Kappa chain

The presence of oligoclonal free kappa and lambda chains in CSF is a sensitive indication for recent antigenic immune response within the central nervous system, comparable with IgM. The detection of oligoclonal free kappa chains in CSF supports the diagnosis of multiple sclerosis. In addition, free light chains can also be found in the CSF of patients having inflammatory diseases of the central nervous system (LI). 

Alemtuzumab is a humanized IgGi with a kappa chain that binds to CD52 found on normal and malignant and T lymphocytes,... 

Genes Encoding Human and Mouse Kappa Chains... 

Stavnezer, J., Huang, R.C.C., Stavnezer, E., Bishop, J.M. (1974). Isolation of messenger RNA for an immunoglobulin kappa chain and enumeration of the genes for the constant region of kappa chain in the mouse. J. Mol. Biol. 88,43-63. 

Domer, T., S. J. Foster, N. L. Famer, and P. E. Lipsky. 1998. Immunoglobulin kappa chain receptor editing in systemic lupus erythematosus. J. Clin. Invest. 102 688-694. 

Kappa chain composition Protein L Stereospecific complex effect... 

Broad specificity similar to that of pepsin A. Clots milk by cleavageof a single bond in casein (kappa chain). 

Kotula, L. and Curtis, P.J. (1991) Evaluation of foreign gene codon optimization in yeast expression of a mouse Ig kappa chain. Nat. Biotechnol, 9 (12), 1386-1389. 

The variable regions of both k and X chains can be divided into subgroups, according to homologies in amino acid sequence. These subdivisions are based on sequences of L chains of myeloma proteins and of Bence Jones proteins. Kappa chains fall naturally into three major subgroups on the basis of the length of the variable region and the presence of certain amino acids at particular positions in the sequence. ... 

We should emphasize that these generalizations apply to human and rabbit immunoglobulins and that interspecies variability exists for example, mouse kappa chains isolated from IgG may be only sparingly soluble in neutral buffer. 

The Inv system can be described in terms of amino acid sequence. Kappa chains which are Inv(l,2,—3) have leucine at position 191, whereas chains which are Inv(—1,—2,3) have valine at this position (187-189). More recently, a Bence Jones protein which is Inv(l,—2,—3) was examined and found to have leucine at position 191 (189a). Unexpectedly, valine was found at position 153 in place of alanine. Valine had not previously been identified at position 153 because of the rarity of proteins which are Inv(l,—2,—3). The relationship between Inv type and sequence is ... 

Three genetic markers have been described for the L chains. These were initially called Inv markers but are now designated Km(l), Km(2) and Km(3) because they are all on the k chain. They played an important role in early work on Ig genetics but their importance has decreased, partially due to the lack of availability of good reagents. The Km(l) and (2) markers frequently but not always occur together on the same kappa chain while the (3) marker is inherited as if controlled by an allelic gene. 

A new reagent is Protein L from Peptococcus magnus which binds to Ig kappa chains (14,15). In principle this provide an alternative to Protein A and G as well as being appropriate for Fab and scFv fragments. As well as being specific for kappa light chains. Protein L is reported to bind human Ig better than rat or mouse. As yet there is no widespread experience—however, it appears to be very useful for IgM antibodies and other antibodies and their fragments whidi do not bind Protein A or G. 

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