Natural human tumor necrosis factor beta (lymphotoxin). Variable O-glycosylation at Thr7, proteolytic processing, and allelic variation

FEBS Lett. 1992 Dec 7;314(1):85-8. doi: 10.1016/0014-5793(92)81467-z.

Abstract

Natural human tumor necrosis factor beta (TNF-beta) purified from supernatants of a human B-lymphoblastoid cell line was found to be heterogeneous in molecular mass, with seven components resolved by gel electrophoresis. All components are N-glycosylated at Asn62; N-glycosylation does not contribute to heterogeneity. In addition, part of the molecules are O-glycosylated at Thr7; O-glycosylation is heterogeneous due to variable decoration with neuraminic acid. The four lower molecular mass forms are derived from the full-length protein by trypsin-like proteolytic cleavage in the N-proximal region; these clipped molecules lack O-linked carbohydrates. Two allelic variants differing in amino acid position 26 (threonine/asparagine) were identified.

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Asparagine / metabolism
  • B-Lymphocytes / chemistry*
  • Genetic Variation
  • Glycosylation
  • Humans
  • Lymphotoxin-alpha / genetics*
  • Lymphotoxin-alpha / isolation & purification
  • Lymphotoxin-alpha / metabolism*
  • Molecular Sequence Data
  • Neuraminic Acids / analysis
  • Protein Processing, Post-Translational*
  • Threonine / metabolism

Substances

  • Lymphotoxin-alpha
  • Neuraminic Acids
  • Threonine
  • Asparagine