title: Immobilization of active human carboxylesterase 1 in biomimetic silica nanoparticles.
abstract: The encapsulation of proteins in biomimetic silica has recently been shown to successfully maintain enzymes in their active state. Organophosphate (OP) compounds are used as pesticides as well as potent chemical warfare nerve agents. Because these toxicants are life threatening, we sought to generate biomimetic silicas capable of responding to OPs. Here, we present the silica encapsulation of human drug metabolism enzyme carboxylesterase 1 (hCE1) in the presence of a range of catalysts. hCE1 was successfully encapsulated into silica particles when lysozyme or the peptide R5 were used as catalysts; in contrast, polyethyleneimine, a catalyst used to encapuslate other enzymes, did not facilitate hCE1 entrapment. hCE1 silica particles in a column chromatography format respond to the presence of the OP pesticides paraoxon and dimethyl-p-nitrophenyl phosphate in solution. These results may lead to novel approaches to detect OP pesticides or other weaponized agents that bind hCE1.
authors.affiliation: Dept. of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Edwards
authors.forename: Amar
authors.initials: A
authors.lastname: Kumbhar
authors.forename: Adam
authors.initials: A
authors.lastname: Roberts
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Hemmert
authors.forename: Carol C
authors.initials: CC
authors.lastname: Edwards
authors.forename: Philip M
authors.initials: PM
authors.lastname: Potter
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Redinbo
mesh_terms: D040761:Biomimetic Materials; D002214:Capsules; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002619:Chemical Warfare Agents / Q000032:analysis; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry*; D010755:Organophosphates / Q000032:analysis* / Q000378:metabolism; D010575:Pesticides / Q000032:analysis* / Q000378:metabolism; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D002214:Capsules; D002619:Chemical Warfare Agents; D004800:Enzymes, Immobilized; D010755:Organophosphates; D010575:Pesticides; D012822:Silicon Dioxide; D002265:Carboxylic Ester Hydrolases; C474609:CES1 protein, human