The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Lode Wyns - One of the best experts on this subject based on the ideXlab platform.
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antigen specificity and high affinity binding provided by one single loop of a camel single domain antibody
Journal of Biological Chemistry, 2001Co-Authors: Aline Desmyter, Serge Muyldermans, Klaas Decanniere, Lode WynsAbstract:Abstract Detailed knowledge on antibody-antigen recognition is scarce given the unlimited antibody specificities of which only few have been investigated at an atomic level. We report the crystal Structures of an antibody fragment derived from a camel heavy chain antibody against carbonic anhydrase, free and in complex with antigen. Surprisingly, this single-domain antibody interacts with nanomolar affinity with the antigen through its third hypervariable loop (19 amino acids long), providing a flat interacting surface of 620 A2. For the first time, a single-domain antibody is observed with its first hypervariable loop adopting a type-1 Canonical Structure. The second hypervariable loop, of unique size due to a somatic mutation, reveals a regular β-turn. The third hypervariable loop covers the remaining hypervariable loops and the side of the domain that normally interacts with the variable domain of the light chain. Specific amino acid substitutions and reoriented side chains reshape this side of the domain and increase its hydrophilicity. Of interest is the substitution of the conserved Trp-103 by Arg because it opens new perspectives to ‘humanize’ a camel variable domain of heavy chain of heavy chain antibody (VHH) or to ‘camelize’ a human or a mouse variable domain of heavy chain of conventional antibody (VH).
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antigen specificity and high affinity binding provided by one single loop of a camel single domain antibody
Journal of Biological Chemistry, 2001Co-Authors: Aline Desmyter, Serge Muyldermans, Klaas Decanniere, Lode WynsAbstract:Detailed knowledge on antibody-antigen recognition is scarce given the unlimited antibody specificities of which only few have been investigated at an atomic level. We report the crystal Structures of an antibody fragment derived from a camel heavy chain antibody against carbonic anhydrase, free and in complex with antigen. Surprisingly, this single-domain antibody interacts with nanomolar affinity with the antigen through its third hypervariable loop (19 amino acids long), providing a flat interacting surface of 620 A(2). For the first time, a single-domain antibody is observed with its first hypervariable loop adopting a type-1 Canonical Structure. The second hypervariable loop, of unique size due to a somatic mutation, reveals a regular beta-turn. The third hypervariable loop covers the remaining hypervariable loops and the side of the domain that normally interacts with the variable domain of the light chain. Specific amino acid substitutions and reoriented side chains reshape this side of the domain and increase its hydrophilicity. Of interest is the substitution of the conserved Trp-103 by Arg because it opens new perspectives to 'humanize' a camel variable domain of heavy chain of heavy chain antibody (VHH) or to 'camelize' a human or a mouse variable domain of heavy chain of conventional antibody (VH).
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a single domain antibody fragment in complex with rnase a non Canonical loop Structures and nanomolar affinity using two cdr loops
Structure, 1999Co-Authors: Klaas Decanniere, Aline Desmyter, Serge Muyldermans, Marc Lauwereys, Mehdi Arbabi Ghahroudi, Lode WynsAbstract:Abstract Background: Camelid serum contains a large fraction of functional heavy-chain antibodies – homodimers of heavy chains without light chains. The variable domains of these heavy-chain antibodies (VHH) have a long complementarity determining region 3 (CDR3) loop that compensates for the absence of the antigen-binding loops of the variable light chains (VL). In the case of the VHH fragment cAb-Lys3, part of the 24 amino acid long CDR3 loop protrudes from the antigen-binding surface and inserts into the active-site cleft of its antigen, rendering cAb-Lys3 a competitive enzyme inhibitor. Results: A dromedary VHH with specificity for bovine RNase A, cAb-RN05, has a short CDR3 loop of 12 amino acids and is not a competitive enzyme inhibitor. The Structure of the cAb-RN05–RNase A complex has been solved at 2.8 A. The VHH scaffold architecture is close to that of a human VH (variable heavy chain). The Structure of the antigen-binding hypervariable 1 loop (H1) of both cAb-RN05 and cAb-Lys3 differ from the known Canonical Structures; in addition these H1 loops resemble each other. The CDR3 provides an antigen-binding surface and shields the face of the domain that interacts with VL in conventional antibodies. Conclusions: VHHs adopt the common immunoglobulin fold of variable domains, but the antigen-binding loops deviate from the predicted Canonical Structure. We define a new Canonical Structure for the H1 loop of immunoglobulins, with cAb-RN05 and cAb-Lys3 as reference Structures. This new loop Structure might also occur in human or mouse VH domains. Surprisingly, only two loops are involved in antigen recognition; the CDR2 does not participate. Nevertheless, the antigen binding occurs with nanomolar affinities because of a preferential usage of mainchain atoms for antigen interaction.
