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61.
Alberto Utrero-Rico Javier Ruiz-Hornillos Cecilia González-Cuadrado Claudia Geraldine Rita Berta Almoguera Pablo Minguez Antonio Herrero-González Mario Fernández-Ruiz Octavio Carretero Juan Carlos Taracido-Fernández Rosario López-Rodriguez Marta Corton José María Aguado Luisa María Villar Carmen Ayuso-García Estela Paz-Artal Rocio Laguna-Goya 《The Journal of allergy and clinical immunology》2021,147(5):1652-1661.e1
62.
An acid phosphatase from derepressed cells of the yeast form of Yarrowia lipolytica was purified 176-fold by ammonium sulfate precipitation, chromatography on DEAE-Sephacel and gel filtration in Biogel A 5-M. The enzyme is a glycoprotein with a sugar content of 60%. The MICHAELIS constant of the enzyme is 5.5 × 10?4 M for p-nitrophenyl phosphate as substrate; the isoelectric point estimated by electrofocusing is around 4.6 and the optimum pH is 6.2. Phosphatase activity was destroyed by exposure of the enzyme to 40 °C for 30 min or at pH 3 for 30 min. The purified enzyme shows size heterogeneity within a linear concentration gradient of polyacrylamide (4–20%) which indicates an apparent molecular weight in the range of 90,000–200,000 in the presence of sodium dodecyl sulfate. The heterogeneity of the enzyme is due to its carbohydrate content, as can be demonstrated by gel filtration and by treatment with endoglycosidase H. The carbohydrate-depleted protein has a molecular weight of 60,000. Aminoacid analysis revealed a high content of aspartic acid, serine, threonine, glycine and alanine. Antibodies against the protein moiety show cross reactivity with the acid phosphatase of Saccharomyces cerevisiae. 相似文献
63.
64.
Changes in the human immunodeficiency virus p7-p1-p6 gag gene in drug-naive and pretreated patients 下载免费PDF全文
Resistance to antiretroviral agents often results from mutations within the human immunodeficiency virus (HIV) pol gene. Moreover, insertions within the p6 gag-pol region have recently been found to be involved with resistance to nucleoside analogs. Overall, we found that 21% of 156 specimens collected from HIV-infected individuals (17.6% from 74 drug-naive patients and 24.4% from 82 pretreated patients) harbored these insertions. Insertions around the KQE (Lys-Gln-Glu) motif were found in 12.2% of the pretreated patients but in none of the drug-naive subjects (P = 0.002). In contrast, insertions around the PTAP (Prol-Thre-Ala-Prol) motif were seen at similar rates ( approximately 15%) among drug-naive and pretreated patients, which supports the idea that they may be natural polymorphisms. 相似文献
65.
Asturias JA Eraso E Arilla MC Gómez-Bayón N Inácio F Martínez A 《International archives of allergy and immunology》2002,128(2):90-96
BACKGROUND: Gastropod consumption is quite frequent in the Mediterranean countries and cross-reactivities with crustaceans have been described, but the mechanism of this allergenic cross-reactivity has not been studied in detail. This study aimed to produce recombinant Helix aspersa (brown garden snail) tropomyosin and investigate its implication for cross-reactivity among invertebrates. METHODS: A tropomyosin-specific cDNA encoding H. aspersa tropomyosin was synthetized, and recombinant allergen was overexpressed in Escherichia coli as nonfusion protein. IgE-binding reactivity was studied by immunoblotting and immunoblot inhibition experiments with sera from snail-allergic patients. RESULTS: Cloned brown garden snail tropomyosin shares high homology with other edible mollusk tropomyosins (84-69% identity) as well as with those from arthropods (65-62%), and less homology with vertebrate ones (56% identity). Tropomyosin reacted with 18% of the sera from patients with snail allergy. Inhibition experiments, using natural and recombinant tropomyosins, showed different degrees of cross-reactivity between invertebrate tropomyosins. Sera from snail-allergic subjects recognized tropomyosins in both mollusks and crustacean extracts. CONCLUSIONS: Tropomyosin represents a minor allergen in snail extracts, but it is clearly involved in invertebrate cross-reactivity. 相似文献
66.
