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111.
The binding cavity of mouse major urinary protein is optimised for a variety of ligand binding modes
Thelma A. Pertinhez Emanuela Casali Alberto Spisni Lorna J. Smith 《Biochemical and biophysical research communications》2009,390(4):1266-18521
15N and 1HN chemical shift data and 15N relaxation studies have been used to characterise the binding of N-phenyl-naphthylamine (NPN) to mouse major urinary protein (MUP). NPN binds in the β-barrel cavity of MUP, hydrogen bonding to Tyr120 and making extensive non-bonded contacts with hydrophobic side chains. In contrast to the natural pheromone 2-sec-butyl-4,5-dihydrothiazole, NPN binding gives no change to the overall mobility of the protein backbone of MUP. Comparison with 11 different ligands that bind to MUP shows a range of binding modes involving 16 different residues in the β-barrel cavity. These finding justify why MUP is able to adapt to allow for many successful binding partners. 相似文献
112.
Zamoner A Bruno AN Casali EA Corbelini PF Diniz GP Barreto-Chaves ML Silva FR Sarkis JJ Pessoa-Pureur R 《Life sciences》2006,80(1):51-58
The Sertoli cells play an essential role in the maintenance and control of spermatogenesis. The ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) and 5'-nucleotidase activities can modulate the extracellular adenine nucleotide levels, controlling nucleotide-mediated signaling events in Sertoli cells. Since thyroid hormones (TH) and adenine nucleotides and nucleosides play important modulatory roles in Sertoli cell proliferation and differentiation, the aim of our study was to investigate the effect of hypothyroidism upon the NTPDase and 5'-nucleotidase activities in Sertoli cell cultures, as well as to verify whether these effects may be reversed by short and long-term supplementation with TH. Congenital hypothyroidism was induced by adding 0.02% methimazole in the drinking water from day 9 of gestation and continually until 18 days of age. Hypothyroidism significantly decreased the extracellular ATP and ADP hydrolysis and this effect was significantly reversed when cell cultures were supplemented with 1 microM T3 or 0.1 microM T4 for 30 min. In contrast, AMP hydrolysis was not altered by hypothyroidism, but was increased by T4 supplementation for 24 h. The presence of the enzymes NTPDase 1, 2 and 3 was detected by RT-PCR in Sertoli cell cultures, however, hypothyroidism was not able to alter the expression of these enzymes. These findings demonstrate that TH modify NTPDase activities in hypothyroid Sertoli cells, probably via nongenomic mechanisms and, consequently, may influence the reproductive function throughout development. 相似文献
113.
Henz SL Ribeiro CG Rosa A Chiarelli RA Casali EA Sarkis JJ 《Cell biology international》2006,30(3):214-220
The participation of ecto-ATP diphosphohydrolase (CD39; ecto-NTPDase) and ecto-5'-nucleotidase (CD73) activities in the nucleotide hydrolysis by salivary gland cells from rats was evaluated. We investigated the biochemical characteristics of these ectoenzymes in cells cultured from submandibular salivary glands of rats. The V(max) for the hydrolysis of ATP, ADP and AMP were 2275+/-153 (mean+/-SEM, n = 4), 941+/-96 (mean+/-SEM, n = 5) and 175+/-5 (mean+/-SEM, n = 5) nmol Pi liberated per min per mg of protein, respectively. The K(m) values for ATP, ADP and AMP were 224+/-8 microM (mean+/-SEM, n = 4), 163+/-15 microM (mean+/-SEM, n = 5) and 117+/-5 microM (mean+/-SEM, n = 5), respectively. The competition plot showed that ATP and ADP were hydrolyzed at the same active site on the enzyme. It may be postulated that the physiological role for this ecto-enzyme cascade is to terminate the action of the co-transmitter ATP, generating adenosine. 相似文献
114.
Porta A Casali KR Casali AG Gnecchi-Ruscone T Tobaldini E Montano N Lange S Geue D Cysarz D Van Leeuwen P 《American journal of physiology. Regulatory, integrative and comparative physiology》2008,295(2):R550-R557
We exploit time reversibility analysis, checking the invariance of statistical features of a series after time reversal, to detect temporal asymmetries of short-term heart period variability series. Reversibility indexes were extracted from 22 healthy fetuses between 16th to 40th wk of gestation and from 17 healthy humans (aged 21 to 54, median=28) during graded head-up tilt with table inclination angles randomly selected inside the set {15, 30, 45, 60, 75, 90}. Irreversibility analysis showed that nonlinear dynamics observed in short-term heart period variability are mostly due to asymmetric patterns characterized by bradycardic runs shorter than tachycardic ones. These temporal asymmetries were 1) more likely over short temporal scales than over longer, dominant ones; 2) more frequent during the late period of pregnancy (from 25th to 40th week of gestation); 3) significantly present in healthy humans at rest in supine position; 4) more numerous during 75 and 90 degrees head-up tilt. Results suggest that asymmetric patterns observable in short-term heart period variability might be the result of a fully developed autonomic regulation and that an important shift of the sympathovagal balance toward sympathetic predominance (and vagal withdrawal) can increase their presence. 相似文献
115.
