Nitrification Mechanisms for the P460 Enzymes
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide The oxidation of hydroxylamine was studied by quantum chemical modeling. Hydroxylamine is the product of ammonia oxidation in ammonia monooxygenase. That mechanism has been studied recently by quantum chemical modeling as here. Only two enzymes can oxidize hydroxylamine, hydroxylamine oxidase and cytochrome-P460. Both employ the unusual P460-heme cofactor. In hydroxylamine oxidase, there is a covalently linked tyrosine, while in cytochrome-P460, there is a covalently linked lysine. The calculations give explanations for the experimental findings that NO is the final product in hydroxylamine oxidase, while N 2 O is the final product in cytochrome-P460. The effect of the covalent attachments has been investigated, and reasons for their presence have been given. The methodology used, which was proven to give very good agreement with experiments for several redox enzymes, again leads to excellent agreement with experimental findings.
Author: Per E. M. Siegbahn
Institution: Stockholm University
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Funders: Vetenskapsrådet, Stockholms Universitet
OpenAlex ID: W4405519587