The effect of sodium fluoride on the content of adenine nucleotides, adenine nucleotide pool and energy potential of erythrocytes was studied in male Wistar rats, depending on the dose and time of exposure. Sodium fluoride was administered for 4 and 8 weeks at 4 or 16 ppm through a gastric tube. The concentration of fluorine in serum, ATP, ADP and AMP content in blood and erythrocytes, adenine ...

The AG dinucleotide at the 3' splice sites of metazoan nuclear pre-mRNAs plays a critical role in catalytic step II of the splicing reaction. Previous studies have shown that replacement of the guanine by adenine in the AG (AG --> GG) inhibits this step. We find that the second step was even more severely inhibited by cytosine (AG --> CG) or uracil (AG --> UG) substitutions at this position. By...

The mechanism of the photodimerization of adjacent adenine bases on the same strand of DNA has been elucidated by determining the structure of one of the two major photoproducts that are formed by UV irradiation of the deoxydinucleoside monophosphate d(ApA). The photoproduct, denoted d(ApA)*, corresponds to a species of adenine photodimer first described by Pörschke (Pörschke, D. (1973) J.Am.Ch...

Gene activation in eukaryotes is inherently combinatorial depending on cooperation between different transcription factors. An example where this cooperation seems to be directly exploited for regulation is the Bas1p/Bas2p couple in yeast. Bas1p is a Myb-related transcription factor that acts together with the homeodomain-related Bas2p (Pho2p) to regulate purine and histidine biosynthesis genes...

Chemically synthesized duplex oligodeoxynucleotides having different average numbers of adenine tracts (A6) per helix turn were ligated into multimers and analyzed by electrophoresis on polyacrylamide gels. The magnitude of the anomaly in gel mobility is found to be a quadratic function of the curvature of the DNA molecule. Parameters that describe intrinsic DNA bending, expressed as the tilt a...

Purified PGH synthase when acting on arachidonic acid in the presence of reduced nicotinamide-adenine dinucleotide or reduced nicotinamide-adenine dinucleotide 3'-phosphate generated superoxide in burst-like fashion. In eight experiments using different batches of enzyme, the mean +/- SE rate of superoxide generation from 100 U of enzyme measured as the superoxide dismutase-inhibitable reductio...

Chelation reactions of the antimitotic drug, 6-amino-purine (adenine; abbr. ADN) with the metal ions: Be ( I I ) , AI ( I II ) , Cr ( I I I ) , M n ( I I ) , Fe ( I I I ) , Co (II ) , N i ( I I ) , C u ( I I ) , P b ( I I ) , and U 0 2 ( I I ) have been investigated in aqueous solution at 3 0 ° using B j e r r u m C a l v i n pH titration technique. The formation constants have been determined ...

1. We have compared urinary purine excretion by two different methods in three separate paediatric disorders of purine metabolism: purine nucleo­ side phosphoryiase deficiency, adenosine deaminase deficiency and adenine phosphoribosyltransferase deficiency. 2. The abnormal purines identified in each case were specific for the defect and directly related to it: adenine in adenine phophoribosyltr...

The purpose of the present study was to determine if repetitive myocardial ischemia would result in the cumulative loss of mitochondrial adenine nucleotides. Isolated perfused rat hearts were subjected to continuous or intermittent ischemia. A single 5-minute period of continuous ischemia did not result in a significant decrease in the mitochondrial adenine nucleotide pool; a single 10-minute p...