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crystal Structure of a camel single domain vh antibody fragment in complex with lysozyme
Nature Structural & Molecular Biology, 1996Co-Authors: Aline Desmyter, Serge Muyldermans, Mehdi Arbabi Ghahroudi, Thomas R Transue, Minhhoa Dao Thi, Freddy Poortmans, Raymond Hamers, Lode WynsAbstract:The Camelidae is the only taxonomic family known to possess functional heavy-chain antibodies, lacking light chains. We report here the 2.5 A resolution crystal Structure of a camel VH in complex with its antigen, lysozyme. Compared to human and mouse VH domains, there are no major backbone rearrangements in the VH framework. However, the architecture of the region of VH that interacts with a VL in a conventional Fv is different from any previously seen. Moreover, the CDR1 region, although in sequence homologous to human CDR1, deviates fundamentally from the Canonical Structure. Additionally, one half of the CDR3 contacts the VH region which in conventional immunoglobulins interacts with a VL, whereas the other half protrudes from the antigen binding site and penetrates deeply into the active site of lysozyme.
Aline Desmyter - One of the best experts on this subject based on the ideXlab platform.
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antigen specificity and high affinity binding provided by one single loop of a camel single domain antibody
Journal of Biological Chemistry, 2001Co-Authors: Aline Desmyter, Serge Muyldermans, Klaas Decanniere, Lode WynsAbstract:Abstract Detailed knowledge on antibody-antigen recognition is scarce given the unlimited antibody specificities of which only few have been investigated at an atomic level. We report the crystal Structures of an antibody fragment derived from a camel heavy chain antibody against carbonic anhydrase, free and in complex with antigen. Surprisingly, this single-domain antibody interacts with nanomolar affinity with the antigen through its third hypervariable loop (19 amino acids long), providing a flat interacting surface of 620 A2. For the first time, a single-domain antibody is observed with its first hypervariable loop adopting a type-1 Canonical Structure. The second hypervariable loop, of unique size due to a somatic mutation, reveals a regular β-turn. The third hypervariable loop covers the remaining hypervariable loops and the side of the domain that normally interacts with the variable domain of the light chain. Specific amino acid substitutions and reoriented side chains reshape this side of the domain and increase its hydrophilicity. Of interest is the substitution of the conserved Trp-103 by Arg because it opens new perspectives to ‘humanize’ a camel variable domain of heavy chain of heavy chain antibody (VHH) or to ‘camelize’ a human or a mouse variable domain of heavy chain of conventional antibody (VH).
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antigen specificity and high affinity binding provided by one single loop of a camel single domain antibody
Journal of Biological Chemistry, 2001Co-Authors: Aline Desmyter, Serge Muyldermans, Klaas Decanniere, Lode WynsAbstract:Detailed knowledge on antibody-antigen recognition is scarce given the unlimited antibody specificities of which only few have been investigated at an atomic level. We report the crystal Structures of an antibody fragment derived from a camel heavy chain antibody against carbonic anhydrase, free and in complex with antigen. Surprisingly, this single-domain antibody interacts with nanomolar affinity with the antigen through its third hypervariable loop (19 amino acids long), providing a flat interacting surface of 620 A(2). For the first time, a single-domain antibody is observed with its first hypervariable loop adopting a type-1 Canonical Structure. The second hypervariable loop, of unique size due to a somatic mutation, reveals a regular beta-turn. The third hypervariable loop covers the remaining hypervariable loops and the side of the domain that normally interacts with the variable domain of the light chain. Specific amino acid substitutions and reoriented side chains reshape this side of the domain and increase its hydrophilicity. Of interest is the substitution of the conserved Trp-103 by Arg because it opens new perspectives to 'humanize' a camel variable domain of heavy chain of heavy chain antibody (VHH) or to 'camelize' a human or a mouse variable domain of heavy chain of conventional antibody (VH).
