Purification and characterization of human interleukin-1 alpha produced in Escherichia coli

Eur J Biochem. 1987 Jun 15;165(3):537-41. doi: 10.1111/j.1432-1033.1987.tb11472.x.

Abstract

The production of human interleukin-1 alpha (IL-1 alpha) in Escherichia coli is described together with a method for its purification. The isolated protein was shown to be pure and physically homogeneous. The in vitro biological activity of IL-1 alpha was tested with the mononuclear-cell factor and the lymphocyte-activating factor assays. The specific activity determined with both assays was about 3 X 10(7) units mg-1 and is similar to that observed with recombinant human IL-1 beta. The purified protein was resolved by chromatofocusing into two species of isoelectric points 5.45 and 5.20 (75% and 25%, respectively, of the total protein). Both species had similar chemical properties and biological activities to the unfractionated protein. The charge difference between the species was attributed to the deamidation of a single Asn or Gln residue.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / analysis
  • DNA
  • Electrophoresis, Polyacrylamide Gel
  • Escherichia coli / metabolism*
  • Humans
  • Interleukin-1 / biosynthesis
  • Interleukin-1 / isolation & purification*
  • Interleukin-1 / physiology
  • Isoelectric Focusing
  • Molecular Weight
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / physiology
  • Spectrophotometry, Ultraviolet
  • Ultracentrifugation

Substances

  • Amino Acids
  • Interleukin-1
  • Recombinant Proteins
  • DNA