Figure 2.

Identification of peptides from the 64-kD protein as internal sequences of the α-subunit of CF₁. The predicted amino acid sequence of the wheat CF₁ α-subunit (Howe et al., 1985) is presented, with lysyl residues denoted by a box. Purified 64-kD protein from wheat was cleaved with a commercial lysyl endopeptidase, and four peptides from the digest were isolated and sequenced. The peptides corresponded to the four underlined sequences noted within the wheat CF₁ α-subunit. Asterisks (*) indicate amino acid residues definitively identified; †, low signal level, putatively identified as Arg; −, residues not determined during sequencing due to low yield. Peptide 2 followed a methionyl residue, indicating a nonspecific cleavage by the commercial lysyl endopeptidase. Such cleavages have been noted previously in proteins cleaved by this enzyme (J. Pohl, personal communication).