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1.
Citrullinemia is one of the five aminoacidurias associated with the Krebs-Henseleit urea cycle. A long-term lymphocyte line (UM-21) derived from a patient with this disease and nine of ten clones of this line were found to have no activity for the enzyme argininosuccinate synthetase (AS), as demonstrated by their inability to grow in medium in which citrulline had been substituted for arginine, by their inability to incorporate arginine-C14 derived from citrulline-C14 into cellular protein, and by direct enzyme assay. One clone had normal or nearly normal argininosuccinate synthetase activity, as demonstrated by the same criteria. Nutritional "variants" able to grow logarithmically in medium containing citrulline were isolated from UM-21 and three clones. The apparent Kms of AS for citrulline in UM-21, the ten clones, the variant lines, and a normal line were measured and fell into three groups: AS in UM-21 and nine clones had no measurable apparent Km for citrulline; AS in the variant cells had apparent Kms for citrulline of approximately 20 mM; and AS in the normal cell line and one clone had apparent Kms for citrulline of 0.2 mM. The data suggest that the defect in the citrullinemic cell lines is due to a mutation in the structural gene coding for argininosuccinate synthetase. 相似文献
2.
Olivia Sveidahl Johansen Tao Ma Jakob Bondo Hansen Lasse Kruse Markussen Renate Schreiber Laia Reverte-Salisa Hua Dong Dan Ploug Christensen Wenfei Sun Thorsten Gnad Iuliia Karavaeva Thomas Svava Nielsen Sander Kooijman Cheryl Cero Oksana Dmytriyeva Yachen Shen Maria Razzoli Shannon L. O’Brien Zachary Gerhart-Hines 《Cell》2021,184(13):3502-3518.e33
3.
Mihai Moldovan Volodymyr Pinchenko Oksana Dmytriyeva Stanislava Pankratova K?re Fugleholm Jorg Klingelhofer Elisabeth Bock Vladimir Berezin Christian Krarup Darya Kiryushko 《Molecular medicine (Cambridge, Mass.)》2013,19(1):43-53
We recently found that S100A4, a member of the multifunctional S100 protein family, protects neurons in the injured brain and identified two sequence motifs in S100A4 mediating its neurotrophic effect. Synthetic peptides encompassing these motifs stimulated neuritogenesis and survival in vitro and mimicked the S100A4-induced neuroprotection in brain trauma. Here, we investigated a possible function of S100A4 and its mimetics in the pathologies of the peripheral nervous system (PNS). We found that S100A4 was expressed in the injured PNS and that its peptide mimetic (H3) affected the regeneration and survival of myelinated axons. H3 accelerated electrophysiological, behavioral and morphological recovery after sciatic nerve crush while transiently delaying regeneration after sciatic nerve transection and repair. On the basis of the finding that both S100A4 and H3 increased neurite branching in vitro, these effects were attributed to the modulatory effect of H3 on initial axonal sprouting. In contrast to the modest effect of H3 on the time course of regeneration, H3 had a long-term neuroprotective effect in the myelin protein P0 null mice, a model of dysmyelinating neuropathy (Charcot-Marie-Tooth type 1 disease), where the peptide attenuated the deterioration of nerve conduction, demyelination and axonal loss. From these results, S100A4 mimetics emerge as a possible means to enhance axonal sprouting and survival, especially in the context of demyelinating neuropathies with secondary axonal loss, such as Charcot-Marie-Tooth type 1 disease. Moreover, our data suggest that S100A4 is a neuroprotectant in PNS and that other S100 proteins, sharing high homology in the H3 motif, may have important functions in PNS pathologies. 相似文献
4.
Vladimir A. Efimov Oksana G. Chakhmakhcheva Eric Wickstrom 《Nucleosides, nucleotides & nucleic acids》2013,32(10-12):1853-1874
Negatively charged DNA mimics containing phosphonate analogues of peptide nucleic acids were designed, and their physicochemical and biological properties were evaluated in the comparison with natural oligonucleotides, classical peptide nucleic acids, and morpholino phosphorodiamidate oligonucleotide analogues. The results obtained revealed a high potential of phosphonate-containing PNA derivatives for a number of biological applications, such as diagnostic, nucleic acids analysis, and inhibition of gene expression. 相似文献
5.
Tammi Vesth Asl? Ozen Sandra C. Andersen Rolf Sommer Kaas Oksana Lukjancenko Jon Bohlin Intawat Nookaew Trudy M. Wassenaar David W. Ussery 《Standards in genomic sciences》2013,9(2):431-448
The Firmicutes represent a major component of the intestinal microflora. The intestinal Firmicutes are a large, diverse group of organisms, many of which are poorly characterized due to their anaerobic growth requirements. Although most Firmicutes are Gram positive, members of the class Negativicutes, including the genus Veillonella, stain Gram negative. Veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerobes. In this work, the genomes of 24 Negativicutes, including eight Veillonella spp., are compared to 20 other Firmicutes genomes; a further 101 prokaryotic genomes were included, covering 26 phyla. Thus a total of 145 prokaryotic genomes were analyzed by various methods to investigate the apparent conflict of the Veillonella Gram stain and their taxonomic position within the Firmicutes. Comparison of the genome sequences confirms that the Negativicutes are distantly related to Clostridium spp., based on 16S rRNA, complete genomic DNA sequences, and a consensus tree based on conserved proteins. The genus Veillonella is relatively homogeneous: inter-genus pair-wise comparison identifies at least 1,350 shared proteins, although less than half of these are found in any given Clostridium genome. Only 27 proteins are found conserved in all analyzed prokaryote genomes. Veillonella has distinct metabolic properties, and significant similarities to genomes of Proteobacteria are not detected, with the exception of a shared LPS biosynthesis pathway. The clade within the class Negativicutes to which the genus Veillonella belongs exhibits unique properties, most of which are in common with Gram-positives and some with Gram negatives. They are only distantly related to Clostridia, but are even less closely related to Gram-negative species. Though the Negativicutes stain Gram-negative and possess two membranes, the genome and proteome analysis presented here confirm their place within the (mainly) Gram positive phylum of the Firmicutes. Further studies are required to unveil the evolutionary history of the Veillonella and other Negativicutes. 相似文献
6.
