A green catalyst WELPSA-catalyzed three-component condensation (Biginelli) process involving an aldehyde, barbituric/thiobarbituric/1,3-dimethylbarbituric acid, and urea/thiourea/guanidine hydrochloride in a single pot in presence of a green solvent for the production of DHPM have been presented. The catalyst is reusable and this methodology is scalable. By using the in vitro experiments, the antidiabetic potentiality of synthesized compounds that inhibit α-amylase along with α-glucosidase efficiencies was assessed. All the synthesized compounds except for 4a and 4e, showed the most significant inhibition for α-amylase and α-glucosidase activities. Among the synthesized DHPM compounds, 4c and 4b exhibited significant inhibition profiles compared to the standard antidiabetic drug acarbose. Furthermore, synthesized substances' energy-minimized structures, 3D structures, and DFT calculations were performed using Gaussian 09 software, hybrid models, and MM2 force approaches. Strong hydrogen bonds with amino acid residues Arg-672, Arg-600, Trp-613, Asp-404, Asp-282, and Asp-616 indicate that an α-glucosidase-inhibitory peptide may have hypoglycemic efficacy confirmed by the molecular docking study of the synthesized DHPM.

• Klíčová slova
• Biginelli, Green catalyst, Multicomponent, α-Amylase along with α-glucosidase,
• MeSH
• alfa-amylasy metabolismus   MeSH
• alfa-glukosidasy * metabolismus   MeSH
• barbituráty chemie   MeSH
• hypoglykemika farmakologie   chemie   MeSH
• inhibitory glykosidových hydrolas * chemie   MeSH
• katalýza MeSH
• simulace molekulového dockingu MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 1,3-dimethylbarbituric acid MeSH Prohlížeč
• alfa-amylasy MeSH
• alfa-glukosidasy * MeSH
• barbituráty MeSH
• hypoglykemika MeSH
• inhibitory glykosidových hydrolas * MeSH

Oat (Avena sativa L.) is considered to be a healthy food. In contrast to other grain crops, oat is high in protein, lipids, dietary fiber, antioxidants, and uniquely in avenanthramides. The question of whether it can also be consumed by people suffering from celiac disease is still unresolved. The main aim of this study was to extract and sequence genes for potentially harmful avenins, globulins, and α-amylase/trypsin inhibitors in six oat varieties and to establish their variability using PacBio sequencing technology of enriched libraries. The results were compared with sequences of the genes already present in databases. In total, 21 avenin, 75 globulin, and 25 α-amylase/trypsin inhibitor genes were identified and mapped in the hexaploid oat chromosomes. In all of the three gene families, only marginal sequence differences were found between the oat varieties within the individual genes. Avenin epitopes were found in all four types of avenin genes occurring in all oat varieties tested within this study. However, the number of avenin genes was nearly four times lower than of globulin genes and, on the protein level, formed only 10% of storage proteins. Therefore, the question of whether oat is safe to celiac disease people is a question of boundary values.

• MeSH
• alergeny metabolismus   MeSH
• alfa-amylasy metabolismus   MeSH
• celiakie * genetika   metabolismus   MeSH
• globuliny * metabolismus   MeSH
• lidé MeSH
• oves genetika   metabolismus   MeSH
• prolaminy genetika   MeSH
• semena rostlinná genetika   metabolismus   MeSH
• transkriptom MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alergeny MeSH
• alfa-amylasy MeSH
• globuliny * MeSH
• prolaminy MeSH

Production of amylases by fungi under solid-state fermentation is considered the best methodology for commercial scaling that addresses the ever-escalating needs of the worldwide enzyme market. Here response surface methodology (RSM) was used for the optimization of process variables for α-amylase enzyme production from Trichoderma virens using watermelon rinds (WMR) under solid-state fermentation (SSF). The statistical model included four variables, each detected at two levels, followed by model development with partial purification and characterization of α-amylase. The partially purified α-amylase was characterized with regard to optimum pH, temperature, kinetic constant, and substrate specificity. The results indicated that both pH and moisture content had a significant effect (P < 0.05) on α-amylase production (880 U/g) under optimized process conditions at a 3-day incubation time, moisture content of 50%, 30 °C, and pH 6.98. Statistical optimization using RSM showed R2 values of 0.9934, demonstrating the validity of the model. Five α-amylases were separated by using DEAE-Sepharose and characterized with a wide range of optimized pH values (pH 4.5-9.0), temperature optima (40-60 °C), low Km values (2.27-3.3 mg/mL), and high substrate specificity toward large substrates. In conclusion, this study presents an efficient and green approach for utilization of agro-waste for production of the valuable α-amylase enzyme using RSM under SSF. RSM was particularly beneficial for the optimization and analysis of the effective process parameters.

