Single-site glycine-specific labeling of proteins Journal Articles uri icon

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  • AbstractLabeling of native proteins invites interest from diverse segments of science. However, there remains the significant unmet challenge in precise labeling at a single¬†site of a protein. Here, we report the site-specific labeling of natural or easy-to-engineer N-terminus Gly in proteins with remarkable efficiency and selectivity. The method generates a latent nucleophile from N-terminus imine that reacts with an aldehyde¬†to deliver an aminoalcohol under physiological conditions. It differentiates N-Gly as a unique target amongst other proteinogenic amino acids. The method allows single-site labeling of proteins in isolated form and extends to lysed cells. It administers an orthogonal aldehyde group primed for late-stage tagging with an affinity tag, 19F NMR probe, and a fluorophore. A user-friendly protocol delivers analytically pure tagged proteins. The mild reaction conditions do not alter the structure and function of the protein. The cellular uptake of fluorophore-tagged insulin and its ability to activate the insulin-receptor mediated signaling remains unperturbed.


  • Purushottam, Landa
  • Adusumalli, Srinivasa Rao
  • Singh, Usha
  • Unnikrishnan, VB
  • Rawale, Dattatraya Gautam
  • Gujrati, Mansi
  • Mishra, Ram
  • Rai, Vishal

publication date

  • June 10, 2019