Evaluation of Interaction Between Histidine Binding Cu²⁺ Ion and Histidine by Atomic Force Microscopy

Abstract

This paper presents a direct interaction force measurement between histidine molecules using AFM force-distance curve measurement. AFM force-distance curves between the histidine-modified cantilever and substrate in the different conditions with or without intercalating Cu2+ ion were measured and interpreted via Gaussian curve fitting analyses. The adhesion force between histidine molecules was shown to be 110 pN under the presence of Cu2+. The result was compareable to the measured adhesion force about 0 pN, which was measured by the removal of Cu2+ ion with the addition of EDTA. The result indicated the direct histidine-histidie interaction was difficult without the role of the bridigible ionic component. From the results, the possibility of direct measurement on chemical affinities between biomolecules was suggested by using AFM force-distance curve analyses. Especially, the current approach showed the possible affinity measurement techniques that elucidate the role of bridge ions.

Observation of Interaction Force in Large Area Between Actin Modified Surface and Actin Antibody Modified Microsphere Probe

“…The original AFM cantilevers were commercially available and pre-coated with Au (OMCL-TR400PB, Olympus). The spring constant of the cantilever, always calibrated by the thermal vibration mode, 16 was nearly 0.07 N/m. After cleaning the cantilever with 1 M HCl solution and rinsing with deionized water, a hemispherical docking adapter was fabricated by the TPAP as shown in Figures 1(a) and (c).…”

Comparative Evaluation of Interaction Force Between Cofilin Protein and Peptide Probe to Actin Protein

“…[21][22][23] In a previous report, some of the authors have presented the usability of peptide probes instead of the one protein for evaluating the force interaction between the two different proteins in pN force levels. 24 Peptide probes were synthesized artificial modules, which were confirmed as the same binding function with the functional region of the original proteins.…”