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81.
Monica J. Chau Anita I. Stone Sally P. Mendoza Karen L. Bales 《Ethology : formerly Zeitschrift fur Tierpsychologie》2008,114(10):989-998
Monogamy is a relatively rare social system in mammals, occurring only in about 3% of mammalian species. Monogamous species are characterized by the formation of pair‐bonds, biparental care, and a very low level of sexual dimorphism. Whereas in most polygynous species males engage in more rough‐and‐tumble play than females, we predicted that males and females of monogamous species would have similar, or monomorphic, play behavior. In this study, we focused on two monogamous species: coppery titi monkeys (Callicebus cupreus) and prairie voles (Microtus ochrogaster). We documented the development of play behavior in both species, and quantified different types of play behavior. We did not find any sex differences in either species in the frequencies and types of play. However, we did find sex differences in the choice of play partner in titi monkeys: female offspring spent a higher proportion of time playing with their father, while male offspring played equally with their mother and father. It is possible that rough‐and‐tumble play behavior is monomorphic in many monogamous mammals, perhaps reflecting differences from polygynous species in the effects of exposure to early androgens or in the estrogen receptor distribution. However, more subtle differences in monomorphic play behavior, such as choice of partner, may still exist. 相似文献
82.
A high-yielding serum-free, suspension cell culture process to manufacture recombinant adenoviral vectors for gene therapy 总被引:3,自引:0,他引:3
G. Schoofs T. J. Monica J. Ayala J. Horwitz T. Montgomery G. Roth F. J. Castillo 《Cytotechnology》1998,28(1-3):81-89
We have developed an efficient, reproducible, and scaleable cell culture process for a recombinant adenoviral vector expressing
therapeutic transgenes for clinical trials. HEK 293 cells – which support the propagation of E1 deficient adenovirus – were
first adapted to serum free media and suspension growth. Subsequent studies focused on the infection, virus production and
harvest from suspension culture bioreactors. Future studies are planned to address the kinetics of adenovirus production in
HEK 293 as well as in other cell lines.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
83.
Significance of the immune response to a major, conformational B-cell epitope on the hepatitis C virus NS3 region defined by a human monoclonal antibody. 总被引:4,自引:0,他引:4
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M U Mondelli A Cerino P Boender P Oudshoorn J Middeldorp C Fipaldini N La Monica W Habets 《Journal of virology》1994,68(8):4829-4836
The nonstructural protein NS3 of hepatitis C virus (HCV) possesses two enzymatic domains which are thought to be essential for the virus life cycle: an N-terminal serine-type proteinase, responsible for the processing of nonstructural polypeptides, and a C-terminal nucleoside triphosphatase/helicase, presumably involved in the unwinding of the viral genome. The human antibody response to NS3 usually appears early in the course of HCV infection and is predominantly directed against the carboxyl-terminal portion; however, its fine specificity and clinical significance are largely unknown. We have generated a human monoclonal antibody (hMAb), designated CM3.B6, from a cloned B-cell line obtained from the peripheral blood of a patient with chronic HCV infection, which selectively recognized the purified NS3 protein expressed in bacteria or in eukaryotic cells transfected with full-length or NS3 cDNA. Fine-specificity studies revealed that CM3.B6 recognized a 92-amino-acid sequence (clone 8, amino acids 1363 to 1454) selected from an NS3 DNase fragment library but failed to bind to 12-mer peptides synthesized from the same region, suggesting recognition of a conformational B-cell epitope. Experiments using deletion mutants of clone 8 and competitive inhibition studies using a panel of NS3 peptide-specific murine MAbs indicated that limited N-terminal and C-terminal deletions resulted in a significant reduction of hMAb binding to clone 8, thus identifying a minimal antibody binding domain within clone 8. Competition experiments showed that binding of CM3.B6 to the NS3 protein was efficiently inhibited by 39 of 44 (89%) sera from HCV-infected patients, suggesting that the hMAb recognized an immunodominant epitope within the NS3 region. More importantly, recognition of the sequence defined by CM3.B6 appeared to accurately discriminate between viremic and nonviremic anti-HCV positive sera, suggesting potentially relevant clinical applications in the diagnosis and treatment of HCV infection. 相似文献
84.
Interdomain salt‐bridges in the Ebola virus protein VP40 and their role in domain association and plasma membrane localization
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Jeevan B. GC Kristen A. Johnson Monica L. Husby Cary T. Frick Bernard S. Gerstman Robert V. Stahelin Prem P. Chapagain 《Protein science : a publication of the Protein Society》2016,25(9):1648-1658
The Ebola virus protein VP40 is a transformer protein that possesses an extraordinary ability to accomplish multiple functions by transforming into various oligomeric conformations. The disengagement of the C‐terminal domain (CTD) from the N‐terminal domain (NTD) is a crucial step in the conformational transformations of VP40 from the dimeric form to the hexameric form or octameric ring structure. Here, we use various molecular dynamics (MD) simulations to investigate the dynamics of the VP40 protein and the roles of interdomain interactions that are important for the domain–domain association and dissociation, and report on experimental results of the behavior of mutant variants of VP40. The MD studies find that various salt‐bridge interactions modulate the VP40 domain dynamics by providing conformational specificity through interdomain interactions. The MD simulations reveal a novel salt‐bridge between D45‐K326 when the CTD participates in a latch‐like interaction with the NTD. The D45‐K326 salt‐bridge interaction is proposed to help domain–domain association, whereas the E76‐K291 interaction is important for stabilizing the closed‐form structure. The effects of the removal of important VP40 salt‐bridges on plasma membrane (PM) localization, VP40 oligomerization, and virus like particle (VLP) budding assays were investigated experimentally by live cell imaging using an EGFP‐tagged VP40 system. It is found that the mutations K291E and D45K show enhanced PM localization but D45K significantly reduced VLP formation. 相似文献
85.
