Site-specific modification of a single-chain antibody using a novel glyoxylyl-based labeling reagent

Zhan G. Zhao, Jin S. Im, Kit Lam, Douglas F. Lake

Research output: Contribution to journalArticle

29 Scopus citations


A novel, highly specific protein modification approach is described. By using conventional molecular cloning techniques, a protein can be constructed and expressed such that the N-terminal residue is replaced by cysteine. Its 1,2-aminothiol structure reacts very specifically with a glyoxylyl group at pH 7 or below, forming a relatively stable thiazolidine bridge. Therefore, a glyoxylyl-based labeling agent (e.g., radioactive tags, fluorescent probes, biotin) can be used to specifically modify a protein at its N-terminus. To highlight this novel approach, a recombinant anti-insulin single chain antibody (scFv) was specifically biotinylated at its N-terminus even in the presence of other proteins in the total cell lysate. The glyoxylyl-biotinylated scFv retained binding activity similar to unmodified scFv.

Original languageEnglish (US)
Pages (from-to)424-430
Number of pages7
JournalBioconjugate Chemistry
Issue number3
StatePublished - May 1999
Externally publishedYes


ASJC Scopus subject areas

  • Chemistry(all)
  • Organic Chemistry
  • Clinical Biochemistry
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry

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