title: Horseradish peroxidase as a catalyst for atom transfer radical polymerization.
abstract: The hemoprotein horseradish peroxidase (HRP) catalyzes the polymerization of N-isopropylacrylamide with an alkyl bromide initiator under conditions of activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) in the absence of any peroxide. This is a novel activity of HRP, which we propose to name ATRPase activity. Bromine-terminated polymers with polydispersity indices (PDIs) as low as 1.44 are obtained. The polymerization follows first order kinetics, but the evolution of molecular weight and the PDI upon increasing conversion deviate from the results expected for an ATRP mechanism. Conversion, M(n) and PDI depend on the pH and on the concentration of the reducing agent, sodium ascorbate. HRP is stable during the polymerization and does not unfold or form conjugates.
authors.affiliation: Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland.
authors.forename: Severin J
authors.initials: SJ
authors.lastname: Sigg
authors.forename: Farzad
authors.initials: F
authors.lastname: Seidi
authors.forename: Kasper
authors.initials: K
authors.lastname: Renggli
authors.forename: Tilana B
authors.initials: TB
authors.lastname: Silva
authors.forename: Gergely
authors.initials: G
authors.lastname: Kali
authors.forename: Nico
authors.initials: N
authors.lastname: Bruns
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods*; D006735:Horseradish Peroxidase / Q000737:chemistry*; D007700:Kinetics; D008970:Molecular Weight; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000178:Acrylamides; D011108:Polymers; C067295:N-isopropylacrylamide; D006735:Horseradish Peroxidase