Search results for "Deamination"
showing 6 items of 16 documents
Über die Hemmung von Desoxyribonucleotide spaltenden Fermenten durch Colchicin
1949
The authors raise the question, if enzymatic processes possibly linked with the mitotic cell division may be influenced by mitotic poisons. The presented date show an inhibition of the dephosphorylation of desoxyribonucleotides at a rate of about 50% and of the deamination of about 40% by colchicine (final concentration 1·2·10−2M).
A putative antiviral role of plant cytidine deaminases
2014
[Background]: A mechanism of innate antiviral immunity operating against viruses infecting mammalian cells has been described during the last decade. Host cytidine deaminases (e.g., APOBEC3 proteins) edit viral genomes, giving rise to hypermutated nonfunctional viruses; consequently, viral fitness is reduced through lethal mutagenesis. By contrast, sub-lethal hypermutagenesis may contribute to virus evolvability by increasing population diversity. To prevent genome editing, some viruses have evolved proteins that mediate APOBEC3 degradation. The model plant Arabidopsis thaliana genome encodes nine cytidine deaminases ( AtCDAs), raising the question of whether deamination is an antiviral mec…
The Rate and Molecular Spectrum of Spontaneous Mutations in Arabidopsis thaliana
2010
Evolution in Action Rates of evolution in gene and genome sequences have been estimated, but these estimates are subject to error because many of the steps of evolution over the ages are not directly measurable or are hidden under subsequent changes. Ossowski et al. (p. 92 ) now provide a more accurate measurement of how often spontaneous mutations arise in a nuclear genome. Mutations arising over 30 generations were compared by sequencing DNA from individual Arabidopsis thaliana plants. UV- and deamination-induced mutagenesis appeared to bias the type of mutations found.
APOBEC4 Enhances the Replication of HIV-1
2016
APOBEC4 (A4) is a member of the AID/APOBEC family of cytidine deaminases. In this study we found a high mRNA expression of A4 in human testis. In contrast, there were only low levels of A4 mRNA detectable in 293T, HeLa, Jurkat or A3.01 cells. Ectopic expression of A4 in HeLa cells resulted in mostly cytoplasmic localization of the protein. To test whether A4 has antiviral activity similar to that of proteins of the APOBEC3 (A3) subfamily, A4 was co-expressed in 293T cells with wild type HIV-1 and HIV-1 luciferase reporter viruses. We found that A4 did not inhibit the replication of HIV-1 but instead enhanced the production of HIV-1 in a dose-dependent manner and seemed to act on the viral L…
Metabolism of tresperimus by rat aorta semicarbazide-sensitive amine oxidase (SSAO).
2002
Tresperimus (Cellimis), a new immunosuppressive agent, is mainly eliminated in the rat through metabolism, in which the oxidative deamination of the primary amine of the drug plays a major role. We have previously demonstrated in vivo the significant involvement of semicarbazide-sensitive amine oxidase (SSAO) in this reaction. Rat aorta, a tissue with one of the highest specific SSAO activities, was tested as a new in vitro model to elucidate tresperimus metabolism, using a combination of liquid chromatography/mass spectrometry (LC/MS) and high-performance liquid chromatography (HPLC) analyses. The metabolites resulting from the main metabolic pathway of the drug were formed in rat aorta ho…
Human D-Amino Acid Oxidase: Structure, Function, and Regulation
2018
D-Amino acid oxidase (DAAO) is an FAD-containing flavoenzyme that catalyzes with absolute stereoselectivity the oxidative deamination of all natural D-amino acids, the only exception being the acidic ones. This flavoenzyme plays different roles during evolution and in different tissues in humans. Its three-dimensional structure is well conserved during evolution: minute changes are responsible for the functional differences between enzymes from microorganism sources and those from humans. In recent years several investigations focused on human DAAO, mainly because of its role in degrading the neuromodulator D-serine in the central nervous system. D-Serine is the main coagonist of N-methyl D…