Site-specific and complete enzymic deglycosylation of the native human chorionic gonadotropin alpha-subunit

Eur J Biochem. 1995 Aug 1;231(3):754-60. doi: 10.1111/j.1432-1033.1995.tb20758.x.


Numerous studies have shown that glycosylation of the alpha-subunit of human chorionic gonadotropin (alpha hCG) is essential for the biological activity of this hormone. To obtain detailed insight into the function of N-glycosylation, the availability of site-specifically and fully deglycosylated alpha-subunits obtained under non-denaturing conditions is a prerequisite. NMR spectroscopy in combination with FAB-mapping demonstrates that only Asn52 of the alpha-subunit is accessible to digestion by peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase F under native conditions. Treatment of native alpha hCG with endo-beta-N-acetylglucosaminidase B results in full deglycosylation yielding alpha hCG with one GlcNAc residue at both Asn52 and Asn78.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amidohydrolases / metabolism
  • Amino Acid Sequence
  • Carbohydrate Sequence
  • Glycoprotein Hormones, alpha Subunit / metabolism*
  • Glycosylation
  • Humans
  • Magnetic Resonance Spectroscopy
  • Molecular Sequence Data
  • Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase
  • Spectrometry, Mass, Fast Atom Bombardment


  • Glycoprotein Hormones, alpha Subunit
  • Amidohydrolases
  • Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase