title: Toward selective covalent inactivation of pathogenic antibodies: a phosphate diester analog of vasoactive intestinal peptide that inactivates catalytic autoantibodies.
abstract: We report the selective inactivation of proteolytic antibodies (Abs) to an autoantigen, the neuropeptide vasoactive intestinal peptide (VIP), by a covalently reactive analog (CRA) of VIP containing an electrophilic phosphonate diester at the Lys(20) residue. The VIP-CRA was bound irreversibly by a monoclonal Ab that catalyzes the hydrolysis of VIP. The reaction with the VIP-CRA proceeded more rapidly than with a hapten CRA devoid of the VIP sequence. The covalent binding occurred preferentially at the light chain subunit of the Ab. Covalent VIP-CRA binding was inhibited by VIP devoid of the phosphonate diester group. These results indicate the importance of noncovalent VIP recognition in guiding Ab nucleophilic attack on the phosphonate group. Consistent with the covalent binding data, the VIP-CRA inhibited catalysis by the recombinant light chain of this Ab with potency greater than the hapten-CRA. Catalytic hydrolysis of VIP by a polyclonal VIPase autoantibody preparation that cleaves multiple peptide bonds located between residues 7 and 22 essentially was inhibited completely by the VIP-CRA, suggesting that the electrophilic phosphonate at Lys(20) enjoys sufficient conformational freedom to react covalently with Abs that cleave different peptide bonds in VIP. These results suggest a novel route to antigen-specific covalent targeting of pathogenic Abs.
authors.affiliation: Chemical Immunology and Therapeutics Research Center, Department of Pathology and Laboratory Medicine, University of Texas-Houston Medical School, Houston, Texas 77030, USA. yasuhiro.nishiyama@uth.tmc.edu
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nishiyama
authors.forename: Gita
authors.initials: G
authors.lastname: Bhatia
authors.forename: Yogesh
authors.initials: Y
authors.lastname: Bangale
authors.forename: Stephanie
authors.initials: S
authors.lastname: Planque
authors.forename: Yukie
authors.initials: Y
authors.lastname: Mitsuda
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Taguchi
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Karle
authors.forename: Sudhir
authors.initials: S
authors.lastname: Paul
mesh_terms: D000154:Aconitate Hydratase; D000595:Amino Acid Sequence; D017151:Antibodies, Catalytic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000918:Antibody Specificity; D000941:Antigens / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D001323:Autoantibodies / Q000378:metabolism*; D001666:Binding Sites, Antibody; D004952:Esters / Q000276:immunology* / Q000378:metabolism; D006241:Haptens / Q000737:chemistry / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D007147:Immunoglobulin Light Chains / Q000235:genetics / Q000378:metabolism; D008239:Lysine / Q000737:chemistry / Q000276:immunology; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D063065:Organophosphonates / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D011994:Recombinant Proteins; D021241:Spectrometry, Mass, Electrospray Ionization; D014660:Vasoactive Intestinal Peptide / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D017151:Antibodies, Catalytic; D000941:Antigens; D001323:Autoantibodies; D004952:Esters; D006241:Haptens; D007074:Immunoglobulin G; D007147:Immunoglobulin Light Chains; D063065:Organophosphonates; D011994:Recombinant Proteins; D014660:Vasoactive Intestinal Peptide; D000154:Aconitate Hydratase; D008239:Lysine