Uporaba 4-okso-4H-piridino[1,2-a]pirimidin-3-diazonijevega in 1-ciano-4-okso-4H-kinolizin-3-diazonijevega tetrafluoroborata v fluorescenčnem označevanju proteinov

Grošelj, Lena (author), Svete, Jurij (mentor)

4-okso-4H-piridino[1,2-a]pirimidin–3–diazonijev in 1-ciano-4-okso-4H-kinolizin–3– diazonijev tetrafluoroborat sta bila izbrana kot reagenta za izvedbo fotokemijskih sulfanilacij in arilacij ter termičnih sulfanilacij z N-Boc-zaščitenimi estri cisteina in cistina ter aromatskimi aminokislinami. Raziskali smo stabilnost obeh izhodnih reagentov v vodnem mediju z namenom nadaljnje vezave (aza)kinolizinskih diazonijevih soli na proteine. Obe diazonijevi soli sta bili uspešno uporabljeni v reakcijah biokonjugacije. Dokazali smo, da je (aza)kinolizin diazonijeve tetrafluoroborate mogoče uporabiti pri fluorescentnem označevanju proteinov, saj se pod fotokataliziranimi pogoji vežejo tako na tiolne skupine in disulfidne vezi cisteinskih ostankov, kot tudi na arilne skupine aromatskih aminokislin. Pod termičnimi pogoji pa je prednostna reakcija sulfaniliranja (vezava na tiolne skupine cisteinskih preostankov). Kot modelni protein je bil izbran goveji serumski albumin (BSA). Razvili smo tudi metodo za kvantifikacijo vezave in optimizirali pogoje vezave.

• Language: Slovenian
• Keywords: diazonijeve soli, sulfanilacije, arilacije, fotoredoks kataliza, biokonjugacija, fluorescentno označevanje
• Work type: Master's thesis/paper
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2026
• PID: 20.500.12556/RUL-182297
• Publication date in RUL: 06.05.2026

Secondary language

• Language: English
• Title: Application of 4-oxo-4H-pyridino[1,2-a]pyrimidine-3-diazonium and 1-cyano-4-oxo-4H-quinolizine-3-diazonium tetrafluoroborate in fluorescent labeling of proteins

Abstract

4-Oxo-4H-pyridino[1,2-a]pyrimidine–3–diazonium and 1-cyano-4-oxo-4H-quinolizine–3–diazonium tetrafluoroborate were selected as starting reagents for photochemical sulfanylations and arylations, as well as thermal sulfanylations with esters of N-Boc-protected cysteine, cystine and aromatic amino acid. The stability of both starting reagents in aqueous media was investigated to enable further coupling of (aza)quinolizine diazonium salts to proteins. Both diazonium salts were successfully used in bioconjugation reactions. We demonstrated that (aza)quinolizine diazonium tetrafluoroborates can be used for fluorescent labeling. Under photocatalyzed conditions, these diazonium salts bind to thiol and disulfide bonds of cysteine residues, as well as to aryl groups of aromatic amino acid residues. In contrast, the sulfanylation reaction is favored under thermal conditions. Bovine serum albumin (BSA) was selected as a model protein. We also developed a method for quantifying binding and optimized binding conditions.

• Keywords: diazonium salts, sulfanylations, arylations, photoredox catalysis, bioconjugation, fluorescent labeling