Monica Y. Burgos Zepeda Kevin Alessandri Dorothée Murat Chahrazade El Amri Elie Dassa 《Biochimica et Biophysica Acta - Proteins and Proteomics》2010,1804(4):755-761
The Uup protein belongs to a subfamily of soluble ATP-binding cassette (ABC) ATPases that have been implicated in several processes different from transmembrane transport of molecules, such as transposon precise excision. We have demonstrated previously that Escherichia coli Uup is able to bind DNA. DNA binding capacity is lowered in a truncated Uup protein lacking its C-terminal domain (CTD), suggesting a contribution of CTD to DNA binding. In the present study, we characterize the role of CTD in the function of Uup, on its overall stability and in DNA binding. To this end, we expressed and purified isolated CTD and we investigated the structural and functional role of this domain. The results underline that CTD is essential for the function of Uup, is stable and able to fold up autonomously. We compared the DNA binding activities of three versions of the protein (Uup, UupΔCTD and CTD) by an electrophoretic mobility shift assay. CTD is able to bind DNA although less efficiently than intact Uup and UupΔCTD. These observations suggest that CTD is an essential domain that contributes directly to the DNA binding ability of Uup. 相似文献
86.
Agromayor M Soler N Caballe A Kueck T Freund SM Allen MD Bycroft M Perisic O Ye Y McDonald B Scheel H Hofmann K Neil SJ Martin-Serrano J Williams RL 《Structure (London, England : 1993)》2012,20(3):414-428
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87.
Scotti C Iamele L Alessandrini A Vannini V Cazzalini O Lazzè MC Melli R Savio M Pizzala R Stivala LA Biglieri S Tomasi A Bianchi L 《Mitochondrion》2003,2(5):361-373
We investigated the molecular relationships between lipid peroxidation and mitochondrial DNA (mtDNA) single strand breaks (ssb) in isolated rat hepatocytes and mitochondria exposed to tert-butylhydroperoxide (TBH). Our results show that mtDNA ssb induced by TBH are independent of lipid peroxidation and dependent on the presence of iron and of hydroxyl free radicals. These data contribute to the definition of the mechanisms whereby mtDNA ssb are induced and provide possible molecular targets for the prevention of this kind of damage in vivo. 相似文献
88.
Protons at the gate: DEG/ENaC ion channels help us feel and remember 总被引:13,自引:0,他引:13
The DEG/ENaC ion channel family contributes to channels of striking functional diversity. Neuronally expressed family members include the C. elegans degenerins that mediate touch and are thought to be mechanically gated, and the mammalian ASICs, which are gated by protons. ASICs affect a range of sensory functions that includes perception of gentle touch, harsh touch, heat, sour taste, and pain. Family member ASIC1 is now implicated in long-term potentiation, suggesting that minute fluxes in synaptic pH may activate ASICs to enhance learning. 相似文献
89.
90.
Lactuca capensis reverses memory deficits in Aβ1‐42‐induced an animal model of Alzheimer's disease
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Paula Alexandra Postu Jaures A. K. Noumedem Oana Cioanca Monica Hancianu Marius Mihasan Mitica Ciorpac Dragos Lucian Gorgan Brindusa Alina Petre Lucian Hritcu 《Journal of cellular and molecular medicine》2018,22(1):111-122
We investigated the neuropharmacological effects of the methanolic extract from Lactuca capensis Thunb. leaves (100 and 200 mg/kg) for 21 days on memory impairment in an Alzheimer's disease (AD) rat model produced by direct intraventricular delivery of amyloid‐β1‐42 (Aβ1‐42). Behavioural assays such as Y‐maze and radial arm maze test were used for assessing memory performance. Aβ1‐42 decreased cognitive performance in the behavioural tests which were ameliorated by pre‐treatment with the methanolic extract. Acetylcholinesterase activity and oxidant–antioxidant balance in the rat hippocampus were abnormally altered by Aβ1‐42 treatment while these deficits were recovered by pre‐treatment with the methanolic extract. In addition, rats were given Aβ1‐42 exhibited in the hippocampus decreased brain‐derived neurotrophic factor (BDNF) mRNA copy number and increased IL‐1β mRNA copy number which was reversed by the methanolic extract administration. These findings suggest that the methanolic extract could be a potent neuropharmacological agent against dementia via modulating cholinergic activity, increasing of BDNF levels and promoting antioxidant action in the rat hippocampus. 相似文献