Protein L was first isolated from the surface of bacterial species Peptostreptococcus magnus and was found to bind immunoglobulins through L chain interaction, from which the name was suggested.[2] It consists of 719 amino acid residues.[3] The molecular weight of protein L purified from the cell walls of Peptostreptoccus magnus was first estimated as 95kD by SDS-PAGE in the presence of reducing agent 2-mercaptoethanol, while the molecular weight was determined to 76kD by gel chromatography in the presence of 6 M guanidine HCl. Protein L does not contain any interchain disulfide loops, nor does it consist of disulfide-linked subunits. It is an acidic molecule with a pI of 4.0.[4] Unlike protein A and protein G, which bind to the Fc region of immunoglobulins (antibodies), protein L binds antibodies through light chain interactions. Since no part of the heavy chain is involved in the binding interaction, Protein L binds a wider range of antibody classes than protein A or G. Protein L binds to representatives of all antibody classes, including IgG, IgM, IgA, IgE and IgD. Single chain variable fragments (scFv) and Fab fragments also bind to protein L.
Despite this wide binding range, protein L is not a universal antibody-binding protein. Protein L binding is restricted to those antibodies that contain kappa light chains. In humans and mice, most antibody molecules contain kappa (κ) light chains and the remainder have lambda (λ) light chains. Protein L is only effective in binding certain subtypes of kappa light chains. For example, it binds human VκI, VκIII and VκIV subtypes but does not bind the VκII subtype. Binding of mouse immunoglobulins is restricted to those having VκI light chains.[5]
Given these specific requirements for effective binding, the main application for immobilized protein L is purification of monoclonal antibodies from ascites or cell culturesupernatant that are known to have the kappa light chain. Protein L is extremely useful for purification of VLκ-containing monoclonal antibodies from culture supernatant because it does not bind bovine immunoglobulins, which are often present in the media as a serum supplement. Also, protein L does not interfere with the antigen-binding site of the antibody, making it useful for immunoprecipitation assays, even using IgM.
Gene for protein Ledit
The gene for protein L contains five components: a signal sequence of 18 amino acids; a NH2-terminal region ("A") of 79 residues; five homologous "B" repeats of 72-76 amino acids each; a COOH terminus region of two additional "C" repeats (52 amino acids each); a hydrophilic, proline-rich putative cell wall-spanning region ("W") after the C repeats; a hydrophobic membrane anchor ("M"). The B repeats (36kD) were found to be responsible for the interaction with Ig light chains.[2]
Other antibody binding proteinsedit
In addition to protein L, other immunoglobulin-binding bacterial proteins such as protein A, protein G and protein A/G are all commonly used to purify, immobilize or detect immunoglobulins. Each of these immunoglobulin-binding proteins has a different antibody binding profile in terms of the portion of the antibody that is recognized and the species and type of antibodies it will bind.
Referencesedit
^Graille M, Harrison S, Crump MP, Findlow SC, Housden NG, Muller BH, Battail-Poirot N, Sibaï G, Sutton BJ, Taussig MJ, Jolivet-Reynaud C, Gore MG, Stura EA (December 2002). "Evidence for plasticity and structural mimicry at the immunoglobulin light chain-protein L interface". J Biol Chem. 277 (49): 47500–6. doi:10.1074/jbc.M206105200. PMID 12221088.
^Björck L (February 1988). "Protein L. A novel bacterial cell wall protein with affinity for Ig L chains". J. Immunol. 140 (4): 1194–7. doi:10.4049/jimmunol.140.4.1194. PMID 3125250. S2CID 35781778.
^Kastern W, Sjöbring U, Björck L (June 1992). "Structure of peptostreptococcal protein L and identification of a repeated immunoglobulin light chain-binding domain". J. Biol. Chem. 267 (18): 12820–5. doi:10.1016/S0021-9258(18)42349-6. PMID 1618782.
^Akerström B, Björck L (November 1989). "Protein L: an immunoglobulin light chain-binding bacterial protein. Characterization of binding and physicochemical properties". J. Biol. Chem. 264 (33): 19740–6. doi:10.1016/S0021-9258(19)47174-3. PMID 2479638.
^Nilson BH, Lögdberg L, Kastern W, Björck L, Akerström B (August 1993). "Purification of antibodies using protein L-binding framework structures in the light chain variable domain". J. Immunol. Methods. 164 (1): 33–40. doi:10.1016/0022-1759(93)90273-a. PMID 8360508.
