Investigating and Annotating the Human Peptidome Profile from Urine under Normal Physiological Conditions

Area of Science:

• Biochemistry
• Proteomics
• Human Physiology

Background:

• The urinary peptidome reflects physiological status.
• Altered peptidome profiles may indicate disease.
• Understanding normal urine peptide composition is crucial for biomarker discovery.

Purpose of the Study:

• To characterize the normal urinary peptidome.
• To identify enzymes responsible for generating native urine peptides.
• To establish a reference dataset for disease biomarker research.

Main Methods:

• Analysis of 19 human urine samples.
• Identification and quantification of endogenous peptides.
• Enzyme activity profiling and comparison with existing datasets.

Main Results:

• 1503 endogenous peptides from 436 precursor proteins were identified.
• Liver and kidney genes were highly represented in the peptidome.
• Cathepsin D (CTSD) and matrix metalloproteinase-2 (MMP2) were prominent enzymes.
• Consistent relative abundance of core peptides across datasets.

Conclusions:

• Established a comprehensive profile of the normal urinary peptidome.
• Identified key enzymes, CTSD and MMP2, involved in peptide formation.
• Findings provide a foundational reference for urinary biomarker discovery in human diseases.