• MeSH
• alfa-amylasy chemie   metabolismus   MeSH
• amylasy MeSH
• Citrullus * metabolismus   MeSH
• fermentace MeSH
• Hypocrea * metabolismus   MeSH
• koncentrace vodíkových iontů MeSH
• průmyslová mikrobiologie metody   MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alfa-amylasy MeSH
• amylasy MeSH

This study examined the biochemical characteristics of α-amylase and hormonal (adipokinetic hormone: AKH) stimulation of α-amylase activity in the cockroach (Periplaneta americana) midgut. We applied two AKHs in vivo and in vitro, then measured resultant amylase activity and gene expression, as well as the expression of AKH receptor (AKHR). The results revealed that optimal amylase activity is characterized by the following: pH: 5.7, temperature: 38.4 °C, Km (Michaelis-Menten constant): 2.54 mg starch/mL, and Vmax (maximum reaction velocity): 0.185 μmol maltose/mL/min. In vivo application of AKHs resulted in significant increase of amylase activity: by two-fold in the gastric caeca and 4-7 fold in the rest of the midgut. In vitro experiments supported results seen in vivo: a 24-h incubation with the hormones resulted in the increase of amylase activity by 1.4 times in the caeca and 4-9 times in the midgut. Further, gene expression analyses reveal that AKHR is expressed in both the caeca and the rest of the midgut, although expression levels in the former were 23 times higher than levels in the latter. A similar pattern was found for the amylase (AMY) gene. Hormonal treatment did not affect the expression of either gene. This study is the first to provide evidence indicating direct AKH stimulation of digestive enzyme activity in the insect midgut, supported by specific AKHR gene expression in this organ.

• Klíčová slova
• AKH, AKH receptor, amylase, enzyme, gene expression, midgut,
• MeSH
• alfa-amylasy metabolismus   MeSH
• gastrointestinální trakt účinky léků   enzymologie   MeSH
• hmyzí hormony metabolismus   farmakologie   MeSH
• kyselina pyrrolidonkarboxylová analogy a deriváty   metabolismus   farmakologie   MeSH
• oligopeptidy metabolismus   farmakologie   MeSH
• Periplaneta účinky léků   enzymologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adipokinetic hormone MeSH Prohlížeč
• alfa-amylasy MeSH
• hmyzí hormony MeSH
• kyselina pyrrolidonkarboxylová MeSH
• oligopeptidy MeSH

In germinating seeds under unfavorable environmental conditions, the mobilization of stores in the cotyledons is delayed, which may result in a different modulation of carbohydrates balance and a decrease in seedling vigor. Tall fescue (Festuca arundinacea Schreb.) caryopses grown at 4°C in the dark for an extended period in complete absence of nutrients, showed an unexpected ability to survive. Seedlings grown at 4°C for 210 days were morphologically identical to seedlings grown at 23°C for 21 days. After 400 days, seedlings grown at 4°C were able to differentiate plastids to chloroplast in just few days once transferred to the light and 23°C. Tall fescue exposed to prolonged period at 4°C showed marked anatomical changes: cell wall thickening, undifferentiated plastids, more root hairs and less xylem lignification. Physiological modifications were also observed, in particular related to sugar content, GA and ABA levels and amylolytic enzymes pattern. The phytohormones profiles exhibited at 4 and 23°C were comparable when normalized to the respective physiological states. Both the onset and the completion of germination were linked to GA and ABA levels, as well as to the ratio between these two hormones. All plants showed a sharp decline in carbohydrate content, with a consequent onset of gradual sugar starvation. This explained the slowed then full arrest in growth under both treatment regimes. The analysis of amylolytic activity showed that Ca2+ played a central role in the stabilization of several isoforms. Overall, convergence of starvation and hormone signals meet in crosstalk to regulate germination, growth and development in tall fescue.

