Structural Investigation on the Cytochrome C Oxidase Protein to Assess the Stability of Protein

CoxB is a protein in the inner membrane of Acidithiobacillus ferrooxidans. This protein, present in the electron transmission pathway and cause ferrous iron oxidation to ferric leading to the electron release. Two copper atoms CuA and CuB presence in the CoxB structure and CuA plays an important role in electron transport. According to prior studies, methionine substitution for a highly conserved histidine in a similar protein leads to an increase the stability of protein and to improve its function. Also, the binding of methionine to CuB in the wild protein structure is another reason for the selection of the H230M mutation in CuA site. Both amino acids tend to contribute more in the alpha helix structure. The following of mutation, protein stability is probably. Then, wild-type and H230M mutants are simulated in the presence of a bilayer membrane POPC using gromacs version 5.1.4. The conformational changes of mutated protein were surveyed by RMSD, RMSF, SASA, Rg, NH bond, DSSP, Density, FEL and residue interaction networks. Our results confirm that the mutated protein retains its stability during the simulation. It seems that the H230M mutation increases the amount of electron reception requiring further studies. Our results provide compelling evidence that this H230M mutation contributes to enhance the stability of protein. Thus, this finding defines new metjods in structural properties, accurate survey, and probability improves the electron transfer.

Keywords:

Acidithiobacillus ferrooxidans , CoxB , Molecular dynamic simulation , Mutation , POPC.