Imaging the binding ability of proteins immobilized on surfaces with different orientations by using liquid crystals

Yan Yeung Luk, Matthew L. Tingey, Kimberly A. Dickson, Ronald T. Raines, Nicholas L. Abbott

Research output: Contribution to journalArticle

90 Scopus citations

Abstract

We report an investigation of the binding ability of a protein immobilized on surfaces with different orientations but in identical interfacial microenvironments. The surfaces present mixed self-assembled monolayers (SAMs) of 11 -[19-carboxymethylhexa(ethylene glycol)]undecyl-1-thiol, 1, and 11-tetra(ethylene glycol) undecyl-1-thiol, 2. Whereas 2 is used to define an interfacial microenvironment that prevents nonspecific adsorption of proteins, 1 was activated by two different schemes to immobilize ribonuclease A (RNase A) in either a preferred orientation or random orientations. The binding of the ribonuclease inhibitor protein (RI) to RNase A on these surfaces was characterized by using ellipsometry and the orientational behavior of liquid crystals. Ellipsometric measurements indicate identical extents of immobilization of RNase A via the two schemes. Following incubation of both surfaces with RI, however, ellipsometric measurements indicate a 4-fold higher binding ability of the RNase A immobilized with a preferred orientation over RNase A immobilized with a random orientation. The higher binding ability of the oriented RNase A over the randomly oriented RNase A was also apparent in the orientational behavior of nematic liquid crystals of 4-cyano-4′- pentylcyanobiphenyl (5CB) overlayed on these surfaces. These results demonstrate that the orientations of proteins covalently immobilized in controlled interfacial microenvironments can influence the binding activities of the immobilized proteins. Results reported in this article also demonstrate that the orientational states of proteins immobilized at surfaces can be distinguished by examining the optical appearances of liquid crystals.

Original languageEnglish (US)
Pages (from-to)9024-9032
Number of pages9
JournalJournal of the American Chemical Society
Volume126
Issue number29
DOIs
StatePublished - Jul 28 2004

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Fingerprint Dive into the research topics of 'Imaging the binding ability of proteins immobilized on surfaces with different orientations by using liquid crystals'. Together they form a unique fingerprint.

  • Cite this