• MeSH
• alfa-amylasy metabolismus   MeSH
• buněčná stěna metabolismus   fyziologie   MeSH
• časové faktory MeSH
• Festuca metabolismus   fyziologie   MeSH
• fyziologická adaptace fyziologie   účinky záření   MeSH
• fyziologický stres fyziologie   MeSH
• gibereliny metabolismus   MeSH
• kořeny rostlin metabolismus   fyziologie   MeSH
• kotyledon metabolismus   fyziologie   MeSH
• kyselina abscisová metabolismus   MeSH
• lignin metabolismus   MeSH
• nízká teplota MeSH
• rostlinné proteiny metabolismus   MeSH
• sacharidy analýza   MeSH
• semenáček fyziologie   MeSH
• světlo MeSH
• tma MeSH
• vápník metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alfa-amylasy MeSH
• gibberellic acid MeSH Prohlížeč
• gibereliny MeSH
• kyselina abscisová MeSH
• lignin MeSH
• rostlinné proteiny MeSH
• sacharidy MeSH
• vápník MeSH

Anoxia tolerance can be evaluated not only in terms of growth or survival of plant organs during oxygen deprivation, but also in relation to carbohydrate utilization in the context of a well-modulated fermentative metabolism. Rice (Oryza spp.) is unique among cereals, in that it has the distinctive ability to germinate under complete anaerobiosis by using the starchy reserves in its seeds to fuel the anaerobic metabolism. The aim of the present study was to evaluate the ability of germinating rice seedlings to survive a long-term oxygen deficiency [40 days after sowing (DAS)] and the effects on sugar metabolism, focusing on starch degradation as well as soluble sugars transport and storage under anoxia. No significant decline in vitality occurred until 30 DAS though no recovery was detected following longer anoxic treatments. Growth arrest was observed following anoxic treatments longer that 20 DAS, in concomitance with considerably lower ethanol production. Amylolytic activity in embryos and endosperms had similar responses to anoxia, reaching maximum content 30 days after the onset of stress, following which the levels declined for the remainder of the experiment. Under anoxia, average amylolytic activity was twofold higher in embryos than endosperms. Efficient starch degradation was observed in rice under anoxia at the onset of the treatment but it decreased over time and did not lead to a complete depletion. Our analysis of α-amylase activity did not support the hypothesis that starch degradation plays a critical role in explaining differences in vitality and coleoptile growth under prolonged oxygen deprivation.

• Klíčová slova
• Anoxia, Coleoptile, Ethanol, Rice, Starch, α-Amylase,
• MeSH
• alfa-amylasy metabolismus   MeSH
• anaerobióza MeSH
• endosperm metabolismus   MeSH
• ethanol metabolismus   MeSH
• klíčení * MeSH
• kotyledon metabolismus   MeSH
• metabolismus sacharidů * MeSH
• rozpustnost MeSH
• rýže (rod) embryologie   metabolismus   MeSH
• škrob metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alfa-amylasy MeSH
• ethanol MeSH
• škrob MeSH

The alkaline α-amylase produced by Texcoconibacillus texcoconensis 13CC(T) strain was identified by random mutagenesis and confirmed by directed mutagenesis. A transposon mutagenesis approach was taken to identify the gene responsible for the degradation of starch in T. texcoconensis 13CC(T) strain. The deduced amino acids of the amy gene had a 99% similarity with those of Bacillus selenitireducens MLS10 and 97% with those of Paenibacillus curdlanolyticus YK9. The enzyme showed a maximum activity of 131.1 U/mL at 37 °C and pH 9.5 to 10.5. In situ activity of the enzyme determined by polyacrylamide gel electrophoresis showed only one band with amylolytic activity. This is the first report of a bacterium isolated from the extreme alkaline-saline soil of the former Lake Texcoco (Mexico) with amylolytic activity in alkaline conditions while its potential as a source of amylases for the industry is discussed.

• MeSH
• alfa-amylasy genetika   metabolismus   MeSH
• Bacillus enzymologie   genetika   růst a vývoj   izolace a purifikace   MeSH
• jezera MeSH
• mutace MeSH
• mutageneze * MeSH
• půda chemie   MeSH
• půdní mikrobiologie * MeSH
• salinita * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Mexiko MeSH
• Názvy látek
• alfa-amylasy MeSH
• půda MeSH

An extracellular amylase secreted by Aspergillus niveus was purified using DEAE fractogel ion exchange chromatography and Sephacryl S-200 gel filtration. The purified protein migrated as a single band in 5 % polyacrylamide gel electrophoresis (PAGE) and 10 % sodium dodecyl sulfate (SDS-PAGE). The enzyme exhibited 4.5 % carbohydrate content, 6.6 isoelectric point, and 60 and 52 kDa molar mass estimated by SDS-PAGE and Bio-Sil-Sec-400 gel filtration column, respectively. The amylase efficiently hydrolyzed glycogen, amylose, and amylopectin. The end-products formed after 24 h of starch hydrolysis, analyzed by thin layer chromatography, were maltose, maltotriose, maltotetraose, and maltopentaose, which classified the studied amylase as an α-amylase. Thermal stability of the α-amylase was improved by covalent immobilization on glyoxyl agarose (half-life of 169 min, at 70 °C). On the other hand, the free α-amylase showed a half-life of 20 min at the same temperature. The optima of pH and temperature were 6.0 and 65 °C for both free and immobilized forms.

