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Wyniki wyszukiwania dla: cystathionine-γ-synthase
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Rotation Triggers Nucleotide-Independent Conformational Transition of the Empty β Subunit of F1-ATPase
PublikacjaF1-ATPase (F1) is the catalytic portion of ATP synthase, a rotary motor protein that couples proton gradients to ATP synthesis. Driven by a proton flux, the F1 asymmetric γ subunit undergoes a stepwise rotation inside the α3β3 headpiece and causes the β subunits’ binding sites to cycle between states of different affinity for nucleotides. These concerted transitions drive the synthesis of ATP from ADP and phosphate. Here, we study...
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Mechanochemical Energy Transduction during the Main Rotary Step in the Synthesis Cycle of F1-ATPase
PublikacjaF1-ATPase is a highly efficient molecular motor that can synthesize ATP driven by a mechanical torque. Its ability to function reversibly in either direction requires tight mechanochemical coupling between the catalytic domain and the rotating central shaft, as well as temporal control of substrate binding and product release. Despite great efforts and significant progress, the molecular details of this synchronized and fine-tuned...
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Isolation and properties of recombinant trehalose synthase
PublikacjaBiosynthesis of trehalose is carried out via various matabolic pathways, including the use of trehalose synthase. Bacteria of the genus Deionococcus are microorganisms which produce trehalose synthase catalizing conversion of maltose into trehalose. In this work recombinant trehalose synthase from D.radiodurans was characterized.
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f-γ current fluctations in organic semiconductors: evidence for percolation
PublikacjaSzumowe spektra o nachyleniu f-γ były obserwowane w organicznych półprzewodnikach i interpretowane przy pomocy hoppingowego modelu szumów. S(f) spektra wykazywały max w regionie wypełniania się pułapek nośników ładunku. W tym artykule dyskutujemy warunki określające poszczególne rodzaje SCLC transportu. Model perkolacyjny został użyty do opisu przejść pomiędzy fazą izolatora a przewodnika, gdzie małe zmiany przełożonego napięcia...
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Glucosamine-6-phosphate synthase with an oligoHis insert
PublikacjaGlucosamine-6-phosphate (GlcN-6-P) synthase known also as L-Glutamine: D-fructose-6-phosphate aminotransferase (EC 2.6.1.16), catalyzes the first committed step in the amino sugar biosynthetic pathway in prokaryotic and eukaryotic organisms. The final product of this pathway is an activated precursor of numerous macromolecules containing amino sugars, including chitin and mannproteins in fungi, peptydoglican and lipopolysaccharides...
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Immobilization on magnetic nanoparticles of therecombinant trehalose synthase from Deinococcusgeothermalis
PublikacjatIn our study the gene encoding trehalose synthase from Deinococcus geothermalis was cloned and overexpressed inEscherichia coli Rosetta (DE3)pLysS. Wild-type trehalose synthase has been purified from host protein after cell dis-ruption and precipitation at 20% ammonium sulphate saturation. Recombinant trehalose synthase was immobilizedonto glutaraldehyde activated silanized magnetic ferrous-ferric oxide by using covalent binding...
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Cloning, expression, purification and characterization of recombinant trehalose synthase from Deinococcus radiodurans.
PublikacjaTrehalose (α-D-glucopyranosyl-1,1-α-D-glucopyranoside) is a nonreducing disacharide in which the two glucose molecules are linked trough a α-1,1-glycosidic bond. Trehalose is readily hydrolyzed to glucose and can be used as a reserve of that sugar in the cell. The presence of trehalose was found in the cells of fungi and yeasts, bacteria, nematodes, insects, eggs, pupae and some plants. The characteristics of trehalose make it...
