The Chromosome-centric Human Proteome Project (C-HPP) aims at identifying the proteins as gene products encoded by the human genome, characterizing their isoforms and functions. The existence of products has now been confirmed for 93.1% of the genes at the protein level. The remaining mostly correspond to proteins of low abundance or difficult to access. Over the past decade, we have significantly contributed to the identification of over 300 missing proteins in the human sperm. Thanks to technical progresses in mass spectrometry and to the development of efficient sample preparation, we have been able to push further our MS analyses of the human spermatozoa, with the aim to identify new missing proteins. Interestingly, we were able to characterize additional missing proteins using the TimsTOF Ultra coupled to a NanoElute but also using the TimsTOF Pro coupled to a NanoElute based on seven different sample preparations with PreOmics kits. Here, we present the characterization of 9 new missing proteins, and can also propose 12 one-hit wonders proteins, thus contributing again to the efforts of the C-HPP.

Keywords: Human Proteome Project, Missing Proteins, human Sperm, Bruker, PreOmics