Immunochemistry of sperm-whale myoglobin--XX. Accurate delineation of the single reactive region in sequence 80-103 by immunochemical studies of synthetic peptides

Previous work from this laboratory on the antigenic structure of myoglobin (Mb) has shown that an antigenic reactive region exists within, but may not include all of, sequence 86–102 of Mb. Also, recently we have reported evidence that this reactive region is centered around histidine-97 and lysine-98. The present communication present independent evidence aimed at the accurate delineation of the reactive region by studying the immunochemistry of synthetic peptides corresponding to various parts of the region. Four peptides corresponding to sequence 92–100, 93–100, 94–100 and 93–99 were synthesized, exhaustively purified and characterized. The immunochemical interactions of the peptides were studied with four different antisera to Mb. With the antisera studied here, the presence or absence of Ser-92, His-93 or Pro-100 did not infleunce the immunochemical reactivity of the peptides. The reactive region, therefore, occupies the sequence 94–99 accurately. This is a small (six residue) surface location on the corner between helices F and G in native Mb.