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Functionalized quinolizinium-based fluorescent reagents for modification of cysteine-containing peptides and proteins.

ABSTRACT: A series of quinolizinium-based fluorescent reagents were prepared by visible light-mediated gold-catalyzed cis-difunctionalization between quinolinium diazonium salts and electron-deficient alkyne-linked phenylethynyl trimethylsilanes. The electron-deficient alkynyl group of the quinolizinium-based fluorescent reagents underwent nucleophilic addition reaction with the sulfhydryl group on cysteine-containing peptides and proteins. The quinolizinium-based fluorescent reagents were found to function as highly selective reagents for the modification of cysteine-containing peptides and proteins with good to excellent conversions (up to 99%). Moreover, the modified BCArg mutants bearing cationic quinolizinium compounds 1b, 1d, 1e and 1h exhibit comparable activity in enzymatic and cytotoxicity assays to the unmodified one.

SUBMITTER: Kung KK

PROVIDER: S-EPMC8981741 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature

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Functionalized quinolizinium-based fluorescent reagents for modification of cysteine-containing peptides and proteins.

Kung Karen Ka-Yan KK Xu Cai-Fung CF O Wa-Yi WY Yu Qiong Q Chung Sai-Fung SF Tam Suet-Ying SY Leung Yun-Chung YC Wong Man-Kin MK

RSC advances 20220222 10

A series of quinolizinium-based fluorescent reagents were prepared by visible light-mediated gold-catalyzed <i>cis</i>-difunctionalization between quinolinium diazonium salts and electron-deficient alkyne-linked phenylethynyl trimethylsilanes. The electron-deficient alkynyl group of the quinolizinium-based fluorescent reagents underwent nucleophilic addition reaction with the sulfhydryl group on cysteine-containing peptides and proteins. The quinolizinium-based fluorescent reagents were found to ...[more]

PMID: 35424586

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