Biochemical and Physiological Properties

Biochemical and Physiological Properties.—2-Arylimino-3-(p-chloro-phenethyl)thiazolidin-4-ones inhibit the oxidation of 2-oxoglutarate, citrate, 3-hydroxybutyrate, and pyruvate, but have no inhibitory effect on the respiratory activity of rat brain homogenate with sodium succinate used as substrate. They thus appear to exert selective inhibition of NAD -dependent oxidations. 

The radioprotective properties of thiazolidines continue to be a subject of considerable interest (cf. ref. 183 for a brief list of the relevant literature).Activity has been found in simple derivatives such as 2,2-dimethyl-, 2-methy 1-2-ethyl-, and 2-phenyl-thiazolidines. Thiazolidines substituted in their 3-position with 5-halogeno-2-pyridyloxy-pentyl or -hexyl groups possess relatively high radioprotective action when administered orally. Promising activity is also shown by their thio-analogues.  

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Eukaryotic genomes contain information for more than 20 E2s and hundreds of E3s. In contrast to the wealth of components devoted to marking protein substrates for destruction, only one enzyme, the 26S proteasome, has been found to degrade ubiquitylated proteins. However, there is complexity here as well, since the 26S proteasome is an assemblage of at least 30 different subunits. Moreover, there is a growing list of proteins that act as proteasome activators, adapters, or accessory factors. In this chapter I focus on basic biochemical and physiological properties... 

Neuronal differentiation is the process by which neuronal precursor cells develop the morphological, biochemical, and physiological properties of neurons. This is characterized by cell elongation, development of neurites, decreased... 

This chapter reviews the chemical, biochemical, and physiological properties of ascorbic acid and attempts to. summarize the. significant knowledge gained from nutritional investigations about the nature and... 

The supply of cells with cholesterol via receptor-mediated endocytosis of LDL is one of the best characterized processes of macromolecular transport across the plasma membrane of eukaryotic cells. The following sections describe this process, provide an overview of the biochemical and physiological properties of the LDL receptor, and discuss the molecular basis for the genetic disease, familial hypercholesterolemia (FH). 

For these reasons alone, a vitamin E symposium will not be short of problems and material for discussion. Many more unanswered questions come to light, however, when the biochemical and physiological properties of vitamin E are considered. The program of this meeting includes papers on the metabolism of vitamin E interrelations among vitamin E, metals, and ubi( uinones vitamin E and nucleic acid metabolism interrelations between vitamin E and polyunsaturated fatty acids vitamin E requirements of human infants vitamin E in health and disease of poultry, sheep, cattle, and pigs and so on. Everywhere, alongside established facts, there are unanswered questions and unsolved problems. 

Substantial quantities of edible cyanobacteria are produced globally to meet the high demands of both food and pharmaceutical industries. These cyanobacteria contain substantial quantities of phycobiliproteins, of which phycocy-anin, in particular, has various therapeutic effects owing to the linear tetrapyrrole chromophore phycocyanobilin. Cyanobacteria can also synthesize macrocyclic tetrapyrrole corrinoid compounds. However, various edible cyanobacteria contain substantial quantities of inactive pseudo-Bi2 rather than active Bi2- To overcome this nutritional defect of edible cyanobacteria, it is vital to determine the genetic, biochemical, and physiological properties of pseudo-Bi2-... 

Ascorbic acid is a reasonably strong reducing agent. The biochemical and physiological functions of ascorbic acid most likely derive from its reducing properties—it functions as an electron carrier. Loss of one electron due to interactions with oxygen or metal ions leads to semidehydro-L-ascorbate, a reactive free radical (Figure 18.30) that can be reduced back to L-ascorbic acid by various enzymes in animals and plants. A characteristic reaction of ascorbic acid is its oxidation to dehydro-L-aseorbie add. Ascorbic acid and dehydroascor-bic acid form an effective redox system. 

The different fibres have different properties, and different proportions are present in different individuals. The biochemical and physiological characteristics of the different fibres explain why some individuals are good sprinters whereas others are good endurance athletes. These differences are most marked in... 

Properties of the air pollutants sulfur dioxide, nitrogen oxides, peroxyacyl nitrates, and ozone have been considered from chemical, biochemical, and physiological points of view. Physiological observations cannot demonstrate the chemical mode of toxicity. Chemical and in vitro biochemical studies may be irrelevant at the physiological level. Consideration of all three approaches indicates which hypotheses of toxicity are more plausible and suggests new areas of investigation. 

Edsall, J. T. (1969) Carbon Dioxide, Carbonic Acid and Bicarbonate Ion Physical Properties and Kinetics of Interconversion. In CO2 Chemical, Biochemical and Physiological Aspects, Forster, R. E., et al., Eds., NASA SP-188, Washington, DC. 

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