Protein tyrosine phosphatase oligomerization studied by a combination of 15N NMR relaxation and 129Xe NMR. Effect of buffer containing arginine and glutamic acid.
15N NMR relaxation and 129Xe NMR chemical shift measurements offer complementary information to study weak protein-protein interactions. They have been applied to study the oligomerization equilibrium of a low-molecular-weight protein tyrosine phosphatase in the presence of 50 mM arginine and 50 mM glutamic acid. These experimental conditions are shown to enhance specific protein-protein interactions while decreasing nonspecific aggregation. In addition, 129Xe NMR chemical shifts become selective reporters of one particular oligomer in the presence of arginine and glutamic acid, indicating that a specific Xe binding site is created in the oligomerization process. It is suggested that the multiple effects of arginine and glutamic acid are related to their effective excluded volume that favors specific protein association and the destabilization of partially unfolded forms that preferentially interact with xenon and are responsible for nonspecific protein aggregation.
Blobel
Jascha
J
Laboratory of Biomolecular NMR, Institute for Research in Biomedicine, Parc Científic de Barcelona, Josep Samitier, 1-5, E-08028 Barcelona, Spain.
Schmidl
Sabine
S
Vidal
David
D
Nisius
Lydia
L
Bernadó
Pau
P
Millet
Oscar
O
Brunner
Eike
E
Pons
Miquel
M
D001120:Arginine / Q000737:chemistry*; D001704:Biopolymers / Q000737:chemistry*; D018698:Glutamic Acid / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry*; D014978:Xenon
D001704:Biopolymers; D009587:Nitrogen Isotopes; D014978:Xenon; D018698:Glutamic Acid; D001120:Arginine; D017027:Protein Tyrosine Phosphatases