A New Serum Factor in Normal Rabbits

[摘要] A hexapeptide was specifically cleaved from the C-terminus of the Fd of rabbit (Fab')2 fragments. The amino acid composition and sequence of the peptide was identical to that reported for the hinge peptide. These studies further showed that the hinge peptide could be recovered as a disulfide bonded dimer from d 11 but not from d 12 (Fab')2 fragments by digestion with CNBr.The results of this investigation also demonstrated that the isolated peptides were reactive with a specific natural antiglobulin factor in rabbit sera, namely, homoreactant. As such, the peptide represents one of the smallest naturally occurring antigenic determinants isolated from a protein.The chemical and serological properties of the isolated hinge peptide were confirmed by comparison with a synthetic peptide of determined amino acid sequence.

[学科分类] 生物科学（综合）