Mehanizmi enzimske selektivnosti

undergraduate thesis

• Title (english): Mechanisms of enzyme selectivity
• Author: Gaj Keresteš
• Mentor: Ita Gruić-Sovulj (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2022-09-19, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Enzimi su biološke makromolekule koje efikasno i selektivno kataliziraju specifične
reakcije. Selektivnost enzima se temelji na uspostavljanju specifičnih pozitivnih interakcija s
pripadnim supstratima i negativnih interakcija s nepripadnim supstratima u njihovom osnovnom
ili prijelaznom stanju. Porodica kimotripsinskih serinskih proteaza obuhvaća enzime koji imaju
vrlo različite razine selektivnosti. Za razliku od njih, aminoacil-tRNA-sintetaze (aaRS) su enzimi
koji različitim mehanizmima postižu izrazito visoke razine selektivnosti – u sintetskoj reakciji
njihova selektivnost doseže fizikalno-kemijske granice, a kasnije se dodatno povećava
mehanizmima popravka pogreške. Tijekom evolucije većina enzima prati trend sužavanja
supstratne specifičnosti i povećanja selektivnosti, pri čemu selektivnost može biti selektirana
izravno ili se razviti kao posljedica optimizacije katalitičke efikasnosti. Evolucija aaRS prati ovaj
trend te je aktivno utjecala na razvoj suvremenog genetičkog koda.

Abstract (english)

Enzymes are biological macromolecules that efficiently and selectively catalyze specific
reactions. Enzyme selectivity is based on establishing specific positive interactions with cognate
substrates and negative interactions with noncognate substrates in their ground or transition states.
The chymotrypsin family of serine proteases includes enzymes with very different levels of
selectivity. Conversely, aminoacyl-tRNA synthetases (aaRS) are enzymes which, through various
mechanisms, achieve extremely high levels of selectivity – their selectivity in the synthetic reaction
reaches physicochemical limits and is later additionally increased by proofreading. Throughout
evolution, most enzymes followed the trend of narrowing substrate specificity and increasing
selectivity. Selectivity can be directly selected for or developed as a consequence of optimizing
catalytic efficiency. The evolution of aaRS follows this trend and actively influenced the
development of the contemporary genetic code.

• Keywords: aminoacil-tRNA-sintetaze; serinske proteaze; enzimska specifičnost; popravak pogreške; evolucija enzima
• Keywords (english): aminoacyl-tRNA-synthetases; serine proteases; enzyme specificity; editing; enzyme evolution
• Language: croatian
• URN:NBN: urn:nbn:hr:217:661190
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-10-04 09:26:18