Preparation of peptide-protein immunogens using N-succinimidyl bromoacetate as a heterobifunctional crosslinking reagent

✍ Scribed by Michael S. Bernatowicz; Gary R. Matsueda

• Book ID: 102986211
• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 762 KB
• Volume: 155
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(86)90231-9

✦ Synopsis

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.