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排序方式: 共有207条查询结果,搜索用时 15 毫秒
1.
2.
Sonia Coni Silvia Maria Serrao Zuleyha Nihan Yurtsever Laura Di Magno Rosa Bordone Camilla Bertani Valerio Licursi Zaira Ianniello Paola Infante Marta Moretti Marialaura Petroni Francesca Guerrieri Alessandro Fatica Alberto Macone Enrico De Smaele Lucia Di Marcotullio Giuseppe Giannini Marella Maroder Enzo Agostinelli Gianluca Canettieri 《Cell death & disease》2020,11(12)
3.
Polyamines and Anaerobic Elongation of Rice Coleoptile 总被引:2,自引:0,他引:2
The role of polyamines in the anaerobic elongation of rice (Oryzasativa L.) coleoptiles was studied. The reduced growth of ricecoleoptiles under anoxic conditions was accompanied by a massiveaccumulation of free putrescine. Putrescine was synthesizedfrom arginine in a reaction catalyzed by arginine decarboxylase(ADC). The anoxic titer of putrescine was closely correlatedwith elongation of coleoptiles. In experiments in which putrescineand inhibitors [-difluoromethylarginine (DFMA) and -difluoromethylornithine(DFMO)] of the synthesis of polyamines were exogenously supplied,we demonstrated an absolute requirement for putrescine, synthesizedby ADC, for anaerobic elongation of coleoptiles. The presenceof exogenous putrescine (alone or in combination with DFMA)increased the rate of anaerobic elongation of coleoptile by3040%. (Received December 1, 1988; Accepted June 19, 1989) 相似文献
4.
Reggiani Remo; Cantu Carlo Alberto; Brambilla Ida; Bertani Alcide 《Plant & cell physiology》1988,29(6):981-987
In excised rice roots, anaerobic degradation of proteins gaverise to an increase of free-amino acids. Anoxic accumulationof alanine, -aminobutyric acid and proline was the consequenceof the interconversion of glutamate, aspartate and amides. Theshift in the composition of the amino acid pool appears to becaused by changes in keto acid levels. The role of reactionsinvolved in amino acid interconversion and the physiologicalsignificance of these interconversions are considered and discussed. (Received November 25, 1988; Accepted June 9, 1988) 相似文献
5.
Umberto Belluco Roberta Bertani Rino A. Michelin Mirto Mozzon Franco Benetollo Gabriella Bombieri Robert J. Angelici 《Inorganica chimica acta》1995,240(1-2):567-574
The chloro complexes trans-[Pt(Me)(Cl)(PPh3)2], after treatment with AgBF4, react with 1-alkynes HC---C---R in the presence of NEt3 to afford the corresponding acetylide derivatives trans-[Pt(Me) (C---C---R) (PPh3)2] (R = p-tolyl (1), Ph (2), C(CH3)3 (3)). These complexes, with the exception of the t-butylacetylide complex, react with the chloroalcohols HO(CH2)nCl (n = 2, 3) in the presence of 1 equiv. of HBF4 to afford the alkyl(chloroalkoxy)carbene complexes trans-[Pt(Me) {C[O(CH2)nCl](CH2R) } (PPh3)2][BF4] (R = p-tolyl, N = 2 (4), N = 3 (5); R=Ph, N = 2 (6)). A similar reaction of the bis(acetylide) complex trans-[Pt(C---C---Ph)2(PMe2Ph)2] with 2 equiv. HBF4 and 3-chloro-1-propanol affords trans-[Pt(C---CPh) {C(OCH2CH2CH2Cl)(CH2Ph) } (PMe2Ph)2][BF4] (7). T alkyl(chloroalkoxy)-carbene complex trans-[Pt(Me) {C(OCH2CH2Cl)(CH2Ph) } (PPh3)2][BF4] (8) is formed by reaction of trans-[Pt(Me)(Cl)(PPh3)2], after treatment with AgBF4 in HOCH2CH2Cl, with phenylacetylene in the presence of 1 equiv. of n-BuLi. The reaction of the dimer [Pt(Cl)(μ-Cl)(PMe2Ph)]2 with p-tolylacetylene and 3-chloro-1-propanol yields cis-[PtCl2{C(OCH2CH2CH2Cl)(CH2C6H4-p-Me}(PMe2Ph)] (9). The X-ray molecular structure of (8) has been determined. It crystallizes in the orthorhombic system, space group Pna21, with a = 11.785(2), B = 29.418(4), C = 15.409(3) Å, V = 4889(1) Å3 and Z = 4. The carbene ligand is perpendicular to the Pt(II) coordination plane; the PtC(carbene) bond distance is 2.01(1) Å and the short C(carbene)-O bond distance of 1.30(1) Å suggests extensive electronic delocalization within the Pt---C(carbene)---O moietry. 相似文献
6.