January 01, 1970
protein, first, isolated, from, surface, bacterial, species, peptostreptococcus, magnus, found, bind, immunoglobulins, through, chain, interaction, from, which, name, suggested, consists, amino, acid, residues, molecular, weight, protein, purified, from, cell,. Protein L was first isolated from the surface of bacterial species Peptostreptococcus magnus and was found to bind immunoglobulins through L chain interaction from which the name was suggested 2 It consists of 719 amino acid residues 3 The molecular weight of protein L purified from the cell walls of Peptostreptoccus magnus was first estimated as 95kD by SDS PAGE in the presence of reducing agent 2 mercaptoethanol while the molecular weight was determined to 76kD by gel chromatography in the presence of 6 M guanidine HCl Protein L does not contain any interchain disulfide loops nor does it consist of disulfide linked subunits It is an acidic molecule with a pI of 4 0 4 Unlike protein A and protein G which bind to the Fc region of immunoglobulins antibodies protein L binds antibodies through light chain interactions Since no part of the heavy chain is involved in the binding interaction Protein L binds a wider range of antibody classes than protein A or G Protein L binds to representatives of all antibody classes including IgG IgM IgA IgE and IgD Single chain variable fragments scFv and Fab fragments also bind to protein L Protein L b1 domainStructure of protein L binding to the light chain of a murine Fab PDB 1MHH 1 IdentifiersSymbolPpLPfamPF02246InterProIPR003147SCOP21MHH SCOPe SUPFAMAvailable protein structures Pfam structures ECOD PDBRCSB PDB PDBe PDBjPDBsumstructure summaryPDB1mhh 1xcq 1xct 1hez 1ynt 1xf5 1ymh 1k52 1k50 1hz5 1hz6 1k51 1k53 2ptl 2jzp 2kac 1jml 1kh0 Despite this wide binding range protein L is not a universal antibody binding protein Protein L binding is restricted to those antibodies that contain kappa light chains In humans and mice most antibody molecules contain kappa k light chains and the remainder have lambda l light chains Protein L is only effective in binding certain subtypes of kappa light chains For example it binds human VkI VkIII and VkIV subtypes but does not bind the VkII subtype Binding of mouse immunoglobulins is restricted to those having VkI light chains 5 Given these specific requirements for effective binding the main application for immobilized protein L is purification of monoclonal antibodies from ascites or cell culture supernatant that are known to have the kappa light chain Protein L is extremely useful for purification of VLk containing monoclonal antibodies from culture supernatant because it does not bind bovine immunoglobulins which are often present in the media as a serum supplement Also protein L does not interfere with the antigen binding site of the antibody making it useful for immunoprecipitation assays even using IgM Gene for protein L editThe gene for protein L contains five components a signal sequence of 18 amino acids a NH2 terminal region A of 79 residues five homologous B repeats of 72 76 amino acids each a COOH terminus region of two additional C repeats 52 amino acids each a hydrophilic proline rich putative cell wall spanning region W after the C repeats a hydrophobic membrane anchor M The B repeats 36kD were found to be responsible for the interaction with Ig light chains 2 Other antibody binding proteins editIn addition to protein L other immunoglobulin binding bacterial proteins such as protein A protein G and protein A G are all commonly used to purify immobilize or detect immunoglobulins Each of these immunoglobulin binding proteins has a different antibody binding profile in terms of the portion of the antibody that is recognized and the species and type of antibodies it will bind References edit Graille M Harrison S Crump MP Findlow SC Housden NG Muller BH Battail Poirot N Sibai G Sutton BJ Taussig MJ Jolivet Reynaud C Gore MG Stura EA December 2002 Evidence for plasticity and structural mimicry at the immunoglobulin light chain protein L interface J Biol Chem 277 49 47500 6 doi 10 1074 jbc M206105200 PMID 12221088 Bjorck L February 1988 Protein L A novel bacterial cell wall protein with affinity for Ig L chains J Immunol 140 4 1194 7 doi 10 4049 jimmunol 140 4 1194 PMID 3125250 S2CID 35781778 Kastern W Sjobring U Bjorck L June 1992 Structure of peptostreptococcal protein L and identification of a repeated immunoglobulin light chain binding domain J Biol Chem 267 18 12820 5 doi 10 1016 S0021 9258 18 42349 6 PMID 1618782 Akerstrom B Bjorck L November 1989 Protein L an immunoglobulin light chain binding bacterial protein Characterization of binding and physicochemical properties J Biol Chem 264 33 19740 6 doi 10 1016 S0021 9258 19 47174 3 PMID 2479638 Nilson BH Logdberg L Kastern W Bjorck L Akerstrom B August 1993 Purification of antibodies using protein L binding framework structures in the light chain variable domain J Immunol Methods 164 1 33 40 doi 10 1016 0022 1759 93 90273 a PMID 8360508 Retrieved from https en wikipedia org w index php title Protein L amp oldid 1198091900, wikipedia, wiki, book, books, library,
