20.500.12556/DKUM-99428 Imobilizacija MenD encima na mezoporozno siliko Immobilization of MenD enzyme on mesoporous silica V tej študiji smo se osredotočili na imobilizacijo 2-sukcinil-5-enolpiruvil-6-hidroksi-3-cikloheksen-1-karboksilata sintaze (MenD) na mezoporozno siliko SBA-15. MenD katalizira prvi odločilni korak pri biosintezi menakinona (vitamina K2) in zaradi svoje sposobnosti izvedbe encimsko katalizirane Stetterjeve reakcije predstavlja obetaven biokatalizator za organsko sintezo. Encim smo imobilizirali na mezoporozno siliko SBA-15, ki je bila izbrana kot nosilec zaradi svoje velike površine, dobro urejene strukture por in možnosti vgradnje funkcionalnih skupin na njeno površino. Te lastnosti spodbujajo učinkovito imobilizacijo encima, zagotavljajo boljši dostop substrata do aktivnega mesta in zmanjšujejo izpiranje encima iz nosilca. Sintetizirani mezoporozni nosilec SBA-15 smo karakterizirali s pomočjo vrstičnega elektronskega mikroskopa (SEM) za določitev morfologije delcev. Za določitev specifične površine, volumna por in porazdelitve velikosti por smo uporabili analizo po Brunauerju–Emmettu–Tellerju (BET), medtem ko smo za potrditev prisotnosti značilnih funkcionalnih skupin po funkcionalizaciji površine uporabili infrardečo spektroskopijo s Fourierovo transformacijo (FTIR). Učinkovitost imobilizacije smo ocenili z uporabo Bradfordovega testa za določanje beljakovin. Vzorce reakcijskega medija, reakcije s prostim ali imobiliziranim encimom, smo analizirali s tekočinsko kromatografijo visoke ločljivosti (HPLC). Merili smo porabo α-ketoglutarne kisline med reakcijo kot funkcijo časa. Iz rezultatov je razvidno, da je bila imobilizacija encima na nosilec delno uspešna. Ugotovili smo, da ima prost encim višjo katalitično učinkovitost v primerjavi z imobiliziranim encimom. In this study, we focused on the immobilization of 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylate synthase (MenD) on mesoporous SBA-15 silica. MenD catalyzes the first committed step in the biosynthesis of menaquinone (vitamin K2) and, owing to its ability to catalyze the enzyme-mediated Stetter reaction, represents a promising biocatalyst for organic synthesis. The enzyme was immobilized on mesoporous silica SBA-15, which was selected as the support because of its high surface area, well-ordered pore structure, and the possibility of introducing functional groups onto its surface. These properties promote efficient enzyme immobilization, provide better substrate accessibility to the active site, and reduce enzyme leaching from the support. The synthesized SBA-15 mesoporous silica was characterized by scanning electron microscopy (SEM) to determine particle morphology. Brunauer–Emmett–Teller (BET) analysis was used to determine the specific surface area, pore volume, and pore size distribution, while Fourier-transform infrared (FTIR) spectroscopy was employed to confirm the presence of characteristic functional groups after surface functionalization. The immobilization efficiency was evaluated using the Bradford protein assay Samples of the reaction medium from reactions with free or immobilized enzyme were analyzed by high-performance liquid chromatography (HPLC). The consumption of α-ketoglutaric acid during the reaction was monitored as a function of time. The results showed that enzyme immobilization on the support was partially successful. The free enzyme exhibited higher catalytic efficiency compared with the immobilized enzyme. encim imobilizacija mezoporozna silika Stetterjeva reakcija enzyme immobilization mesoporous silica Stetter reaction true true false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-08-17 08:53:36 2026-09-14 11:50:37 2026-09-15 03:06:05 0000-00-00 00:00:00 2026 0 Maribor 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 VS_Kovacic_Jure_2026.pdf VS_Kovacic_Jure_2026.pdf 1 6AF1426271A18CCD0AFAC436B6AEBE8E e7f06eb2c9028dc0346e4acaf578cad20eaf53710cb42b6ac9aa18c9daf940a5 9b1cdfa6-ac66-11f1-9c32-00155d0001be https://dk.um.si/Dokument.php?lang=slv&id=211997 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0