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1.
Ruth Duncan Pavla Rejmanova Jindrich Kopeček John B. Lloyd 《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,678(1):143-150
Synthetic 125I-labelled N-(2-hydroxypropyl)methacrylamide copolymers containing four different, potentially degradable peptidyl side chains were incubated with rat visceral yolk sacs cultured in vitro. All copolymers were captured by fluid-phase pinocytosis and three of the side chains were susceptible to lysosomal hydrolysis, resulting in release of [125I]iodotyrosine back into the culture medium. Uptake and degradation was completely inhibited by 2,4-dinitrophenol. The thiol-proteinase inhibitor leupeptin did not affect the rate of pinocytosis, but caused different degrees of inhibition of hydrolysis depending on side chain composition. 相似文献
2.
Group A streptococcus is a Gram-positive bacteria that causes a range of infectious diseases. Targeting the bacteria, a new self-adjuvanting vaccine candidate, incorporating a carbohydrate carrier and an amino acid-based adjuvant, was synthesised utilising carbohydrate chemistry and solid-phase peptide synthesis procedures. Characterisation of the candidate was achieved using reverse-phase HPLC and electrospray ionisation mass spectrometry. The successful synthesis and characterisation of the vaccine candidate may contribute to the discovery of a therapeutically and clinically viable vaccine against group A streptococcus. 相似文献
3.
Aryl sulfamates were originally developed as inhibitors of steroid sulfatase, and have recently been shown to be powerful inactivators of a bacterial sulfatase, PaAtsA from Pseudomonas aeruginosa. We demonstrate that a simple aryl sulfamate, 3-nitrophenyl sulfamate, can inactivate sulfatases from various sources including snail, limpet and abalone. In each case inactivation was time-dependent and active-site directed, as demonstrated by protection against inactivation by substrate. These results suggest that such easily acquired aryl sulfamates can be used as reliable biochemical reagents for the study of sulfatases from a diverse array of sources. 相似文献
4.
Evaluation and indirect estimation of nitrate losses from the agricultural microbasin Rybárik 总被引:1,自引:0,他引:1
The long-term trends of mean monthly nitrate concentrations in stream and drainage runoff were evaluated in the experimental
microbasin Rybárik (0.119 km2) at the Institute of Hydrology, Slovak Academy of Sciences, during the period 1987–2005. The results of analyses indicate
a decreasing trend of nitrate concentration after the year 1989, but with relatively high losses in some years and relatively
low losses in other years. This decreasing trend is mainly caused by a decrease in the use of nitrogen fertilizers. The nitrate
concentration in surface runoff strongly correlates with runoff and fertilization. Based on measured data, an empirical relation
was found describing the dependence of annual nitrate transport in the stream on annual runoff depth and on the annual amount
of applied nitrogen fertilizers.
Presented at the International Conference on Bioclimatology and Natural Hazards, Poľana nad Detvou, Slovakia, 17–20 September
2007. 相似文献
5.
The recurrent drying out of small streams in past decades has shown an urgent need to pay attention to the impact of global
climate change. The objectives of this study were to describe the effect of drying out on the composition of the mayfly taxocene
and evaluate the relevance of individual species traits for survival of mayflies to drying out. The mayfly taxocenes of two
model localities, one at an intermittent and one at a permanent brook, were investigated in 2002, 2003 and 2005. Compared
with the permanent stream, the taxocene of the intermittent stream was short of nine species, foremost rheobionts and high
oxygen demand species. To explain further differences between both stream types in survival and recolonisation ability, 15
species traits were evaluated. These included so-called “ecological traits” (e.g., habitat and substrate range, density, distribution,
current velocity adaptation) and “biological traits” connected with life cycle and larval/adult adaptations. Species showing
the highest number of advantageous traits (with only exception of Electrogena sp. cf. ujhelyii — species of taxonomically unclear status) were able to successfully survive under the unfavourable conditions of the intermittent
brook. Biological traits considered more important in many respects seem to be good predictors for assessing sensitivity to
extreme temperature changes, hydrological regime fluctuations and the survival/recolonisation ability of species in exposed
habitats. 相似文献
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The effect of reactive oxygen species on motility parameters,DNA integrity,tyrosine phosphorylation and phosphatase activity of common carp (Cyprinus carpio L.) spermatozoa 下载免费PDF全文
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