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The amino-acid sequence of the Fe fragment of a mouse monoclonal IgG2a molecule is presented. With the exception of one deletion, this region possesses the same length as that of the human γl chain or that of the rabbit γ chain. Identities between the Fc fragments of 3 animal species (human, mouse and rabbit) average 50% and are markedly more pronounced for the CH2 domain than for the CH3 domain, observation which is in agreement with an independent evolution of each homology region. Strikingly, the degree of conservation of the VH region is of the same order of magnitude as that observed for the Fc fragment. This parallelism in evolution is discussed. [ABSTRACT FROM AUTHOR]

All cysteine-containing peptides of the MOPC 173 (γG2a) monoclonal immunoglobulin were isolated and sequenced, allowing characterization of the twelve intrachain disulfide bonds, and extension of previous work concerning the interchain disulfide budges [3]. Positioning of the various bonds was deduced from homology with the known sequences of the mouse ℵ chains [6,21], MOPC 173 VH region [2], and human γ chains [8], and allowed corroboration of the previous proposed order of the CNBr fragments isolated from the whole molecule [1]. The general pattern of the γG2a, mouse immunoglobulin seems in agreement with the accepted view that this molecule contains two heavy chains and two light chains linked by disulfide bonds, and having intrachain bridges disposed in a strictly linear manner [4,8]. [ABSTRACT FROM AUTHOR]

The reactions of two monoclonal IgM lambda cold agglutinins, Sch and Sher, have been studied in detail with human and animal erythrocyte antigens. Although they were unusual in having lambda and not kappa polypeptide chains, they could be assigned to the anti I and anti-Pr1 groups of cold agglutinins. The findings with serum Sher indicated that the Pr1 antigen may be more complex than previously thought. The occurrence of unexpectedly large numbers of specificities among monoclonal anti-I, anti-i and anti-Pr antibodies is discussed and it is suggested that each monoclonal antibody may recognize only a limited portion of a complex red cell antigen. [ABSTRACT FROM AUTHOR]

The inbred LOU/Wsl rat strain presents a high incidence of spontaneous ileocoecal immunocytoma which secrete monoclonal immunoglobulins. These tumours are transplantable in histocompatible animals and their secreting properties are maintained over many passages. A screening of monoclonal immunoglobulins secreted by 250 such tumours revealed sixty-three proteins which shared class-specific determinants, physico-chemical features and biological properties different from those of rat IgM, IgA, IgG1, IgG2a, IgG2b and IgG2c classes, and characteristic of proteins of the IgE class. [ABSTRACT FROM AUTHOR]

Covalently linked subunits, subunits aggregated from two half subunits, half subunits, F(ab'μ)2 and Fab'μ were prepared. K-values 1900-5800 times lower than those for intact IgM and rabbit red cells were found for the covalently linked subunits, the aggregated subunits, and F(ab'μ)2, and 12,500-38,500 times lower for half subunits and F(ab'μ)2. Only whole subunits and F(ab'μ)2 agglutinated rabbit red cells; compared to intact IgM the titre was reduced markedly, but from the calculated amount of molecules bound per red cell, IgM was found to be on a weight basis only twice as effective as the subunits and F(ab'μ)2 in agglutinating the cells. [ABSTRACT FROM AUTHOR]

Monoclonal immunoglobulins in serum and cerebrospinal fluid (CSF) were found in newborns with congenital toxoplasmosis. The M-components were of igG-class and of both κ and λ type. The monoclonal proteins were found in the serum of new- borns but not in the serum of their mothers. The monoclonal immunoglobulins were therefore selectively transferred or synthesized by the newborn. There was a local production or selective local accumulation of immunoglobulins in the cerebro- spinal fluid. The M-components disappeared and the IgM level in serum and cerebrospinal fluid decreased after therapy. IgA was found to be elevated between 2-4 months of age. CRP was elevated in the first weeks after birth but afterwards returned to normal. The Dye test localized antibody activity to the site of the M- components in the electrophoresis of both serum and cerebrospinal fluid. The Dye test antibodies of mothers' sera also showed restricted heterogeneity with about the same electrophoretic localization as in the children's sera. Rheumatoid factors were found in serum and CSF of newborns with congenital toxoplasmosis, but not in serum of their mothers. [ABSTRACT FROM AUTHOR]

A case of scleromyxoedema (lichen myxoedematosus) associated with an IgG1, type kappa paraproteinaemia is reported. Culture of bone marrow material demonstrated that this tissue synthesized monoclonal IgG (subclass γ1) with a light chain of type kappa. The culture of a biopsy specimen of the diseased skin demonstrated low-speed IgG synthesis. It is concluded that the bone marrow and pathological skin synthesize a paraprotein with the same characteristics as that in the serum. Microchemical analysis of pathological skin demonstrated an increase in the content of neutral glycoproteins, hyaluronic acid and chondroitin sulphates as well as the presence of heparin and keratan sulphates. It could not be demonstrated that the serum of this patient contained antibody against connective tissue ground substance or other skin constituents. [ABSTRACT FROM AUTHOR]