Protein Elemental Formula
Sum C/H/N/O/S protein elemental formula from residue compositions and termini.
Description
A protein elemental formula adds residue compositions and terminal water for one unmodified chain.
A protein elemental formula adds residue compositions and terminal water for one unmodified chain. Residue formulas already account for water lost in peptide bonds.1
Sum C/H/N/O/S protein elemental formula from residue compositions and termini.
When to use Protein Elemental Formula
Use this tool to sum C/H/N/O/S protein elemental formula from residue compositions and termini.
Prepare the canonical sequence, peptide assignments, fitted assay parameters or upstream measurements requested. Keep corresponding entries aligned, use the stated mass and signal units, and remove FASTA headers before entering sequence text.
How to use Protein Elemental Formula and understand its results
- Prepare the canonical sequence, peptide assignments, fitted assay parameters or upstream measurements requested. Keep corresponding entries aligned, use the stated mass and signal units, and remove FASTA headers before entering sequence text.
- Enter sequence using the field table and calculation rules, then run the tool.
- Read carbon, hydrogen, nitrogen, oxygen, sulfur. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| sequence | Sequence | string | Required |
Enter a canonical sequence. Initialize hydrogen to two and oxygen to one, then sum committed residue element counts. Return carbon, hydrogen, nitrogen, oxygen and sulfur totals.
The shared sequence helper trims outer whitespace and uppercases the sequence. It requires at least one residue from ACDEFGHIKLMNPQRSTVWY. Internal whitespace, FASTA headers, ambiguous letters and modified-residue notation are rejected. Sequence indexes refer to the normalized sequence; individual tools may preserve original strings in their returned lists as explained above.
atoms=Σresidue(C,H,N,O,S)+terminal H2O Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| carbon | Carbon | number |
| hydrogen | Hydrogen | number |
| nitrogen | Nitrogen | number |
| oxygen | Oxygen | number |
| sulfur | Sulfur | number |
{
"input": {
"sequence": "A"
},
"output": {
"carbon": 3,
"hydrogen": 7,
"nitrogen": 1,
"oxygen": 2,
"sulfur": 0
}
}Limitations and assumptions
Disulfide formation, modifications, conjugates, salts and multiple chains are not represented. Each disulfide would alter hydrogen count beyond this reduced-chain model.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Extremely large text inputs are rejected. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Protein Average Mass: Sum average isotopic residue masses plus terminal water for a protein sequence. For a complementary task, use Peptide Neutral Mass: Calculate monoisotopic neutral peptide mass from its canonical sequence.
References
-
Protein Elemental Formula — tool.io
Similar or alternative tools
- Protein Average Mass
Sum average isotopic residue masses plus terminal water for a protein sequence.
- Peptide Neutral Mass
Calculate monoisotopic neutral peptide mass from its canonical sequence.