Crystal structure of Urtica dioica agglutinin, a superantigen presented by MHC molecules of class I and class II.

Background: Urtica dioica agglutinin (UDA), a monomeric lectin extracted from stinging nettle rhizomes, is specific for saccharides containing N-acetylglucosamine (GlcNAc). The lectin behaves as a superantigen for murine T cells, inducing the exclusive proliferation of Vbeta8.3(+) lymphocytes.

Dimerization of soluble major histocompatibility complex-peptide complexes is sufficient for activation of T cell hybridoma and induction of unresponsiveness.

Major histocompatibility complex (MHC) class I molecules are cell-surface proteins that present peptides to CD8+ T cells. These peptides are mostly derived from endogenously synthesized protein. Recombinant, soluble MHC class I molecules were produced, purified, and loaded homogeneously with synthetic peptide.

Crystal structure of the beta chain of a T cell antigen receptor.

The crystal structure of the extracellular portion of the beta chain of a murine T cell antigen receptor (TCR), determined at a resolution of 1.7 angstroms, shows structural homology to immunoglobulins. The structure of the first and second hypervariable loops suggested that, in general, they adopt more restricted sets of conformations in TCR beta chains than those found in immunoglobulins; the third hypervariable loop had certain structural characteristics in common with those of immunoglobulin heavy chain variable domains.

Bound water molecules and conformational stabilization help mediate an antigen-antibody association.

We report the three-dimensional structures, at 1.8-A resolution, of the Fv fragment of the anti-hen egg white lysozyme antibody D1.3 in its free and antigen-bound forms.

Crystallization and preliminary X-ray diffraction analysis of the beta-chain of a T-cell antigen receptor.

A secreted form of the beta-chain of a T-cell receptor specific for a hemagglutinin peptide of influenza virus in the context of the major histocompatibility complex class II I-Ed molecule has been crystallized in a form suitable for X-ray diffraction analysis. The crystals are tetragonal, space group P4(1)2(1)2 (or P4(3)2(1)2), with cell dimensions a = b = 71.4 A, c = 312.

Secretion of disulfide-linked human T-cell receptor gamma delta heterodimers.

The availability of soluble forms of T-cell antigen receptors (sTCR) should be of great use in the detailed characterization of their interactions with ligands, for the generation of anti-TCR monoclonal antibodies (mAb), and for the eventual determination of their three-dimensional structures by x-ray crystallography. Here, we show that efficient secretion of nonchimeric disulfide-linked human gamma delta TCR could be achieved by simply introducing translational termination codons upstream from the sequences encoding TCR chain transmembrane regions. This recombinant protein appeared to be correctly folded, as judged by its reactivity with a panel of anti-gamma and anti-delta mAbs, and proved to be a powerful immunogen, allowing generation of mAb that are able to recognize both soluble- and membrane-bound gamma delta TCR.

Crystallographic refinement of the three-dimensional structure of the FabD1.3-lysozyme complex at 2.5-A resolution.

The three-dimensional crystal structure of the complex between the Fab from the monoclonal anti-lysozyme antibody D1.3 and the antigen, hen egg white lysozyme, has been refined by crystallographic techniques using x-ray intensity data to 2.5-A resolution.

Three-dimensional structure determination of an anti-2-phenyloxazolone antibody: the role of somatic mutation and heavy/light chain pairing in the maturation of an immune response.

The three-dimensional structure of the Fab fragment of an anti-2-phenyloxazolone monoclonal antibody (NQ10/12.5) in its native and complexed forms has been determined at 2.8 and 3.

Three-dimensional structure of an idiotope-anti-idiotope complex.

Serologically detected antigenic determinants unique to an antibody or group of antibodies are called idiotopes. The sum of idiotopes of an antibody constitute its idiotype. Idiotypes have been intensively studied following a hypothesis for the self-regulation of the immune system through a network of idiotype-anti-idiotype interactions.

Small rearrangements in structures of Fv and Fab fragments of antibody D1.3 on antigen binding.

The potential use of monoclonal antibodies in immunological, chemical and clinical applications has stimulated the protein engineering and expression of Fv fragments, which are heterodimers consisting of the light and heavy chain variable domains (VL and VH) of antibodies. Although Fv fragments exhibit antigen binding specificity and association constants similar to their parent antibodies or Fab moieties, similarity in their interactions with antigen at the level of three-dimensional structure has not been investigated. We have determined the high-resolution crystal structure of the genetically engineered FvD1.

