Institute of Pharmacy, Medicinal Chemistry, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195, Berlin, Germany.
Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195, Berlin, Germany.
Angew Chem Int Ed Engl. 2024 Dec 2;63(49):e202411006. doi: 10.1002/anie.202411006. Epub 2024 Nov 5.
Diazo peptides have been described earlier, however, due to their high reactivity have not been broadly used until today. Here, we report the preparation, properties, and applications of chemically stable internal diazo peptides. Peptidyl phosphoranylidene-esters and amides were found to react with triflyl azide primarily to novel 3,4-disubstituted triazolyl-peptides. Nonaflyl azide instead furnished diazo peptides, which are chemically stable from pH 1-14 as amides and from pH 1-8 as esters. Thus, diazo peptides prepared by solid phase peptide synthesis were stable to final deprotection with 95 % trifluoroacetic acid. Diazo peptides with the recognition sequence of caspase-3 were identified as specific, covalent, and irreversible inhibitors of this enzyme at low nanomolar concentrations. A fluorescent diazo peptide entered living cells enabling microscopic imaging and quantification of apoptotic cells via flow cytometry. Thus, internal diazo peptides constitute a novel class of activity-based probes and enzyme inhibitors useful in chemical biology and medicinal chemistry.
叠氮肽此前已有描述，但由于其高反应性，直到今天才得到广泛应用。在这里，我们报告了化学稳定的内部叠氮肽的制备、性质和应用。发现肽基膦酰亚胺酯和酰胺与三氟甲磺酸叠氮主要反应生成新型 3,4-二取代三唑基肽。而非氟甲磺酸叠氮则提供了叠氮肽，其酰胺在 pH 1-14 以及酯在 pH 1-8 条件下化学稳定。因此，通过固相肽合成制备的叠氮肽在 95%三氟乙酸的最终脱保护条件下稳定。具有半胱天冬酶-3识别序列的叠氮肽被鉴定为该酶在低纳摩尔浓度下的特异性、共价和不可逆抑制剂。荧光叠氮肽进入活细胞，通过流式细胞术能够进行细胞凋亡的微观成像和定量。因此，内部叠氮肽构成了一类新的基于活性的探针和酶抑制剂，可用于化学生物学和药物化学。
