C‐Terminal antibodies (CTAbs): A simple and broadly applicable approach for the rapid generation of protein‐specific antibodies with predefined specificity

Recent advances in proteomic techniques have resulted in an ever‐increasing need to produce antibodies. Here, to address this problem, a technically simple approach of targeting the extreme C‐termini of proteins with antibodies (CTAbs) was investigated in proteins secreted by the human pathogen Streptococcus pyogenes . Target proteins were identified by a conventional proteomic approach and CTAbs produced against synthetic five amino acid peptides representing the C‐terminus of each target protein. In every case where protein secretion was demonstrated ( n  = 20), CTAbs were successfully produced and bound specifically to the target protein (100% success rate). The apparent specificity was consistent with the structural heterogeneity of the C‐termini of S. pyogenes proteins. The global specificity of CTAb binding was defined using a combinatorial library of synthetic peptides representing structural variants of the original synthetic immunogen. This is a systematic and comprehensive approach for the development of antibodies with defined specificity that can be used in a range of applications.