Salt-Induced Universal Slowing Down of the Short-Time Self-Diffusion of a Globular Protein in Aqueous Solution.
The short-time self-diffusion D of the globular model protein bovine serum albumin in aqueous (D2O) solutions has been measured comprehensively as a function of the protein and trivalent salt (YCl3) concentration, noted cp and cs, respectively. We observe that D follows a universal master curve D(cs,cp) = D(cs = 0,cp) g(cs/cp), where D(cs = 0,cp) is the diffusion coefficient in the absence of salt and g(cs/cp) is a scalar function solely depending on the ratio of the salt and protein concentration. This observation is consistent with a universal scaling of the bonding probability in a picture of cluster formation of patchy particles. The finding corroborates the predictive power of the description of proteins as colloids with distinct attractive ion-activated surface patches.
†Institut Max von Laue - Paul Langevin (ILL), CS 20156, 71 avenue des Martyrs, F-38042 Grenoble, France.|‡Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany.
Marco
M
Grimaldo
†Institut Max von Laue - Paul Langevin (ILL), CS 20156, 71 avenue des Martyrs, F-38042 Grenoble, France.
Felix
F
Roosen-Runge
†Institut Max von Laue - Paul Langevin (ILL), CS 20156, 71 avenue des Martyrs, F-38042 Grenoble, France.|‡Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany.
Marcus
M
Hennig
‡Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany.
Fabio
F
Zanini
‡Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany.
Fajun
F
Zhang
§Jülich Centre for Neutron Science (JCNS), Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.|∥JCNS Outstation at the MLZ, Lichtenbergstraße 1, D-85747 Garching, Germany.
Michaela
M
Zamponi
§Jülich Centre for Neutron Science (JCNS), Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.|⊥Chemical and Engineering Materials Division, Neutron Sciences Directorate, and JCNS Outstation at the Spallation Neutron Source (SNS), Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, United States.
Niina
N
Jalarvo
‡Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany.
Frank
F
Schreiber
†Institut Max von Laue - Paul Langevin (ILL), CS 20156, 71 avenue des Martyrs, F-38042 Grenoble, France.
Tilo
T
Seydel
D004058:Diffusion; D012965:Sodium Chloride / Q000737:chemistry*; D012996:Solutions / Q000032:analysis / Q000737:chemistry*; D014867:Water
D012996:Solutions; D014867:Water; D012965:Sodium Chloride
cluster formation; neutron spectroscopy; protein dynamics; self-assembly; “patchy” colloids