biostudies-literatureUnknown5(4)Barber LJThe site-selective modification of protein N-termini represents a powerful strategy for producing homogeneous bioconjugates. 2-Pyridinecarboxaldehydes have emerged as a leading reagent class in this area. However, these conjugations suffer from relatively slow rates and a degree of reversibility. In this work, we therefore studied the effects of pyridinecarboxaldehyde functionalization on N-terminal modification. This allowed us to provide insight into the factors governing relative contributions from competing reaction pathways and design criteria for second generation reagents for protein labeling. Importantly, 3-methoxy-2-pyridinecarboxaldehydes were identified as providing both accelerated and more stable protein labeling, enabling further applications of this powerful technology.JACS Au1983-1991https://www.ebi.ac.uk/biostudies/studies/S-EPMC12042018biostudies-literatureEffect of Pyridinecarboxaldehyde Functionalization on Reactivity and N-Terminal Protein Modification.PMC12042018Stankevich KSSpicer CDBarber LJfalseEffect of Pyridinecarboxaldehyde Functionalization on Reactivity and N-Terminal Protein Modification.The site-selective modification of protein N-termini represents a powerful strategy for producing homogeneous bioconjugates. 2-Pyridinecarboxaldehydes have emerged as a leading reagent class in this area. However, these conjugations suffer from relatively slow rates and a degree of reversibility. In this work, we therefore studied the effects of pyridinecarboxaldehyde functionalization on N-terminal modification. This allowed us to provide insight into the factors governing relative contributions from competing reaction pathways and design criteria for second generation reagents for protein labeling. Importantly, 3-methoxy-2-pyridinecarboxaldehydes were identified as providing both accelerated and more stable protein labeling, enabling further applications of this powerful technology.2025-01-01T00:00:00Z2025 Apr2025-06-25T03:06:35.932Z2025-06-25T03:06:35.932ZS-EPMC120420184031384310.1021/jacsau.5c00238