Figure 2.

Tryptic mapping of homogeneous beef kidney QR₂. (Upper) HPLC trace from a Zorbax C₁₈ column monitored at 215 nm is shown and three peptides selected for MALDI-MS and Edman sequencing are identified as A, B, and C (Table 1). Simultaneous monitoring at 277 nm and 292 nm (not shown) indicated the presence of tyrosine residues in A and B, and a tryptophan residue in C. (Lower) MALDI-MS (20) of peptide fragments A, B, and C. The molecular weights and Edman sequences of the peptides are given in Table 1.