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A Functional Analysis of the Projection Domain of the Microtubule Associated Protein Tau Using Force Spectroscopy
Author(s) -
Saunders Jared,
Donhauser Zachary
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.1036.4
Subject(s) - microtubule , tau protein , biophysics , force spectroscopy , microtubule associated protein , chemistry , projection (relational algebra) , domain (mathematical analysis) , ionic strength , mica , physics , molecule , biology , microbiology and biotechnology , mathematics , algorithm , medicine , mathematical analysis , disease , organic chemistry , pathology , alzheimer's disease , paleontology , aqueous solution
The microtubule associated proteins (MAP) tau helps stabilize and organize microtubules and plays a role in several neurodegenerative diseases. This study focused specifically on the projection domain of the tau protein, which is a region of the protein that projects outward from the microtubule surface in the tau‐microtubule complex and controls spacing between microtubules in vivo. Our aim was to measure the long‐range repulsive interactions produced by the projection domains of three versions of tau, where this region has been modified, using atomic force microscopy and force spectroscopy. The tau is immobilized on mica surfaces, a model substrate that binds protein in a similar manner to microtubules. We found that as increasingly larger portions of tau's projection domain are removed, the long‐range repulsive interactions decrease. Systematic examination of the behavior of the protein under a range of experimental conditions indicated that a high ionic strength solution essentially removes the long‐range tau‐tau interactions and is consistent with interactions that are primarily electrostatic in nature. Furthermore, we have determined that buffer type does not influence force measurements of the protein, which is evidence that our measurements may be generalized to describe how tau behaves in vivo.