Modifying the Steric Properties in the Second Coordination Sphere of Designed Peptides Leads to Enhancement of Nitrite Reductase Activity.

ABSTRACT: Protein design is a useful strategy to interrogate the protein structure-function relationship. We demonstrate using a highly modular 3-stranded coiled coil (TRI-peptide system) that a functional type 2 copper center exhibiting copper nitrite reductase (NiR) activity exhibits the highest homogeneous catalytic efficiency under aqueous conditions for the reduction of nitrite to NO and H₂ O. Modification of the amino acids in the second coordination sphere of the copper center increases the nitrite reductase activity up to 75-fold compared to previously reported systems. We find also that steric bulk can be used to enforce a three-coordinate Cu^I in a site, which tends toward two-coordination with decreased steric bulk. This study demonstrates the importance of the second

SUBMITTER: Koebke KJ 

PROVIDER: S-EPMC5869106 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature