Abstract
Embryonic stem (ES) cell has attracted the attention of many scientists for application to regenerative medicine. ES cell is a cell line derived from an early embryo which is called blastocyst and is capable of differenciating into all kinds of cell. On the other hand, metallic elements in proteins play important roles as active centers in biological reaction. In this study, we elucidated the differential mechanism of embryonic stem cells by means of elemental analyses, x-ray fluorescence (XRF) and x-ray near edge structure (XANES) analysis. From the results, we found that concentrations of Fe and Zn in the dopaminergic neurons were higher than those in the undifferentiated ES cells. And the results of XANES analysis made it clear that (the number of Fe2+)/(the number of Fe atoms) ratio in the dorpaminergic neurons was higher than that in the undifferentiated ES cells. These consequences indicate that tyrosinases (tyrosine hydroxylases) which have Fe2+ as active centers during the reaction of dopamine synthesis are actively correlated with the differentiation of ES cells into dopaminergic neurons.
