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951.
Livigni A Scorziello A Agnese S Adornetto A Carlucci A Garbi C Castaldo I Annunziato L Avvedimento EV Feliciello A 《Molecular biology of the cell》2006,17(1):263-271
AKAP121 focuses distinct signaling events from membrane to mitochondria by binding and targeting cAMP-dependent protein kinase (PKA), protein tyrosine phosphatase (PTPD1), and mRNA. We find that AKAP121 also targets src tyrosine kinase to mitochondria via PTPD1. AKAP121 increased src-dependent phosphorylation of mitochondrial substrates and enhanced the activity of cytochrome c oxidase, a component of the mitochondrial respiratory chain. Mitochondrial membrane potential and ATP oxidative synthesis were enhanced by AKAP121 in an src- and PKA-dependent manner. Finally, siRNA-mediated silencing of endogenous AKAP121 drastically impaired synthesis and accumulation of mitochondrial ATP. These findings indicate that AKAP121, through its role in enhancing cAMP and tyrosine kinase signaling to distal organelles, is an important regulator in mitochondrial metabolism. 相似文献
952.
Annalisa Miele Paola Giardina Eugenio Notomista Alessandra Piscitelli Giovanni Sannia Vincenza Faraco 《Molecular biotechnology》2010,46(2):149-156
In order to develop improved laccase-based bio-catalysts, semi-rational mutagenesis of the laccase POXA1b from Pleurotus ostreatus was performed through a combination of directed evolution with elements of rational enzyme modification. The R4 laccase was
prepared by joining mutations of previously selected POXA1b random variants. An enhancement of stability features was thus
obtained, making the novel enzyme R4 more appropriate as scaffold for directed evolution. A library of 1000 randomly mutated
variants of R4 was prepared and screened for the ability of oxidising 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)
(ABTS). One of the variants selected (V148L) for improved activity was also proved to show higher stability than R4 at pH
5, and to retain its high stability at pH 7 and 10. In comparison with the POXA1b wild-type laccase, the semi-rational approach
allowed us to develop a more efficient bio-catalyst, rising specific activity on ABTS up to around 5-fold. The new variant
was also proved to be both more versatile and more durable than the wild-type enzyme, exhibiting higher activity in wide temperature
and pH ranges and higher stability at acidic (t
1/2 at pH 5 = 35 days), neutral (t
1/2 at pH 7 = 38 days) and alkaline (t
1/2 at pH 10 = 62 days) pH values. 相似文献
953.
Annalisa Tassoni Nello Bagni Maura Ferri Marina Franceschetti Alex Khomutov Maria Paula Marques Sonia M. Fiuza Alina R. Simonian Donatella Serafini-Fracassini 《Plant Physiology and Biochemistry》2010,48(7):496-505
The earliest studies concerning polyamines (PAs) in plants were performed by using in vitro cultured explants of Helianthus tuberosus dormant tuber. This parenchyma tissue was particularly useful due to its susceptibility to several growth substances, including PAs. During tuber dormancy, PA levels are too low to sustain cell division; thus Helianthus represents a natural PA-deficient model. When cultivated in vitro in the presence of auxins, Helianthus tuber dormant parenchyma cells at the G0 stage start to divide synchronously acquiring meristematic characteristics. The requirement for auxins to induce cell division can be substituted by aliphatic PAs such as putrescine, spermidine or spermine. Cylinders or slices of explanted homogeneous tuber parenchyma were cultured in liquid medium for short-term studies on the cell cycle, or on solid agar medium for long-term experiments. Morphological and physiological modifications of synchronously dividing cells were studied during the different phases of the cell cycle in relation to PAs biosynthesis and oxidation. Long-term experiments led to the identification of the PAs as plant growth regulators, as the sole nitrogen source, as tuber storage substances and as essential factors for morphogenetic processes and cell homeostasis. More recently this system was used to study the effects on plant cell proliferation of platinum- or palladium-derived drugs (cisplatin and platinum or palladium bi-substituted spermine) that are used in human cancer cell lines as antiproliferative and cytotoxic agents. Cisplatin was the most active both in cell proliferation inhibition and on PA metabolism. Similar experiments were performed using three agmatine analogous. Different effects of these compounds were observed on cell proliferation, free PA levels and enzyme activities, leading to a hypothesis of a correlation between their chemical structure and the agmatine metabolism in plants. 相似文献
954.
