10.1021/acs.jproteome.7b00353.s001 Siqi Li Siqi Li Yanbin He Yanbin He Zhilong Lin Zhilong Lin Shaohang Xu Shaohang Xu Ruo Zhou Ruo Zhou Feng Liang Feng Liang Jian Wang Jian Wang Huanming Yang Huanming Yang Siqi Liu Siqi Liu Yan Ren Yan Ren Digging More Missing Proteins Using an Enrichment Approach with ProteoMiner American Chemical Society 2017 protein detection low-abundance proteins benefits MPs Missing Proteins ProteoMiner enrichment ProteoMiner Human Proteome Project PE nucleus proteins low-abundance proteins HPP Enrichment Approach peptide fractionation PRM assay 20 MPs equalizing technique high-abundance proteins 2017-09-29 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Digging_More_Missing_Proteins_Using_an_Enrichment_Approach_with_ProteoMiner/5544214 Human Proteome Project (HPP) aims at mapping entire human proteins with a systematic effort upon all the emerging techniques, which would enhance understanding of human biology and lay a foundation for development of medical applications. Until now, 2563 missing proteins (MPs, PE2–4) are still undetected even using the most sensitive approach of protein detection. Herein, we propose that enrichment of low-abundance proteins benefits MPs finding. ProteoMiner is an equalizing technique by reducing high-abundance proteins and enriching low-abundance proteins in biological liquids. With triton X-100/TBS buffer extraction, ProteoMiner enrichment, and peptide fractionation, 20 MPs (at least two non-nested unique peptides with more than eight a.a. length) with 60 unique peptides were identified from four human tissues including eight membrane/secreted proteins and five nucleus proteins. Then 15 of them were confirmed with two non-nested unique peptides (≥9 a.a.) identified by matching well with their chemically synthetic peptides in PRM assay. Hence, these results demonstrated ProteoMiner as a powerful means in discovery of MPs.