Imobilizacija enzima na silanizirane magnetske nanočestice funkcionalizirane (3-aminopropil)trimetoksisilanom

master's thesis

• Title (english): Enzyme immobilisation on silanized magnetic nanoparticles functionalised by (3-aminopropyl)trimethoxysilane
• Author: Doroteja Mutak
• Mentor: Ana Vrsalović Presečki (mentor)
• Committee member: Ana Vrsalović Presečki (predsjednik povjerenstva)
• Committee member: Ana Lončarić Božić (član povjerenstva)
• Committee member: Anita Šalić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2022-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Enzim deoksiriboza-5-fosfat aldolaza (DERA) katalizira reakciju dvostruke aldolne adicije dvije molekule acetaldehida i jedne molekule kloracetaldehida. Spomenuta reakcija koristi se , prilikom sinteze prekursora u proizvodnji statina. Visoka koncentracija aldehida u DERA kataliziranoj reakciji negativno utječe na stabilnost enzima. Cilj ovog rada bio je provesti imobilizaciju enzima DERA-e na magnetske nanočestice u svrhu povećanja njegove stabilnosti. Magnetske nanočestice obložene su silikom po Stöberovom procesu te funkcionalizirane APTMS-om ((3-aminpropil)trimetoksisilanom)). Za aktivaciju su korištena tri aktivacijska sredstva: benzokinon, glutaraldehid i sukcinski anhidrid različitih koncentracija. Najbolji parametri uspješnosti procesa imobilizacije dobiveni su prilikom korištenja nosica aktiviranim s 15 %-tnim sukcinskim anhidridom kao aktivacijskog sredstva, te je taj korišteno u daljnjim ispitivanjima. Isto tako, poznato je da pH vrijednost pufera i temperatura prilikom procesa imobilizacije enzima mogu imati veliki utjecaj na aktivnost enzima, pa tako i na uspješnost procesa imobilizacije. Stoga, ispitan je utjecaj pH i temperature prilikom procesa imobilizacije enzima DERA-e. Najveća efikasnost i iskorištenje postignuti su pri temperaturi od 30 °C i pH 6.

Abstract (english)

Deoxyribose-5-phosphate aldolase (DERA) catalyzes the reaction of the double aldol addition of two acetaldehyde molecules and one chloroacetaldehyde molecule. The mentioned reaction is used in the synthesis of precursors for the production of statins. The high concentration of aldehyde in the DERA catalyzed reaction negatively affects the stability of the enzyme. The aim of this work was to immobilize the DERA enzyme on magnetic nanoparticles to increase its stability. Magnetic nanoparticles were coated with silica using the Stöber method and functionalized with APTMS ((3-aminopropyl)trimethoxysilane)). Three activation agents were used: benzoquinone, glutaraldehyde and succinic anhydride at different concentrations. The higest efficiency for the immobilization process were obtained when the carrier was activated with 15 % succinic anhydride, so this carrier was used in further tests. It is known that the pH of buffers and temperature during the process of enzyme immobilization can have an impact not only on the activity of enzymes, but also on the success of the immobilization process. Therefore, the influence of pH and temperature during the immobilization process of DERA enzyme was also investigated. The highest efficiency and yield were achieved at a temperature of 25 °C and a pH of 6.

• Keywords: deoksiriboza-5-fosfat aldolaza; DERA; imobilizacija enzima; magnetske nanočestice; silanizacija; benzokinon; glutaraldehid; sukcinski anhidrid
• Keywords (english): deoxyribose-5-phosphate aldolase; DERA; enzyme immobilization; magnetic nanoparticles; silanization; benzoquinone; glutaraldehyde; succinic anhydride
• Language: croatian
• URN:NBN: urn:nbn:hr:149:752653
• Study programme: Title: Environmental Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka ekoinženjerstva (magistar/magistra inženjer/inženjerka ekoinženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2023-10-01
• Created on: 2023-03-23 14:14:06