Deposition of intra-articular calcium pyrophosphate is associated with both aging and arthropathy; increased concentrations of free pyrophosphate (PPi) may contribute to such deposition. Free pyrophosphate and nucleoside triphosphate pyrophosphatase (NTPase) were estimated in synovial fluids from 50 subjects with normal knees and from 44 patients with rheumatoid arthritis, 61 with pyrophosphate...

Recent observations in this laboratory suggested that urinary pyrophosphate excretion may reflect the rate of bone resorption in clinical disorders of bone metabolism (1). Since parathyroid hormone is known to accelerate bone resorption (2, 3), changes in parathyroid function might also be expected to be associated with parallel changes in pyrophosphate excretion. An elevated urinary excretion ...

The intermediate, discovered by Rilling, between farnesyl pyrophosphate and squalene was synthesized in milligram quantities with yeast subcellular particles from farnesylJ4Cpyrophosphate and from farnesyl-l-3H&4C-pyrophosphate. The 3H : l4C ratio in the new squalene precursor was found to be identical with that in the farnesyl pyrophosphate, whereas the ratio in squalene was close to the expec...

Ferric pyrophosphate is a water-insoluble Fe compound used to fortify infant cereals and chocolate-drink powders as it causes no organoleptic changes to the food vehicle. However, it is only of low absorption in man. Recently, an innovative ferric pyrophosphate has been developed (Sunactive Fe trade mark ) based on small-particle-size ferric pyrophosphate (average size 0.3 microm) mixed with em...

Biosynthesis of ent-kaurene was investigated in extracts of cell suspension cultures derived from tobacco callus (Nicotiana tabacum L.), tomato callus (Solanum lycopersicum L.), and in germinating tomato seeds. Incubation of extracts derived from the two cell cultures with either isopentenyl pyrophosphate-(14)C or with (14)C-labeled mevalonate, followed by alkaline phosphatase hydrolysis, resul...

The conversion of geranyl pyrophosphate to (-)-endo-fenchol is considered to proceed by the initial isomerization of the substrate to (-)-(3R)-linalyl pyrophosphate and the subsequent cyclization of this bound intermediate. To test this stereochemical scheme, phosphatase-free preparations of (-)-endo-fenchol cyclase from fennel (Foeniculum vulgare M.) fruit were repeatedly incubated with a samp...

Pyrophosphate is a potent mitogen, capable of stimulating proliferation in multiple cell types, and a critical participant in bone mineralization. Pyrophosphate can also affect the resorption rate and bioactivity of orthopedic ceramics. The present study investigated whether calcium pyrophosphate affected proliferation, differentiation and gene expression in early (MC3T3 pre-osteoblast) and lat...

Two types of mutants of Escherichia coli were isolated, one of which (mutant 70-23-107) responded to thiamine pyrophosphate, and the other (mutant 70-23-102) to thiamine monophosphate and thiamine pyrophosphate. They were produced by further mutation of a thiamine auxotroph of E. coli 70-23 with N-methyl-N'-nitro-N-nitrosoguanidine. The parent organism required thiamine because phosphohydroxyme...

Some nonphotosynthetic microorganisms synthesize carotenes in response to light. Previous experiments demonstrated that the enzymes necessary for the synthesis and metabolism of phytoene were photoinduced in a Mycobacterium sp. We now report that prephytoene pyrophosphate synthetase is also totally photoinduced. Geranylgeranyl pyrophosphate synthetase (prenyltransferase), which is present in da...