Crystallization and preliminary X-ray diffraction study of the bacterially expressed Fv from the monoclonal anti-lysozyme antibody D1.3 and of its complex with the antigen, lysozyme.

The associated heavy (VH) and light (VL) chain variable domains (Fv) of the monoclonal anti-lysozyme antibody D1.3, secreted from Escherichia coli, have been crystallized in their antigen-bound and free forms. FvD1.

Studies of structure and specificity of some antigen-antibody complexes.

By using X-ray diffraction and immunochemical techniques, we have exploited the use of monoclonal antibodies raised against hen egg lysozyme (HEL) to study systematically those factors responsible for the high specificity of antigen-antibody interactions. HEL was chosen for our investigations because its three-dimensional structure and immunochemistry have been well characterized and because naturally occurring sequence variants from different avian species are readily available to test the fine specificity of the antibodies. The X-ray crystal structure of a complex formed between HEL and the Fab D1.

Three-dimensional structure of Fab R19.9, a monoclonal murine antibody specific for the p-azobenzenearsonate group.

The crystal structure of Fab R19.9, derived from an anti-p-azobenzenearsonate monoclonal antibody, has been determined and refined to 2.8-A resolution by x-ray crystallographic techniques.

Crystallization and preliminary X-ray diffraction studies of antigen--antibody complexes.

Monoclonal antibodies of predefined specificity have been purified and crystallized as single components or complexed with their specific antigens. The intersegmental flexibility of antibody molecules has imposed the strategy of attempting to crystallize their Fab fragments separately. Intrasegmental mobility in Fabs has rarely been an obstacle to their crystallization.

Crystallization of the met repressor from Escherichia coli.

The met repressor from Escherichia coli has been crystallized in space group P21, with unit cell dimensions a = 35.6 A, b = 62.6 A, c = 44.

Preliminary crystallographic study of a complex between the Fab fragment of a monoclonal anti-lysozyme antibody (D1.3) and the Fab fragment from an anti-idiotopic antibody against D1.3.

An anti-lysozyme antibody, D1.3, was used as immunogen to obtain syngeneic (Balb/c) monoclonal anti-idiotopic antibodies. The complex between Fab D1.

Antigen specificity and cross-reactivity of monoclonal anti-lysozyme antibodies.

Twenty-seven murine monoclonal anti-hen egg-white lysozyme (HEL) antibodies were tested with a panel of nine antigens; eight avian lysozymes and human lysozyme. The antibodies were arranged into 10 groups based on their antigen specificity and cross-reactivity. Antigenic determinants recognized by each group of antibodies were tentatively identified.

Preliminary crystallographic study of the Fab fragments of two monoclonal anti-2-phenyloxazolone antibodies.

We report on the preparation, crystallization, and preliminary x-ray crystallographic study of the Fab fragments of two monoclonal anti-2-phenyloxazolone antibodies obtained from the secondary response to this hapten. The Fab fragment from one of these (NQ10/12.5) has been crystallized from polyethylene glycol 8000 solutions in a form suitable for high-resolution x-ray crystallographic studies.

X-ray diffraction studies of an anti-azophenylarsonate antibody and of an antigen-antibody complex.

X-ray crystallographic studies of the Fab fragments of two murine monoclonal antibodies of predefined specificity are under way. Diffracted X-ray intensities of the crystalline native Fab fragment of an anti-azophenylarsonate antibody and of three heavy atom derivatives have been measured to a resolution of 3.5 A.

Crystallization of the fab fragments of monoclonal anti-p-azophenylarsonate antibodies and their complexes with haptens.

We report on the preparation, crystallization, and preliminary x-ray crystallographic study of Fab fragments from monoclonal anti-p-azophenylarsonate antibodies. Several crystalline forms were obtained with the Fab fragment from the R19.9 monoclonal antibody as well as with the complex between the hapten p-aminobenzenearsonic acid and Fab R19.

Preliminary crystallographic study of the complex between the Fab fragment of a monoclonal anti-lysozyme antibody and its antigen.

Preliminary crystallographic data are given for the complex between the Fab fragment of a monoclonal anti-lysozyme antibody and its antigen. This crystalline complex was found by screening a number of Fab-lysozyme complexes prepared from monoclonal anti-lysozyme antibodies produced by hybrids of BALB/c immune spleen cells with a non-secreting mouse hybrid myeloma line. The complex crystallizes in the monoclinic space group P21 with a = 55.