Proučevanje vpliva vpeljave linearnih in razvejanih maščobnokislinskih ostankov na agonistično aktivnost dezmuramilpeptidov na nukleotid-vezočo oligomerizacijsko domeno vsebujoč protein 2

Hameršak, Nuša (author), Jakopin, Žiga (mentor), Janež, Špela (comentor)

Človeško telo ima za obrambo pred tujki razvite zelo učinkovite, a kompleksne in strogo nadzorovane mehanizme, ki se povezujejo v imunski sistem. Tega delimo na prirojenega in pridobljenega. Odzivi celic prirojenega imunskega sistema so regulirani tudi preko receptorjev za prepoznavo vzorcev, med katere spada tudi nukleotid vezoča oligomerizacijska domena 2 (NOD2). NOD2 je ključnega pomena za aktivacijo prirojenega imunskega odziva, hkrati pa vpliva tudi na pridobljen imunski odziv. Zaradi tega so se agonisti NOD2 izkazali kot potencialni adjuvansi v cepivih. Na Katedri za farmacevtsko kemijo Fakultete za farmacijo se ukvarjajo s sintetiziranjem in proučevanjem dezmuramilnih sintetičnih agonistov NOD2, izmed katerih je po agonistični aktivnosti izstopala spojina SG8, trans-ferulni derivat tripeptida Gly-L-Val-D-Glu. V sklopu magistrske naloge smo SG8 uporabili kot spojino vodnico, vanjo uvedli maščobnokislinske acilne substituente in proučevali vpliv njihove dolžine in razvejanosti na agonistično aktivnost na NOD2. Sintetizirali smo 17 končnih spojin, pri čemer se je kot najmočnejši agonist v seriji izkazal linearen C4-aciliran derivat, spojina 12, z vrednostjo EC50 4,6 nM, kar predstavlja več kot 20-kratno izboljšavo v primerjavi s spojino vodnico. Pri derivatih z dolžino alkilne verige do 14 C-atomov je bilo možno opaziti povečanje agonistične aktivnosti v primerjavi z nesubstituirano spojino vodnico, vendar se je aktivnost z daljšanjem verige začela zmanjševati. Prav tako se je izkazalo, da razvejanost acilne verige bistveno ne vpliva na agonistično aktivnost. Vpeljava dvojne vezi v verigo je izboljšala agonistično aktivnost na NOD2 v primerjavi z lineranim derivatom z enakim številom C-atomov. Vpeljava dodatnega aromatskega obroča ni bistveno vplivala na aktivnost, medtem ko je vpeljava terminalne hidroksilne skupine v acilno stransko verigo za kar 6-krat povečala agonistično aktivnost NOD2 v primerjavi z nesubstituiranim linearnim derivatom z enakim številom C-atomov v stranski verigi. Naše ugotovitve so tako dodatno osvetlile odnos med strukturo in delovanjem agonistov NOD2.

• Language: Slovenian
• Keywords: Imunski sistem, NOD2 agonisti, adjuvansi, dezmuramilpeptidi, strukturna modifikacija
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2025
• PID: 20.500.12556/RUL-169458
• Publication date in RUL: 29.05.2025

Secondary language

• Language: English
• Title: Investigating the impact of linear and branched fatty acid residue introduction on nucleotide-binding oligomerization domain protein 2 agonistic activity of desmuramylpeptides

Abstract

The human body has developed very effective, yet complex and strictly controlled mechanisms to defend itself against foreign substances, which are connected to the immune system. This is divided into innate and acquired immunity. The responses of cells of the innate immune system are also regulated through pattern recognition receptors, which include nucleotide-binding oligomerization domain 2 (NOD2). NOD2 is crucial for the activation of the innate immune response, but it also affects the acquired immune response. For this reason, NOD2 agonists have proven to be potential adjuvants in vaccines. The Department of Pharmaceutical Chemistry at the Faculty of Pharmacy is engaged in the synthesis and study of desmuramyl synthetic NOD2 agonists, among which the compound SG8, a trans-ferulic derivative of the tripeptide Gly-L-Val-D-Glu, stood out in terms of agonist activity. As part of the master's thesis, we used SG8 as a lead compound, introduced fatty acid acyl substituents into it and studied the effect of their length and branching on agonistic activity on NOD2. We synthesized 17 final compounds, with the linear C4-acylated derivative 12 proving to be the most potent agonist in the series, with an EC50 value of 4,6 nM, representing a more than 20-fold improvement compared to the lead compound. In derivatives with an alkyl chain length of up to 14 C-atoms, an increase in agonistic activity was observed compared to the unsubstituted lead compound, but the activity began to decrease with the lengthening of the chain. It was also shown that the branching of the acyl chain itself does not significantly affect the agonistic activity. The introduction of a double bond into the chain improved the agonistic activity on NOD2 compared to the linear derivative with the same number of C-atoms. The introduction of an additional aromatic ring did not significantly affect the activity, while the introduction of a terminal hydroxyl group into the acyl side chain increased NOD2 agonist activity by as much as 6-fold compared to the unsubstituted linear derivative with the same number of C-atoms in the side chain. Our findings thus shed additional light on the structure-activity relationship of NOD2 agonists.

• Keywords: Immune system, NOD2 agonists, adjuvants, desmuramylpeptides, structural modification