Nascent peptide-mediated translation elongation arrest coupled with mRNA degradation in the CGS1 gene of Arabidopsis 下载免费PDF全文
Onouchi H Nagami Y Haraguchi Y Nakamoto M Nishimura Y Sakurai R Nagao N Kawasaki D Kadokura Y Naito S 《Genes & development》2005,19(15):1799-1810
Expression of the Arabidopsis CGS1 gene that codes for cystathionine gamma-synthase is feedback regulated at the step of mRNA stability in response to S-adenosyl-L-methionine (AdoMet). A short stretch of amino acid sequence, called the MTO1 region, encoded by the first exon of CGS1 itself is involved in this regulation. Here, we demonstrate, using a cell-free system, that AdoMet induces temporal translation elongation arrest at the Ser-94 codon located immediately downstream of the MTO1 region, by analyzing a translation intermediate and performing primer extension inhibition (toeprint) analysis. This translation arrest precedes the formation of a degradation intermediate of CGS1 mRNA, which has its 5' end points near the 5' edge of the stalled ribosome. The position of ribosome stalling also suggests that the MTO1 region in nascent peptide resides in the ribosomal exit tunnel when translation elongation is temporarily arrested. In addition to the MTO1 region amino acid sequence, downstream Trp-93 is also important for the AdoMet-induced translation arrest. This is the first example of nascent peptide-mediated translation elongation arrest coupled with mRNA degradation in eukaryotes. Furthermore, our data suggest that the ribosome stalls at the step of translocation rather than at the step of peptidyl transfer. 相似文献
67.
Two siblings presenting slight mental retardation showed an abnormal elimination of histidine, their blood levels for the same amino acid being normal. The percentage of tubular resorption of histidine was calculated in both boys, and the values were 40.1 per cent (case 1) and 52.8 per cent (case 2). All other amino acids essayed were normal. After an oral overload test with histidine, a low intestinal absorption was found in the two boys, the values of this test in the parents being intermediate between those of the children and of the three normal controls and corresponding to heterozygosity. In view of the studies carried out on the two boys, it is possible to conclude that they are suffering from an impairment in their histidine membrane transport system which affects the kidney and intestines. Since they are siblings a genetically determined trait may be suspected. 相似文献
68.
Campos B Díez O Odefrey F Domènech M Moncoutier V Martínez-Ferrandis JI Osorio A Balmaña J Barroso A Armengod ME Benítez J Alonso C Stoppa-Lyonnet D Goldgar D Baiget M 《Human mutation》2003,21(4):452-452
A frame-shift 9254del5 mutation was independently identified in 12 families, eleven of them with Spanish ancestors, in a BRCA2 screening performed in 841 breast and/or ovarian cancer families and in 339 women with breast cancer diagnosed before the age of 40 at different centers in France and Spain. We sought to analyze in detail the haplotype and founder effects of the 9254del5 and to estimate the time of origin of the mutation. Eight polymorphic microsatellite markers and two BRCA2 polymorphisms were used for the haplotype analyses. The markers were located flanking the BRCA2 gene spanning a region of 6.1 cM. Our results suggest that these families shared a common ancestry with BRCA2 9254del5, which is a founder mutation originating in the Northeast Spanish, with an estimated age of 92 (95% CI 56-141) generations. 相似文献
69.
Marta Pacio Miguez Fernando Santos‐Simarro Sixto García‐Miñaúr Ramón Velázquez Fragua Ángela del Pozo Mario Solís Carmen Jiménez Rodríguez Virginia Rufo‐Rabadán Victoria Eugenia Fernandez Inmaculada Rueda Maria Victoria Gomez del Pozo Natividad Gallego Pablo Lapunzina María Palomares‐Bralo 《American journal of medical genetics. Part A》2020,182(10):2222-2225
70.
Relationships between striatal dopamine denervation and frontal executive tests in Parkinson's disease 总被引:2,自引:0,他引:2
Indirect evidence from human and monkey investigations supports the idea that impaired frontal tasks in Parkinson's disease (PD) may result from striato-frontal disruption caused by dopamine (DA) denervation of the caudate nucleus. To directly investigate this hypothesis, we used PET with 11C-S-Nomifensine (11C-S-NMF), a sensitive marker of striatal DA denervation, in 10 non-demented PD patients in whom two frontal executive tests, the object alternation (OA) and the conditional associative learning (CAL) tasks, thought to reflect mainly set-shifting/inhibition and planning, respectively, were given. In addition, the central executive function of verbal working memory was assessed with the Brown Peterson paradigm (BPP). We found a highly significant correlation between right caudate 11C-S-NMF specific binding and OA performance, less significant and reverse-direction correlations between CAL performance and putamen 11C-S-NMF binding, and no significant correlation with BPP performance. Thus, caudate DA denervation may subtend poor set-shifting/inhibition process in PD. Our results also point to distinct and complex relationships between striatal DA and specific frontal tasks. 相似文献