Figure 2.

Identification of ¹⁴C-NEM-labeled tryptic peptides of the human carboxylase. A tryptic digest of ¹⁴C-NEM-modified carboxylase was subjected to LC-ESMS, and postcolumn fractions were split with half of the sample being analyzed by mass spectrometry and aliquots (12% of the total digest) of the remainder analyzed by scintillation counting. The ¹⁴C-NEM-labeled peptides identified by mass spectrometry in the radioactive peaks are indicated and described in Table 2.