Protein L, Recombinant, Lyophilized

Protein L is an immunoglobulin-binding protein originally derived from the surface of bacterium Peptostreptococcus magnus. Protein L binds to Ig through the L chain interaction, from which the name was derived. The native Protein L consists of 719 amino acid residues with the molecular weight estimated as 95 kDa by SDS-PAGE analysis. Protein L does not contain any inter chain disulfide loops or disulfide-linked subunits.

Protein L has the unique ability to bind through kappa light chain interaction without interfering with an antibody antigen-binding site. This gives Protein L the ability to bind a wider range of Ig classes compared to Proteins A and G. Protein L can bind to all classes of Ig (IgA, IgD, IgE. IgG and IgM) and single chain variable fragment (scFV), Fab, and Dab fragments. Protein L binds kappa 1, 3, 4, making it optimal for the purification of many newer engineered antibodies.

See Table below for comparison of Protein A, Protein G, Protein A/G and Protein L binding affinities.

Recombit Protein L is expressed in E. coli using innovative liquid-free purification methods. Luna otech's recombit Protein L is a non-glycosylated polypeptide with the molecular mass of 41 kDa that includes 5 IgG-binding regions of Protein L (B1-B5). The cell wall-binding region, cell membrane-binding region and albumin-binding regions have been removed from the recombit Protein L to reduce non-specific binding.

Intended Use

Luna otech Protein L is provided for research laboratory or bioprocessing purposes only. Not for use in diagnostic or theraputic human or animal applications.

Formulation

Lyophilized without additives and carrier free.

Purity

≥ 97% by SDS PAGE and HPLC analysis.

Source

Escherichia coli

Storage

Store at 4°C if entire vial with lyophilized product will be used within 5 weeks. Store, frozen at -20°C . After reconstitution in distilled water or buffer, aliquot and store at -20°C. Avoid repeated freeze / thaw cycles.