Circularly permuted interleukin 4 retains proliferative and binding activity

Cytokine. 1995 May;7(4):311-8. doi: 10.1006/cyto.1995.0039.

Abstract

In human interleukin 4(IL-4), the carboxyl and amino termini of the 129 amino acid hormone are close to each other and this region is believed to be important for binding to the IL-4 receptor (IL-4r). We constructed plasmids encoding circularly permuted IL-4 mutants with the peptide Gly-Gly-Asn-Gly-Gly (GGNGG) joining the carboxyl to the amino terminus and with new amino and carboxyl termini elsewhere. Mutant IL-4(38-37) is composed of IL-4 residues 38-129 GGNGG and 1-37. Mutant IL-4(105-104) is composed of IL-4 residues 105-129, GGNGG and 1-104. IL-4(38-37) and IL-4(105-104) were purified from E. coli to near homogeneity and retained 50-100% of the binding and proliferative activity of IL-4, and in addition retained the ability to upregulate CD23 on Burkitt's lymphoma cells. Circular dichroism studies indicated that the tertiary structures of both IL-4(38-37) and IL-4(105-104) were retained, with the former molecule most similar to native IL-4. We conclude that while both native termini of IL-4 may be near its binding site, neither is required to be free for optimum activity.

MeSH terms

  • Amino Acid Sequence
  • B-Lymphocytes / drug effects
  • B-Lymphocytes / immunology
  • Base Sequence
  • Burkitt Lymphoma / pathology
  • Cell Division / drug effects
  • Circular Dichroism
  • Escherichia coli
  • Humans
  • Interleukin-4 / analogs & derivatives*
  • Interleukin-4 / chemistry
  • Interleukin-4 / pharmacology
  • Molecular Sequence Data
  • Mutagenesis
  • Polymerase Chain Reaction
  • Protein Structure, Tertiary
  • Receptors, IgE / biosynthesis
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / pharmacology
  • Tumor Cells, Cultured

Substances

  • Receptors, IgE
  • Recombinant Fusion Proteins
  • Interleukin-4