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Covalent Immobilization of Proteins for the Single Molecule Force Spectroscopy
Published on: August 20, 2018
Application of HaloTag protein to covalent immobilization of recombinant proteins for single molecule force
Yukinori Taniguchi1, Masaru Kawakami
1School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan.
Abstract:
We have developed the HaloTag system for the covalent immobilization of polyproteins onto a mica substrate for single molecule force spectroscopy using the atomic force microscope. A recombinant fusion polyprotein of titin I27 with HaloTag7 protein was produced, and the covalent and site-specific attachment on a HaloTag-ligand-modified mica surface was confirmed by force-extension measurements. Two mechanical unfolding intermediates of HaloTag7 protein were found by contour length analysis. This tethering method allows site-specific covalent immobilization of a protein that complements the standard method utilizing thiol-gold interaction, thus facilitating force-extension measurements for cysteine-containing proteins.

