Probing the human natural autoantibody repertoire using an immunoscreening approach

Comtesse, Nicole; Heckel, Dirk; Maldener, Esther; Glass, Brenda; Meese, Eckart

doi:10.1046/j.1365-2249.2000.01322.x

Cited by 13 publications

(8 citation statements)

References 29 publications

(51 reference statements)

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“…Abs specific for a foreign molecule may then be evolved when a rapid change in concentration or presentation of the foreign molecule triggers a mutagenic proliferation of the germ-line Ab (12,13). During this process, known as somatic evolution, mutations may be selected that simultaneously increase affinity and selectivity if they act, at least in part, to restrict the Ab to a conformation that is appropriate for recognition of the foreign molecule (8,10,11,(14)(15)(16)(17)(18)(19)(20)(21). The resulting Abs are specific for their foreign targets and thus may be produced at increased levels without risk of self-recognition and autoimmunity.…”

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confidence: 99%

Antibody evolution constrains conformational heterogeneity by tailoring protein dynamics

Zimmermann¹,

Oakman²,

Thorpe

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

114

141

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The evolution of proteins with novel function is thought to start from precursor proteins that are conformationally heterogeneous. The corresponding genes may be duplicated and then mutated to select and optimize a specific conformation. However, testing this idea has been difficult because of the challenge of quantifying protein flexibility and conformational heterogeneity as a function of evolution. Here, we report the characterization of protein heterogeneity and dynamics as a function of evolution for the antifluorescein antibody 4-4-20. Using nonlinear laser spectroscopy, surface plasmon resonance, and molecular dynamics simulations, we demonstrate that evolution localized the Ab-combining site from a heterogeneous ensemble of conformations to a single conformation by introducing mutations that act cooperatively and over significant distances to rigidify the protein. This study demonstrates how protein dynamics may be tailored by evolution and has important implications for our understanding of how novel protein functions are evolved.flexibility ͉ nonlinear spectroscopy ͉ fluorscein ͉ molecular recognition

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mentioning

confidence: 99%

Antibody evolution constrains conformational heterogeneity by tailoring protein dynamics

Zimmermann¹,

Oakman²,

Thorpe

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

114

141

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“…These highly specific Ab are typically isolated in the later stages of an immune response and are usually highly mutated compared with their corresponding germ-line gene sequences (17). It has thus been argued that during affinity maturation, somatic mutations act to rigidify the Ab, leading to more specific epitope recognition (9,13,(18)(19)(20)(21)(22)(23)(24). In this model, the binding sites of germ-line Ab (Ab before somatic mutation) are flexible, able to adopt many different conformations, and bind a range of epitopes with a conformational selection or induced fit-like mechanism.…”

mentioning

confidence: 99%

“…In this model, the binding sites of germ-line Ab (Ab before somatic mutation) are flexible, able to adopt many different conformations, and bind a range of epitopes with a conformational selection or induced fit-like mechanism. Although these flexible germ-line Ab are also expected to recognize self epitopes (18), they are not present at concentrations sufficient to be problematic (19). A rapid change in epitope concentration or presentation upon introduction of a foreign substance (25,26) then induces affinity maturation of the flexible germ-line Ab into a more rigid mature Ab.…”

mentioning

confidence: 99%

Protein dynamics and the immunological evolution of molecular recognition

Jimenez

Salazar

Yin

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

115

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While it is accepted that protein flexibility plays a role in protein folding, catalysis, and molecular recognition, few techniques are capable of the rigorous measurement of protein motions required to quantify flexibility. Three-pulse photon echo shift spectroscopy can be used to measure the time scale of protein motions, and we have used this technique, along with steady-state spectroscopy and binding and structural data, to examine the immunological evolution of protein flexibility in an anti-fluorescein antibody. Two light chain somatic mutations increase affinity for fluorescein by 12-fold but also significantly affect flexibility. Specifically, a rigidification of the protein is seen in each of three observable motions; two slower motions undergo decreased amplitudes of displacement, by 3-and 20-fold, respectively, in response to an applied force, and the distribution associated with the amplitude of a faster motion is narrowed upon somatic mutation. The somatic mutations appear to rigidify the antibody-fluorescein complex by more strongly anchoring fluorescein to the protein and by more tightly packing the complex. The data demonstrate that in addition to affinity, antibody dynamics are systematically manipulated during affinity maturation, and they imply that the evolution of protein flexibility may be a central component of the immune response. The results also reflect the type of protein rigidification that may be important for other biological interactions, such as protein-protein, protein-ligand or protein-drug, and enzymesubstrate recognition. M odels of molecular recognition, based on conformational selection (1-3), induced-fit (4-6), or lock-and-key-type mechanisms (5, 7), are central to describing virtually all proteinprotein and protein-ligand interactions. However, these models have been difficult to test, because they differ only in the flexibility of the protein, and protein flexibility has been difficult to quantify (8). Thus, studies of molecular recognition have not focused directly on flexibility, but instead have searched for manifestations of it, such as changes in on or off rates, varying binding entropies, and structural rearrangements. Nowhere is molecular recognition more important than in the immune system, where a finite number of receptors [antibodies (Ab) and T cell receptors] must bind a virtually infinite range of foreign molecules and peptides (9-16).While it is apparent that during the initial stages of an immune response, there must be Ab present that have a broad range of specificities, Ab may also be isolated that are highly specific. These highly specific Ab are typically isolated in the later stages of an immune response and are usually highly mutated compared with their corresponding germ-line gene sequences (17). It has thus been argued that during affinity maturation, somatic mutations act to rigidify the Ab, leading to more specific epitope recognition (9,13,(18)(19)(20)(21)(22)(23)(24). In this model, the binding sites of germ-line Ab (Ab before somatic mutation) ...

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“…Les amorces sont les séquences encadrant le site de clonage. La séquence déduite de l'ADNc amplifié permet l'identification de la protéine immunoréactive par comparaison avec les séquences déposées dans les banques de données géno-miques [23,79,133].…”

Section: L'immunocriblageunclassified