The photoreceptor cGMP phosphodiesterase (PDE6) plays a key role in vertebrate vision, but its enzymatic mechanism and the roles of metal ion co-factors have yet to be determined. We have determined the amount of endogenous Zn in rod PDE6 and established a requirement for tightly bound Zn in catalysis. Purified PDE6 contained 3–4-g atoms of zinc/mole, consistent with an initial content of two t...

Materials and Methods: The silver (Ag), cobalt (Co), chromium (Cr), iron (Fe), mercury (Hg), rubidium (Rb), antimony (Sb), selenium (Se), and zinc (Zn) content and Co/Ag, Cr/Ag, Fe/Ag, Hg/Ag, Sb/Ag, Se/Ag, Co/Rb, Cr/Rb, Fe/Rb, Hg/Rb, Sb/ Rb, Se/Rb, Co/Zn, Cr/Zn, Fe/Zn, Hg/Zn, Sb/Zn, and Se/Zn ratios were estimated in normal bone samples from 27 patients with intact bone (12 females and 15 males...

DNA-dependent RNA polymerase from Escherichia coli contains 2 mol of zinc/mol of holoenzyme (alpha 2 beta beta' sigma) with one zinc each in the beta and beta' subunits. A new method to substitute selectively the zinc in the beta subunit was developed by the inactivation of RNA polymerase with 0.25 M NaNO3, 1 M NaCl, 1 mM diaminocyclohexane tetraacetic acid, and 0.1 mM dithiothreitol followed b...

the study aimed to come up with a list of specific macroalgae species, which could be used to biomonitor specific metal elements in the coastal waters of east africa. water extraction, edta, aqua regia extraction and optimized bcr 3-step sequential extracts were used to mimic bioavailable metals under various environmental conditions. the results indicated that ulva lactuca could be used as a ...

in order to study concentrations of soil micro and heavy metal elements in some saffron planting regions of birjand province, an experiment was performed as factorial layout based on a completely randomized block design with three replications at year 2013. treatments were three field ages (annual, triennial and quinquennial) and five saffron regions including aryan shahr, hosseinabad, khosef, ...