DISCOVERy OF THE ROLE OF UBIQUITIN IN PROTEIN DEGRADATION HISTORICAL FACTS Courtesy of Sam Griffiths-Jones. Used with permission Source: \Peptide models for protein beta-sheets hD thesis, University of Nottingham, 2001 8(1975)Ubiquitin was first isolated by Gideon Goldstein and colleagues from the thymus(reason why it was originally thought to be a thymic hormone)