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Electrochemical Investigations of Tau Protein Phosphorylations and Interactions with Pin1
Author(s) -
Martić Sanela,
Beheshti Samaneh,
Kraatz HeinzBernhard,
Litchfield David W.
Publication year - 2012
Publication title -
chemistry and biodiversity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 70
eISSN - 1612-1880
pISSN - 1612-1872
DOI - 10.1002/cbdv.201100418
Subject(s) - pin1 , chemistry , phosphorylation , isomerase , dielectric spectroscopy , tau protein , biophysics , peptidylprolyl isomerase , electrochemistry , biochemistry , enzyme , electrode , alzheimer's disease , biology , medicine , disease , pathology
Phosphorylation of Tau by the protein kinase GSK‐3 β was monitored by electrochemical impedance spectroscopy of immobilized Tau on gold surfaces. As a result of Tau phosphorylation, the film resistance decreases significantly due to conformational changes and reorganization of the immobilized phosphorylated Tau (pTau) protein, which in turn enables the interactions of pTau with the peptidyl‐prolyl cis / trans isomerase, Pin1. Interactions are specific to phospho‐Ser (pSer) and phospho‐Thr (pThr) residues of pTau. Impedance changes occurred as a function of pTauPin1 interactions and are related to the amount of Pin1 bound, which resulted in an increase of the charge‐transfer resistance, R CT . Our results clearly indicate that the isomerase Pin1 interacts favorably with pSer/pThr‐Pro residues in Tau, but does not bind non‐phosphorylated Tau or phospho‐Tyr residues in Tau films. Our study demonstrates the utility of electrochemical impedance studies to probe protein modifications and biomolecular interactions.