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排序方式: 共有2999条查询结果,搜索用时 359 毫秒
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G Amiconi E Antonini M Brunori E Chiancone P Vecchini 《The Journal of biological chemistry》1971,246(6):1883-1888
3.
E Lendaro R Ippoliti A Brancaccio A Bellelli B Vallone G Ivaldi G V Sciarratta C Castello S Tomova M Brunori 《Biochimica et biophysica acta》1992,1180(1):15-20
Hemoglobin Dallas, an alpha-chain variant with a substitution of lysine for asparagine at position 97(G4), was found to have increased oxygen affinity (p1/2 = 1 mmHg at pH 7.3 and 20 degrees C), diminished cooperativity (n, the Hill coefficient = 1.7) and reduced Bohr effect (about 50%). Addition of allosteric effectors (such as 2,3-diphosphoglycerate, inositol hexakisphosphate and bezafibrate) led to a decrease in oxygen affinity and increase in cooperative energy. Kinetic studies at pH 7.0 and 20 degrees C revealed that (i), the overall rate of oxygen dissociation is 1.4-fold slower than that for HbA and (ii), the carbon monoxide dissociation rate is unaffected. The abnormal properties of this hemoglobin variant can be attributed to a more 'relaxed' T-state. 相似文献
4.
Lodovica Vergani Marina Fanin Andrea Martinuzzi Andrea Galassi Andrea Appi Rosalba Carrozzo Maurizio Rosa Corrado Angelini 《Molecular and cellular biochemistry》1990,98(1-2):225-230
Summary FABPs in the various tissues play an important role in the intracellular fatty acid transport and metabolism. Reye's syndrome (RS) and multisystemic lipid storage (MLS) are human disorders characterized by a disturbance of lipid metabolism of unknown etiology. We investigated for the first time L-FABP in these two conditions. Affinity purified antibodies against chicken L-FABP were raised in rabbits, and found to cross-react specifically with partially purified human L-FABP. L-FABP content in liver samples of two patients with RS and MLS was investigated by immuno-histochemistry, SDS-PAGE and ELISA. L-FABP immuno-histochemistry showed increased reactivity in the liver of RS patient and normal reactivity in MLS liver. L-FABP increase in RS liver was confirmed by densitometry of SDS-PAGE and ELISA method. By these two methods the increase amounted to 180% and 199% (p < 0.02), respectively, as compared to controls. A possible role of L-FABP in the pathogenesis of RS is discussed. 相似文献
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6.
Johan R. Michaux† Joëlle Goüy De Bellocq‡ Maurizio SarৠSerge Morand‡ 《Global Ecology and Biogeography》2002,11(5):427-436
Insular mammalian populations living in areas of small size are often characterized by a drastic change in body mass compared to related continental populations or species. Generally, small mammals (less than 100 g) evolve into giant forms while large mammals (up to 100 g) evolve into dwarf forms. These changes, coupled with changes in other life, behavioural, physiological or demographic traits are referred to generally as the insular syndrome. We tested in this study the relative contribution of three factors — area of island, numbers of competitor species and number of predator species — to changes in body size of the woodmouse (Apodemus sylvaticus) in the Western Mediterranean Sea. Our results, based on a comparative analysis using the phylogenetic independent contrasts method, indicate that the increase in body size is related both to the decrease of island size and to the lower number of predator species. A decrease of competitor species does not seem to have an important effect. 相似文献
7.
Fioretta Rambelli Maurizio Brigotti Simonetta Sperti Lucio Montanaro 《Bioscience reports》1987,7(9):737-743
Diphtheria toxin fragment A interacts with Cibacron blue in solution, although it is not retained by blue Sepharose columns. Difference spectral titration of fragment A with the dye gives a dissociation constant of the order of 10–5 M and a 11 stoichiometry for the complex. In equilibrium dialysis experiments Cibacron blue behaves as a competitive inhibitor of the binding of NAD to diphtheria toxin fragment A. The dye inhibits in a non-competitive way the fragment A-catalysed transfer of ADP-ribose from NAD to elongation factor 2 (EF2). By affinity chromatography on blue Sepharose a binding of EF2 and of ADP-ribosyl-EF2 with the dye is also demonstrated. GDP, GTP and GDP(CH2)P are able to displace EF2 from blue Sepharose. 相似文献
8.
Cytochrome-c oxidase. Subunit structure and proton pumping 总被引:5,自引:0,他引:5
M Brunori G Antonini F Malatesta P Sarti M T Wilson 《European journal of biochemistry》1987,169(1):1-8
This article reviews the significance of the subunit structure of cytochrome-c oxidase in proton pumping and in particular summarizes available evidences for or against a role of subunit III in the control of this important function of the enzyme. 相似文献
9.
A Bellelli M Brunori S G Condò B Giardina 《The Journal of biological chemistry》1987,262(6):2624-2629
The properties of human hemoglobin reacted with 2-nor-2-formylpyridoxal 5'-phosphate, a bifunctional derivative of pyridoxal 5'-phosphate, have been investigated both from an equilibrium and kinetic point of view. The experimental data, interpreted in terms of the two-state allosteric model, indicate that a perturbed R state is characteristic of this modified low ligand affinity hemoglobin. In flash photolysis experiments, a quickly reacting component is always observed, in spite of the lack of dissociation into free dimers; this kinetic behavior is thought to reflect the presence of functionally independent alpha beta dimers, still connected by the flexible cross-link but forming an open hemoglobin tetramer. Two possible models for the interpretation of the kinetics of CO and/or haptoglobin binding are presented and discussed. 相似文献
10.
Fiorenzo A. Peverali Maurizio D'Esposito Dario Acampora Giuseppe Bunone Mario Negri Antonio Faiella Anna Stornaiuolo Maria Pannese Enrica Migliaccio Antonio Simeone Giuliano Della Valle Edoardo Boncinelli 《Differentiation; research in biological diversity》1990,45(1):61-69
Mammalian genes containing a class-I homeobox (HOX genes) are highly expressed in the embryonic nervous system. As a first step towards the molecular analysis of the role these genes play in neural cells, we studied the expression of four human HOX genes in five neuroblastoma (NB) cell lines - SK-N-BE, CHP-134, IMR-32, SK-N-SH and LAN-1 - during the process of differentiation induced by treatment with retinoic acid (RA). The four genes, HOX1D, 2F, 3E and 4B, located at corresponding positions in the four HOX loci, share a high degree of sequence similarity with the Drosophila Deformed homeotic gene and constitute a homology group, group 10. One of these genes, HOX1D, is not expressed in the cells used, whereas the other three are highly expressed in untreated and RA-induced NB cells, even though the expression pattern in the various lines is slightly different for the three genes. Our analysis reveals a complex and specific expression pattern in these lines, paving the way to an identification of different NB-cell populations by means of specific HOX gene expression schemes. On the other hand, in every line studied, morphological maturation toward a neuronal differentiated phenotype appears to be associated with increased HOX gene expression. 相似文献