Development of fluorogenic substrates for colorectal tumor-related neuropeptidases for activity-based diagnosis

The M3 metalloproteases, neurolysin and THOP1, are neuropeptidases that are expressed in various tissues and metabolize neuropeptides, such as neurotensin. The biological roles of these enzymes are not well characterized, partially because the chemical tools to analyse their activities are not well developed. Here, we developed a fluorogenic substrate probe for neurolysin and thimet oligopeptidase 1 (THOP1), which enabled the analysis of enzymatic activity changes in tissue and plasma samples. In particular, the probe was useful for studying enzyme activities in a single-molecule enzyme assay platform, which can detect enzyme activity with high sensitivity. We detected the activity of neurolysin in plasma samples and revealed higher enzyme activity in the blood samples of patients with colorectal tumor. The result indicated that single-molecule neurolysin activity is a promising candidate for a blood biomarker for colorectal cancer diagnosis.

Automated summary

In this study, a fluorogenic substrate probe was developed to analyze enzymatic activity changes in tissue and plasma samples. The probe was particularly useful for studying enzyme activities in a single-molecule enzyme assay platform. We detected the activity of neurolysin in plasma samples and found higher enzyme activity in the blood samples of colorectal tumor patients. The results suggest that single-molecule neurolysin activity could be a promising blood biomarker for colorectal cancer diagnosis.