Protein Weight Calculator Kda

Protein Weight Formula:

\[ MW (kDa) = \frac{\sum (AA\ masses\ (Da))}{1000} \]

Molecular Weight:

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1. What Is Protein Molecular Weight Calculation?

Protein molecular weight calculation determines the mass of a protein based on its amino acid sequence. The result is typically expressed in kilodaltons (kDa), where 1 kDa equals 1000 daltons.

2. How Does The Calculator Work?

The calculator uses the formula:

\[ MW (kDa) = \frac{\sum (AA\ masses\ (Da))}{1000} \]

Where:

\( MW \) — Molecular weight in kilodaltons
\( AA\ masses \) — Sum of individual amino acid masses in daltons

Explanation: The calculator sums the mass of each amino acid in the sequence (using standard molecular weights) and converts the total from daltons to kilodaltons by dividing by 1000.

3. Importance Of Molecular Weight Calculation

Details: Knowing a protein's molecular weight is essential for protein characterization, gel electrophoresis, chromatography, concentration determination, and various biochemical applications.

4. Using The Calculator

Tips: Enter the protein amino acid sequence using single-letter codes. The calculator accepts standard 20 amino acids (A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W, Y). Non-standard characters will be flagged as errors.

5. Frequently Asked Questions (FAQ)

Q1: What are daltons and kilodaltons?
A: A dalton is a unit of mass equal to 1/12 the mass of a carbon-12 atom. A kilodalton (kDa) equals 1000 daltons.

Q2: Does this include post-translational modifications?
A: No, this calculator calculates theoretical molecular weight based solely on the amino acid sequence without modifications.

Q3: Why are there different values for molecular weight?
A: Different sources may use slightly different atomic masses or include/exclude the mass of water molecules in hydrolysis.

Q4: How accurate is this calculation?
A: This provides a theoretical molecular weight. Actual experimental values may vary due to protein folding, modifications, and measurement techniques.

Q5: Can I calculate molecular weight for nucleic acids?
A: This calculator is specifically designed for proteins. Different calculators are needed for DNA/RNA molecular weight calculations.