Immunoglobulin-binding domains: Protein L from Peptostreptococcus magnus.
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.
Housden
N G
NG
Division of Biochemistry and Molecular Biology, Institute of Biomolecular Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK.
Harrison
S
S
Roberts
S E
SE
Beckingham
J A
JA
Graille
M
M
Stura
E
E
Gore
M G
MG
D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology*; D001665:Binding Sites; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D007136:Immunoglobulins / Q000737:chemistry*; D008024:Ligands; D008969:Molecular Sequence Data; D010462:Peptostreptococcus / Q000276:immunology*
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D000939:Epitopes; C055047:Ig L-binding protein, Peptostreptococcus; D007136:Immunoglobulins; D008024:Ligands