When pyrophosphate has been found to influence an enzymatic reaction, its action is usually indirect, that is as a chelator of free essential metal ions rather than directly on the protein catalyst. However, it appears that the latter situation holds for the action of pyrophosphate in the modification of reduced diphosphopyridine nucleotide’ to the product obtained by the action of 3-phosphogly...

The rate of hydrolysis of adenosine triphosphate and the binding of inorganic pyrophosphate to myosin vary inversely with increasing concentration of free Mg++, in the presence of a magnesium ethylenediaminetetraacetate buffer system; half-maximum binding of pyrophosphate and 50% inhibition of adenosine triphosphatase activity occur at a free Mg++ concentration about 10M7 M at 3O. The binding o...

Manganese represents an essential trace element that is accumulated and utilized by virtually all forms of life. This redox active metal is a key cofactor for a wide range of metalloenzymes, including oxidases and dehydrogenases, DNA and RNA polymerases, kinases, decarboxylases, and sugar transferases (11, 25). In addition to serving as an essential nutrient, manganese can also be toxic. In hum...

A l*C-diterpene alcohol (copalol) was isolated as its 4-(4’nitrophenylazo)benzoyl ester from a soluble enzyme system which had been prepared from a cell-free extract of mycelia of the fungus Gibberella fujikuroi and incubated with ZJ*Cmevalonate, ATP, and MgC12. Copalol was identified as trans-( -)-labda-8(16), 13-dien-15-01 from its properties, in comparison with those of the enantiomeric alco...

Hydroxymethyl glutaryl (HMG)-coenzyme A (CoA) reductase inhibitors (statins) protect the myocardium against ischemia-reperfusion injury via a mechanism unrelated to cholesterol lowering. Statins may inhibit isoprenylation and thereby prevent activation of proteins such as RhoA. We hypothesized that statins protect the myocardium against ischemia-reperfusion injury via a mechanism involving inhi...

A procedure was devised to detect and assay uridine 5'-pyrophosphate (UDP)-glucuronic acid pyrophosphorylase in plant extracts. Substrates are UDP-glucuronic acid and (32)P-pyrophosphate, and the (32)P-uridine 5'-triphosphate produced is selectively adsorbed to charcoal. The charcoal adsorption procedure is a modification of that used to determine (32)P-adenosine 5'-triphosphate produced by ade...

Oxidation of manganese (II) to manganese (III,IV) demands oxidants with very high redox potentials; consequently, manganese oxides are both excellent proxies for molecular oxygen and highly favorable electron acceptors when oxygen is absent. The first of these features results in manganese-enriched sedimentary rocks (manganese deposits, commonly Mn ore deposits), which generally correspond to t...

Bisphosphonates are chemical-related to pyrophosphate. The oxygen atom in pyrophosphate is substituted by a carbon these compounds, resulting P-C-P bond. They potent antiresorptive medicines because they have strong inhibitory effect on osteoclasts. It lowers fracture risk reducing bone turnover, increasing mineral density, and decreasing the lumbar spine hip. strongly attracted surfaces, where...