confirming that the binding of PI in the absence of Mn2+ is reversible. This was also demonstrated by the fact that it was possible to separate I 32PlPl completely from the enzyme by Sephadex G-100 gel filtration. When Pi followed by MnZ+ was added to the enzyme, dialysis did not restore activity. However, a substantial proportion of the activity reappeared during storage after dialysis, sugges...

Carbon nanotubes CNT was modified on the surface of glassy carbon electrode (GCE) using mechanical method to prepare working electrode CNT/GCE and CNT/Li+/GCE were used in cyclic voltammetry analysis. The nanostructured electrodes showed individual voltammetric of Mn2+ two reduction peaks at +800 and +100 mV. The reduction current of Mn2+ on CNT/Li+/GCE was largely influenced by low concentrati...

Pyrophosphatase (PPase) from Bacillus subtilis has recently been found to be the first example of a family II soluble PPase with a unique requirement for Mn2+. In the present work, we cloned and overexpressed in Escherichia coli putative genes for two more family II PPases (from Streptococcus mutans and Streptococcus gordonii), isolated the recombinant proteins, and showed them to be highly spe...

MEMRI offers the exciting possibility of tracing neuronal circuits in living animals by MRI. Here we use the power of mouse genetics and the simplicity of the visual system to test rigorously the parameters affecting Mn2+ uptake, transport and trans-synaptic tracing. By measuring electrical response to light before and after injection of Mn2+ into the eye, we determine the dose of Mn2+ with the...

alcohol oxidation is an important reaction in organic syntheses. some of these reactions must beunder difficult conditions in respect of high temperature and pressure. in many cases, reactions areconducted by environmentally in appropriate solutions. in this study, preparing an effectivenanocatalyst and estimating the optimum provisions of its production processes are assessed. twomajor and cru...

It has long been known that manganese is an essential micronutrient of plants. Although the precise functions of manganese are unknown there is evidence that it may be concerned in chlorophyll synthesis, photosynthesis, respiration and nitrate assimilation. Decreased photosynthesis under conditions of manganese deficiency was originally attributed to the diminished chlorophyll content, but more...

Ribonucleases H (RNases H) comprise a family of metal-dependent enzymes that catalyze the hydrolysis of the 3'-O---P bond of RNA in RNA.DNA hybrids. The mechanism by which RNases H use active-site metal(s) for catalysis is unclear. Based upon the seemingly contradictory structural observations of one divalent metal bound to Escherichia coli RNase HI and two divalent metals bound to the HIV RNas...

Mn2+ was shown to catalyze a nonenzymatic oxidation of NADPH in the presence of superoxide anion by means of an isotopic assay for measurement of the oxidation of NADPH to NADP+. Human polymorphonuclear leukocyte granule NADPH oxidase activity was evaluated in the absence of Mn2+ and was found to be higher in granules from phagocytizing cells than in granules from resting cells. The drug phorbo...

The deoxyribonuclease induced in KB cells by herpes simplex virus (HSV) type 1 and type 2 has been purified. Both enzymes are able to completely degrade single- and double-stranded DNA yielding 5'-monophosphonucleotides as the sole products. A divalent cation, either Mg2+ or Mn2+, is an absolute requirement for catalysis and a reducing agent is necessary for enzyme stability. The maximum rate o...