The first evidence for the existence of uridine diphosphate compounds was limited to the observation that Staphylococcus aureus cells, when grown in the presence of penicillin, accumulated a new form of acid-labile phosphate in their internal environment (1). The labile phosphate appeared to be part of a complex compound which also contained uracil. In a brief note (2), it has since been report...

In this study, we attempted to adopt the auxotrophic mevalonate synthase mutant (ΔmvaS mutant) of Staphylococcus aureus to study whether a nongrowing but viable cell population is tolerant to bactericidal antibiotics. The mevalonate-depleted nongrowing ΔmvaS mutant was found tolerant to antibiotics. Surprisingly, after prolonged cultivation, we obtained stable ΔmvaS variants that were able to g...

The application of 2-(3,4-dichlorophenoxy)-triethylamine to guayule (Parthenium argentatum Gray var 593) plants results in a 2-fold stimulation of rubber synthesis and a 1.5- to 3-fold increase in mevalonic acid kinase, isopentenyl pyrophosphate isomerase, and rubber transferase. The increase in these enzymic activities accounts in part for the chemical induction of rubber synthesis.

The conversion of isopentenyl pyrophosphate to phytoene in Neurospora crassa requires both a soluble and a particulate fraction. Soluble and particulate enzyme fractions obtained from light-treated and dark-grown wild type, albino-1, albino-2, albino-3, and white collar-1 strains were mixed in various combinations, and the activity for conversion of [1-(14)C]isopentenyl pyrophosphate to phytoen...

SYNOPSIS Analysis of five brains from patients with Leigh's disease demonstrates an accumulation of thiamine pyrophosphate and a deficiency of thiamine triphosphate. The enzyme which converts thiamine pyrophosphate to thiamine triphosphate was normally active in two of these brains, suggesting that the inhibitor found in Leigh's disease is probably producing the observed neurochemical changes. ...

The various nucleosides and nucleotides used in this study were commercial preparations. This was also true for inorganic pyrophosphate, tripolyphosphate, and adenosine tetraphosphate. ATP was a crystalline preparation; UTP was further purified by ion exchange chromatography. 1-Pyrophosphoryl ribose 5-phosphate was isolated by the procedure of Kornberg, Lieberman, and Simms (I) to whom we are i...

The underlying molecular defect resulting in the abnormal calcification observed in ank/ank mice has been identified. The responsible nonsense mutation affects the protein product of ank, resulting in diminished production of extracellular inorganic pyrophosphate, an important inhibitor of nucleation and of the growth of apatite crystals. The ank gene product is one of several cell membrane pro...

The incorporation of 12-14C,(5R)-5-3Hj]MVA* and 12-14C,5-3H2]MVA into geranylgeraniol and phytoene by a preparation of 'non-aqueous' bean leaf chloroplasts has been studied. In the formation of phytoene from two molecules of geranylgeranyl pyrophosphate, the loss of hydrogen is stereospecific, the hydrogen atom lost from C-1 of each molecule of geranylgeranyl pyrophosphate being that which was ...