Study on the conversion of wool keratin by steam explosion 总被引:1,自引:0,他引:1
Tonin C Zoccola M Aluigi A Varesano A Montarsolo A Vineis C Zimbardi F 《Biomacromolecules》2006,7(12):3499-3504
A wool fiber sample was submitted to chemical-free steam explosion in view of potential exploitation of keratin-based industrial and farm wastes. Fiber keratin was converted into a dark-yellow sludge that was submitted to phase separation by filtration, centrifugation, and precipitation of the soluble materials from the supernatant liquid. The resulting products, when compared with the original wool, showed the extent of disruption of the histology structure, reduction of the molecular weight to water-soluble peptides and free amino acids, and change of the structure of the remainder of the protein associated with breaking of disulfide bonds and decomposition of the high-sulfur-content protein fraction. 相似文献
955.
956.
Mini R Bernardini G Salzano AM Renzone G Scaloni A Figura N Santucci A 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2006,833(1):63-79
Helicobacter pylori is a Gram-negative bacterium which causes ulcer, atrophic gastritis, adenocarcinoma, or mucosa-associated lymphoid tissue lymphoma. A comparative proteomic and immunoproteomic analysis was chosen to identify the antigenic patterns of three different H. pylori strains. These strains were probed against single sera from H. pylori-positive patients affected by gastric adenocarcinoma or duodenal ulcer. We found a quite heterogeneous antigenic pattern, both from strain and sera points of view, thus underlying both a strain- and a host-specificity. The different antigenic repertoires introduced the importance of the strain to be used for immunoblotting as a diagnostic test. 相似文献
957.
958.
Licia Colli Annalisa Paglianti Roberto Berti Gilberto Gandolfi James Tagliavini 《Environmental Biology of Fishes》2009,84(1):95-107
The phylogenetic relationships of two cavefish, Phreatichthys andruzzii and Garra barreimiae, belonging to the family Cyprinidae, were investigated by sequencing the mitochondrial cytochrome b gene. These cavefish
species are native to Somalia (eastern Africa) and Oman (southeastern Arabian peninsula), respectively, and so far no molecular
support to their taxonomy and phylogenetic position was ever provided. The analysis of cytochrome b sequences showed that
the species are monophyletic taxa, closely related to each other and to other species of the genus Garra. Molecular clock calculations allowed to date the origin of these hypogaean species back to the Plio-Pleistocene and support
the hypothesis that African cyprinids originated from Miocenic immigrations of Asian ancestors. 相似文献
959.
960.
Jana Koperdáková Hedviga Komarovská Ján Košuth Annalisa Giovannini Eva Čellárová 《Acta Physiologiae Plantarum》2009,31(2):351-358
Hairy root-regenerated clones of Hypericum perforatum L. grown in vitro similarly to those successfully adapted to ex vitro conditions showed phenotype features typical for plants
transformed with Agrobacterium rhizogenes T-DNA. These included reduced apical dominance, increased branching, dwarfing and reduced fertility. Transgenic clones differed
in ability to develop root system as a necessary condition for transfer to the soil. One of the profiling characters, capability
of hypericin biosynthesis was altered as well. Dark glands as the sites of hypericin accumulation and/or synthesis exhibited
significantly higher densities on both, leaves and petals of transgenic clones comparing to controls. In the genome of transgenic
clones, rolABC genes were detected. Both clones harboured similar copy number of individual rol genes. However, copy numbers descended from rolA to rolC gene in both clones. 相似文献