Manipulating the Click Reactivity of Dibenzoazacyclooctynes: From Azide Click Component to Caged Acylation Reagent by Silver Catalysis

Abstract

Strain-promoted azide-alkyne cycloaddition using dibenzoazacyclooctyne (DBCO) is widely applied in copperfree bioorthogonal reactions. Reported here is the efficient acid-promoted rearrangement and silver-catalyzed amidation of DBCO, which alters its click reactivity robustly. In the switched click reaction, DBCO, as a caged acylation reagent, enables rapid peptide/protein modification after decaging facilitated by silver catalysts, rendering site-specific conjugation of an IgG antibody by a Fc-targeting peptide.

Enhanced transglycosylation activity of an Endo-F3 mutant by ligand-directed localization

“…The purchased linear peptide was cyclized to give cyclic Fc binding peptide (FcBP) as in our previously reported work. 44 FcBP (FcBP1 or FcBP2 or FcBP3, 2 μmol, 1.0 eq. ), linker ( 1a or 1b or 1c , 4 μmol, 2.0 eq., see the ESI† for the synthesis of 1b and 1c ), and Et 3 N (0.56 μL, 2.0 eq.)…”

Optimized Production of Fc Fusion Proteins by Sortase Enzymatic Ligation

“…The LC–ESI-MS analysis for Fc-DBCO required that the deglycosylated sample be five times more concentrated (800 ng/μL) than the Fc-LPETGGH 6 , Fc-N 3 , and Fc-FITC samples to get a spectrum of sufficient quality for transformation. The SML yield is slightly lower than what was observed with Fc-FITC and Fc-azide, and the presence of multiple peaks near the theoretical MW of Fc-DBCO suggests degradation of DBCO may have occurred . Therefore, the yield of desired product may be lower than estimated.…”

“…A reduction in Fc-DBCO-insulin Mon yields was not observed over time with EDTA present. However, the SPAAC approach also shows limitations: DBCO is susceptible to acid-mediated degradation, making the use of common acidic elution buffers for affinity purification undesirable for the intermediate purification of Fc-DBCO . Additionally, strained alkynes can react with thiols resulting in nonspecific conjugation to reduced cysteines or off-target reactions with reducing agents. , Such limitations could be mitigated with careful optimization of the intermediate purification step, but at the expense of added complexity.…”

“…The SML yield is slightly lower than what was observed with Fc-FITC and Fc-azide, and the presence of multiple peaks near the theoretical MW of Fc-DBCO suggests degradation of DBCO may have occurred. 59 Therefore, the yield of desired product may be lower than estimated.…”

Recent Progress of Bioorthogonal Chemistry in China

“…在这之后, 钯催化的生物正交偶 联反应得到了快速的发展. 2018 年, 曲晓刚课题组 [25] 2 Metal-mediated bioorthogonal ligation reactions [20,22,25,27] 值得注意的是, 黄蔚课题组 [27] 3 Photo-mediated bioorthogonal ligation reactions [28,[30][31] 加成的生物正交体系, 实现了活细胞中不同多肽以及蛋 白质的偶联标记, 进一步丰富了生物正交偶联反应的类 型, 为生命体系时空分辨的精准研究提供了有力工具. 此外, 尹正课题组 [38] 设计将有机合成中最常见的…”