Fluorescence correlation spectroscopy analysis of the dynamics of tubulin interaction with RB3, a stathmin family protein.
We have used fluorescence correlation spectroscopy to analyze the interaction of GTP-tubulin with rhodamine-labeled RB3, a neural protein of the stathmin family, and to determine the kinetic pathway of the association process. RB3 displayed slow association-dissociation kinetics with tubulin depending on the square of the tubulin concentration. The values of the apparent association and dissociation rate constants of the complex of two tubulin dimers and RB3 are determined to be (3.52+/-0.14)x10(-3) micro;M(-2)/s and (1.9+/-0.6)x10(-3) s(-1) respectively. The value of the equilibrium dissociation constant for the first tubulin-RB3 interaction is estimated to be >or=7 microM at 20 degrees C.
Krouglova
Tatiana
T
Laboratory of Biomolecular Dynamics, University of Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
Amayed
Phedra
P
Engelborghs
Yves
Y
Carlier
Marie-France
MF
D000595:Amino Acid Sequence; D000818:Animals; D004058:Diffusion; D008868:Microtubule Proteins; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000737:chemistry / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid; D013050:Spectrometry, Fluorescence / Q000379:methods*; D050777:Stathmin; D013552:Swine; D014404:Tubulin / Q000378:metabolism*
D008868:Microtubule Proteins; D009414:Nerve Growth Factors; D010750:Phosphoproteins; C491795:STMN4 protein, human; D050777:Stathmin; D014404:Tubulin