RT Journal Article T1 Identification of the Missing Protein Hyaluronan Synthase 1 in Human Mesenchymal Stem Cells Derived from Adipose Tissue or Umbilical Cord. A1 Clemente, Luis Felipe A1 Hernáez, María Luisa A1 Ramos-Fernández, Antonio A1 Ligero, Gertrudis A1 Gil, Concha A1 Corrales, Fernando José A1 Marcilla, Miguel AB Currently, 14% of the human proteome is made up of proteins whose existence is not confirmed by mass spectrometry. We performed a proteomic profiling of human mesenchymal stem cells derived from adipose tissue or umbilical cord (PRIDE accession number: PXD009893) and identified peptides derived from 13 of such missing proteins. Remarkably, we found compelling evidence of the expression of hyaluronan synthase 1 (NX_Q92839-1) and confirmed its identification by the fragmentation of four heavy-labeled peptides that coeluted with their endogenous light counterparts. Our data also suggest that mesenchymal stem cells constitute a promising source for the detection of missing proteins. YR 2018 FD 2018-07-06 LK http://hdl.handle.net/10668/12675 UL http://hdl.handle.net/10668/12675 LA en DS RISalud RD Jul 5, 2025