these data show that alpha-synuclein, a natively unfolded protein, is collapsed even in dilute solution, but lacks structure.
Morar
A S
AS
Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
Olteanu
A
A
Young
G B
GB
Pielak
G J
GJ
D002942:Circular Dichroism; D003574:Cytochrome c Group / Q000737:chemistry*; D005947:Glucose; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009419:Nerve Tissue Proteins / Q000737:chemistry*; D011489:Protein Denaturation; D017433:Protein Structure, Secondary; D012996:Solutions; D012997:Solvents / Q000737:chemistry*; D051843:Synucleins; D013696:Temperature; D051844:alpha-Synuclein
D003574:Cytochrome c Group; D009419:Nerve Tissue Proteins; D012996:Solutions; D012997:Solvents; D051843:Synucleins; D051844:alpha-Synuclein; D005947:Glucose