Myeloma proteins specificity

Acetyluracil can cause the production of certain pyrimidine-specific antibodies [306]. This interesting activity is responsible for the antibody precipitation of some mouse myeloma proteins [307]. 

Affinity adsorbents having carbohydrate ligands have been used for the isolation and purification of many types of macromolecular substances. To illustrate, several types of antibodies, enzymes, lectins, and myeloma proteins have been obtained in highly purified form. All of the substances that have been purified by this procedure exhibit specificity for a particular carbohydrate moiety. It is the purpose of this article to assemble information on the methods for preparing affinity adsorbents having carbohydrate ligands, and to illustrate the use of these adsorbents for the purification of representative, macromolecular substances. 

Myeloma proteins occur in animal tumors of various types. The synthesis of these proteins can be induced in some experimental animals by injection of mineral oil, or the implantation of plastic discs.161 Myeloma proteins were shown to possess antibody activity, with specificity for different types of substances.161 Some of these proteins were found to combine with such carbohydrates as bacterial, cell-wall polysaccharides, lipopolysaccharides, dextrans, levans, and galactans.162 Myeloma proteins that combine with galactans or dextrans possess anti-galactan activity,163,164 or anti-dextran activity,165-167 and have been studied most extensively. 

The Binding Constants of a Number of Derivatives of D-Galactose with Two IgA Myeloma Proteins Having Anti-galaetan Specificity"... 

For three other myeloma proteins having anti-(l — 6)-a-D-glucopyranan specificity (W 3129, W 3434, and QUPC 52), the authors found a somewhat different pattern of cross-reactivity.63 The reaction of W 3129 with its anti-idiotypic antibody was not totally inhibitable by even high concentrations of W 3434 protein, and not at all by protein QUPC 52. Thus, proteins W 3129 and W 3434 share some determinants, but are clearly different from each other and from QUPC 52. 

Eleven IgA myeloma proteins that precipitate with Pneumococcus C polysaccharide (PnC) have been described.65-69 This antigen has a structure whose general features are known,70 71 and it is a somatic, species-specific polysaccharide. 

Lundblad, A., Steller, R., Kabat, E A, Hirst, J. W., Weigert, M. G., and Cohn, M. (1972) Immunochemical studies on mouse myeloma proteins with specificity for dextran or for levan. Immunochemistry 9, 535—544. 

Myeloma antibodies to fructosans could be divided into two groups those specific for )8-(2- l)-linked fructosans as evidenced by the ability of inulin, a linear/3-(2- l) linked polymer, to precipitate, and those specific for /3-(2- 6) linkages as seen from the reaction with ryegrass levan, a linear polymer of /3-(2- 6) linkages. The j8-(2- l) specific myeloma proteins did not react with ryegrass levan and the /8-(2- 6) specific myeloma proteins did not react with inulin. 

Another crucial development was the finding that the BALB/c (Potter, 1972, 1977a) and later that the NZB strains of mice (Warner, 1975) when injected with paraffin oil develop a disease like multiple myeloma and also often excrete Bence Jones proteins. This not only provided an experimental model, but also permitted detailed comparison of mouse Bence Jones proteins and immunoglobulins with their human counterparts, an indispensable prerequisite for the study of antibody specificity. Relatively enormous quantities (kilograms in some instances) of Bence Jones proteins were obtainable from the urine of patients plasmapheresis yielded substantial quantities of myeloma proteins. Large amounts of the corresponding mouse proteins were also obtainable proteins from such neoplasms were in almost all instances monoclonal and homogeneous. 

Idiotypic specificity—Antibodies and myeloma globulins of a given specificity show differences in antigenic specificity ascribable to differences in sequence in the variable regions of their light and heavy chains. Some of these idiotypic determinants are inhibitable by the antigenic determinant or ligand for which the antibody or myeloma protein is specific, whereas others are not. Those idiotypic determinants which are inhibitable are hypothesized to in-... 

Myeloma protein or antibody specific for Residue labeled0 ... 

Five of the phosphocholine mouse myeloma H chains have Asx 31 while the remaining three and the human protein have Asp. Position 31 is seen to be a surface residue. If the remaining five proteins with Asx are found also to have Asp, it will probably not be in idiotypic4 determinant since the different phosphocholine-binding myeloma proteins have distinct idiotypic specificities although it could also exert a conformational role on other residues in the CDR. 

The accumulation of sequence data on the al —> 6 and al — 3 dex-tran, /32 —> 1 and /32 —> 6 fructosan, and /31 — 6 galactan specific myeloma proteins, for each of which substantial numbers are being studied, should soon provide further tests of this predictive procedure. 

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