Calculate Protein Molecular Weight From Dna Sequence

Protein Molecular Weight Formula:

\[ MW_{protein} = \frac{length_{DNA}}{3} \times average\ AA\ MW \]

Protein Molecular Weight (MW_protein):

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1. What Is Protein Molecular Weight Calculation?

Protein molecular weight calculation estimates the mass of a protein based on its DNA sequence length and average amino acid molecular weight. This provides an approximate molecular weight useful for various biochemical applications.

2. How Does The Calculator Work?

The calculator uses the formula:

\[ MW_{protein} = \frac{length_{DNA}}{3} \times average\ AA\ MW \]

Where:

\( length_{DNA} \) — Length of DNA sequence in bases
\( average\ AA\ MW \) — Average molecular weight of amino acids (typically 110 g/mol)

Explanation: Since each amino acid is coded by 3 DNA bases, dividing the DNA length by 3 gives the number of amino acids. Multiplying by the average amino acid molecular weight provides the estimated protein molecular weight.

3. Importance Of Protein MW Calculation

Details: Accurate protein molecular weight estimation is crucial for protein purification, gel electrophoresis, mass spectrometry analysis, and various biochemical experiments where protein size matters.

4. Using The Calculator

Tips: Enter DNA length in bases (must be divisible by 3), and average amino acid molecular weight (default is 110 g/mol). All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why divide DNA length by 3?
A: Because each amino acid is encoded by 3 DNA bases (a codon), so dividing by 3 gives the number of amino acids in the protein.

Q2: Why use 110 g/mol as average AA MW?
A: 110 g/mol is the commonly used average molecular weight for amino acids in proteins, accounting for the natural abundance of different amino acids.

Q3: How accurate is this calculation?
A: This provides an approximate molecular weight. Actual MW may vary depending on the specific amino acid composition and post-translational modifications.

Q4: Can I use this for modified proteins?
A: This calculation provides the theoretical molecular weight of the unmodified protein chain. Modifications like phosphorylation or glycosylation will increase the actual molecular weight.

Q5: What about start/stop codons?
A: This calculation assumes the entire DNA sequence codes for the protein. Start and stop codons are typically included in the total DNA length.