Substitution of histidine 30 by asparagine in manganese superoxide dismutase alters biophysical properties and supports proliferation in a K562 leukemia cell line.
Rosalin BonettaGary J HunterChi H TrinhTomasz BorowskiAnthony G FenechMaria KulpLeandro C TabaresSun UnThérèse HunterPublished in: European biophysics journal : EBJ (2021)
We have generated a mutant of C. elegans manganese superoxide dismutase at histidine 30 by site-directed mutagenesis. The structure was solved at a resolution of 1.52 Å by X-ray crystallography (pdb: 6S0D). His30 was targeted, as it forms as a gateway residue at the top of the solvent access funnel to the active site, together with Tyr34. In the wild-type protein, these gateway residues are involved in the hydrogen-bonding network providing the protons necessary for the catalytic reaction at the metal center. However, biophysical characterization and cell viability experiments reveal that a mutation from histidine to asparagine in the H30N mutant modifies metal selectivity in the protein, favoring the uptake of iron over manganese in minimal media conditions, alters active-site coordination from the characteristic trigonal bipyramidal to octahedral geometry, and encourages cellular proliferation in K562 cells, when added exogenously to the cells.
Keyphrases
- wild type
- induced apoptosis
- cell cycle arrest
- signaling pathway
- amino acid
- hydrogen peroxide
- oxidative stress
- bone marrow
- protein protein
- cell death
- crispr cas
- gene expression
- binding protein
- ionic liquid
- dna methylation
- drug delivery
- single molecule
- nitric oxide
- oxide nanoparticles
- small molecule
- pi k akt
- crystal structure