Table 1.

HEL peptides presented by the wild-type mHEL transfectant

Relative yield, %		Position	Sequence																	Mass, amu
			47	48	49	50	51	52	53	54	55	56	57	58	59	60	61	62	63	Predicted	Observed
9	2	47–62	T	D	G	S	T	D	Y	G	I	L	Q	I	N	S	R	W		1825.95	1825.66
	7	47–63	T	D	G	S	T	D	Y	G	I	L	Q	I	N	S	R	W	W	2011.17	2011.92
88	32	48–62		D	G	S	T	D	Y	G	I	L	Q	I	N	S	R	W		1724.85	1724.86
	56	48–63		D	G	S	T	D	Y	G	I	L	Q	I	N	S	R	W	W	1911.06	1910.86
3	1	49–62			G	S	T	D	Y	G	I	L	Q	I	N	S	R	W		1609.76	1609.84
	2	49–63			G	S	T	D	Y	G	I	L	Q	I	N	S	R	W	W	1795.97	1795.85

Sequences of the six recovered HEL peptides are given in single-letter amino acid code. The numbers above each amino acid refer to its position within the HEL molecule. The predicted mass was calculated as the average isotopic mass of each peptide plus an additional hydrogen for ionization. The observed masses were obtained using matrix-assisted laser desorption ionization–time of flight as described. The relative yield for each peptide was calculated by integration of the mass spectrum shown in Fig. 2b.