Calculate Molecular Weight Of Protein From Amino Acid

Molecular Weight Formula:

\[ MW (Da) = \sum (AA MW (Da)) \]

Molecular Weight:

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1. What is Protein Molecular Weight Calculation?

Protein molecular weight calculation determines the mass of a protein molecule by summing the molecular weights of its constituent amino acids. This is essential for various biochemical applications including protein purification, characterization, and research.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ MW (Da) = \sum (AA MW (Da)) \]

Where:

\( MW \) — Molecular weight in daltons (Da)
\( \sum \) — Summation of all amino acid weights
\( AA MW \) — Individual amino acid molecular weight

Explanation: The calculator processes each amino acid in the sequence, looks up its molecular weight from a predefined table, and sums all values to get the total protein molecular weight.

3. Importance of Molecular Weight Calculation

Details: Accurate molecular weight determination is crucial for protein characterization, SDS-PAGE analysis, mass spectrometry, chromatography, and understanding protein structure-function relationships.

4. Using the Calculator

Tips: Enter the amino acid sequence using single-letter codes (A, R, N, D, C, E, Q, G, H, I, L, K, M, F, P, S, T, W, Y, V). The sequence should not contain spaces or invalid characters.

5. Frequently Asked Questions (FAQ)

Q1: What are the standard amino acid molecular weights used?
A: The calculator uses standard molecular weights for the 20 common amino acids based on their residue masses.

Q2: Does this include post-translational modifications?
A: No, this calculator only calculates the molecular weight of the unmodified polypeptide chain. Modifications like phosphorylation or glycosylation would require additional calculations.

Q3: What is the unit of measurement?
A: Molecular weight is calculated in daltons (Da), which is equivalent to grams per mole.

Q4: Can I use three-letter amino acid codes?
A: No, this calculator only accepts single-letter amino acid codes for sequence input.

Q5: How accurate is this calculation?
A: The calculation provides a theoretical molecular weight based on amino acid composition. Actual experimental values may vary slightly due to isotopic distributions and other factors.