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a single domain antibody fragment in complex with rnase a non Canonical loop Structures and nanomolar affinity using two cdr loops
Structure, 1999Co-Authors: Klaas Decanniere, Aline Desmyter, Serge Muyldermans, Marc Lauwereys, Mehdi Arbabi Ghahroudi, Lode WynsAbstract:Abstract Background: Camelid serum contains a large fraction of functional heavy-chain antibodies – homodimers of heavy chains without light chains. The variable domains of these heavy-chain antibodies (VHH) have a long complementarity determining region 3 (CDR3) loop that compensates for the absence of the antigen-binding loops of the variable light chains (VL). In the case of the VHH fragment cAb-Lys3, part of the 24 amino acid long CDR3 loop protrudes from the antigen-binding surface and inserts into the active-site cleft of its antigen, rendering cAb-Lys3 a competitive enzyme inhibitor. Results: A dromedary VHH with specificity for bovine RNase A, cAb-RN05, has a short CDR3 loop of 12 amino acids and is not a competitive enzyme inhibitor. The Structure of the cAb-RN05–RNase A complex has been solved at 2.8 A. The VHH scaffold architecture is close to that of a human VH (variable heavy chain). The Structure of the antigen-binding hypervariable 1 loop (H1) of both cAb-RN05 and cAb-Lys3 differ from the known Canonical Structures; in addition these H1 loops resemble each other. The CDR3 provides an antigen-binding surface and shields the face of the domain that interacts with VL in conventional antibodies. Conclusions: VHHs adopt the common immunoglobulin fold of variable domains, but the antigen-binding loops deviate from the predicted Canonical Structure. We define a new Canonical Structure for the H1 loop of immunoglobulins, with cAb-RN05 and cAb-Lys3 as reference Structures. This new loop Structure might also occur in human or mouse VH domains. Surprisingly, only two loops are involved in antigen recognition; the CDR2 does not participate. Nevertheless, the antigen binding occurs with nanomolar affinities because of a preferential usage of mainchain atoms for antigen interaction.
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crystal Structure of a camel single domain vh antibody fragment in complex with lysozyme
Nature Structural & Molecular Biology, 1996Co-Authors: Aline Desmyter, Serge Muyldermans, Mehdi Arbabi Ghahroudi, Thomas R Transue, Minhhoa Dao Thi, Freddy Poortmans, Raymond Hamers, Lode WynsAbstract:The Camelidae is the only taxonomic family known to possess functional heavy-chain antibodies, lacking light chains. We report here the 2.5 A resolution crystal Structure of a camel VH in complex with its antigen, lysozyme. Compared to human and mouse VH domains, there are no major backbone rearrangements in the VH framework. However, the architecture of the region of VH that interacts with a VL in a conventional Fv is different from any previously seen. Moreover, the CDR1 region, although in sequence homologous to human CDR1, deviates fundamentally from the Canonical Structure. Additionally, one half of the CDR3 contacts the VH region which in conventional immunoglobulins interacts with a VL, whereas the other half protrudes from the antigen binding site and penetrates deeply into the active site of lysozyme.
Serge Muyldermans - One of the best experts on this subject based on the ideXlab platform.
