Structural Analysis of Antibody Specificity

Arevalo, Jairo H.; Hassig, Christian A.; Stura, E.A.; Sims, Martin; Taussig, Michael J.; Wilson, Ian A.

doi:10.1006/jmbi.1994.1543

Cited by 108 publications

(59 citation statements)

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“…Similarities in the Steroid Binding in the Known Antibody Structures-The molecular interactions that affect antibody specificity for steroid molecules have been previously discussed in a few articles (5)(6)(7)(8)11). Two to four hydrogen bonds are observed (5) in the anti-progesterone complex structures, whereas a single hydrogen bond exists between the steroid and the protein in the Fv4155 structures (11) and in the antitestosterone Fab structure.…”

Section: Discussionmentioning

confidence: 99%

“…Two to four hydrogen bonds are observed (5) in the anti-progesterone complex structures, whereas a single hydrogen bond exists between the steroid and the protein in the Fv4155 structures (11) and in the antitestosterone Fab structure. Thus, high affinity and specificity displayed by steroid binding antibodies primarily arises from shape complementarity (5)(6)(7)(8)11). The binding mode is very similar in the steroid-related Fab structures.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Structural Insights into Steroid Hormone Binding

Valjakka¹,

Takkinenz²,

Teerinen³

et al. 2002

Journal of Biological Chemistry

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The monoclonal anti-testosterone antibody (3-C 4 F 5 ) has a relatively high affinity (3 ؋ 10 8 M ؊1 ) with an overall good specificity profile. However, the earlier characterized binding properties have shown that both the affinity and specificity of this antibody must be improved if it is intended for use in clinical immunoassays. In this paper, the crystal structures of the recombinant antitestosterone (3-C 4 F 5 ) Fab fragment have been determined in the testosterone-bound and free form at resolutions of 2.60 and 2.72 Å, respectively. The high affinity binding of the (3-C 4 F 5 ) Fab is mainly determined by shape complementarity between the protein and testosterone. Only one direct hydrogen bond is formed between the hydroxyl group of the testosterone D-ring and the main-chain oxygen of Gly100 J H. The testosterone is deeply bound in a hydrophobic pocket, and the close shape complementarity is mainly formed by the third complementarity-determining regions ( The number of different, closely related steroid hormones in human serum is high, and their relative concentrations, which usually are very low, can vary greatly even between normal healthy individuals. Testosterone, the main male sex hormone, is one of the structurally similar steroid hormones. Measurement of serum testosterone levels is important in the evaluation of conditions associated with hyperandrogenism in women (1, 2) and to diagnose hypogonadism, impotence, and problems in spermatogenesis and pubertical development in men (3, 4). Development of monoclonal antibodies that would fulfill the high affinity and selectivity requirements needed for the accurate measurement of testosterone levels in serum samples has not been successful with the use of hybridoma technology. Rabbit polyclonal antibodies are used in most current immunoassays of steroid hormones. However, the supply of polyclonal reagents with consistent quality is a severe problem for the immunodiagnostic industry and requires continuous immunization of many animals. The inherent batch-to-batch variation of the polyclonal sera makes it necessary to optimize the assay parameters for each new serum batch.The three-dimensional structures of steroid binding Fab fragments are important for a general understanding of the molecular basis of specific interactions between antibodies and hydrophobic molecules such as steroids. The molecular basis of steroid antibody interactions has been studied in detail by determining the structures of a progesteronebinding antibody (DB3) in its free and bound form and with different high affinity cross-reactive progesterone derivatives (5-7). The binding site of the DB3 antibody is a hydrophobic pocket, and the binding affinity and specificity are determined by van der Waals interactions and a few hydrogen bonds formed with the progesterone hapten (5). The high affinity binding mode of a number of progesterone derivatives is due to two alternate docking orientations for the steroid skeleton (6). In the cases of the anti-digoxin 26-10 and 40-50 antibodies, the h...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Structural Insights into Steroid Hormone Binding

Valjakka¹,

Takkinenz²,

Teerinen³

et al. 2002

Journal of Biological Chemistry

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“…To accommodate the intruding anesthetic the protein molecule undergoes structural rearrangement that results in the loss of its Ca 2ϩ -ATPase activity. In proposing this mechanism of anesthetic action on the Ca 2ϩ -ATPase we are considering multiple x-ray diffraction and NMR data that have demonstrated binding of gaseous anesthetics and other molecules, including urea and steroids, in hydrophobic "cavities" in the interior of several proteins (Schoenborn, 1965;Schoenborn et al, 1965;Schoenborn and Featherstone, 1967;Nunes and Schoenborn, 1973;Brown et al, 1976;Sachsenheimer et al, 1977;Hibbard and Tulinsky, 1978;Tilton and Kuntz, 1982;Tilton et al, 1984;Otting et al, 1991;Arevalo et al, 1994;Jain et al, 1994;Williams et al, 1994;Hubbard et al, 1994).…”

Section: Ca 2ϩ -Atpases and Volatile Anestheticsmentioning

confidence: 99%

How Do Volatile Anesthetics Inhibit Ca2+-ATPases?

López¹,

Kosk‐Kosicka²

1995

Journal of Biological Chemistry

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“…Here K d represents the equilibrium dissociation constant. In this context, it is pertinent to recall that, as demonstrated for a variety of systems (17,(42)(43)(44), Ag-Ab interactions in the early primary response do not involve idealized surface complementarity. Rather, this is subsequently achieved by the combined processes of somatic mutation and positive selection within GCs (45)(46)(47).…”

Section: Discussionmentioning

confidence: 99%

B Cell Responses to a Peptide Epitope. X. Epitope Selection in a Primary Response Is Thermodynamically Regulated

Nakra

Manivel

Vishwakarma

et al. 2000

The Journal of Immunology

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We examine the etiological basis of hierarchical immunodominance of B cell epitopes on a multideterminant Ag. A model T-dependant immunogen, containing a single immunodominant B cell epitope, was used. The primary IgM response to this peptide included Abs directed against diverse determinants presented by the peptide. Interestingly, affinity of individual monomeric IgM Abs segregated around epitope recognized and was independent of their clonal origins. Furthermore, affinity of Abs directed against the immunodominant epitope were markedly higher than that of the alternate specificities. These studies suggested that the affinity of an epitope-specific primary response, and variations therein, may be determined by the chemical composition of epitope. This inference was supported by thermodynamic analyses of monomer IgM binding to Ag, which revealed that this interaction occurs at the expense of unfavorable entropy changes. Permissible binding required compensation by net enthalpic changes. Finally, the correlation between chemical composition of an epitope, the resultant affinity of the early primary humoral response, and its eventual influence on relative immunogenicity could be experimentally verified. This was achieved by examining the effect of various amino-terminal substitutions on immunogenicity of a, hitherto cryptic, amino-terminal determinant. Such experiments permitted delineation of a hierarchy of individual amino acid residues based on their influence; which correlated well with calculated Gibbs-free energy changes that individual residue side chains were expected to contribute in a binding interaction. Thus, maturation of a T-dependant humoral response is initiated by a step that is under thermodynamic control.

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Structural Analysis of Antibody Specificity

Cited by 108 publications

References 0 publications

Structural Insights into Steroid Hormone Binding

Structural Insights into Steroid Hormone Binding

How Do Volatile Anesthetics Inhibit Ca2+-ATPases?

B Cell Responses to a Peptide Epitope. X. Epitope Selection in a Primary Response Is Thermodynamically Regulated

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