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Metabolic enzymes that bind RNA: yet another level of cellular regulatory network?

100%
Cieśla J.
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EN
Several enzymes that were originally characterized to have one defined function in intermediatory metabolism are now shown to participate in a number of other cellular processes. Multifunctional proteins may be crucial for building of the highly complex networks that maintain the function and structure in the eukaryotic cell possessing a relatively low number of protein-encoding genes. One facet of this phenomenon, on which I will focus in this review, is the interaction of metabolic enzymes with RNA. The list of such enzymes known to be associated with RNA is constantly expanding, but the most intriguing question remains unanswered: are the metabolic enzyme-RNA interactions relevant in the regulation of cell metabolism? It has been proposed that metabolic RNA-binding enzymes participate in general regulatory circuits linking a metabolic function to a regulatory mechanism, similar to the situation of the metabolic enzyme aconitase, which also functions as iron-responsive RNA-binding regulatory element. However, some authors have cautioned that some of such enzymes may merely represent "molecular fossils" of the transition from an RNA to a protein world and that the RNA-binding properties may not have a functional significance. Here I will describe enzymes that have been shown to interact with RNA (in several cases a newly discovered RNA-binding protein has been identified as a well-known metabolic enzyme) and particularly point out those whose ability to interact with RNA seems to have a proven physiological significance. I will also try to depict the molecular switch between an enzyme's metabolic and regulatory functions in cases where such a mechanism has been elucidated. For most of these enzymes relations between their enzymatic functions and RNA metabolism are unclear or seem not to exist. All these enzymes are ancient, as judged by their wide distribution, and participate in fundamental biochemical pathways.
2
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The unconventional single stage hydrolysis of potato starch

100%
Słomińska L., Zielonka R., Jarosławski L.
Polish Journal of Chemical Technology
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2013
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vol. 15
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issue 3
7-14
EN
Enzymatic depolymerisation of starch to glucose or maltose is carried out by starch- degrading amylases during a two-stage hydrolysis: liquefaction using bacterial α-amylase followed by saccharification with glucogenic (fungal amylase) or maltogenic (fungal or bacterial) amylases. As a rule, these enzymes are applied separately, following the recommendations concerning their action provided by the enzyme manufacturers. The study presents our attempts to determine the reaction conditions for a simultaneous action of liquefying and saccharifying enzymes on pre-treated potato starch. Hydrolysis was run by Liquozyme Supra, Maltogenase 4000L and San Super 360L enzymes (Novozymes) at different temperatures. During the single-stage method of starch hydrolysate production the most desirable results was obtained for the maltose hydrolysate at 80°C (51.6 DE) and for the glucose hydrolysate at 60°C (96 DE). The analyses indicate that the application of a single-stage hydrolysis of starch to maltose or glucose makes it possible to obtain a degree of starch saccharification comparable with that obtained in the traditional two-stage hydrolysis.
3
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Biochemical and electrophoretic analyses of saliva from the predatory reduviid species Rhynocoris marginatus (Fab.)

75%
Kitherian S., Muthukumar S., Rivers D.
Acta Biochimica Polonica
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2013
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vol. 60
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issue 1
91-97
EN
The saliva of Rhynocoris marginatus consists of amylase, invertase, trehalase, protease, acid phosphatase, alkaline phosphatase, phospholipase, lipase, trypsin, hyaluronidase, and esterase. All enzyme activities were significantly higher in the saliva of female R. marginatus when compared to the saliva of male individuals. The saliva was analyzed by tricine SDS/PAGE, sephadex column chromatography, FT-IR, and MALDI-TOF. The pH of the saliva was slightly alkali. The SDS/PAGE revealed a few proteins with molecular masses greater than 29.5 and 36.2 kDa for male and female predator saliva respectively. The FT-IR spectrum confirmed the acidic, proteinaceous, enzymatic, and aromatic nature of the saliva. The MALDI-TOF-MS revealed the presence of enzymes, proteins, peptides, and other biomolecules. The most prominent peptides were named as RmIT-1 (3.79kDa), RmIT-2 (9.7kDa), and RmIT-3 (10.94kDa) (Rhynocoris marginatus Insect Toxin). Further studies are underway to isolate and identify these biomolecules.
4
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Enzyme activity: acetylcholinesterase and glucose-6-phosphate dehydrogenase in winter swimmers

63%
Piech M., Ptaszek B., Teległów A., Marchewka J., Mardyła M.
Medical Rehabilitation
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2017
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vol. 21(4)
38-42
PL
Cel badań: Celem pracy było wykazanie zmian aktywności acetylocholinesterazy (AChE) i dehydrogenazy glukozo-6-fosforanowej (G-6-PD) u „Morsów” między końcem (kwiecień) a początkiem następnego sezonu morsowego (listopad). Materiał i metodyka: Grupę badaną stanowiło 16 „Morsów” (nietrenujący mężczyźni) z Krakowskiego Klubu Morsów „Kaloryfer”, regularnie poddający się zanurzeniu w zimnej wodzie o temperaturze 2-7,2ºC na czas nie dłuższy niż 3 minuty podczas sezonu morsowego. Badania przeprowadzano po zakończeniu oraz przed rozpoczęciem kolejnego sezonu zimowego przy użyciu metody spektrofotometrycznej. Wyniki: Analizując średnie wartości enzymów po (kwiecień) i przed kolejnym (listopad) sezonem zimowych kąpieli zanotowano zmniejszenie aktywności AChE [U/gHb] o 18,26% i G-6-PD [U/gHb] o 22,11% u mężczyzn korzystających z zimowych kąpieli. Wnioski: Regularne korzystanie z zabiegów zimowych kąpieli wpływa na zwiększenie aktywności enzymów: AChE i G-6-PD, a przerwa w morsowaniu powoduje obniżenie aktywności tych enzymów.
EN
Study aim: The aim of the study was to show changes in the activity of acetylcholinesterase (AChE) and glucose-6-phosphate dehydrogenase (G-6-PD) in winter swimmers between the end (April) and beginning of the consecutive winter swimming season (November). Material and methodology: The study group consisted of 16 winter swimmers (non-training males) from the Krakow “Kaloryfer” [Radiators] Winter Swimming Club, regularly undergoing submersion in cold water at a temperature of 2-7.2ºC for a maximum of three minutes during the winter swimming season. The tests were carried out at the end and before the beginning of the following winter season using the method of spectrophotometry. Results: Analysing the average values of enzymes after (April) and before the next (November) winter bathing season, there was a decrease in the activity of AChE [U/gHb] by 18.26% and G-6-PD [U/gHb] by 22.11% in men undergoing winter baths. Conclusions: Regular use of winter bath treatments results in increased enzyme activity: AChE and G-6-PD; and while break in winter swimming reduces the activity of these enzymes.
5
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The influence of short-term cold stress on the metabolism of non-structural carbohydrates in polar grasses

63%
Giełwanowska I., Łopieńska-Biernat E., Pastorczyk M., Żółtowska K., Stryiński R., Zaobidna E.
Polish Polar Research
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2017
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vol. 38
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issue 2
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