Immunoglobulin-binding domains: Protein L from Peptostreptococcus magnus

Nicholas G Housden (1) , Steven Harrison (1) , Hazel R Housden (1) , Karen-Anne Thomas (1) , Jennifer A Beckingham (1) , Siân E Roberts (1) , Stephen P Bottomley (1) , Marc Graille (2) , Enrico Stura (2) , Michael G Gore (1)

1 University of Southampton
2 DIEP - Département d'Ingenierie et d'Etudes des Protéines

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 κ-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 κ-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 κ-chain than the second site.

Domaines: Biologie structurale [q-bio.BM]; Bactériologie

Nicholas G Housden, Steven Harrison, Hazel R Housden, Karen-Anne Thomas, Jennifer A Beckingham, et al.. Immunoglobulin-binding domains: Protein L from Peptostreptococcus magnus. Journal of Biological Chemistry, 2003, 279 (10), pp.9370 - 9378. ⟨10.1074/jbc.m312938200⟩. ⟨hal-03299363⟩