Characterization of antibodies to chicken riboflavin carrier protein. Immunoneutralizing ability of antibodies to a sequence-specific region of the protein.
The properties of antibodies generated in rabbits against native riboflavin carrier protein (cRCP), riboflavin carrier protein that had been denatured/renatured by SDS treatment (SDS-RCP) or disulphide-bond-reduced then S-carboxymethylated (Carb-RCP) were studied. SDS-RCP could displace native RCP in radioimmunoassay (r.i.a.), whereas Carb-RCP could not. By using antibodies raised in five different rabbits against native cRCP, 125I-labelled Carb-RCP could bind between 0 and 30% of the native antibodies. Antibodies raised against native RCP appear to be largely directed towards specific conformational determinants of RCP. Carb-RCP displaced native RCP in an r.i.a. using antibodies raised against SDS-RCP. SDS denaturation presumably unmasks cryptic epitopes in native RCP. Carb-RCP was a weak immunogen and elicited, presumably, antibodies to sequential epitope/epitopes. When injected into pregnant mice the antibodies caused neutralization of RCP, leading to termination of pregnancy, indicating highly conserved sequential epitopes in chicken and rodent RCP. Antibodies raised against Carb-RCP or native RCP reacted with CNBr fragments of native RCP, further confirming the presence of sequence-specific antibodies elicited by Carb-RCP.
Natraj
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U
Institute for Research in Reproduction (ICMR), Parel, Bombay, India.
George
S
S
Kadam
M S
MS
D000818:Animals; D000906:Antibodies / Q000276:immunology*; D002352:Carrier Proteins / Q000276:immunology*; D002645:Chickens; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000032:analysis; D005260:Female; D007106:Immune Sera; D007122:Immunoelectrophoresis; D007457:Iodine Radioisotopes; D026901:Membrane Transport Proteins; D008745:Methylation; D051379:Mice; D010446:Peptide Fragments / Q000276:immunology; D011247:Pregnancy; D011863:Radioimmunoassay; D013050:Spectrometry, Fluorescence
D000906:Antibodies; D002352:Carrier Proteins; D000939:Epitopes; D007106:Immune Sera; D007457:Iodine Radioisotopes; D026901:Membrane Transport Proteins; D010446:Peptide Fragments; C019079:riboflavin-binding protein