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antigen specificity and high affinity binding provided by one single loop of a camel single domain antibody
Journal of Biological Chemistry, 2001Co-Authors: Aline Desmyter, Serge Muyldermans, Klaas Decanniere, Lode WynsAbstract:Abstract Detailed knowledge on antibody-antigen recognition is scarce given the unlimited antibody specificities of which only few have been investigated at an atomic level. We report the crystal Structures of an antibody fragment derived from a camel heavy chain antibody against carbonic anhydrase, free and in complex with antigen. Surprisingly, this single-domain antibody interacts with nanomolar affinity with the antigen through its third hypervariable loop (19 amino acids long), providing a flat interacting surface of 620 A2. For the first time, a single-domain antibody is observed with its first hypervariable loop adopting a type-1 Canonical Structure. The second hypervariable loop, of unique size due to a somatic mutation, reveals a regular β-turn. The third hypervariable loop covers the remaining hypervariable loops and the side of the domain that normally interacts with the variable domain of the light chain. Specific amino acid substitutions and reoriented side chains reshape this side of the domain and increase its hydrophilicity. Of interest is the substitution of the conserved Trp-103 by Arg because it opens new perspectives to ‘humanize’ a camel variable domain of heavy chain of heavy chain antibody (VHH) or to ‘camelize’ a human or a mouse variable domain of heavy chain of conventional antibody (VH).
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antigen specificity and high affinity binding provided by one single loop of a camel single domain antibody
Journal of Biological Chemistry, 2001Co-Authors: Aline Desmyter, Serge Muyldermans, Klaas Decanniere, Lode WynsAbstract:Detailed knowledge on antibody-antigen recognition is scarce given the unlimited antibody specificities of which only few have been investigated at an atomic level. We report the crystal Structures of an antibody fragment derived from a camel heavy chain antibody against carbonic anhydrase, free and in complex with antigen. Surprisingly, this single-domain antibody interacts with nanomolar affinity with the antigen through its third hypervariable loop (19 amino acids long), providing a flat interacting surface of 620 A(2). For the first time, a single-domain antibody is observed with its first hypervariable loop adopting a type-1 Canonical Structure. The second hypervariable loop, of unique size due to a somatic mutation, reveals a regular beta-turn. The third hypervariable loop covers the remaining hypervariable loops and the side of the domain that normally interacts with the variable domain of the light chain. Specific amino acid substitutions and reoriented side chains reshape this side of the domain and increase its hydrophilicity. Of interest is the substitution of the conserved Trp-103 by Arg because it opens new perspectives to 'humanize' a camel variable domain of heavy chain of heavy chain antibody (VHH) or to 'camelize' a human or a mouse variable domain of heavy chain of conventional antibody (VH).
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a single domain antibody fragment in complex with rnase a non Canonical loop Structures and nanomolar affinity using two cdr loops
Structure, 1999Co-Authors: Klaas Decanniere, Aline Desmyter, Serge Muyldermans, Marc Lauwereys, Mehdi Arbabi Ghahroudi, Lode WynsAbstract:Abstract Background: Camelid serum contains a large fraction of functional heavy-chain antibodies – homodimers of heavy chains without light chains. The variable domains of these heavy-chain antibodies (VHH) have a long complementarity determining region 3 (CDR3) loop that compensates for the absence of the antigen-binding loops of the variable light chains (VL). In the case of the VHH fragment cAb-Lys3, part of the 24 amino acid long CDR3 loop protrudes from the antigen-binding surface and inserts into the active-site cleft of its antigen, rendering cAb-Lys3 a competitive enzyme inhibitor. Results: A dromedary VHH with specificity for bovine RNase A, cAb-RN05, has a short CDR3 loop of 12 amino acids and is not a competitive enzyme inhibitor. The Structure of the cAb-RN05–RNase A complex has been solved at 2.8 A. The VHH scaffold architecture is close to that of a human VH (variable heavy chain). The Structure of the antigen-binding hypervariable 1 loop (H1) of both cAb-RN05 and cAb-Lys3 differ from the known Canonical Structures; in addition these H1 loops resemble each other. The CDR3 provides an antigen-binding surface and shields the face of the domain that interacts with VL in conventional antibodies. Conclusions: VHHs adopt the common immunoglobulin fold of variable domains, but the antigen-binding loops deviate from the predicted Canonical Structure. We define a new Canonical Structure for the H1 loop of immunoglobulins, with cAb-RN05 and cAb-Lys3 as reference Structures. This new loop Structure might also occur in human or mouse VH domains. Surprisingly, only two loops are involved in antigen recognition; the CDR2 does not participate. Nevertheless, the antigen binding occurs with nanomolar affinities because of a preferential usage of mainchain atoms for antigen interaction.
