Absolute Quantification of Flavin-containing Monooxygenases (FMOs) in Human Liver Microsomes by UPLC-MS/MS-based Targeted Quantitative Proteomic Approach

摘要

UPLC-MRM-based targeted quantitative proteomic method was developed and optimized for the quantification of FMO1, FMO3 and FMO5 in human liver microsomes (HLMs). A post-in silico product ion screening process was incorporated to verify LC-MRM detection of potential signature peptides prior to their synthesis. The developed method was validated by correlating marker substrate activity and the expression of FMO3 and FMO5 in a panel of adult individual donor HLMs. The protein expression of FMO3 and FMO5 averaged (range and 95% CI) at 46 (26 - 65 and 36 - 56) pmol/mg HLM and 27 (11.5 - 49 and 18.5 - 36) pmol/mg HLM, respectively.