Covalent and oriented immobilization of scFv antibody fragments via an engineered glycan moiety

Biomacromolecules. 2013 Jan 14;14(1):153-9. doi: 10.1021/bm301518p. Epub 2012 Dec 21.

Abstract

Antibody-derived fragments have enormous potential application in solid-phase assays such as biomarker detection and protein purification. Controlled orientation of the immobilized antibody molecules is a critical requirement for the sensitivity and efficacy of such assays. We present an approach for covalent, correctly oriented attachment of scFv antibody fragments on solid supports. Glycosylated scFvs were expressed in Escherichia coli and the C-terminal, binding pocket-distal glycan tag was oxidized for covalent attachment to amine-functionalized beads. The glycosylated scFvs could be immobilized at salt concentrations that precluded nonspecific adsorption of unglycosylated molecules and the covalently attached antibody fragments exhibited 4-fold higher functional activity than ionically adsorbed scFvs. The glyco-tethered scFvs were stable in NaCl concentrations that removed greater than 90% of adsorbed scFvs and they exhibited improved stability of antigen binding over both adsorbed scFvs and soluble, nonimmobilized scFvs in accelerated degradation tests. The simple expression and immobilization approach reported is likely to find broad application in in vitro antibody tests.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Immobilized / chemistry
  • Antibodies, Immobilized / metabolism*
  • Binding Sites / physiology
  • Campylobacter jejuni / metabolism
  • Polysaccharides / chemistry
  • Polysaccharides / metabolism*
  • Protein Engineering / methods*
  • Protein Structure, Secondary
  • Single-Chain Antibodies / chemistry
  • Single-Chain Antibodies / metabolism*

Substances

  • Antibodies, Immobilized
  • Polysaccharides
  • Single-Chain Antibodies