It has been demonstrated by studies in vitro and in vivo that two absorptive processes are involved in the intestinal absorption of amino acids. It is also apparent that the vitamins of the Bggroup play a role in the “active” process of cellular uptake of amino acids (2) and that deoxpyridoxine (3) and 2,4-dinitrophenol (3,4), have an inhibitory effect upon active absorptive processes. We are p...

The uncoupler 2,4-dinitrophenol prevents in vivo synthesis of O antigen in Salmonella typhimurium by inhibiting the first reaction of the pathway, formation of galactosyl-pyrophosphoryl-undecaprenol. Inhibition was observed only in intact cells; dinitrophenol had no effect on activity of the synthase enzyme in isolated membrane fractions. In vivo inhibition could not be explained by changes in ...

Salicylic acid inhibited ethylene formation from ACC in self-buffered (pH 3.8) pear (Pyrus communis) cell suspension cultures with a K(1) (app) of about 10 micromolar after 1 to 3 hours incubation. Inhibition appeared noncompetitive. Among 22 related phenolic compounds tested, only acetylsalicylic acid showed similar levels of inhibition. Inhibition by salicylic acid was inversely dependent on ...

Comparative time-course studies of glycogen synthesis from glucose 6-phosphate, glucose 1-phosphate and UDP-glucose show that glucose 1-phosphate forms glycogen at an initial rate faster than that obtained with glucose 6-phosphate and UDP-glucose. After 5min. the rates from glucose monophosphates are considerably slower. 2,4-Dinitrophenol decreases glycogen synthesis from both glucose monophosp...

The addition of nitrite, the product of the reaction catalysed by nitrate reductase, to cell suspensions of the yeast Hansenula anomala caused a reversible inactivation of NADPH-dependent nitrate reductase activity. The haem- and Mo-dependent and Mo-dependent activities of nitrate reductase, determined with the non-physiological electron donors FMNH2 and reduced methyl viologen respectively, we...

3.3. Magnetic Particle Imaging 3029 4. Challenges for CEST Agents 3029 4.1. Technical Issues 3029 4.2. Chemical Issues 3031 4.3. Biological Issues 3032 5. Challenges for Heteronuclear MR Imaging 3033 5.1. F-Based Probes 3033 6. Challenges for Hyperpolarized Probes 3034 6.1. Brute Force 3034 6.2. Optical Pumping and Spin Exchange 3035 6.3. Dynamic Nuclear Polarization (DNP) 3035 6.4. para-Hydrog...

We propose a design for an electrochemically driven RGB dye based on a tristable [2]catenane, in which the color of the molecule can be switched between Red, Green, and Blue by merely changing voltage. Based on DFT calculations, we conclude that the tristable [2]catenane should consist of a CBPQT4+ ring interlocked with a polyether macrocyle containing DNP (red), TTF (green), and FBZD (blue) un...

Global biodiversity loss has prompted research on the relationship between species diversity and ecosystem functioning. Few studies have examined how plant diversity impacts belowground processes; even fewer have examined how varying resource levels can influence the effect of plant diversity on microbial activity. In a field experiment in a restored wetland, we examined the role of plant trait...

1. Hydrolysis of peptides has been measured in isolated rat small intestine perfused with a pancreatic digest of lactalbumin in the presence of 2,4-dinitrophenol. 2. Although transport of water and amino acids was severely inhibited by 2,4-dinitrophenol, peptide hydrolysis to free amino acids was apparently unimpaired. 3. Only a small fraction of the hydrolysis observed could be accounted for b...

The relation between the phosphorylation of deoxygluoose (2-DG) and levels of adenine nucleotides was investigated in endogenously respiring Ehrlich Lettréascites cells pretreated with various inhibitors. Pretreatment with the respiratory inhib itor, rotenone, caused a 70<; decrease in 2-deoxyglucose-6phosphate formation. The sources of energy for 2-DG phos phorylation in the presence of roten...