Calculate Protein Molecular Weight From Dna Sequence

Protein Molecular Weight Formula:

\[ MW\ protein\ (Da) = \left( \frac{DNA\ length\ (bp)}{3} - stops \right) \times 110 \]

Protein Molecular Weight:

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1. What is Protein Molecular Weight Calculation?

Protein molecular weight calculation estimates the mass of a protein molecule based on its DNA sequence length and number of stop codons. This approximation uses the average molecular weight of amino acids to provide a quick estimate.

2. How Does the Calculator Work?

The calculator uses the protein molecular weight formula:

\[ MW\ protein\ (Da) = \left( \frac{DNA\ length\ (bp)}{3} - stops \right) \times 110 \]

Where:

\( DNA\ length \) — Length of DNA sequence in base pairs
\( stops \) — Number of stop codons in the sequence
\( 3 \) — Conversion factor (3 bp per amino acid codon)
\( 110 \) — Average molecular weight of an amino acid in daltons

Explanation: The formula calculates the number of amino acids from DNA length, subtracts stop codons, and multiplies by the average amino acid molecular weight.

3. Importance of Protein MW Calculation

Details: Protein molecular weight estimation is crucial for protein purification, gel electrophoresis, mass spectrometry analysis, and biochemical research applications.

4. Using the Calculator

Tips: Enter DNA length in base pairs (must be multiple of 3) and number of stop codons. DNA length must be at least 3 bp, and stop codons cannot exceed DNA length divided by 3.

5. Frequently Asked Questions (FAQ)

Q1: Why use 110 daltons as average amino acid weight?
A: 110 daltons represents the average molecular weight of the 20 standard amino acids, accounting for their natural abundance in proteins.

Q2: What are typical protein molecular weights?
A: Proteins range from small peptides (few thousand daltons) to large complexes (hundreds of thousands to millions of daltons).

Q3: How accurate is this estimation method?
A: This provides an approximate value. Actual molecular weight depends on the specific amino acid composition and post-translational modifications.

Q4: Why subtract stop codons?
A: Stop codons signal translation termination and do not code for amino acids, so they shouldn't contribute to the protein's molecular weight.

Q5: Can this calculator handle partial codons?
A: No, the calculator assumes complete codons. DNA length must be a multiple of 3 for accurate calculation.