TABLE 1

Ubiquitinated peptides of ubiquitin

Modified amino acid is shown in boldface. Periods represent the beginning and end of the tryptic peptide.

Identification	Peptides^{^a}	Charge
Ubiquitin	R.LIFAGK^48*QLEDGR.T	+2
Ubiquitin	R.LIFAGK^48*QLEDGR.T	+3

↵^a An asterisk denotes Gly-Gly modification of the amino group of the lysine side chain.