Reentrant condensation of proteins in solution induced by multivalent counterions.
Negatively charged globular proteins in solution undergo a condensation upon adding trivalent counterions between two critical concentrations C and C, C <C. This reentrant condensation behavior above C is caused by short-ranged electrostatic interactions between multivalent cations and acidic residues, mechanistically different from the case of DNA. Small-angle x-ray scattering indicates a short-ranged attraction between counterion-bound proteins near C and C. Monte Carlo simulations (under these strong electrostatic coupling conditions) support an effective inversion of charge on surface side chains through binding of the multivalent counterions.
Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
F
F
Zhang
M W A
MW
Skoda
R M J
RM
Jacobs
S
S
Zorn
R A
RA
Martin
C M
CM
Martin
G F
GF
Clark
S
S
Weggler
A
A
Hildebrandt
O
O
Kohlbacher
F
F
Schreiber
D002412:Cations / Q000737:chemistry; D003198:Computer Simulation; D007811:Lanthanum / Q000737:chemistry; D008956:Models, Chemical; D009010:Monte Carlo Method; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D053838:Scattering, Small Angle; D012996:Solutions; D055672:Static Electricity; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction; D015019:Yttrium / Q000737:chemistry*
D002412:Cations; D011506:Proteins; D012996:Solutions; C028521:lanthanum chloride; D014867:Water; C064782:yttrium chloride; D015019:Yttrium; D007811:Lanthanum