Preparation of peptide-protein immunogens using N-succinimidyl bromoacetate as a heterobifunctional crosslinking reagent.
Synthetic peptides derived from human fibrin were unidirectionally conjugated to three carrier proteins (bovine serum albumin, bovine alpha-lactalbumin, and keyhole limpet hemocyanin) by a method that employs N-succinimidyl bromoacetate. This heterobifunctional crosslinking reagent was prepared with a 79% yield in gram quantities from inexpensive starting materials. With this reagent, carrier proteins were first bromoacetylated, then reacted with the thiol groups of cysteine-containing peptides. The extent of peptide conjugation was assessed by amino acid analysis after acid hydrolysis, which liberated 1 mol of S-carboxymethylcysteine for each mole of thioether linkage between peptide and protein. The results of several conjugation experiments indicated that the efficiency of peptide incorporation ranged between 22 and 37% based on the recovery of S-carboxymethylcysteine relative to lysine. When the conjugates were used as immunogens, the S-carboxymethyl linkage was not antigenic in comparison with the S-maleimidobenzoyl linkage, even though their antipeptide immunoreactivities were similar.
D000818:Animals; D000941:Antigens; D002417:Cattle; D003432:Cross-Linking Reagents / Q000138:chemical synthesis; D006433:Hemocyanins / Q000276:immunology; D007120:Immunochemistry; D007768:Lactalbumin / Q000276:immunology; D010455:Peptides / Q000276:immunology*; D011506:Proteins / Q000276:immunology*; D012710:Serum Albumin, Bovine / Q000276:immunology; D013388:Succinimides / Q000138:chemical synthesis; D014302:Trinitrobenzenesulfonic Acid
D000941:Antigens; D003432:Cross-Linking Reagents; D010455:Peptides; D011506:Proteins; D013388:Succinimides; D012710:Serum Albumin, Bovine; C049271:N-succinimidyl bromoacetate; C013097:3-maleimidobenzoyl N-hydroxysuccinimide; D014302:Trinitrobenzenesulfonic Acid; D006433:Hemocyanins; D007768:Lactalbumin; C032808:keyhole-limpet hemocyanin