Immunoglobulin-binding domains: Protein L from Peptostreptococcus magnus

Biochem Soc Trans. 2003 Jun;31(Pt 3):716-8. doi: 10.1042/bst0310716.

Abstract

Protein L is a multidomain cell-wall protein isolated from Peptostreptococcus magnus. It belongs to a group of proteins that contain repeated domains that are able to bind to Igs without stimulating an immune response, the most characterized of this group being Protein A ( Staphylococcus aureus ) and Protein G ( Streptococcus ). Both of these proteins bind predominantly to the interface of C(H)2-C(H)3 heavy chains, while Protein L binds exclusively to the V(L) domain of the kappa -chain. The function of these proteins in vivo is not clear but it is thought that they enable the bacteria to evade the host's immune system. Two binding sites for kappa -chain on a single Ig-binding domain from Protein L have recently been reported and we give evidence that one site has a 25-55-fold higher affinity for kappa -chain than the second site.

Publication types

  • Review

MeSH terms

  • Amino Acid Sequence
  • Antigens, Bacterial / immunology*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / immunology*
  • Binding Sites
  • Epitopes / chemistry
  • Epitopes / immunology
  • Immunoglobulins / chemistry*
  • Ligands
  • Molecular Sequence Data
  • Peptostreptococcus / immunology*

Substances

  • Antigens, Bacterial
  • Bacterial Proteins
  • Epitopes
  • Ig L-binding protein, Peptostreptococcus
  • Immunoglobulins
  • Ligands