Baculoviral expression of a natural inhibitor of the human insulin receptor tyrosine kinase

Biochem Biophys Res Commun. 1995 Mar 17;208(2):879-85. doi: 10.1006/bbrc.1995.1417.


We had earlier reported that the human serum alpha 2-HS glycoprotein (1) is a physiological and specific inhibitor of the human insulin receptor tyrosine kinase (IR-TK). We have now expressed this human protein in the baculoviral expression system using the Sf-9 and High Five insect cells. The protein was optimally expressed at 72 h post infection. alpha 2-HSGbac completely inhibited the insulin-stimulated autophosphorylation and TK activity of partially purified IR preparations. It also abolished insulin-induced DNA synthesis in the H-35 rat hepatoma cell line. The effective concentration of the baculoviral derived alpha 2-HSG necessary for inhibiting IR-TK activity was significantly lower than that of the protein purified from human plasma.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Blood Proteins / genetics
  • Blood Proteins / pharmacology*
  • Cell Division / drug effects
  • Cloning, Molecular
  • DNA Primers / chemistry
  • Humans
  • In Vitro Techniques
  • Insulin / pharmacology
  • Molecular Sequence Data
  • Nucleopolyhedroviruses
  • Phosphorylation
  • Protein-Tyrosine Kinases / antagonists & inhibitors
  • Receptor, Insulin / antagonists & inhibitors*
  • Recombinant Proteins / pharmacology
  • Spodoptera
  • Time Factors
  • alpha-2-HS-Glycoprotein


  • AHSG protein, human
  • Blood Proteins
  • DNA Primers
  • Insulin
  • Recombinant Proteins
  • alpha-2-HS-Glycoprotein
  • Protein-Tyrosine Kinases
  • Receptor, Insulin