Enzyme I and HPr, the general proteins of the phosphoenolpyruvate-sugar phosphotransferase system, play a pivotal role in the control of sugar utilization in gram-negative and gram-positive bacteria. To determine whether growth conditions could modify the rate of biosynthesis of these proteins in Streptococcus mutans, we first purified to homogeneity enzyme I and HPr from S. mutans ATCC 27352. ...

Department o f Biology, University of California at San Diego, La Jolla, CA 92093-01 16, USA Lactococcus lactis takes up glucose and the nonmetabolizable glucose analogue 2-deoxyglucose (2DG) via the phosphotransferase system and extrudes the accumulated sugar phosphates in a process apparently dependent on a cytoplasmic sugar-phosphate phosphatase. Uptake of 2DG into L. lactis vesicles was sho...

These studies describe the detection of a haptoglobin species, its characterization as the HPR gene product, and its association with both pregnancy and neoplasia. Previous work showed that the early recurrence of human breast cancer correlated with immunohistochemical staining with a commercial antiserum ostensibly directed against pregnancy-associated plasma protein A (PAPP-A). Use of this an...

Lung cancer remains the number one cause of cancer-related deaths in the United States. To reduce the mortality associated with this disease, individuals at risk must be identified prior to the development of lung cancer, and effective prevention strategies must be developed. One such strategy is to use retinoids like N-(4-hydroxyphenyl)retinamide (4-HPR), which has been found to possess chemop...

sulfide production has been one of the most important problems in sewage collection systems that came to be known as an important factor of corrosion in concrete sewerage systems since early 1900. the emission of hydrogen sulfide gas in sewerage conduits creates problems including biological corrosion of concrete, release of repulsive odors in the city environment, as well as the potential dang...

steam reforming is one of the most important processes for producing hydrogen from hydrocarbon fuels such as lpg and has attracted much attention due to its high efficiency and economy. in this study, the lpg steam reforming reaction was investigated on nickel catalysts supported on four various zeolites (h-y, na-y, hzsm5 and ferrierite). the catalytic tests were performed in a tubular fixed be...

the main objective of this study is the modelling and optimization of an industrial hydrocracker unit (hu) by means of adaptive neuro fuzzy inference system (anfis) model. in this case, some data were collected from an industrial hydrocracker plant. inputs of an anfis include flow rate of fresh feed and recycle hydrogen, temperature of reactors, mole percentage of h2 and h2s, feed flow rate and...

1H and 31P nuclear magnetic resonance investigations of the phosphoprotein intermediate P-HPr and the parent molecule HPr of the E. coli phosphoenolpyruvate dependent phosphotransferase system (PTS) show that HPr can exist in two conformations. These conformations influence the protonation state of the reactive histidine residue, thereby determining the reaction pathway in the phosphoryl group ...

The dihydroceramide, ceramide, sphingomyelin, lactosylceramide, and ganglioside species of A2780 human ovarian carcinoma cells treated with the synthetic retinoids N-(4-hydroxyphenyl)retinamide (fenretinide, 4-HPR) and 4-oxo-N-(4-hydroxyphenyl)retinamide (4-oxo-4-HPR) in culture were characterized by ESI-MS. We characterized 32 species of ceramide and dihydroceramide, 15 of sphingomyelin, 12 of...

Ralstonia eutropha H16 possesses an incomplete phosphoenolpyruvate (PEP):sugar phosphotransferase system (PTS) composed of EI, HPr, EIIA(Ntr) (PtsN) and EIIA(Man) (PtsM). We could show that in vitro the incomplete PTS phosphorylation cascade is partially functional. HPr becomes phosphorylated by PEP and EI, and transfers the phosphoryl group to EIIA(Ntr), but only extremely slowly to EIIA(Man)....