A Micro-Scale Model to Monitor the Major Proteins in Human Urine Before and After Medication with Angiotensin-Converting Enzyme Inhibitor: A Preliminary Study

A simple and micro-scale liquid chromatographic (LC) method coupled with mass spectrometry was developed for analyzing major proteins in human urine. After one-step sample preparation, proteins were precipitated, redissolved, and digested. Only micro-liter level (10 μL) of urine was sufficient for major protein identification. This method was applied in clinical study, and urine proteins were monitored after medication with angiotensin-converting enzyme inhibitor within 24 hr. This method can identify many important proteins in human urine. Bioactive peptides associated with blood pressure control can also be identified simultaneously. We hope this simple method may prove useful in clinical research and disease diagnosis.