L. Elizabeth Bertani 《Molecular & general genetics : MGG》1980,178(1):91-99
Summary The excision of prophage P2 is controlled by two genes, int and cox. (The cox gene discussed in this report is defined by the cox class II mutants, defined by Six and Lindqvist, 1978). The combined activity of these two genes is rather inefficient, however, since only about 1% of the lysogens carrying an int
+
cox
+ prophage actually produce phage when derepressed. The efficiency of phage production (and presumably excision) can be increased 100-fold by an additional mutation called nip1 (Calendar et al., 1972), which is dominant and is located in or near the int gene.The nip1 mutation was mapped between c5, a mutation in the C gene, and an amber int mutation, int150. Phages carrying nip1 and either int150 or a cox mutation, cox3, were prepared by recombination. The nip1 mutation was found to increase excision only when it was located on the same chromosome as an active int
+ gene and only if cox
+ gene product was also available. The cox gene, known to be located between genes B and C (Lindahl and Sunshine, 1972), was further localized to a region between 77.2 to 78.1% from the conventional left end of the P2 chromosome by comparing the ability of phages with overlapping deletions to promote excision of the prophage in a P2 nip1 c5 cox3 lysogen.Other features of the integration-excision system in P2 are discussed. 相似文献
7.
Summary A deletion of phage P2, del6 (L.E. Bertani, 1980), thought to remove the structural gene int, and a deletion/substitution, vir94, thought to remove genes int, C and cox, were mapped by electron microscopy, using the heteroduplex technique.Four independent deletion/substitution mutations, all affecting the regulatory region of P2, were compared in all possible combinations with the same technique: two showed sequence homology in their substitution DNA. The results confirm the model proposed for the origin of these mutants, analogous to that for the origin of transducing variants in phage , but suggest in first approximation that the exchange between the P2 DNA and the chromosome of the host bacterium may occur at several different bacterial sites.A map of the regulatory region of P2, based on all data available from the study of deletions and insertions, is presented. 相似文献
8.
Tandem pentuplication of a DNA segment in a derivative of bacteriophage P2: its use in the study of the mechanism of DNA annealing. 总被引:2,自引:0,他引:2 下载免费PDF全文
From a tandem duplication mutant of phage P2, triplication, quadruplication and pentuplication forms were derived. They were recognized by decreased virion heat stability resulting from the increase in DNA content, and were confirmed by electron microscope heteroduplex mapping. These forms of partially repeated DNA are quite stable in P2 because of the low level of recombination typical of this phage. Under conditions normally employed for full DNA renaturation, these high order repeat chromosomes gave often incomplete renaturation over the repeated segments. Based on current models for DNA renaturation, several predictions were made and tested. The results, although not quantitatively exhaustive, indicated that base pairing proceeding from a nucleation site was sufficiently slow to allow a second nucleation to occur with a fair probability over a length of a few thousand base pairs. 相似文献
9.
Summary Bacteriophage P2 is known for its exceptionally low rate of spontaneous (non-integrative) recombination, which however may be stimulated by ultraviolet irradiation of the phage. We show here that ligated dimers, made in vitro from mixtures of DNAs of two P2 mutants, upon transfection of lysozyme-spheroplasts give origin to recombinants at high frequency. While spontaneous P2 recombination occurs independently of the main recombination pathway of the bacteria, P2 recombinant formation following either ultraviolet irradiation or transfection with DNA dimers requires at least some element of such a pathway, since it is absent or greatly reduced in recA
- bacteria or spheroplasts. It would seem that, in the course of its lytic development, P2 deploys a mechanism that inhibits the main recombination pathway of the host cell, or assumes DNA configurations refractory to it. 相似文献
10.
Diego Ribeiro Migueis Ortega Roberto Hiroaki Nagahama Paulo Cesar Motta Rogério Bertani 《ZooKeys》2013,(352):93-116
The mygalomorph neotropical genus Fufius Simon, 1888 comprises ten species, distributed from Guatemala in Central America to southeastern Brazil, in South America. Most of the species were described from northern South America, in the Amazonian region. Only F. funebris Vellard, 1924 and F. lucasae Guadanucci & Indicatti, 2004 are known from regions more to the south of the continent. Herein we describe three new Brazilian species, Fufius minusculus
sp. n. and F. jalapensis
sp. n. from the state of Tocantins, and F. candango
sp. n. from Distrito Federal. The female of F. lucasae is described for first time and the male and female of F. funebris are redescribed based on specimens collected at the type locality. 相似文献