Fig. 4.

Characterization of the epitope recognized by the αFp-AB. (a) Shown are the amino acid sequences of the 6-hydroxy-d-nicotine oxidase (6HDNO) peptides generated by digestion with trypsin, chymotrypsin and endopeptidase Lys and a schematic representation of the predicted secondary structure of the peptides. (b) 6HDNO (100 μg per assay) was subjected to treatment with trypsin (lane 2), chymotrypsin (lane 3) and endopeptidase Lys (lane 4). The peptides were separated by SDS–PAGE (15%), blotted onto nitrocellulose membrane and decorated overnight with purified human αFp-AB. Undigested 6HDNO was applied as control (lane 1); 96 kD and 48 kD indicate the dimeric and monomeric form of 6HDNO, respectively.