Peter Reichard

Bio: Peter Reichard is an academic researcher from University of Padua. The author has contributed to research in topics: Ribonucleotide reductase & Escherichia coli. The author has an hindex of 75, co-authored 207 publications receiving 16117 citations. Previous affiliations of Peter Reichard include Karolinska Institutet & Stockholm University.

Reduction of ribonucleotides.

Abstract: PERSPECTIVES AND SUMMARY 1 33 RIBONUCLEOTIDE REDUCTASE FROM ES CHERICHIA COLI 136 Structural Aspects 136 Reaction Mechanism ....... .. ..... ......... ..... ... ...... ... ... ... ....... .. ..... .. ... ..... ... . 138 Allosteric Control 1 39 Hydrogen Transport System 140 RIBONUCLEOTIDE REDUCING SYSTEMS INDUCED BY BACTERIOPHAGES .... . . . . . . . . .. ... .. . . .. . . . . . . . . . . . . . . . . . . . . . . . . ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 RIBONUCLEOTIDE REDUCTASE FROM LACTOBACILLUS LEICHMANNII ... . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . ... . . ... . . . . ... . .. . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . 144 Structural Aspects ... .. ....... .... . . .. . ... . . . . ... . . . . . . . . . . 144 Reaction Mechanism 145 Allosteric Regulation ..... .. . .. .. . .. .. .. ...... ........ ........ ... ... ... ........ ..... ..... ....... ... . ....... 146 OTHER B12-DEPENDENT REDUCTASES.... .. . . . . . . . . . . . . . . .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 MAMMALIAN RIBONUCLEOTIDE REDUCTASE . . .. . .. . . . ... . .. . .. . . . . . . .... . . . . . . . .. . . . . . . .. 147 Structural Aspects and Reaction Mechanism 147 Allosteric Regulation . .. ... ....... .. .. . ...... ........ . ..... ..... ..... ... ... . ..... ..... . .. ... . .. . . .. . .. .. ..... .. . .. .. ... 149 Hydrogen Donor System .. ..... .. . ... 150 RIBONUCLEOTIDE REDUCTION AND DNA SyNTHESIS 1 5 1 Correlation o f I n Vitro and I n Vivo Activities 151 Regulation of Enzyme Synthesis 154 Deoxyribonucleotide Pools ... ..... .. .. ..... ........ ... ... .. ... .. . .. .. . ... ... ... ... ... ... .. . .. .. .. . .. .. ..... ... . . . ... 154

From RNA to DNA, why so many ribonucleotide reductases ?

Abstract: It is generally accepted that DNA appeared after RNA during the chemical evolution of life. To synthesize DNA, deoxyribonucleotides are required as building blocks. At present, these are formed from the corresponding ribonucleotides through the enzymatic action of ribonucleotide reductases. Three classes of enzymes are present in various organisms. There is little sequence similarity among the three classes of reductases. However, enzymic mechanisms and the allosteric behavior of the enzymes from various organisms are strongly conserved, suggesting that the enzymes might have evolved from a common ancestor, with the class III anaerobic Escherichia coli reductase as its closest relative.

Inhibition of Ribonucleoside Diphosphate Reductase by Hydroxyurea

Abstract: Hydroxyurea, a compound which inhibits the growth of rapidly proliferating tissues in animals and man, is known to inhibit DNA synthesis, and studies in crude systems have indicated that it does so by preventing the reduction of ribonucleotides to deoxyribonucleotides. This study demonstrates hydroxyurea-induced inhibition of the reduction of ribonucleotides by a highly purified enzyme system from Escherichia coli B. The inhibition (70% at 3 × 10-3 m under standard incubation conditions) is dependent on the concentration of hydroxyurea and on the duration of exposure of the enzyme to hydroxyurea. The effect of hydroxyurea is specific for protein B2 of the ribonucleoside diphosphate reductase system. The inhibition of enzymatic activity is apparently irreversible, although there is negligible irreversible binding of 14C-labeled hydroxyurea to the enzyme protein.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Principles of plant nutrition

Abstract: 1. Plant Nutrients. 2. The Soil as a Plant Nutrient Medium. 3. Nutrient Uptake and Assimilation. 4. Plant Water Relationships. 5. Plant Growth and Crop Production. 6. Fertilizer Application. 7. Nitrogen. 8. Sulphur. 9. Phosphorus. 10. Potassium. 11. Calcium. 12. Magnesium. 13. Iron. 14. Manganese. 15. Zinc. 16. Copper. 17. Molybdenum. 18. Boron. 19. Further Elements of Importance. 20. Elements with More Toxic Effects. General Readings. References. Index.

Physiological functions of thioredoxin and thioredoxin reductase.

Abstract: Thioredoxin, thioredoxin reductase and NADPH, the thioredoxin system, is ubiquitous from Archea to man. Thioredoxins, with a dithiol/disulfide active site (CGPC) are the major cellular protein disulfide reductases; they therefore also serve as electron donors for enzymes such as ribonucleotide reductases, thioredoxin peroxidases (peroxiredoxins) and methionine sulfoxide reductases. Glutaredoxins catalyze glutathione-disulfide oxidoreductions overlapping the functions of thioredoxins and using electrons from NADPH via glutathione reductase. Thioredoxin isoforms are present in most organisms and mitochondria have a separate thioredoxin system. Plants have chloroplast thioredoxins, which via ferredoxin-thioredoxin reductase regulates photosynthetic enzymes by light. Thioredoxins are critical for redox regulation of protein function and signaling via thiol redox control. A growing number of transcription factors including NF-kappaB or the Ref-1-dependent AP1 require thioredoxin reduction for DNA binding. The cytosolic mammalian thioredoxin, lack of which is embryonically lethal, has numerous functions in defense against oxidative stress, control of growth and apoptosis, but is also secreted and has co-cytokine and chemokine activities. Thioredoxin reductase is a specific dimeric 70-kDa flavoprotein in bacteria, fungi and plants with a redox active site disulfide/dithiol. In contrast, thioredoxin reductases of higher eukaryotes are larger (112-130 kDa), selenium-dependent dimeric flavoproteins with a broad substrate specificity that also reduce nondisulfide substrates such as hydroperoxides, vitamin C or selenite. All mammalian thioredoxin reductase isozymes are homologous to glutathione reductase and contain a conserved C-terminal elongation with a cysteine-selenocysteine sequence forming a redox-active selenenylsulfide/selenolthiol active site and are inhibited by goldthioglucose (aurothioglucose) and other clinically used drugs.