Fig. 7.

Isolation of [³H]dFBr-photolabeled α subunit peptides. The band for nAChR α subunit from the photolabeling experiment described in Fig. 6 was excised and transferred to a 15% acrylamide mapping gel and subjected to in-gel digestion with V8 protease to produce large nAChR α subunit fragments shown schematically in (A). rpHPLC fractionations of EndoLys-C digests of (B) αV8-20, which begins at αSer¹⁷³, and (C) αV8-18, which begins at αThr⁵². Elution of peptides (solid line) and ³H (○-Carb, ⬤+Carb) were monitored. rpHPLC fractions 27–29 and 30–32 from the V8-20 digest and fractions 17–19 from the V8-18 digest were pooled for sequence analysis (Fig. 8).