Tau protein binds single-stranded DNA sequence specifically--the proof obtained in vitro with non-equilibrium capillary electrophoresis of equilibrium mixtures.
Tau is a microtubule-associated protein, which plays an important role in physiology and pathology of neurons. Tau has been recently reported to bind double-stranded DNA (dsDNA) but not to bind single-stranded DNA (ssDNA) [Cell. Mol. Life Sci. 2003, 60, 413-421]. Here, we prove that tau binds not only dsDNA but also ssDNA. This finding was facilitated by using two kinetic capillary electrophoresis methods: (i) non-equilibrium capillary electrophoresis of equilibrium mixtures (NECEEM); (ii) affinity-mediated NECEEM. Using the new approach, we observed, for the first time, that tau could induce dissociation of strands in dsDNA by binding one of them in a sequence-specific fashion. Moreover, we determined the equilibrium dissociation constants for all tau-DNA complexes studied.
Krylova
Svetlana M
SM
Department of Chemistry, York University, Toronto, Ont., Canada M3J 1P3.
Musheev
Michael
M
Nutiu
Razvan
R
Li
Yingfu
Y
Lee
Gloria
G
Krylov
Sergey N
SN
D000818:Animals; D001483:Base Sequence; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism*; D019075:Electrophoresis, Capillary; D004926:Escherichia coli; D011485:Protein Binding; D013379:Substrate Specificity; D013816:Thermodynamics; D016875:tau Proteins / Q000378:metabolism*
D004277:DNA, Single-Stranded; D016875:tau Proteins