pH on-off switching of antibody-hapten binding by site-specific chemical modification of tyrosine.
Tetranitromethane (TNM) chemically mutates the binding sites of antibodies so that the nitrated antibodies exhibit pH-dependent binding near physiological pH. Three monoclonal antibodies were selectively modified, each under different conditions, with the resultant loss of binding activity at pH > 8 which is recovered at pH < 6. Recovery and loss of binding are ascribed to the protonation and deprotonation, respectively, of the hydroxyl group of the resulting 3-nitrotyrosine side chain (pKa approximately 7) at the binding site of these antibodies. pH on-off dependency of binding activity, common to all TNM-modified antibodies studied by us so far, may find use in a variety of applications in which controlled modulation under mild conditions is required.
Tawfik
D S
DS
Department of Chemical Immunology, Weizmann Institute of Science, Rehovot, Israel.
Chap
R
R
Eshhar
Z
Z
Green
B S
BS
D019297:2,4-Dinitrophenol; D000911:Antibodies, Monoclonal / Q000378:metabolism*; D001666:Binding Sites, Antibody / Q000187:drug effects; D004140:Dinitrophenols / Q000276:immunology; D006241:Haptens / Q000378:metabolism*; D006433:Hemocyanins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D013774:Tetranitromethane / Q000494:pharmacology*; D014443:Tyrosine / Q000737:chemistry*
D000911:Antibodies, Monoclonal; D004140:Dinitrophenols; D006241:Haptens; D014443:Tyrosine; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin; D013774:Tetranitromethane; D019297:2,4-Dinitrophenol