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Inhibitors of glucosamine-6-phosphate synthase as potential antimicrobials or antidiabetics – synthesis and properties
PublikacjaGlucosamine-6-phosphate synthase (GlcN-6-P synthase) is known as a promising target for antimicrobial agents and antidiabetics. Several compounds of natural or synthetic origin have been identified as inhibitors of this enzyme. This set comprises highly selective L-glutamine, amino sugar phosphate or transition state intermediate cis-enolamine analogues. Relatively low antimicrobial activity of these inhibitors, poorly penetrating...
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Desensitization of glucosamine-6-phosphate synthase to inhibition by UDP-GlcNAc
PublikacjaGlucosamine-6-phosphate (GlcN-6-P) synthase, known also as L-Glutamine: D-fructose-6-phosphate amidotransferase, catalyzes the first committed step in the pathway leading to the ultimate formation of UDP-GlcNAc. The final product of this pathway is an activated precursor of numerous macromolecules containing amino sugars, including chitin and mannproteins in fungi, peptidoglycan and lipopolysaccharides in bacteria, and glycoproteins...
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Characterization of recombinant homocitrate synthase from Candida albicans
PublikacjaLYS21 and LYS22 genes from Candida albicans encoding isoforms of homocitrate synthase (HCS), an enzyme catalyzing the first committed step in the L-lysine biosynthetic pathway, were cloned and expressed as NoligoHistagged fusion proteins in Escherichia coli. The purified gene products revealed HCS activity, i.e. catalyzed the condensation of α-ketoglutarate with acetyl-coenzyme A to yield homocitrate. The recombinant enzymes were purified...
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Effects of the polyhistidine tag on kinetics and other properties of trehalose synthase from Deionococcus geothermalis
PublikacjaTwo recombinant trehalose synthases from Deinococcus geothermalis (DSMZ 11300) were compared. A significant influence of the artificial polyhistidine tag was observed in protein constitution. The recombinant trehalose synthase from D. geothermalis with His6 -tag has a higher K m value of 254 mM, in comparison with the wild-type trehalose synthase (K m 170 mM), and displayed a lower activity of maltose conversion when compared...
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Properties of recombinant trehalose synthase from Deinococcus radiodurans expressed in Escherichia coli
PublikacjaA trehalose synthase gene from Deinococcus radiodurans(DSMZ 20539)containing 1659 bp reading frame encoding 552 amino acids was amplified using PCR. The gene was finally ligated into pET30Ek/LIC vector and expressed after isopropyl β-d-thiogalactopyranoside induction in Escherichia coli (DE3) Rosetta pLysS. The recombinanttrehalose synthase (DraTreS) containing a His6-tag at the C-terminus was purified by metal affinity chromatography...
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Cloning, Expression and Purification of Wild-Type Trehalose Synthase from Deinococcus geothermalis
PublikacjaThe aim of this study was isolation and cloning of trehalose synthase gene derived from extremophilic microorganism to the expression vectors in the Tabor-Studier system and its expression in Rosetta(DE3)pLysS Escherichia coli cells. The second phase of the study consisted of proteins purification using an initial denaturation of host proteins and salting-out proteins by ammonium sulfate.
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Engineering Candida albicans glucosamine-6-phosphate synthase for efficient enzyme purification
PublikacjaRationally designed muteins of Candida albicans glucosamine-6-phosphate synthase, an enzyme known as a promising target for antifungal chemotherapy, were constructed, overexpressed in Escherichia coli and purified to near homogeneity. To facilitate and to optimize the purification of the enzyme, three recombinant versionscontaining internal oligoHis fragments were constructed: (i) by substituting residues 343 - 348...
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Construction of glucosamine-6-phosphate synthase with an internal hexahistydyl fragment
PublikacjaL-Glutamine: D-fructose-6-phosphate aminotransferase (EC 2.6.1.16), known also as glucosamine-6-phosphate (GlcN-6-P) syntase, catalyzes the first committed step in the amino sugar biosynthetic pathway in prokaryotic and eukaryotic organisms. The enzyme carries out a complex reaction involving ammonia transfer and sugar phosphate isomerization. GlcN-6-P syntase is an important point of metabolic control of amino sugar biosynthesis...
