title: Immobilization of Candida bombicola cells on free-standing organic-gold nanoparticle membranes and their use as enzyme sources in biotransformations.
abstract: Preparation of chemically functionalized biocompatible surfaces is of current interest, with application in the immobilization of various bioactive species such as DNA, enzymes, whole cells, etc. We report herein the one-step synthesis of a self-supporting gold nanoparticle membrane, its surface modification, and application in the immobilization of Candida bombicola (yeast) cells. The gold nanoparticle membrane is prepared by the spontaneous reduction of aqueous chloroaurate ions by a diamine at a liquid-liquid interface. The gold nanoparticles in the polymeric membrane may be capped with octadecylamine (ODA) molecules, thereby rendering the nanoparticle membrane hydrophobic. Exposure of the hydrophobized organic-gold nanoparticle membrane to C. bombicola yeast cells results in their binding to the membrane, possibly through nonspecific interactions such as hydrophobic interactions between the yeast cell walls and the ODA molecules. The enzyme cytochrome P450 present in the yeast cells immobilized on the organic-gold nanoparticle membrane was then used in the transformation of the arachidonic acid (AA) to sophorolipids followed by acid hydrolysis to form 20-hydroxyeicosatetraneoic acid (20-HETE). The organic-gold nanoparticle membrane-C. bombicola bioconjugate could be easily separated from the reaction medium and reused a number of times.
authors.affiliation: Materials Chemistry, Biochemical Sciences, and Polymer Chemistry Divisions, National Chemical Laboratory, Pune 411008, India.
authors.forename: Sumant
authors.initials: S
authors.lastname: Phadtare
authors.forename: Sachin
authors.initials: S
authors.lastname: Shah
authors.forename: Asmita
authors.initials: A
authors.lastname: Prabhune
authors.forename: Prakash P
authors.initials: PP
authors.lastname: Wadgaonkar
authors.forename: Murali
authors.initials: M
authors.lastname: Sastry
mesh_terms: D016718:Arachidonic Acid / Q000378:metabolism; D002175:Candida / Q000166:cytology* / Q000201:enzymology*; D018929:Cell Culture Techniques / Q000379:methods*; D018914:Cells, Immobilized / Q000166:cytology / Q000502:physiology; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000378:metabolism*; D004800:Enzymes, Immobilized / Q000737:chemistry; D017979:Gold Colloid / Q000737:chemistry*; D008055:Lipids / Q000096:biosynthesis; D008567:Membranes, Artificial; D043942:Nanotubes / Q000737:chemistry / Q000648:ultrastructure
chemical_list: D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D017979:Gold Colloid; D008055:Lipids; D008567:Membranes, Artificial; D016718:Arachidonic Acid; D003577:Cytochrome P-450 Enzyme System