Measurement of small molecule binding kinetics on a protein microarray by plasmonic-based electrochemical impedance imaging

Wenbin Liang, Shaopeng Wang, Fernanda Festa, Peter Wiktor, Wei Wang, Dewey Magee, Joshua LaBaer, Nongjian Tao

Research output: Contribution to journalArticle

25 Scopus citations

Abstract

We report on a quantitative study of small molecule binding kinetics on protein microarrays with plasmonic-based electrochemical impedance microscopy (P-EIM). P-EIM measures electrical impedance optically with high spatial resolution by converting a surface charge change to a surface plasmon resonance (SPR) image intensity change, and the signal is not scaled to the mass of the analyte. Using P-EIM, we measured binding kinetics and affinity between small molecule drugs (imatinib and SB202190) and their target proteins (kinases Abl1 and p38-α). The measured affinity values are consistent with reported values measured by an indirect competitive binding assay. We also found that SB202190 has weak bindings to ABL1 with KD > 10 μM, which is not reported in the literature. Furthermore, we found that P-EIM is less prone to nonspecific binding, a long-standing issue in SPR. Our results show that P-EIM is a novel method for high-throughput measurement of small molecule binding kinetics and affinity, which is critical to the understanding of small molecules in biological systems and discovery of small molecule drugs.

Original languageEnglish (US)
Pages (from-to)9860-9865
Number of pages6
JournalAnalytical chemistry
Volume86
Issue number19
DOIs
StatePublished - Oct 7 2014

ASJC Scopus subject areas

  • Analytical Chemistry

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