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Homocitrate synthase gene as a new molecular target in diagnostics of Candida spp. infections
PublikacjaNew potential molecular target which will be investigated during this research (homocitrate synthase gen) is the innovative target other than ribosomal DNA. This gene encodes enzyme present only in fungi and some Archaea what significantly increases specificity. It also reduces risk of contamination or influence of other factors (reaction with other DNA present in sample derived from bacteria or host cells) what excludes false...
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Expression of Deinococcus geothermalis Trehalose Synthase Gene in Escherichia coli and Its Enzymatic Properties
PublikacjaA novel trehalose synthase gene from Deinococcus geothermalis (DSMZ 11300) containing 1,692 bp reading-frame encoding 564 amino acids was amplified using PCR. The gene was ligated into pET30Ek/LIC vector and expressed after isopropyl alfa-D-thiogalactopyranoside induction in Escherichia coli BL21(DE3)pLysS. The recombinant trehalose synthase (DgeoTreS) containing a His6 tag at the C-terminus was purified by metal affinity chromatography...
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Long range molecular dynamics study of regulation of eukaryotic glucosamine-6-phosphate synthase activity by UDP-GlcNAc
PublikacjaGlucosamine-6-phosphate (GlcN-6-P) synthase catalyses the first and practically irreversible step in hexosamine metabolism. The final product of this pathway, uridine 5' diphospho N-acetyl-D-glucosamine (UDPGlcNAc), is an essential substrate for assembly of bacterialand fungal cell walls. Moreover, the enzyme is involved in phenomenon of hexosamine induced insulin resistance in type II diabetes, which makes it a potential target...
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Determinants of Directionality and Efficiency of the ATP Synthase Fo Motor at Atomic Resolution
PublikacjaFo subcomplex of ATP synthase is a membrane-embedded rotary motor that converts proton motive force into mechanical energy. Despite a rapid increase in the number of high-resolution structures, the mechanism of tight coupling between proton transport and motion of the rotary c-ring remains elusive. Here, using extensive all-atom free energy simulations, we show how the motor’s directionality naturally arises from the interplay...
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Structural features responsible for control of the eukaryotic GlcN-6-P synthase activity
PublikacjaGlucosamine-6-phosphate (GlcN-6-P) synthase is responsible for catalysis of the first and practically irreversible step in hexosamine metabolism. As UDP-GlcNAc, the final product of the hexosamine path, constitutes one of the essential substrates for assembly of bacterial and fungal cell walls, the enzyme is an interesting target for antimicrobial therapy.The structure of E. coli enzyme, known since 2001, forms a dimer of two identical...
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Emerging anticancer activity of candidal glucoseamine-6-phosphate synthase inhibitors upon nanoparticle-mediated delivery
PublikacjaNumerous glutamine analogues have been reported as irreversible inhibitors of the glucosamine-6-phosphate (GlcN-6-P) synthase in pathogenic Candida albicans in the last 3.5 decades. Among the reported inhibitors, the most effective N3-(4-methoxyfumaroyl)-L-2,3- diaminopropanoic acid (FMDP) has been extensively studied in order to develop its more active analogues. Several peptide−FMDP conjugates were tested to deliver FMDP to its...
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Isolation of the GFA1 gene encoding glucosamine-6-phosphate synthase of Sporothrix schenckii and its expression in Saccharomyces cerevisiae
PublikacjaGlucosamine-6-phosphate synthase (GlcN-6-P synthase) is an essential enzyme involved in cell wall biogenesis that has been proposed as a strategic target for antifungal chemotherapy. Here we describe the cloning and functional characterization of Sporothrix schenckii GFA1 gene which was isolated from a genomic library of the fungus. The gene encodes a predicted protein of 708 amino acids that is homologous to GlcN-6-P synthases...