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crystal Structure of a camel single domain vh antibody fragment in complex with lysozyme
Nature Structural & Molecular Biology, 1996Co-Authors: Aline Desmyter, Serge Muyldermans, Mehdi Arbabi Ghahroudi, Thomas R Transue, Minhhoa Dao Thi, Freddy Poortmans, Raymond Hamers, Lode WynsAbstract:The Camelidae is the only taxonomic family known to possess functional heavy-chain antibodies, lacking light chains. We report here the 2.5 A resolution crystal Structure of a camel VH in complex with its antigen, lysozyme. Compared to human and mouse VH domains, there are no major backbone rearrangements in the VH framework. However, the architecture of the region of VH that interacts with a VL in a conventional Fv is different from any previously seen. Moreover, the CDR1 region, although in sequence homologous to human CDR1, deviates fundamentally from the Canonical Structure. Additionally, one half of the CDR3 contacts the VH region which in conventional immunoglobulins interacts with a VL, whereas the other half protrudes from the antigen binding site and penetrates deeply into the active site of lysozyme.
Klaas Decanniere - One of the best experts on this subject based on the ideXlab platform.
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antigen specificity and high affinity binding provided by one single loop of a camel single domain antibody
Journal of Biological Chemistry, 2001Co-Authors: Aline Desmyter, Serge Muyldermans, Klaas Decanniere, Lode WynsAbstract:Abstract Detailed knowledge on antibody-antigen recognition is scarce given the unlimited antibody specificities of which only few have been investigated at an atomic level. We report the crystal Structures of an antibody fragment derived from a camel heavy chain antibody against carbonic anhydrase, free and in complex with antigen. Surprisingly, this single-domain antibody interacts with nanomolar affinity with the antigen through its third hypervariable loop (19 amino acids long), providing a flat interacting surface of 620 A2. For the first time, a single-domain antibody is observed with its first hypervariable loop adopting a type-1 Canonical Structure. The second hypervariable loop, of unique size due to a somatic mutation, reveals a regular β-turn. The third hypervariable loop covers the remaining hypervariable loops and the side of the domain that normally interacts with the variable domain of the light chain. Specific amino acid substitutions and reoriented side chains reshape this side of the domain and increase its hydrophilicity. Of interest is the substitution of the conserved Trp-103 by Arg because it opens new perspectives to ‘humanize’ a camel variable domain of heavy chain of heavy chain antibody (VHH) or to ‘camelize’ a human or a mouse variable domain of heavy chain of conventional antibody (VH).
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antigen specificity and high affinity binding provided by one single loop of a camel single domain antibody
Journal of Biological Chemistry, 2001Co-Authors: Aline Desmyter, Serge Muyldermans, Klaas Decanniere, Lode WynsAbstract:Detailed knowledge on antibody-antigen recognition is scarce given the unlimited antibody specificities of which only few have been investigated at an atomic level. We report the crystal Structures of an antibody fragment derived from a camel heavy chain antibody against carbonic anhydrase, free and in complex with antigen. Surprisingly, this single-domain antibody interacts with nanomolar affinity with the antigen through its third hypervariable loop (19 amino acids long), providing a flat interacting surface of 620 A(2). For the first time, a single-domain antibody is observed with its first hypervariable loop adopting a type-1 Canonical Structure. The second hypervariable loop, of unique size due to a somatic mutation, reveals a regular beta-turn. The third hypervariable loop covers the remaining hypervariable loops and the side of the domain that normally interacts with the variable domain of the light chain. Specific amino acid substitutions and reoriented side chains reshape this side of the domain and increase its hydrophilicity. Of interest is the substitution of the conserved Trp-103 by Arg because it opens new perspectives to 'humanize' a camel variable domain of heavy chain of heavy chain antibody (VHH) or to 'camelize' a human or a mouse variable domain of heavy chain of conventional antibody (VH).
