Protein Amino Acid Sequence Determination

The determination of the amino acid sequence of a protein refers to the process of determining the precise arrangement order of amino acids in a protein molecule. Here is a basic introduction to amino acid sequence determination.

Methods

1. Edman Degradation

Developed by Pehr Edman in the 1950s, it sequentially removes the N-terminal amino acids from a protein and identifies them. This method can continuously determine the sequence of about 50 amino acids, but for longer proteins, other strategies are needed.

2. Mass Spectrometry

It uses a mass spectrometer to identify the mass of a protein or its cleavage fragments, thereby inferring the amino acid sequence. Compared with the Edman degradation method, the advantage of mass spectrometry for protein sequence analysis is that it is more sensitive, can cleave peptides faster, and can identify proteins with terminal closures or modifications.

Applications

1. Functional Research

Understanding the amino acid sequence of a protein can help researchers predict the function and structure of the protein.

2. Evolutionary Research

By comparing protein sequences in different species, researchers can understand the phylogenetic relationships and evolutionary patterns between species.

3. Disease Research

Certain genetic diseases are caused by mutations in the protein sequence. By determining the protein sequence, these diseases can be diagnosed and studied.