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Site-Specific Lysine Lactylation via Genetic Code Expansion in E. coli and Mammalian Cells
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Site-Specific Lysine Lactylation via Genetic Code Expansion in E. coli and Mammalian Cells

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A lysine-free mutant of epidermal growth factor as targeting moiety of a targeted toxin

Christopher Bachran1, Stefanie Schneider, Sebastian B Riese

  • 1Charité - Universitätsmedizin Berlin, Zentralinstitut für Laboratoriumsmedizin und Pathobiochemie, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany.

Life Sciences
|November 25, 2010
PubMed
Abstract

Insights

Engineered epidermal growth factor (EGF) with modified lysines retains high specificity for EGF receptor. This EGF variant is suitable for targeted cancer therapies and drug delivery systems.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Oncology

Background:

  • Epidermal Growth Factor (EGF) receptor is overexpressed in various human tumors, presenting a therapeutic target.
  • EGF is a potential ligand for targeting tumor cells, but chemical conjugation challenges limit its application.
  • Current therapies include antibodies and tyrosine kinase inhibitors, but EGF offers an alternative approach.

Purpose of the Study:

  • To design and characterize a modified EGF variant for improved conjugation and targeted therapy.
  • To assess the binding affinity and specificity of the engineered EGF to the EGF receptor.
  • To evaluate the cytotoxic potential of a fusion protein incorporating the modified EGF.

Main Methods:

  • Engineered an EGF variant (EGF(RR)) by substituting lysines at positions 28 and 48 with arginines.
  • Fused EGF(RR) to the saporin toxin to create a model fusion protein.
  • Analyzed EGF receptor binding, saporin enzymatic activity, and fusion protein cytotoxicity.

Main Results:

  • EGF(RR) exhibited retained specificity for the EGF receptor, though with a 5.5-fold increase in Kd.
  • The enzymatic activity of the fused saporin was reduced 2.3-fold.
  • Cytotoxicity of the EGF(RR)-saporin fusion protein remained comparable to the wild-type EGF fusion protein.

Conclusions:

  • The EGF(RR) variant maintains high specificity for the EGF receptor.
  • EGF(RR) is a promising candidate for chemical linkage applications, including drug and dye targeting.
  • This engineered ligand facilitates targeted delivery to EGF receptor-expressing cancer cells.

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