Oksana A. Sergeeva Bo Chen Cameron Haase-Pettingell Steven J. Ludtke Wah Chiu Jonathan A. King 《The Journal of biological chemistry》2013,288(24):17734-17744
Chaperonins are a family of chaperones that encapsulate their substrates and assist their folding in an ATP-dependent manner. The ubiquitous eukaryotic chaperonin, TCP-1 ring complex (TRiC), is a hetero-oligomeric complex composed of two rings, each formed from eight different CCT (chaperonin containing TCP-1) subunits. Each CCT subunit may have distinct substrate recognition and ATP hydrolysis properties. We have expressed each human CCT subunit individually in Escherichia coli to investigate whether they form chaperonin-like double ring complexes. CCT4 and CCT5, but not the other six CCT subunits, formed high molecular weight complexes within the E. coli cells that sedimented about 20S in sucrose gradients. When CCT4 and CCT5 were purified, they were both organized as two back-to-back rings of eight subunits each, as seen by negative stain and cryo-electron microscopy. This morphology is consistent with that of the hetero-oligomeric double-ring TRiC purified from bovine testes and HeLa cells. Both CCT4 and CCT5 homo-oligomers hydrolyzed ATP at a rate similar to human TRiC and were active as assayed by luciferase refolding and human γD-crystallin aggregation suppression and refolding. Thus, both CCT4 and CCT5 homo-oligomers have the property of forming 8-fold double rings absent the other subunits, and these complexes carry out chaperonin reactions without other partner subunits. 相似文献
7.
Bohdan Bilyk Stephen Weber Maksym Myronovskyi Oksana Bilyk Lutz Petzke Andriy Luzhetskyy 《Applied microbiology and biotechnology》2013,97(1):351-359
We report here the in vivo expression of the synthetic transposase gene himar1(a) in Streptomyces coelicolor M145 and Streptomyces albus. Using the synthetic himar1(a) gene adapted for Streptomyces codon usage, we showed random insertion of the transposon into the streptomycetes genome. The insertion frequency for the Himar1-derived minitransposons is nearly 100 % of transformed Streptomyces cells, and insertions are stably inherited in the absence of an antibiotic selection. The minitransposons contain different antibiotic resistance selection markers (apramycin, hygromycin, and spectinomycin), site-specific recombinase target sites (rox and/or loxP), I-SceI meganuclease target sites, and an R6Kγ origin of replication for transposon rescue. We identified transposon insertion loci by random sequencing of more than 100 rescue plasmids. The majority of insertions were mapped to putative open-reading frames on the S. coelicolor M145 and S. albus chromosomes. These insertions included several new regulatory genes affecting S. coelicolor M145 growth and actinorhodin biosynthesis. 相似文献
8.
Oksana Tehlivets Nermina Malanovic Myriam Visram Tea Pavkov-Keller Walter Keller 《生物化学与生物物理学报:疾病的分子基础》2013,1832(1):204-215
S-adenosyl-L-methionine (AdoMet)-dependent methylation is central to the regulation of many biological processes: more than 50 AdoMet-dependent methyltransferases methylate a broad spectrum of cellular compounds including nucleic acids, proteins and lipids. Common to all AdoMet-dependent methyltransferase reactions is the release of the strong product inhibitor S-adenosyl-L-homocysteine (AdoHcy), as a by-product of the reaction. S-adenosyl-L-homocysteine hydrolase is the only eukaryotic enzyme capable of reversible AdoHcy hydrolysis to adenosine and homocysteine and, thus, relief from AdoHcy inhibition. Impaired S-adenosyl-L-homocysteine hydrolase activity in humans results in AdoHcy accumulation and severe pathological consequences. Hyperhomocysteinemia, which is characterized by elevated levels of homocysteine in blood, also exhibits a similar phenotype of AdoHcy accumulation due to the reversal of the direction of the S-adenosyl-L-homocysteine hydrolase reaction. Inhibition of S-adenosyl-L-homocysteine hydrolase is also linked to antiviral effects. In this review the advantages of yeast as an experimental system to understand pathologies associated with AdoHcy accumulation will be discussed. 相似文献
9.
Denis V. Sudarikov Yulia V. Krymskaya Oksana G. Shevchenko Pavel A. Slepukhin Svetlana A. Rubtsova Aleksandr V. Kutchin 《化学与生物多样性》2019,16(11)
The synthesis of sulfenimines and sulfinimines has been carried out with 10‐hydroxyisocamphylthiol. The configuration of the compounds has been deduced by methods of NMR, DFT calculations and X‐ray diffraction analysis. The cytotoxic, antioxidant and membrane‐protective activity of the synthesized compounds as well as of the previously obtained sulfenimines and sulfinimines based on 4‐caranethiol have been determined. 相似文献
10.
Evseeva Nina V. Tkachenko Oksana V. Denisova Alena Yu. Burygin Gennady L. Veselov Dmitry S. Matora Larisa Yu. Shchyogolev Sergei Yu. 《World journal of microbiology & biotechnology》2019,35(12):1-10
World Journal of Microbiology and Biotechnology - Derived from RNA, 5?-ribonucleotides, especially Inosine-5?-monophosphate (IMP) and guanosine-5?-monophosphate (GMP), can enhance... 相似文献