Kostenloser Protein Molecular Gewichts Rechner
Schätzen Sie protein molecular Gewicht aus amino acid residue count. Quick calculation for biochemistry research.
Estimated Molecular Weight
33,018 Da
Estimated Molecular Weight vs Number of Amino Acid Residues
Formel
## Protein Molecular Weight Estimation The molecular weight of a protein can be estimated from the number of amino acid residues using the average residue weight. ### Formula **MW = N × 110 + 18** where N is the number of residues and 110 Da is the average amino acid residue weight (after peptide bond formation removes water). The +18 accounts for the water molecule completing the N-terminus and C-terminus. The actual average residue weight is 111.1 Da for a typical protein composition.
Lösungsbeispiel
A protein with 300 amino acid residues.
- 01MW = 300 × 110 + 18 = 33,018 Da
- 02MW = 33.0 kDa
Häufig Gestellte Fragen
How accurate is this estimate?
Within about 5-10% for most proteins. Actual MW depends on the amino acid composition. Proteins enriched in heavy amino acids (Trp, Tyr) will be heavier, while glycine-rich proteins will be lighter.
What about post-translational modifications?
Glycosylation can add 2-50 kDa or more. Phosphorylation adds ~80 Da per site. Disulfide bonds subtract 2 Da per bond. Prosthetic groups (heme, FAD) add their own mass.
How is protein MW measured precisely?
Mass spectrometry (MALDI-TOF or ESI) gives accuracy within a few Daltons. SDS-PAGE gives estimates within 10-20%. Size exclusion chromatography can give rough estimates for native proteins.
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