Motilité structurale

Publications de l’équipe

Année de publication : 1994

F A Goldbaum, B A Fields, A Cauerhff, X Ysern, A Houdusse, J L Eisele, R J Poljak, R A Mariuzza (1994 Sep 2)

Crystallization and preliminary X-ray diffraction study of an idiotope-anti-idiotope Fv-Fv complex.

Journal of molecular biology : 739-43 En savoir plus
Résumé

A complex between the Fv fragment of an anti-hen eggwhite lysozyme antibody (D1.3) and the Fv fragment of an antibody specific for an idiotypic determinant of D1.3 has been crystallized in a form suitable for X-ray diffraction analysis. Both Fv fragments were expressed in soluble form in Escherichia coli and purified by affinity chromatography; diffraction-quality crystals were only obtained following separation of each Fv into distinct isoelectric forms. The crystals belong to space group C2, have unit cell dimensions a = 152.8 A, b = 79.4 A, c = 51.5 A, beta = 100.2 degrees, and diffract to better than 2.2 A resolution. The solvent content of the crystals is approximately 60% (v/v) with one Fv-Fv complex in the asymmetric unit. The ability to readily express both components of an antigen-antibody system in bacteria will allow us to rigorously assess the energetic contribution of individual amino acids to complex formation through pairwise mutagenesis of interacting residues.

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Année de publication : 1993

V Chitarra, P M Alzari, G A Bentley, T N Bhat, J L Eiselé, A Houdusse, J Lescar, H Souchon, R J Poljak (1993 Aug 15)

Three-dimensional structure of a heteroclitic antigen-antibody cross-reaction complex.

Proceedings of the National Academy of Sciences of the United States of America : 7711-5 En savoir plus
Résumé

Although antibodies are highly specific, cross-reactions are frequently observed. To understand the molecular basis of this phenomenon, we studied the anti-hen egg lysozyme (HEL) monoclonal antibody (mAb) D11.15, which cross-reacts with several avian lysozymes, in some cases with a higher affinity (heteroclitic binding) than for HEL. We have determined the crystal structure of the Fv fragment of D11.15 complexed with pheasant egg lysozyme (PHL). In addition, we have determined the structure of PHL, Guinea fowl egg lysozyme, and Japanese quail egg lysozyme. Differences in the affinity of D11.15 for the lysozymes appear to result from sequence substitutions in these antigens at the interface with the antibody. More generally, cross-reactivity is seen to require a stereochemically permissive environment for the variant antigen residues at the antibody-antigen interface.

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Année de publication : 1992

G A Bentley, A Houdusse (1992 May 1)

Some applications of the phased translation function in macromolecular structure determination.

Acta crystallographica. Section A, Foundations of crystallography : 312-22 En savoir plus
Résumé

Although the phased translation function was first described some time ago [Colman, Fehlhammer & Bartels (1976). In Crystallographic Computing Techniques, edited by F.R. Ahmed, K Huml & B. Sedlácek, pp. 248-258. Copenhagen: Munksgaard], it has been little used, especially in the application of molecular replacement to macromolecular structures. Nevertheless, the procedure is relatively easy to apply and deserves wider use. In this paper the versatility of the phased translation function in a number of different applications is examined and experience gained in obtaining optimal results in protein structure determination by this method is reported. Examples given show how it can be used to position an oriented fragment, to locate independent components with respect to a common crystallographic origin and to choose correctly between enantiomorphic space groups. Its performance is compared with other translation functions in common use.

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Année de publication : 1990

D Tello, S Spinelli, H Souchon, F A Saul, M M Riottot, R A Mariuzza, M B Lascombe, A Houdusse, J L Eiselé, T Fischmann (1990 Aug 1)

Three-dimensional structure and antigen binding specificity of antibodies.

Biochimie : 507-12 En savoir plus
Résumé

A number of specific Fab and Fv fragments and their complexes with antigens (avian lysozymes), haptens, and anti-idiotopic Fabs have been studied by immunochemical and crystallographic techniques. Antigen and antibody interact through closely complementary contacting surfaces, without major conformational changes. An idiotopic determinant of a monoclonal antibody is shown to include parts of most of its complementarity determining regions. The specificity of antigen recognition resides in the close complementarity of the antigenic determinant with the antibody combining site.

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