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排序方式: 共有334条查询结果,搜索用时 15 毫秒
91.
Andrea Fortova Eva Sebestova Veronika Stepankova Tana KoudelakovaLenka Palkova Jiri Damborsky Radka Chaloupkova 《Biochimie》2013
Haloalkane dehalogenases are known as bacterial enzymes cleaving a carbon–halogen bond in halogenated compounds. Here we report the first biochemically characterized non-microbial haloalkane dehalogenase DspA from Strongylocentrotus purpuratus. The enzyme shows a preference for terminally brominated hydrocarbons and enantioselectivity towards β-brominated alkanes. Moreover, we identified other putative haloalkane dehalogenases of eukaryotic origin, representing targets for future experiments to discover dehalogenases with novel catalytic properties. 相似文献
92.
Buchta Vladimír Nekolová Jana Jirásková Naďa Bolehovská Radka Wipler Jan Hubka Vit 《Mycopathologia》2019,184(3):441-453
Mycopathologia - Colletotrichum species are known as important pathogens of plants with an impact on crop production. Some of these species are also known as a cause of rare ophthalmic infections... 相似文献
93.
Arnold JN Saldova R Galligan MC Murphy TB Mimura-Kimura Y Telford JE Godwin AK Rudd PM 《Journal of proteome research》2011,10(4):1755-1764
Lung cancer has a poor prognosis and a 5-year survival rate of 15%. Therefore, early detection is vital. Diagnostic testing of serum for cancer-associated biomarkers is a noninvasive detection method. Glycosylation is the most frequent post-translational modification of proteins and it has been shown to be altered in cancer. In this paper, high-throughput HILIC technology was applied to serum samples from 100 lung cancer patients, alongside 84 age-matched controls and significant alterations in N-linked glycosylation were identified. Increases were detected in glycans containing Sialyl Lewis X, monoantennary glycans, highly sialylated glycans and decreases were observed in core-fucosylated biantennary glycans, with some being detectable as early as in Stage I. The N-linked glycan profile of haptoglobin demonstrated similar alterations to those elucidated in the total serum glycome. The most significantly altered HILIC peak in lung cancer samples includes predominantly disialylated and tri- and tetra-antennary glycans. This potential disease marker is significantly increased across all disease groups compared to controls and a strong disease effect is visible even after the effect of smoking is accounted for. The combination of all glyco-biomarkers had the highest sensitivity and specificity. This study identifies candidates for further study as potential biomarkers for the disease. 相似文献
94.
Bridging global and microregional scales: ploidy distribution in Pilosella echioides (Asteraceae) in central Europe 总被引:1,自引:0,他引:1
Trávnícek P Dockalová Z Rosenbaumová R Kubátová B Szelag Z Chrtek J 《Annals of botany》2011,107(3):443-454
Background and Aims
A detailed knowledge of cytotype distribution can provide important insights into the evolutionary history of polyploid systems. This study aims to explore the spatial distribution of different cytotypes in Pilosella echioides at various spatial scales (from the whole distributional range to the population level) and to outline possible evolutionary scenarios for the observed geographic pattern.Methods
DNA-ploidy levels were estimated using DAPI flow cytometry in 4410 individuals of P. echioides from 46 populations spread over the entire distribution range in central Europe. Special attention was paid to the cytotype structure in the most ploidy-diverse population in south-west Moravia.Key Results
Five different cytotypes (2x, 3x, 4x, 5x and 6x) were found, the last being recorded for the first time. Although ploidy-uniform (di- or tetraploid) sites clearly prevailed, nearly one-quarter of the populations investigated harboured more (up to all five) cytotypes. Whereas penta- and hexaploids constituted only a minority of the samples, a striking predominance of the triploid cytotype was observed in several populations.Conclusions
The representative sampling confirmed previous data on cytotype distribution, i.e. the spatial aggregation of mixed-ploidy populations in south-west Moravia and Lower Austria and the predominance of ploidy-uniform populations in other parts of the area investigated. Recurrent origin of polyploids from diploid progenitors via unreduced gametes and their successful establishment are considered the key factors promoting intrapopulational ploidy mixture (‘primary hybrid zones’). As an alternative to the generally accepted theory of cytotype co-existence based on the development of different means of inter-ploidy reproductive isolation, it is suggested that a long-term ploidy mixture can also be maintained in free-mating populations provided that the polyploids originate with a sufficient frequency. In addition, the prevalence (or subdominance) of the triploid cytotype in several mixed-ploidy populations represents the first evidence of such a phenomenon in plant systems with exclusively sexual reproduction. 相似文献95.
