. 2021 Apr 22;18(5):1895–1904. doi: 10.1021/acs.molpharmaceut.0c00574

Table 4. Tryptic Proteospecific Peptide and Its Respective Ions and Mass Transitions Used for P-gp Quantification.

Molecule name	Peptide sequence	Mass	Transition number	Q1 m/z	Q1-CE	Q3 m/z	Q3-CE
ABCB1 (P-gp)	AGAVAEEVLAAIR (surrogate peptide)	1268.7	1	635.3	30	771.3	30
			2	635.3	30	900.5	30
			3	635.3	30	971.6	30
	AGAVAEEVLAAIR^a (internal standard)	1278.6	1	640.3	30	781.4	30
			2	640.3	30	910.5	30
			3	640.3	30	981.5	30

Isotope-labeled amino acid; the labeling of Arg (R) was done by introducing C¹³ and N¹⁵.