title: Improvement of catalytic activity of Candida rugosa lipase in the presence of calix[4]arene bearing iminodicarboxylic/phosphonic acid complexes modified iron oxide nanoparticles.
abstract: In the present study, iron oxide magnetite nanoparticles, prepared through a co-precipitation method, were coated with phosphonic acid or iminodicarboxylic acid derivatives of calix[4]arene to modulate their surfaces with different acidic groups. Candida rugosa lipase was then directly immobilized onto the modified nanoparticles through sol-gel encapsulation. The catalytic activities and enantioselectivities of the two encapsulated lipases in the hydrolysis reaction of (R/S)-naproxen methyl ester and (R/S)-2-phenoxypropionic acid methyl ester were assessed. The results showed that the activity and enantioselectivity of the lipase were improved when the lipase was encapsulated in the presence of calixarene-based additives; the encapsulated lipase with the phosphonic acid derivative of calix[4]arene had an excellent rate of enantioselectivity against the (R/S)-naproxen methyl and (R/S)-2-phenoxypropionic acid methyl esters, with E=350 and 246, respectively, compared to the free enzyme. The encapsulated lipases (Fe-Calix-N(COOH)) and (Fe-Calix-P) showed good loading ability and little loss of enzyme activity, and the stability of the catalyst was very good; they only lost 6-11% of the enzyme's activity after five batches.
authors.affiliation: Department of Chemistry, Selcuk University, Konya 42075, Turkey.
authors.forename: Elif
authors.initials: E
authors.lastname: Ozyilmaz
authors.affiliation: Karamanoglu Mehmetbey University, Department of Bioengineering, Karaman 70200, Turkey.
authors.forename: Mevlut
authors.initials: M
authors.lastname: Bayrakci
authors.affiliation: Department of Chemistry, Selcuk University, Konya 42075, Turkey. Electronic address: myilmaz42@gmail.com.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Yilmaz
mesh_terms: D055162:Biocatalysis / Q000187:drug effects*; D047250:Calixarenes / Q000737:chemistry / Q000494:pharmacology*; D002175:Candida / Q000201:enzymology*; D002264:Carboxylic Acids / Q000737:chemistry* / Q000494:pharmacology; D006868:Hydrolysis / Q000187:drug effects; D008049:Lipase / Q000378:metabolism*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008968:Molecular Conformation; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D010757:Phosphorous Acids / Q000737:chemistry* / Q000494:pharmacology; D013237:Stereoisomerism
chemical_list: D002264:Carboxylic Acids; D058185:Magnetite Nanoparticles; D010636:Phenols; D010757:Phosphorous Acids; C121325:calix(4)arene; D047250:Calixarenes; C570063:phosphonic acid; D008049:Lipase
keywords: Calix[4]arene; Enantioselective; Lipase immobilization; Magnetite nanoparticles