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Comparison of LaCl3:Ce and NaI(Tl) scintillators in γ-ray spectrometry
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High-pressure and thermal properties of γ-Mg2SiO4 from first-principles calculations
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Low energy γ-rays scintillation detection with large area avalanche photodiodes
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Modification of quaternary structure of Candida albicans GlcN-6-P synthase and its desensitization to inhibition by UDP-GlcNAc by site-directed mutagenesis
PublikacjaSite-directed mutagenesis of the CaGFA1 gene encoding glucosamine-6-phosphate synthase from Candida albicans was performed. Desensitization of the enzyme to inhibition by UDPGlcNAc was achieved upon T487I and H492F substitutions at the UDP-GlcNAc binding site, exchange of D524, S525 and S527 for Ala at the dimer:dimer interface and construction of the tail-lock array (L434R and L460A) at the C-tail region. The first two sets if...
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Synthesis, anticandidal activity of N3-(4-methoxyfumaroyl)-(S)-2,3-diaminopropanoic amide derivatives – Novel inhibitors of glucosamine-6-phosphate synthase
PublikacjaNovel FMDP amiders 4-6 have been synthesized and tested against Candida strains. The anticandidal activity has been confined only to Candida albicans. Anticandidal activity of the tested amides has correlated with their inhibitory activity of glucosamine-6-phosphate synthase in cell free extract from Candida albicans.
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Large size LSO:Ce and YSO:Ce scintillators for 50 MeV range γ-ray detector
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Long range molecular dynamics study of interactions of the eukaryotic glucosamine-6-phosphate synthase with fructose-6-phosphate and UDP-GlcNAc
PublikacjaGlucosamine-6-phosphate synthase (EC 2.6.1.16) is responsible for catalysis of the first and practically irreversible step in hexosamine metabolism. The final product of this pathway, uridine 5 diphospho Nacetyl- d-glucosamine (UDP-GlcNAc), is an essential substrate for assembly of bacterial and fungal cell walls. Moreover, the enzyme is involved in phenomenon of hexosamine induced insulin resistance in type II diabetes, which...
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Synthesis and biological activity of novel ester derivatives of N3-(4-metoxyfumaroyl)-(S)-2,3-diaminopropanoic acid containing amide and keto function as inhibitors of glucosamine-6-phosphate synthase
PublikacjaA short series of novel ester derivatives of N3-4-methoxyfumaroyl-(S)-2,3-diaminopropanoic acid (FMDP) containing amido or keto functions have been designed and synthesized. Their antifungal activity and inhibitory properties toward fungal glucosamine-6-phosphate synthase has also been evaluated. The obtained compounds 11-13 and 15-17 demonstrated good antifunga activity against Candida albicans. Compounds 11-13 displayed also...
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Synthesis of Trehalose by the Erythritol-Producing Yeast Yarrowia lipolytica Co-Displaying Maltooligosyltrehalose Synthase and Maltooligosyltrehalose Trehalohydrolase
PublikacjaIndustrial trehalose production faces economic challenges with costly enzyme preparations, prompting the exploration of eco-friendly alternatives. Here, we established a coupled functional sugar production line leveraging erythritolproducing cells as an innovative enzyme preparation for trehalose synthesis. The erythritol-producing Yarrowia lipolytica was modified to express a fusion protein consisting of maltooligosyltrehalose synthase...
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Time Delay Estimation in Two-Phase Flow Investigation Using the γ-Ray Attenuation Technique.
PublikacjaTime delay estimation is an important research question having many applications in a range of technologies. Measurement of a two-phase flow in a pipeline or an open channel using radioisotopes is an example of such application. For instance, the determination of velocity of dispersed phase in that case is based on estimation of the time delay between two stochastic signals provided by scintillation probes. The proper analysis...
