Svojstva, modifikacije i primjena saharoza fosforilaze

undergraduate thesis

• Title (english): Properties, modifications and employment of sucrose phosphorylase
• Author: Lucija Vrtodušić
• Mentor: Anita Slavica (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biochemical Engineering, Industrial Microbiology and Malting and Brewing Technology); Zagreb
• Defense date and country: 2020-07-01, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Saharoza fosforilaza (EC 2.4.1.7) je bakterijska citosolna glikoziltransferaza. U reakciji sa supstratom ovaj enzim formira kompleks β-glukozil-enzim, koji može sudjelovati u četiri različite reakcije: fosforolizi, sintezi, hidrolizi i transglukozilaciji. U reakciji fosforolize u reakciji s ortofosfatom nastaje α-D-glukoza-1-fosfat, a u suprotnom smjeru se odvija reakcija sinteze supstrata - donora glukozila. Do hidrolize kompleksa β-glukozil-enzim dolazi u reakciji s vodom i nastaje glukoza. Transglukozilacijom se glukozil od donora prenosi na različite molekule akceptora, pri čemu nastaju visoko vrijedni α-konfigurirani glukozilirani spojevi. Saharoza fosforilaza katalizira opisane reakcije ping-pong mehanizmom tipa Bi-Bi. Primjenom točkastih mutacija okarakterizirana su tri ključna bočna lanca aminokiselina u aktivnom mjestu saharoza fosforilaze: Asp-192 (katalitički nukleofil), Glu-232 (katalitička kiselina/baza) i Asp-290 (stabilizator prijelaznog stanja). Preostaje da se naprave mutanti ovog enzima koji imaju zadovoljavajuću stabilnost u uvjetima industrijske proizvodnje i na taj način proizvode visokovrijedni glukozilirani proizvodi s širokom primjenom u prehrambenoj, farmaceutskoj i kozmetičkoj industriji.

Abstract (english)

Sucrose phosphorylase (EC 2.4.1.7) is a bacterial cytosolic glycosyltransferase. β-glucosyl-enzyme complex formed in a reaction of this enzyme with a substrate can be used in four different reactions: phosphorolysis, synthesis, hydrolysis and transglucosylation. α-D-glucose-1-phosphate is produced in a reaction of the complex and an orthophosphate (phosphorolysis). Substrate (glucosyl donor) can be synthesized in opposite direction of phosphorolysis. During transglucosylation glucosyl moiety is transferred from a donor to an acceptor molecule and different high-added value glucosylated compounds can be yielded in this reaction. Ping-pong Bi-Bi mechanism is characteristic for reactions catalysed by the sucrose phosphorylase. Site directed mutagenesis was used to determine three key amino acid side chains in active site of the enzyme: Asp-192 (catalytic nucleophile), Glu-232 (catalytic acid/base) and Asp-290 (stabilizer of the complex). It remains to be seen if mutants with satisfactory stability under industrial conditions will be produced and used in manufacturing of high-added value glycosylated products with versatile applications in industry.

• Keywords: fosforoliza; hidroliza; saharoza fosforilaza; transglukozilacija; visokovrijedni spojevi
• Keywords (english): high-added value products; hydrolysis; phosphorolysis; sucrose phosphorylase; transglucosylation
• Language: croatian
• URN:NBN: urn:nbn:hr:159:076394
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-07-09 10:33:26