title: Unexpectedly enhanced stereoselectivity of peroxidase-catalyzed sulfoxidation in branched alcohols.
abstract: Lyophilized horseradish peroxidase (HRP) exhibits poor stereoselectivity in the sulfoxidation of thioanisole when the enzyme is either redissolved in water or suspended in organic solvents. However, when HRP is co-lyophilized in the presence of lyoprotectants or ligands, its stereoselectivity, although still low in most organic solvents, increases up to 4-fold if assayed in secondary or tertiary alcohols (but not in their linear isomers). A mechanistic hypothesis is presented explaining this puzzling phenomenon on the basis of a model of the active site of the enzyme-substrate complex derived from its X-ray crystal structure by means of molecular dynamics and energy minimization.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Yuchun
authors.initials: Y
authors.lastname: Xie
authors.forename: Prasanta Kumar
authors.initials: PK
authors.lastname: Das
authors.forename: Jose M M
authors.initials: JM
authors.lastname: Caaveiro
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Klibanov
mesh_terms: D000438:Alcohols / Q000737:chemistry*; D002384:Catalysis; D003198:Computer Simulation; D006735:Horseradish Peroxidase / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D010084:Oxidation-Reduction; D013237:Stereoisomerism; D013454:Sulfoxides / Q000737:chemistry*
chemical_list: D000438:Alcohols; D013454:Sulfoxides; D006735:Horseradish Peroxidase