Phosphate Monoester Hydrolysis by Trinuclear Alkaline Phosphatase; DFT Study of Transition States and Reaction Mechanism
2014 (English)In: ChemPhysChem, ISSN 1439-4235, E-ISSN 1439-7641, Vol. 15, no 11, 2321-2330 p.Article in journal (Refereed) Published
Alkaline phosphatase (AP) is a trinuclear metalloenzyme that catalyzes the hydrolysis of a broad range of phosphate monoesters to form inorganic phosphate and alcohol (or phenol). In this paper, by using density functional theory with a model based on a crystal structure, the AP-catalyzed hydrolysis of phosphate monoesters is investigated by calculating two substrates, that is, methyl and p-nitrophenyl phosphates, which represent alkyl and aryl phosphates, respectively. The calculations confirm that the AP reaction employs a ping-pong mechanism involving two chemical displacement steps, that is, the displacement of the substrate leaving group by a Ser102 alkoxide and the hydrolysis of the phosphoseryl intermediate by a Zn2-bound hydroxide. Both displacement steps proceed via a concerted associative pathway no matter which substrate is used. Other mechanistic aspects are also studied. Comparison of our calculations with linear free energy relationships experiments shows good agreement.
Place, publisher, year, edition, pages
2014. Vol. 15, no 11, 2321-2330 p.
alkaline phosphatase, associative mechanism, density functional calculations, enzyme catalysis, phosphate ester hydrolysis
Chemical Sciences Physical Sciences
IdentifiersURN: urn:nbn:se:su:diva-107112DOI: 10.1002/cphc.201402016ISI: 000340175800018OAI: oai:DiVA.org:su-107112DiVA: diva2:743338