Structure of recombinant human interleukin 5 produced by Chinese hamster ovary cells

J Biochem. 1990 Feb;107(2):292-7. doi: 10.1093/oxfordjournals.jbchem.a123041.


The complete peptide map of purified recombinant human interleukin 5 (rhIL-5) was determined to verify its primary structure, glycosylation sites, and disulfide bonding structure. Each peptide fragment generated by Achromobacter protease I (API) digestion was purified and characterized by amino acid analysis and amino acid sequence analysis. After digestion with API, we could identify all the peptides which were expected from human IL-5 cDNA sequence. The analyses of sulfhydryl content in rhIL-5 molecule and disulfide-containing peptide obtained from API digestion indicated that active form of rhIL-5 existed as an antiparallel dimer linked by two pairs of Cys-44 and Cys-86. In addition, we concluded that Thr-3 and Asn-28 were glycosylated. The results indicate that primary structure of rhIL-5 is highly homogeneous and observed heterogeneity is due to the difference in the content of carbohydrate.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cricetinae
  • Disulfides
  • Female
  • Glycosylation
  • Interleukin-5 / isolation & purification*
  • Molecular Sequence Data
  • Ovary / cytology
  • Peptide Mapping
  • Recombinant Proteins / isolation & purification*


  • Disulfides
  • Interleukin-5
  • Recombinant Proteins