FIGURE 5.
Chymotryptic mapping of A-chain-specific photocross-linked complexes. Photoadducts were obtained at the indicated positions and digested with chymotrypsin as described (6). At successive time points, aliquots were reduced by treatment with DTT, heat-denatured, and resolved by SDS-PAGE. Fragments were blotted onto nitrocellulose membrane and detected by NeutrAvidin (NAv; A and C) or antiserum IRα-N (B and D). Dotted boxes in A and C indicate the 19-kDa N-terminal L1-derived tryptic fragment estimated to contain ∼100 residues (and three N-linked carbohydrates). Molecular masses and domain assignments are otherwise as indicated.