Metadata-Version: 2.4
Name: peptide-mass
Version: 0.1.0
Summary: No-dependency calculator for average and monoisotopic peptide masses and ESI [M+nH]n+ m/z values, for checking the identity section of a certificate of analysis.
Author-email: "Peptide.Express" <info@peptide.express>
License: MIT
Project-URL: Homepage, https://github.com/Peptide-Express/peptide-reference-data
Project-URL: Source, https://github.com/Peptide-Express/peptide-reference-data
Project-URL: Dataset, https://doi.org/10.5281/zenodo.23284819
Project-URL: Publisher, https://peptide.express/
Keywords: peptide,mass spectrometry,monoisotopic mass,LC-MS,analytical chemistry,certificate of analysis
Classifier: Programming Language :: Python :: 3
Classifier: License :: OSI Approved :: MIT License
Classifier: Intended Audience :: Science/Research
Classifier: Topic :: Scientific/Engineering :: Chemistry
Classifier: Operating System :: OS Independent
Requires-Python: >=3.8
Description-Content-Type: text/markdown
License-File: LICENSE
Dynamic: license-file

# peptide-mass

A small, no-dependency Python calculator for the theoretical masses of linear peptides built from the 20 standard amino acids. It gives monoisotopic and average masses plus the [M+H]⁺ … [M+5H]⁵⁺ m/z values you'd expect in electrospray, so you can check the identity (LC-MS) line of a certificate of analysis without doing the arithmetic by hand.

It's the packaged form of the calculator in [peptide-reference-data](https://github.com/Peptide-Express/peptide-reference-data) (dataset DOI [10.5281/zenodo.23284819](https://doi.org/10.5281/zenodo.23284819)), maintained by [Peptide.Express](https://peptide.express/).

## Install

```bash
pip install peptide-mass
```

## Use

```bash
peptide-mass GEPPPGKPADDAGLV
# monoisotopic 1418.7042 Da | average 1419.54 Da
#   [M+1H]1+  m/z 1419.7114 ...

peptide-mass CYIQNCPLG --c-amide --disulfides 1   # oxytocin
peptide-mass --csv peptides.csv                   # writes masses.csv
```

Options: `--n-acetyl`, `--c-amide`, `--pyroglu` (N-terminal Q or E), `--disulfides N`.

```python
from peptide_mass import mass, mz
mono, avg = mass("CYIQNCPLG", c_amide=True, disulfides=1)
print(round(mz(mono, 2), 4))
```

## Scope and limits

- Standard residues only. Non-standard residues and lipidated peptides aren't approximated.
- Values are for the neutral free peptide, not a TFA or acetate salt. Counter-ions and water change the weighed mass, not the MS parent mass.
- Average masses use IUPAC standard atomic weights; expect ±0.01–0.05 Da differences from other calculators.

## License

MIT. For laboratory research use only. Not for human or veterinary use. Nothing in this package is dosing, clinical or medical information.