Schmidt SA Dillon S Kolouchova R Henschke PA Chambers PJ 《Applied microbiology and biotechnology》2011,91(2):365-375
Chardonnay, being the predominant white wine-grape cultivar in the Australian wine sector, is subject to widely varying winemaking
processes with the aim of producing a variety of wine styles. Therefore, juice composition might not always be ideal for optimal
fermentation outcomes. Our aim was to better understand the composition of Chardonnay juice and how compositional parameters
impact on fermentation outcomes. This was achieved through a survey of 96 commercially prepared Chardonnay juices during the
2009 vintage. Common juice variables were estimated using near infrared spectroscopy, and elemental composition was determined
using radial view inductively coupled plasma optical emission spectrometry. The influence of elemental composition on fermentation
outcomes was assessed by fermentation of a defined medium formulated to reflect the composition and range of concentrations
as determined by the juice survey. Yeast (Saccharomyces cerevisiae) strain effects were also assessed. Key parameters influencing fermentation outcomes were verified by laboratory scale fermentation
of Chardonnay juice. This exploration of Chardonnay juice identified interactions between juice pH and potassium concentration
as key factors impacting on fermentation performance and wine quality. Outcomes differed depending on yeast strain. 相似文献
96.
Pekárová B Klumpler T Třísková O Horák J Jansen S Dopitová R Borkovcová P Papoušková V Nejedlá E Sklenář V Marek J Zídek L Hejátko J Janda L 《The Plant journal : for cell and molecular biology》2011,67(5):827-839
Multistep phosphorelay (MSP) signaling mediates responses to a variety of important stimuli in plants. In Arabidopsis MSP, the signal is transferred from sensor histidine kinase (HK) via histidine phosphotransfer proteins (AHP1–AHP5) to nuclear response regulators. In contrast to ancestral two‐component signaling in bacteria, protein interactions in plant MSP are supposed to be rather nonspecific. Here, we show that the C‐terminal receiver domain of HK CKI1 (CKI1RD) is responsible for the recognition of CKI1 downstream signaling partners, and specifically interacts with AHP2, AHP3 and AHP5 with different affinities. We studied the effects of Mg2+, the co‐factor necessary for signal transduction via MSP, and phosphorylation‐mimicking BeF3? on CKI1RD in solution, and determined the crystal structure of free CKI1RD and CKI1RD in a complex with Mg2+. We found that the structure of CKI1RD shares similarities with the only known structure of plant HK, ETR1RD, with the main differences being in loop L3. Magnesium binding induces the rearrangement of some residues around the active site of CKI1RD, as was determined by both X‐ray crystallography and NMR spectroscopy. Collectively, these results provide initial insights into the nature of molecular mechanisms determining the specificity of MSP signaling and MSP catalysis in plants. 相似文献
97.
98.
Presence of mutated and/or structurally modified (e.g., denatured, aggregated) protein p53 form is associated with several
disorders such as Alzheimer’s disease, Parkinson’s disease, prion diseases, and many types of tumours. The aim of this work
was to distinguish native, denatured and aggregated form of full-length p53 by flow injection analysis coupled with electrochemical
detector (FIA-ED). Firstly FIA-ED method used for protein native form determination was optimized (detection limit 45.8 amol
per 5 μl injection; 3×S/N). In addition the technique was applied to identify p53 structural forms (denatured and aggregated).
It was found out that denatured form provides about three times higher electrochemical response (protein structure unfolding,
approach of more electroactive centers – aminoacid residues – towards electrode surface) in comparison with native form. On
the other hand, aggregated form offers lower response (steric eclipse of electroactive protein parts) when compared with the
signal of native form. The obtained data show that we are not only able to sensitively determine native, denatured, and aggregated
structural forms of p53 protein but also to distinguish them. 相似文献
99.
Tvrzová L Prokop Z Navrátilová J Müllerová R Neca J 《Journal of microbiological methods》2006,65(3):551-556
A microtiter plate-based assay was developed for the automatic monitoring of degradation profile of the yellow-coloured nitrophenolic compounds. The method enables to reduce the intervals between measurements of substrate concentration to minutes and to overcome the problem of discontinuity of sampling typical for conventional methods. The concentrations of nitrophenolic compounds were calculated from the absorbance values determined automatically by BIOSCREEN C. Verification of the method was based on the comparison of results with the conventional HPLC method results. The values of the rate and saturation constants were comparable for both the microtiter plate-based assay and the conventional HPLC method. The automatic method described here seems to be efficient for the screening degradation studies, which requires the treatment of quantity of samples. 相似文献
100.