title: Hydrolysis of hydrophobic esters in a bicontinuous microemulsion catalysed by lipase B from Candida antarctica.
abstract: Selective enzyme-catalysed biotransformations offer great potential in organic chemistry. However, special requirements are needed to achieve optimum enzyme activity and stability. A bicontinuous microemulsion is proposed as reaction medium because of its large connected interface between oil and water domains at which a lipase can adsorb and convert substrates in the oil phase of the microemulsion. Herein, a microemulsion consisting of buffer-n-octane-nonionic surfactant Ci Ej was used to investigate the key factors that determine hydrolyses of p-nitrophenyl esters catalysed by the lipase B from Candida antarctica (CalB). The highest CalB activity was found around 44 °C in the absence of NaCl and substrates with larger alkyl chains were better hydrolysed than their short-chained homologues. The CalB activity was determined using two different co-surfactants, namely the phospholipid 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and the sugar surfactant decyl β-D-glucopyranoside (β-C10 G1 ). The results show the CalB activity as linear function of both enzyme and substrate concentration with an enhanced activity when the sugar surfactant is used as co-surfactant.
authors.affiliation: Chemistry Department, Durham University, South Road, DH1 3LE Durham (UK).
authors.forename: Anne K
authors.initials: AK
authors.lastname: Steudle
authors.forename: Mireia
authors.initials: M
authors.lastname: Subinya
authors.forename: Bettina M
authors.initials: BM
authors.lastname: Nestl
authors.forename: Cosima
authors.initials: C
authors.lastname: Stubenrauch
mesh_terms: D055162:Biocatalysis; D002175:Candida / Q000201:enzymology*; D004655:Emulsions / Q000737:chemistry*; D004952:Esters; D005656:Fungal Proteins / Q000378:metabolism*; D005997:Glycerylphosphorylcholine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008049:Lipase / Q000378:metabolism*; D010713:Phosphatidylcholines; D013379:Substrate Specificity; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature
chemical_list: D004655:Emulsions; D004952:Esters; D005656:Fungal Proteins; D010713:Phosphatidylcholines; D013501:Surface-Active Agents; D005997:Glycerylphosphorylcholine; D008049:Lipase; C431349:lipase B, Candida antarctica; C017251:1,2-oleoylphosphatidylcholine
keywords: biocatalysis; enzymes; esters; hydrolases; hydrolysis