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a single domain antibody fragment in complex with rnase a non Canonical loop Structures and nanomolar affinity using two cdr loops
Structure, 1999Co-Authors: Klaas Decanniere, Aline Desmyter, Serge Muyldermans, Marc Lauwereys, Mehdi Arbabi Ghahroudi, Lode WynsAbstract:Abstract Background: Camelid serum contains a large fraction of functional heavy-chain antibodies – homodimers of heavy chains without light chains. The variable domains of these heavy-chain antibodies (VHH) have a long complementarity determining region 3 (CDR3) loop that compensates for the absence of the antigen-binding loops of the variable light chains (VL). In the case of the VHH fragment cAb-Lys3, part of the 24 amino acid long CDR3 loop protrudes from the antigen-binding surface and inserts into the active-site cleft of its antigen, rendering cAb-Lys3 a competitive enzyme inhibitor. Results: A dromedary VHH with specificity for bovine RNase A, cAb-RN05, has a short CDR3 loop of 12 amino acids and is not a competitive enzyme inhibitor. The Structure of the cAb-RN05–RNase A complex has been solved at 2.8 A. The VHH scaffold architecture is close to that of a human VH (variable heavy chain). The Structure of the antigen-binding hypervariable 1 loop (H1) of both cAb-RN05 and cAb-Lys3 differ from the known Canonical Structures; in addition these H1 loops resemble each other. The CDR3 provides an antigen-binding surface and shields the face of the domain that interacts with VL in conventional antibodies. Conclusions: VHHs adopt the common immunoglobulin fold of variable domains, but the antigen-binding loops deviate from the predicted Canonical Structure. We define a new Canonical Structure for the H1 loop of immunoglobulins, with cAb-RN05 and cAb-Lys3 as reference Structures. This new loop Structure might also occur in human or mouse VH domains. Surprisingly, only two loops are involved in antigen recognition; the CDR2 does not participate. Nevertheless, the antigen binding occurs with nanomolar affinities because of a preferential usage of mainchain atoms for antigen interaction.
Fabrice Laurent - One of the best experts on this subject based on the ideXlab platform.
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Eimeria tenella ROP kinase EtROP1 induces G0/G1 cell cycle arrest and inhibits host cell apoptosis
Cellular Microbiology, 2019Co-Authors: Mamadou Amadou Diallo, Alix Sausset, Audrey Gnahoui-david, Adeline Ribeiro E Silva, Aurélien Brionne, Yves Le Vern, Françoise I. Bussière, Julie Tottey, Sonia Lacroix-lamandé, Fabrice LaurentAbstract:Coccidia are obligate intracellular protozoan parasites responsible for human and veterinary diseases. Eimeria tenella, the etiologic agent of cecal coccidiosis, is a major pathogen of chickens. In Toxoplasma gondii, some kinases from the rhoptry compartment (ROP) are key virulence factors. ROP kinases hijack and modulate many cellular functions and pathways, allowing T. gondii survival and development. E. tenella's kinome comprises 28 putative members of the ROP kinase family; most of them are predicted, as pseudokinases and their functions have never been characterized. One of the predicted kinase, EtROP1, was identified in the rhoptry proteome of E. tenella sporozoites. Here, we demonstrated that EtROP1 is active, and the N-terminal extension is necessary for its catalytic kinase activity. Ectopic expression of EtROP1 followed by co-immunoprecipitation identified cellular p53 as EtROP1 partner. Further characterization confirmed the interaction and the phosphorylation of p53 by EtROP1. E. tenella infection or overexpression of EtROP1 resulted both in inhibition of host cell apoptosis and G0/G1 cell cycle arrest. This work functionally described the first ROP kinase from E. tenella and its non-Canonical Structure. Our study provides the first mechanistic insight into host cell apoptosis inhibition by E. tenella. EtROP1 appears as a new candidate for coccidiosis control.