. 2021 Feb 6;22(4):1648. doi: 10.3390/ijms22041648

Table 2.

Fragmentation efficiency of the α-MSH analogs and bioconjugates by HCD, ETD and EThcD fragmentation techniques.

Compound	z	Low E HCD (NCE ≤ 20%)	High E HCD (NCE ≥ 25%)	ETD	EThcD
1; (4)	2	+; (−)	+ +; (+ + +)	+ +	+ + ^a
1; (4)	3	+ + +; (+ +)	+ + +; (+ +)	+ + +; (+ +)	+ + + (+ +) ^a
2; (5) Dau at N-terminus	2	−	+ +	−	+; (+ +) ^b
2; (5) Dau at N-terminus	3	+; (−)	+ +	−	−; (+) ^b
3; (6) Dau at Lys	2	−	+; (+ +)	−	− ^c
3; (6) Dau at Lys	3	−	+; (+ +)	−	− ^d

Symbols: −: no peptide sequence related fragments; +: the sequence coverage is 10–30%, where the relative intensity of the fragments is ≥5%; + +: the sequence coverage is 31–60%, where the relative intensity of the fragments is ≥5%; + + +: the sequence coverage is > 61%, where the relative intensity of the fragments is ≥5%; ^a NCE = 10%, ^b NCE = 40%, ^c NCE = 30%, ^d NCE = 35%. Values for the compounds 4, 5 and 6 are in brackets.