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C Schiff

Publications and source records attributed to C Schiff.

61 records · Page 4Linked to original sources
PubMed1975

Determination of the primary structure of a mouse IgG2a immunoglobulin. Amino-acid sequence of the light chain.

The amino acid sequence of the light chain of the mouse monoclonal MOPC 173 immunoglobulin molecule (IgG2a,chi) is presented. This kappa chain contains 214 residues. Comparisons of this sequence with murine kappa chains already published by other workers bring a confirmation of the large size of the murine V chi chain pool. A complete identity was found with the constant region of the light chain of MOPC 21 from residue 97 to residue 214.

Amino Acid Sequence↗
PubMedDate not supplied

Molecular analysis of the anti-GAT repertoire in three strains of mice.

GAT-specific antibodies which express the CGAT (or pGAT) public idiotypic specificities are encoded by a paucigene system. Antibodies expressing discrete specificities, i.e. anti-GAT and anti-NP, appeared to use the same VH germ-line genes, an observation which directly supports the importance of random H-L pairing to generate a large number of distinct antibody molecules.

Amino Acid Sequence↗
PubMedDate not supplied

The internal image and the structural idiotypic network (Ab1, Ab2, Ab3) in the GAT system.

The GAT repertoire expressed at the different levels of the classical idiotypic cascade Ag----Ab1----Ab2----Ab3 has been analysed by direct nucleotide sequencing of H- and L-enriched mRNA. Ab1 and Ab3 expressing the major public idiotypes used similar, if not identical, VH and VK genes. The VH Ab3 of the Ab1 type (Ab1') appeared highly conserved. Ab2 also use a small number of germ-line genes. The D region of Ab2 is of particular interest since it contains either a Tyr-Tyr-Glu or a Glu-Glu-Tyr sequence, characteristic of the GAT major determinants. It is therefore suggested that this D region contains the internal image of the antigen. A large number of VH germ-line genes have been isolated and sequenced. They all pertain to the VH-II family, which contains a large number of members, some of them being very close in sequence.

Amino Acid Sequence↗
PubMedDate not supplied

Structural and functional mapping of immunoglobulin V-regions.

V-regions of immunoglobulins chains contain 3 types of positions, which are equally represented: invariant and sub-group characteristic, which account for the "framework" and hypervariable positions, responsible for antigen recognition. The 3 types of positions are grouped and fall within a very few discrete stretches. Sub-group characteristic segments containing one of the 2 cysteyl residues of the V-regions may be isolated by high voltage paper electrophoresis and provide a basis to type for sub-groups in the VK and in the VH human systems. This allowed to characterize a large set of human myeloma proteins that were used in a series of competitive hybridizations which indicated that sub-groups had no influence on preferential reassociations, which occurred in 80% of the cases. This preference seems to rely mostly on individual structural differences, which may be linked to heterogeneity at the framework level. Distinction between framework heterogeneity and hypervariable regions heterogeneity may be approached by raising antibodies against a mouse myeloma protein, MOPC 173, of known sequence, by means of syngeneic and allogeneic immunizations, using Balb/c and A/J mice. Junction of distinct portions of immunoglobulin chains such as the V and the C regions raises the possibility that some recognition signals may operate at the DNA level. Since rotational symmetry regions in the DNA are known to act as such signals, it is discussed whether such regions can be expected from the amino acid sequence data, especially in the vicinity of the "switch" peptide.

Amino Acid Sequence↗
PubMedDate not supplied

Structural basis for M-173 idiotypic determinants distinctively recognized in syngeneic and allogeneic immunization: contribution of DH, JH, and J kappa regions to an idiotope recognized by allogeneic antisera.

Antiidiotypic antibodies directed against the M-173 (IgG2a) mouse myeloma protein have been raised in syngeneic and allogeneic conditions. The antiidiotypic repertoires of several strains of mice have been compared by isoelectrofocusing, and a major idiotype has been identified by several antisera raised in allogeneic conditions in strains of mice which did not express the Igh-Ca allotype of the BALB background. Since this idiotype could be reformed in hybrid molecules containing the M-173 heavy chains and light chains which contained the J kappa 2 region, we propose that this determinant is dependent upon the J kappa 2, DH and JH regions, in addition, most probably, to a specific contribution of residues 45 and 54 of the heavy chains.

Amino Acid Sequence↗
PubMedDate not supplied

The complete sequence of the murine monoclonal immunoglobulin MOPC 173 (IgG2a): genetic implications.

The complete amino acid sequence of the murine monoclonal immunoglobulin MOPC 173 (IgG2a, kappa) is reported. The heavy chain contains 447 amino-acid residues, and one carbohydrate prosthetic group attached to the ASX residue 299. The kappa light chain is composed of 214 residues. The H chains are covalently linked by 3 interchain disulfide bridges. The H-L bond-forming cysteine of the H chain is between the VH and the CH1 domain. Intrachain bridges are disposed linearly, according to the classical model. There is no simple relationship between the primary structure and any given function of a particular domain. This is presumably due to the fact that the selection pressure exerts itself on the three-dimensional structure which may retain a conserved general organization as a result of balanced multiple mutations. Selection seems to act in two ways: --horizontally, in a multigene system such as the immunoglobulin classes (C domains of the heavy chains), leading to interclass homologies which are particularly marked for all the COOH-terminal domains of H and L chains which have, in addition a fair degree of homology with human beta2 microglobulin (about 30% identities); --vertically, in which case strictly homologous domains appear extremely conserved between distinct animal species. Conservation of the VH domains seems just as high as conservation of the CH domains. The VH region contains 3 types of positions: invariant and subgroup characteristic ("framework") which may be accounted for by a rather small number of germ-line genes, and hypervariable for which the origin of diversity, somatic or germinal, cannot be decided from sequence data alone. Murine VK domains, although basically built according to the same pattern, show a much more marked polymorphism of the framework, which might necessitate a higher number of basic germ-line genes. Finally, a hypothetical model of the switch mechanism is proposed. Rotational symmetry regions can be deduced at the DNA level from the known amino acid sequences of the switch peptides for the three translocational systems: H, kappa and lambda. These would provide recognition signals for restriction-like enzymes such as those which operate in prokaryotes. An implication of this model is the definition of an exact limit between the V and the C regions of all immunoglobulin chains.

Amino Acid Sequence↗