[Analyzing secondary structure of beta2 microglobulin in Escherichia coli with circular dichroism spectrum]

In order to study the structure and function of beta2 microglobulin (beta2 m).

We sub-cloned the mature peptide of beta2 m into the p2X plasmid and transformed them to Escherichia coli TB1. The recombinant bacterium was induced to be expressed and the expressed fusion protein was detected by SDS-PAGE and western blot. After purifying and cleaving with Factor Xa, we separated the monomer protein beta2 m from MBP. Finally, we determined the secondary structure of the beta2 m protein by circular dichroism (CD) spectrum.

MBP-beta2 m was 52.1 kDa, and the monomer protein beta2 m was 10.6 kDa. The alpha-helix, beta-sheet, turn, and random coil of the fusion protein showed 0, 45, 8 and 45 amino acids, respectively, detected by CD estimation.

The beta2 m protein had correct secondary structure and could be used for further research of peptide binding in vitro.