Enhanced expression of the human ferritin H- and L-chain genes (hfH and hfL) was achieved in Saccharomyces cerevisiae by modifying the N-terminal region of the structural genes. The yeast episomal vector YEp352 with the galactokinase1 (GAL1) promoter was used to construct expression plasmids. The expression of each gene was examined using SDS-PAGE and Western blot analysis. Iron uptake was examined and the cellular iron concentration was increased in S. cerevisiae expressing hfH. When cultured cells were incubated with 14.3 mM Fe(2+), the recombinant yeast expressing hfH had a cellular iron concentration 1.5 times greater than that of the control strain. The relationship between the iron taken up by the cells and the expressed proteins was examined. Iron-binding H-chain ferritin (H-ferritin) was seen in the recombinant S. cerevisiae incubated with iron, while small amounts of iron-binding L-chain ferritin (L-ferritin) were observed. Combined, these observations demonstrate that human H-ferritin has a function in iron storage in S. cerevisiae, while L-ferritin does not.
Persistent endometriosis after total hysterectomy and both salpingo-oophorectomy (TH with BSO) is a rare condition and the etiology is uncertain. The exact incidence of persistent endometriosis after definitive surgery is not known. In addition, the treatment of persistent endometriosis after complete surgical excision is controversial. We report a case of persistent endometriosis with vaginal and sigmoid-colonic invasion after TH with BSO. The lesions were not responsive to hormonal therapy. The patient was managed successfully by therapeutic pelvic radiation.
Human ferritin homopolymers with H or L subunits ͑rHF and rLF͒ were genetically engineered in E coli. Apoferritins were then reconstituted with 2000 Fe atoms. A big difference was observed in the rates of iron uptake, whereas the mean core size was similar in rHF and rLF. Magnetization of the recombinant human ferritins were measured as functions of temperature and field. The blocking temperature T B ͑H͒ at low fields is considerably higher in rLF than in rHF. From the fit of M͑H͒ data to a modified Langevin function: M͑H͒ = M 0 L͑ p H / k B T͒ + a H, the effective magnetic moment p is found to be much larger in rLF than in rHF. Experimental data demonstrate that the magnetic properties, in particular, the uncompensated spins of ferritin core are related to the biomineralization process in ferritins.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.