• MeSH
• alfa-amylasy izolace a purifikace   metabolismus   MeSH
• amylopektin metabolismus   MeSH
• amylosa metabolismus   MeSH
• Aspergillus enzymologie   MeSH
• chromatografie iontoměničová MeSH
• chromatografie na tenké vrstvě MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• enzymy imobilizované chemie   metabolismus   MeSH
• gelová chromatografie MeSH
• glykogen metabolismus   MeSH
• hydrolýza MeSH
• koncentrace vodíkových iontů MeSH
• molekulární sekvence - údaje MeSH
• sekvence aminokyselin MeSH
• sekvenční seřazení MeSH
• stabilita enzymů MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alfa-amylasy MeSH
• amylopektin MeSH
• amylosa MeSH
• enzymy imobilizované MeSH
• glykogen MeSH

A halophilic isolate Thalassobacillus sp. LY18 producing extracellular amylase was isolated from the saline soil of Yuncheng Salt Lake, China. Production of the enzyme was synchronized with bacterial growth and reached a maximum level during the early stationary phase. The amylase was purified to homogeneity with a molecular mass of 31 kDa. Major products of soluble starch hydrolysis were maltose and maltotriose, indicating an α-amylase activity. Optimal enzyme activity was found to be at 70°C, pH 9.0, and 10 % NaCl. The α-amylase was highly stable over broad temperature (30-90°C), pH (6.0-12.0), and NaCl concentration (0-20 %) ranges, showing excellent thermostable, alkalistable, and halotolerant nature. The enzyme was stimulated by Ca(2+), but greatly inhibited by EDTA, indicating it was a metalloenzyme. Complete inhibition by diethyl pyrocarbonate and β-mercaptoethanol revealed that histidine residue and disulfide bond were essential for enzyme catalysis. The surfactants tested had no significant effects on the amylase activity. Furthermore, it showed high activity and stability in the presence of water-insoluble organic solvents with log P (ow) ≥ 2.13.

• MeSH
• alfa-amylasy chemie   genetika   metabolismus   MeSH
• Bacillaceae chemie   enzymologie   genetika   izolace a purifikace   MeSH
• bakteriální proteiny chemie   genetika   metabolismus   MeSH
• jezera mikrobiologie   MeSH
• škrob metabolismus   MeSH
• stabilita enzymů MeSH
• vysoká teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Čína MeSH
• Názvy látek
• alfa-amylasy MeSH
• bakteriální proteiny MeSH
• škrob MeSH

Ips typographus (L.), the eight-spined spruce bark beetle, causes severe damage throughout Eurasian spruce forests and suitable nuclear markers are needed in order to study its population structure on a genetic level. Two closely related genes encoding α-amylase in I. typographus were characterized and named AmyA and AmyB. Both α-amylase paralogs consisted of six exons and five introns. AmyA encodes a polypeptide of 483 amino acids, whereas AmyB has two alternative transcripts encoding polypeptides of 483 and 370 amino acids. The expression levels of both genes were high during larval stage and adulthood. The AmyB transcripts were absent in the pupal stage. A modification of the allozyme staining method allowed us to detect two clusters of bands on the electrophoretic gel that may correspond to the two α-amylase genes. There was a correlation between the lack of AmyB expression in pupa and the absence of the fast migrating isozyme cluster at this stage, suggesting that the faster migrating isoforms are products of the AmyB gene, whereas the slowly migrating bands are derived from the AmyA.

• MeSH
• alfa-amylasy genetika   metabolismus   MeSH
• brouci enzymologie   genetika   MeSH
• ektroforéza na škrobovém gelu MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• fylogeneze MeSH
• hmyzí proteiny genetika   metabolismus   MeSH
• izoenzymy genetika   metabolismus   MeSH
• klonování DNA MeSH
• messenger RNA metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• sekvenční homologie aminokyselin * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alfa-amylasy MeSH
• hmyzí proteiny MeSH
• izoenzymy MeSH
• messenger RNA MeSH