Home
Back
Protein Molecular Weight Formula:
| From: | To: |
Molecular weight is a fundamental property of proteins that represents the sum of the atomic weights of all atoms in a molecule. It's typically expressed in Daltons (Da) or grams per mole (g/mol) and is crucial for various biochemical applications.
The calculator uses the simplified protein molecular weight formula:
Where:
Explanation: This formula provides an approximate molecular weight based on the average mass of amino acid residues in proteins.
Details: Knowing a protein's molecular weight is essential for protein purification, gel electrophoresis, mass spectrometry analysis, and determining protein concentration in biochemical experiments.
Tips: Enter the number of amino acid residues in your protein sequence. The value must be a positive integer greater than zero.
Q1: Why use 110 as the average amino acid weight?
A: 110 g/mol is the commonly accepted average molecular weight of an amino acid residue, accounting for water loss during peptide bond formation.
Q2: How accurate is this estimation?
A: This provides a rough estimate. Actual molecular weight varies based on the specific amino acid composition of each protein.
Q3: What's the difference between residue weight and amino acid weight?
A: Amino acid residue weight accounts for the water molecule lost during peptide bond formation, making it approximately 18 g/mol less than the full amino acid weight.
Q4: When would I need a more precise calculation?
A: For exact molecular weight determination, especially in mass spectrometry or precise biochemical applications, use tools that calculate based on the exact amino acid sequence.
Q5: Does this account for post-translational modifications?
A: No, this calculator provides the theoretical molecular weight of the unmodified polypeptide chain only.