. 2011 Mar 24;25(5):776–784. doi: 10.1210/me.2010-0389

Table 1.

Peptides identified by MALDI-TOF mass spectrometry

Peptide	Predicted mass (Da)	Observed mass (Da)
Peptide	Predicted mass (Da)	furin	PC1/3	PC2
His tag-R⁴¹	4510	4511	4512	4511
E⁴²-R⁷⁰	3267	3272	3269	N.D.
E⁴²-K⁶⁹	3111	N.D.	N.D.	3117
Q⁷¹-Y¹⁴⁸	9701	9701	N.D.	N.D.
R⁷⁰-Y¹⁴⁸	9857	N.D.	N.D.	9900
H¹²²-Y¹⁴⁸	3088	N.D.	N.D.	3087
E⁴²-Y¹⁴⁸	12950	N.D.	N.D.	N.D.

Each predicted mass was calculated using ProteinProspector. N.D. indicates not detected. The His tag-R⁴¹ fragment consists of the His-tag-linker region and augurin (N³²-R⁴¹) with calculated masses of 3257 and 1271 Da, respectively; after the subtraction of 18 Da due to the formation of peptide bond between the 3257- and 1271-Da fragments, the total predicted mass of the His tag-R⁴¹ fragment is therefore 4510 Da.