High yield, directed immobilization of a peptide-ligand onto a beaded cellulose support

Aminopropyl derivatized Perloza beaded cellulose was acylated with alpha-bromoacetic anhydride to give alpha-bromo-acetamidopropyl Perloza. (N-Acetyl)-Cys-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2, the 7 C-terminal amino acids of the decapeptide luteinizing hormone-releasing hormone with a cysteine added to the N-terminus, was synthesized using Fmoc chemistry. The purified peptide (1.35-1.9 eq) was coupled to alpha-bromoacetamidopropyl Perloza in 0.1 M NaHCO3 solution, pH 8.3, for 1-2 hours. The peptide was anchored to the support via a thioether linkage. Analysis of the peptide-Perloza conjugate indicated near-quantitative displacement of support-bound bromine by the peptide. The peptidic affinity matrix was able to bind ovine antibodies to luteinizing hormone-releasing hormone (LHRH). Thioether immobilization offers directed, chemically stable, high-yield anchoring of synthetic peptides onto a chromatographic support. The high reaction efficiency means there is little waste of valuable synthetic peptide.