Advancing In-Depth N‑Terminomics Detection with a Cleavable 2‑Pyridinecarboxyaldehyde Probe

Proteolysis, an irreversible post-translational modification
catalyzed
by proteases, plays a crucial role in various biological processes.
Exploring abnormally hydrolyzed proteins in pathological tissues is
a valuable approach for elucidating the mechanisms underlying disease
development. Herein, we have developed a cleavable 2-pyridinecarboxyaldehyde
probe (2PCA-Probe) that enables efficient and in-depth N-terminomics
detection, addressing limitations of previous methods. Furthermore,
we unexpectedly discovered a new marker capable of identifying N-terminal
chemical labeling with the 2PCA-Probe and elucidated the reaction
mechanism. Using this probe, we identified 4686 N-terminal peptides
in colorectal cancer and adjacent tissues, significantly expanding
the depth of the N-terminome and revealing the potential role of abnormal
protein hydrolysis in colorectal cancer development.