Simultaneous multiple synthesis and selective conjugation of cyclized peptides derived from a surface loop of a meningococcal class 1 outer membrane protein.
Starting from the alpha-(2,4-dimethoxybenzyl) ester of N-(9-fluorenylmethoxycarbonyl)aspartic acid [Fmoc-Asp-ODmb], side-chain-protected resin-bound Fmoc-peptides containing an N epsilon-1-(4,4-dimethyl-2,6-dioxocyclohexylidene)ethyl lysyl [Lys(Dde)] residue were prepared. The C-terminal dimethoxybenzyl esters of aspartic acid were removed with 1% trifluoroacetic acid and 10% anisole in dichloromethane, followed by Fmoc-cleavage in the usual manner. The resin-bound peptides were then cyclized using 1-benzotriazolyloxy-tris-[N-pyrrolidino]phosphonium hexafluorophosphate (PyBOP) in the presence of N-methylmorpholine. The (dimethyldioxocyclohexylidene)ethyl groups of lysine were removed with 1% hydrazine hydrate in N,N-dimethylacetamide, and the liberated side-chain amino functions were modified by reaction with pentafluorophenyl S-acetylmercaptoacetate (SAMA-OPfp). Finally, the peptides were side-chain deprotected, with exception of the Lys(SAMA) residue, and cleaved from the solid support with trifluoroacetic acid/anisole/water, 95/2.5/2.5. Cyclic peptides comprising 7-14 amino acid residues were obtained employing this procedure. As a model conjugation, cyclo[Thr-Asn-Asn-Asn-Leu-Lys(SAMA)-Thr-Lys-Asp] was coupled with bromoacetamide. The same peptide was also coupled with a bromoacetylpeptide to give a well defined peptide/peptide conjugate. All peptides were conjugated to bromoacetylated tetanus toxoid for immunization purposes.
Brugghe
H F
HF
RIVM (National Institute of Public Health and Environmental Protection), Uhit for Bacterial Vaccine Development, Bilthoven, The Netherlands.
Timmermans
H A
HA
Van Unen
L M
LM
Ten Hove
G J
GJ
Van de Werken
G
G
Poolman
J T
JT
Hoogerhout
P
P
D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000138:chemical synthesis*; D000922:Immunotoxins / Q000737:chemistry; D008969:Molecular Sequence Data; D009345:Neisseria meningitidis; D010456:Peptides, Cyclic; D013745:Tetanus Toxoid / Q000737:chemistry
D001425:Bacterial Outer Membrane Proteins; D000922:Immunotoxins; D010456:Peptides, Cyclic; D013745:Tetanus Toxoid