The role of porphyrin peripheral substituents in determining the reactivities of ferrous nitrosyl species.

ABSTRACT: Ferrous nitrosyl {FeNO}⁷ species is an intermediate common to the catalytic cycles of Cd₁NiR and CcNiR, two heme-based nitrite reductases (NiR), and its reactivity varies dramatically in these enzymes. The former reduces NO₂ ^- to NO in the denitrification pathway while the latter reduces NO₂ ^- to NH₄ ⁺ in a dissimilatory nitrite reduction. With very similar electron transfer partners and heme based active sites, the origin of this difference in reactivity has remained unexplained. Differences in the structure of the heme d ₁ (Cd₁NiR), which bears electron-withdrawing groups and has saturated pyrroles, relative to heme c (CcNiR) are often invoked to explain thes

SUBMITTER: Amanullah S 

PROVIDER: S-EPMC7407271 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature