. Author manuscript; available in PMC: 2012 Dec 1.

Published in final edited form as: Int J Mass Spectrom. 2011 Dec 1;308(2-3):142–154. doi: 10.1016/j.ijms.2011.04.008

Table 3.

Percentage of w_N, v_N, v_N+1 and x_N-1ions for various N-terminal amino acids.

N-terminal residue	w_N	v_N	v_N+1	v_N+2	x_N-1
Asn^a	69%	46%	15%		93%
Glu^a		42%	90%		89%
Ala^a		28%	20%		86%
Tyr^a		51%	85%		44%
Phe^a		72%			76%
Gly^a	-	-	-	-	51%

Asp^b	x	x
Leu^b		x
Ile^b		x
Val^b		x
His^b		x	x
Trp^b		x	x
Gln^b		x	x
Ser^b		x	x	x
Thr^b		x	x	x
Met^b			x

Peptides derived from synthetic libraries.

Peptides derived from D. radiodurans ribosomal proteins. X indicates that the fragment is present. – indicates ions that cannot be formed for N-terminal glycine.