Isolation and rapid sequence characterization of two novel bovine beta-lactoglobulins I and J

J Protein Chem. 1996 Nov;15(8):743-50. doi: 10.1007/BF01887148.


Two novel bovine beta-lactoglobulins I and J have been isolated from bovine milk and characterized by isoelectric focusing. Their primary structure was determined by a very rapid method consisting of a combination of Edman sequencing, mass analysis, and ladder sequencing by mass spectrometry. We found that both new beta-lactoglobulins are of the bovine beta-lactoglobulin B-variant type. beta-lactoglobulin I shows Gly instead of Glu at position 108, whereas beta-lactoglobulin J shows a Pro-to-Leu exchange at position 126.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cattle
  • Isoelectric Focusing
  • Isoelectric Point
  • Lactoglobulins / chemistry*
  • Lactoglobulins / genetics
  • Lactoglobulins / isolation & purification
  • Mass Spectrometry
  • Milk / chemistry
  • Molecular Sequence Data
  • Molecular Weight
  • Organophosphorus Compounds / metabolism
  • Peptides / chemistry
  • Sequence Analysis
  • Sequence Homology
  • Trypsin / metabolism


  • 2-(4-isothiocyanatophenoxy)-1,3,2-dioxaphosphinene 2-oxide
  • Lactoglobulins
  • Organophosphorus Compounds
  • Peptides
  • Trypsin