Audrey Arnal Camille Jacqueline Beata Ujvari Lucas Leger Céline Moreno Dominique Faugere Aurélie Tasiemski Céline Boidin‐Wichlacz Dorothée Misse François Renaud Jacques Montagne Andreu Casali Benjamin Roche Frédéric Thomas 《Ecology and evolution》2017,7(1):272-276
Hosts often accelerate their reproductive effort in response to a parasitic infection, especially when their chances of future reproduction decrease with time from the onset of the infection. Because malignancies usually reduce survival, and hence potentially the fitness, it is expected that hosts with early cancer could have evolved to adjust their life‐history traits to maximize their immediate reproductive effort. Despite the potential importance of these plastic responses, little attention has been devoted to explore how cancers influence animal reproduction. Here, we use an experimental setup, a colony of genetically modified flies Drosophila melanogaster which develop colorectal cancer in the anterior gut, to show the role of cancer in altering life‐history traits. Specifically, we tested whether females adapt their reproductive strategy in response to harboring cancer. We found that flies with cancer reached the peak period of oviposition significantly earlier (i.e., 2 days) than healthy ones, while no difference in the length and extent of the fecundity peak was observed between the two groups of flies. Such compensatory responses to overcome the fitness‐limiting effect of cancer could explain the persistence of inherited cancer‐causing mutant alleles in the wild. 相似文献
116.
Schaffer A Kim EC Wu X Zan H Testoni L Salamon S Cerutti A Casali P 《The Journal of biological chemistry》2003,278(25):23141-23150
117.
Monica Casali Letizia Tarantini Sergio Riva Zdenka Hunkova Lenka Weignerova Vladimir Kren 《Biotechnology and bioengineering》2002,77(1):105-110
After screening a library of fungal alpha-galactosidases for the synthesis of functionalized alkyl alpha-D-galactopyranosides, four enzymes (isolated from Aspergillus terreus CCM55, Aspergillus commune CCM 2969, Penicillium vinaceum CCM 2384, or Penicillium brasilianum 2155) proved to be suitable for these biotransformations. The effect of different concentrations of alcohol on activity and stability of these enzymes was investigated. After optimization of the reaction conditions, three galactose derivatives (allyl, 2-nitroethyl and 2-(2',2',2'-trifluoroacetamido)-ethyl alpha-D-galactopyranoside, 1a, 3a, and 4a, respectively), suitable for subsequent chemical polymerization, were synthesized using either the "reverse hydrolysis" or the "transglycosylation" protocols. 相似文献
118.
119.
Tryptophan interactions of gramicidin A' channels in lipids: a time-resolved fluorescence study 总被引:1,自引:0,他引:1
L Masotti P Cavatorta G Sartor E Casali A G Szabo 《Biochimica et biophysica acta》1986,862(2):265-272
The evolution of the incorporation of cation transport channels into lysolecithin micelles by gramicidin A was followed by measuring the ns time-resolved fluorescence of the tryptophan residues. In all samples, the tryptophan fluorescence could be resolved into three exponentially decaying components. The three decay times ranged from 6 to 8 ns, 1.8 to 3 ns, and 0.3 to 0.8 ns, depending on the emission wavelength. The fractional fluorescence of each component changed with incubation time. The long lifetime component had a reduced contribution to the total fluorescence while the short decay time component increased. The fluorescence spectra could be resolved into three distinct fluorescent components having maxima at 340 nm, 330 nm and 323 nm after 90 min of incubation, and 335 nm, 325 nm and 320 nm after 24 h of incubation. These maxima were, respectively, associated with the long, medium and short decay components. The fluorescence decay behaviour was interpreted as representing three families of tryptophans, the short lifetime component being due to a stacking interaction between tryptophan residues. The variation with incubation time suggests a two-step process in the channel-lipid organization. The first is associated with the conformational change of the polypeptide as it takes up a left-handed helical head-to-head dimer structure in the lipid. The second step is proposed to involve changes originating from membrane assembly and intermolecular interactions between channels as they form hexameric clusters. 相似文献
120.
Procoagulant activity of mouse transformed cells: Different expression in freshly isolated or cultured cells 总被引:1,自引:0,他引:1
Curatolo Laura Alessio Maria Orazia Casali Bruno Falanga Anna Donati Maria Benedeita Semeraro Nicola 《In vitro cellular & developmental biology. Plant》1988,24(12):1154-1158
Summary This study was originally designed to investigate wheter there is any correlation between the type of procoagulant activity
(PCA) and the tumorigenicity of transformed cells. The data obtained are relevant to this question and to defining the differences
in the expression of cellular activities depending on the in vitro system used. PCA was measured and characterized in normal,
immortalized, and tumorigenic mouse fibroblasts. In all the lines studied the activity was of tissue factor type, as established
with functional, enzymatic, and immunochemical criteria. However, the PCA of cells freshly isolated from the tumors induced
by tumorigenic cell lines was of cancer procoagulant type, i.e. a cysteine protease with direct factor X activator activity.
The same cells, when cultured in vitro, expressed again PCA of tissue-factor type. These results suggest that either a tumor-host
interaction is required for the expression of cancer procoagulant or the latter activity, produced by tumor cells under in
vitro conditions, is destroyed or inactivated during the culture period. Our findings caution against defining the procoagulant
activity of tumors based on experiments on cultured cells.
This work was partially supported by the Italian National Research Council and by the Italian Association for Cancer Research. 相似文献