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Theoretical investigation of the structural insights of the interactions of γ-Fe2O3 nanoparticle with (EMIM TFSI) ionic liquid
PublikacjaOne of the possible applications of ionic liquids is to produce electricity from heat. The iron oxide nanoparticle is a potent electrical particle, which is expected to improve the heat’s efficiency to electricity conversion, however, it is prone to aggregation and sedimentation, which hamper its application. One of the methods to enhance the nanoparticle’s solubility and electrical properties is the use of a stabilizing component...
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A new assay based on terminal restriction fragment length polymorphism of homocitrate synthase gene fragments for Candida species identification
PublikacjaCandida sp. have been responsible for an increasing number of infections, especially in patients with immunodeficiency. Species specific differentiation of the Candida sp. is difficult in routine diagnosis. This identification can have a highly significant association in therapy and prophylaxis. This work has shown a new application of terminal restriction fragment length polymorphism (t-RFLP) method in molecular identification...
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Glucosamine-6-phosphate synthase - the multi-facets enzyme
PublikacjaAmidotransferaza L-glutamina: D-frukozo-6-fosforan, nazywana zwyczajowo syntazą glukozamino-6-fosforanu, jako jedyny enzym należący do grupy amidotransferaz, nie wykazuje aktywności amoniakozależnej. Enzym ten, katalizujący pierwszy wyjątkowy etap w szlaku metabolicznym prowadzącym do ostatecznego wytworzenia 5´difosfourydyno-N-acetylo-D-glukozaminy (UDG-GlcNAc) stanowi ważny punkt kontroli metabolicznej biosyntezy makromolekuł...
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Characterization of novel trehalose synthase from Deinococcus geothermalis.
PublikacjaThe method of trehalose extraction from yeast or othernatural sources is unsuitable for industrial production becauseof its low yield and high cost. Thus, the trehalose synthesizingenzyme systems that originated from a few microorganisms have been investigated.
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Oscillatory Mechanism of α-Fe(N) ↔ γ’-Fe4N Phase Transformations during Nanocrystalline Iron Nitriding
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γ-Butyrolactone-sensitive and -insensitive dopamine release, and their relationship to dopamine metabolism in three rat brain regions
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Molecular Determinants of Proton Transfer in ATP Synthase FO Complex
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Functional domains of Candida albicans glucosamine-6-phosphate synthase.
PublikacjaSkonstruowano oddzielnie dwie domeny syntazy GlcN-6-P z Candida albicans jako białka fuzyjne, tj. domenę glutaminazową oraz domenę izomerazową, zawierające sekwencje poliHis, odpowiednio na C- i N-końcu. Zoptymalizowano warunki nadekspresji domen w komórkach Escherichia coli. Oba białka oczyszczono do homogenności przy zastosowaniu chromatografii metalopowinowactwa oraz zbadano ich podstawowe właściwości. Wyznaczono parametry kinetyczne...
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Allosteric control of Candida albicans glucosamine-6-phosphate synthase.
PublikacjaPrzedstawiono wyniki badań spektrofluorymetrycznych syntazy GlcN-6-P z Candida albicans oraz enzymu zmutowanego, w którym reszty Trp388 i 690 zostały zamienione na drodze ukierunkowanej mutagenezy na reszty Phe. Metodą spektrofluorymetryczną badano wpływ ligandów: Fru-6-P (substrat), Gln (substrat), UDP-GlcNAc (inhibitor), Glc-6-P (aktywator), DON (analog glutaminy) w odpowiednio dobranych stężeniach. Obecność większości efektorów...
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Inhibitors of glucosamine-6-phosphate synthase as potential antifungal drugs.
PublikacjaPrzedstawiono stan obecny i perspektywy zastosowania inhibitorów enzymu syntazy GlcN-6-P jako leków skutecznych w leczeniu grzybic układowych. Używając metod modelowania molekularnego zaprojektowano struktury inhibitorów enzymu należących do dwóch grup strukturalnych: analogów glutaminy oraz analogów stanu przejściowego reakcji katalizowanej przez enzym. Opracowano metody syntezy pochodnych zoptymalizowanych inhibitorów, wykazujących...
