3.4 Edman sequencing
In 1950, Pehr Edman pioneered Edman sequencing, a method to determine protein amino acid sequences by reacting with and identifying N-terminal residues of polypeptide chains. This technique has played a vital role in biological drug development and quality control for therapeutic proteins [10]. It continues to find applications in various life science research fields. Edman’s PITC reaction was successfully used to modify peptide amines and identify proteolytic protein cleavage in cell signaling processes with high throughput [37]. It helped identify the N-terminal tripeptide GTF262 of GP-2 in the Lassa virus, which causes hemorrhagic fever [38].
In plant protein research, both MS and Edman sequencing were employed to analyze rice leaf sheath proteins, revealing shared amino acid sequences and showcasing their complementary use [39]. Moreover, Edman degradation has contributed to the development of a photo thermally responsive Nanoprobe. The probe releases the fluorescent dye Cy5.5 upon exposure to an 808 nm laser, enhancing near-infrared (NIR) fluorescence under slightly acidic conditions. This Nano probe enables fluorescence imaging of v3 over-expressing U87MG cells in vitro and in vivo, presenting a novel tool for biomedical imaging, drug delivery, and gene administration [40].