A History of Deimination Research in Japan: The Founding Fathers

The research on protein deimination and the enzymes responsible for catalyzing this posttranslational modification started from investigations of the hair follicle and myelin in central nerve system. About 60 years ago, in 1958, the presence of protein-bound citrulline was first reported by Dr. George Rogers (Adelaide University, Australia) in the protein of the inner root sheath (IRS) of hair follicles (Rogers 1958). In order to obtain information about the protein composition of the IRS, he conducted a quantitative amino acid analysis of an acid hydrolysate on sufficient amounts of IRS that were dissected from the vibrissae follicle of rats. At that time, the common method for separating amino acids was paper chromatography, and when applied to the IRS hydrolysates, citrulline was discovered as a distinct ninhydrin-positive spot in an area adjacent to the basic amino acids. About 10 years after Rogers’s discovery, Dr. Mario Moscarello (Toronto University, Canada) started an intensive investigation of myelin sheath proteins in the central nerve system. In 1971, he also found the presence of peptide-bound citrulline in myelin basic protein (MBP) using similar methods to Rogers (Finch et al. 1971). Moscarello continued the investigation of MBP until he passed away in 2013, publishing many papers concerning the hyper-deimination of MBP in the pathology of multiple sclerosis. His research career involving the deimination of MBP was described in a eulogy in the first volume of this book series (Nicholas and Bhattacharya 2014).