Peptency Academy · Tool

Mass and m/z calculator

From a peptide sequence: elemental formula, monoisotopic and average mass, and the m/z of [M+zH]z+ ions for charge states 1 to 8. Then look up which catalog molecule has a given mass, m/z or sequence fragment.

ToolsAcademyMass and m/zAnalytical calculation

Sequence (one letter code)

Start with Ac- for an acetylated N terminus and end with -NH2 for a C terminal amide. Write non standard residues in brackets, for example [Aib] or [Nle]. Lower case letters are D residues (same mass).

Catalog molecule

Modifications N terminal acetyl C terminal amideDisulfide bonds

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Formula: C212H350N56O78S
Residues: 43
Monoisotopic mass: 4960.4863 Da
Average mass: 4963.51 Da

ESI m/z of [M+zH]z+ ions
Charge	Monoisotopic m/z	Average m/z
1+	4961.4936	4964.51
2+	2481.2504	2482.76
3+	1654.5027	1655.51
4+	1241.1289	1241.88
5+	993.1045	993.71
6+	827.7550	828.26
7+	709.6482	710.08
8+	621.0681	621.45

Mass and sequence lookup

Which catalog molecule has this mass, gives this m/z, or contains this fragment. Free molecules only; salt forms and counterions are not added.

Mass (Da)

Tolerance (Da)

The number is a neutral mass an m/z, charge 1 to 8

Sequence fragment (3 or more residues, one letter code)

Sources

Research-use information. This library summarises published literature and regulator records. It is not guidance for use, not medical advice, and not a statement that any material is suitable for use in people or animals.