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Anti-cancer effect of Rumex obtusifolius in combination with arginase/nitric oxide synthase inhibitors via downregulation of oxidative stress, inflammation, and polyamine synthesis
PublikacjaCancer continues to be a leading cause of death worldwide, making the development of new treatment methods crucial in the fight against it. With cancer incidence rates increasing worldwide, ongoing research must focus on identifying new and effective ways to prevent and treat the disease. The combination of herbal extracts with chemotherapeutic agents has gained much interest as a novel strategy to combat cancer. Rumex obtusifolius...
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Single-Step Symmetrical Double Alkylation of β,γ-Unsaturated δ-Lactams via Magnesium ‘Ate’ Complexes
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Development of Biocompatible Fe3O4@SiO2 Nanoparticles as Subcellular Delivery Platform for Glucosamine-6-phosphate Synthase Inhibitors
PublikacjaNumerous inhibitors of glucoseamine-6-phophate synthase (GlcN-6-P), the enzyme responsible from catalysis of the first step of metabolic pathway leading to metabolism 5’-diphospho-N-acetyl-D- glucosamine, were reported as effective agents for inhibiting the growth of various fungal pathogens. Among the reported inhibitors,...
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Disruption of homocitrate synthase genes in Candida albicans affects growth but not virulence
PublikacjaDwa geny, LYS21 i LYS22, kodujące izoformy syntazy homocytrynianowej, enzymu katalizującego pierwszy wyjątkowy etap w szlaku biosyntezy lizyny, zostały rozbite z komórkach Candida albicans z wykorzystaniem strategii ''SAT flipper''. Podwójny mutant lys21delta/lys22delta nie wykazywał aktywności syntazy homocytrynianowej, natomiast charakteryzował się auksotrofią wzrostową wobec lizyny w podłożach minimalnych, co można było odwrócić...
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Hybrid analogues of SFTI-1 modified in P1 position by β- and γ-amino acids and N-substituted β-alanines
PublikacjaA series of compounds containing either non-proteinogenic beta-/gamma-amino acids or N-substituted beta-alanine residues (beta-peptoid units) in P-1 specificity position were synthesized based on the structure of sunflower trypsin inhibitor 1 (SFTI-1). The compounds were synthesized on a solid support; the N-substituted beta-alanines (beta Nhlys and beta Nhphe) were introduced into a peptidomimetic chain via a two-step approach...
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Computer-Aided Saturation Mutagenesis of Arabidopsis thaliana Ent-Copalyl Diphosphate Synthase
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The crystal and solution studies of glucosamine-6-phosphate synthase from Candida albicans
PublikacjaOkreślono strukturę krystaliczną domeny izomerazowej syntazy glukozamino-6-fosforanu z Candida albicans w stanie natywnym, oraz w kompleksie z inhibitorem allosterycznym UDP-GlcNAc, fruktozo-6-P, glukozo-6-P oraz analogiem stanu przejściowego reakcji enzymatycznej - 2-amino-2-deoksy-D-mannitolo-6-P (ADMP). Na podstawie wyników badań metodą niskokątowego rozpraszania promieni X (SAXS) wydedukowano przypuszczalną strukturę kompletnej...
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Anticandiadal properties of N-acylpeptides containing inhibitor of glucosamine-6-phosphate synthase
PublikacjaOtrzymano serię N-acylopeptydów zawierających inhibitor syntazy glukozamino-6-fosforanu i zbadano ich aktywność w stosunku do szczepów Candida albicans. Aktywność przeciwgrzybową skorelowano z właściwościami lipofilowymi otrzymanych peptydów. Peptydy zawierające resztę kwasu dekanowego wykazywały najwyższą aktywność przeciwgrzybową.