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Wyniki wyszukiwania dla: cold-adapted enzyme
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Cold-adapted bacterial lipolytic enzymes and their applications
PublikacjaLipolytic enzymes, esterases and lipases catalyze the hydrolysis and transesterification of fatty acid esters. This class of enzymes is the most important group of biocatalysts for biotechnological applications. From this perspective, coldactive lipolytic enzymes from cold adapted bacteria display attractive properties for some industrial purposes, including high catalytic activity at low temperatures and low thermostability. To...
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A cold-adapted esterase from psychrotrophic Pseudoalteromonas sp. strain 643A
PublikacjaDzięki zastosowaniu lipaz możliwa jest biotechnologiczna produkcja m.in. biodegradowalnych biopolimerów, biopaliw (tzw. biodiesel), wielu terapeutyków, herbicydów, pestycydów, kosmetyków, substancji smakowych, serów i in. Szczególnie interesującą grupę stanowią enzymy lipolityczne, pochodzące z organizmów psychrofilnych i psychrotrofowych, ze względu na zdolność do wydajnego katalizowania reakcji w temperaturach rzędu 10-20 ºC....
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Antarctic marine bacterium Pseudoalteromonas sp. 22b as a source of cold adapted á-galaktosidase.
PublikacjaAntarktyczny morski szczep Pseudoalteromonas sp. 22b. jest źródłem wewnątrzkomórkowej beta-galaktozy. Enzym ten wykazuje wysoką aktywność hydrolizy laktozy w zakresie temperatur od 0 do 20 st. C oraz pH 6,0-8,0. W niniejszej pracy opisano metodykę uzyskania homogennego preparatu tego enzymu, oraz pełną charakterystykę jego własności enzymatycznych i kinetycznych.
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Structural studies of a cold-adapted dimeric Beta-D-galactosidase from Paracoccus sp. 32d
PublikacjaThe crystal structure of a novel dimeric [beta]-D-galactosidase from Paracoccus sp. 32d (Par[beta]DG) was solved in space group P212121 at a resolution of 2.4 Å by molecular replacement with multiple models using the BALBES software. This enzyme belongs to glycoside hydrolase family 2 (GH2), similar to the tetrameric and hexameric [beta]-D-galactosidases from Escherichia coli and Arthrobacter sp. C2-2, respectively. It is the second...
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Mapping the Transglycosylation Relevant Sites of Cold-Adapted β-D-Galactosidase from Arthrobacter sp. 32cB
PublikacjaB-Galactosidase from Arthrobacter sp. 32cB (ArthbetaDG) is a cold-adapted enzyme able to catalyze hydrolysis of beta-D-galactosides and transglycosylation reaction, where galactosyl moiety is being transferred onto an acceptor larger than a water molecule. Mutants of ArthbetaDG D207A and E517Q were designed to determine the significance of specific residues and to enable formation of complexes with lactulose and sucrose and to...
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Antarctic, cold-adapted beta-galactosidase of Pseudoalteromonas sp. 22b as an effective tool for alkyl galactopyranosides synthesis
PublikacjaPrzedstawione jest zastosowanie arktycznej beta-galaktozydazy Pseudoalteromonas sp. 22b do katalizy syntezy alkilowych galaktopyranozydów. Njwyższą wydajność syntezy uzyskuje się przy pH 6-9 i 10-30% stężenia wody. Podobnie jak dla mezofilnych beta-galaktozydaz enzym antarktyczny syntetyzował najwydajniej kiedy reakcja przebiega w mieszaninie buforu i rozpuszczalnika organiczego (poniżej 50%, v/v).
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Immobilized preparation of cold-adapted and halotolerant Antarctic β-galactosidase as a highly stable catalyst in lactose hydrolysis
PublikacjaZimnolubna rekombinowana beta-galaktozydaza antarktycznej morskiej bakterii Pseudoalteromonas sp. 22b została immobilizowana na chitozanie za pomocą aldehydu glutarowego. Preparat immobilizowanego enzymu w przeciwieństwie do preparatu enzymu w buforze reakcyjnym nie był inhibowany przez glukozę. Immobilizacja enzymu wpłynęła na podwyższenie o 10°C optymalnej temperatury aktywności względem jego nieimmobilizowanego odpowiednika...
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Cloning, expression, and purification of a recombinant cold-adapted β-galactosidase from antarctic bacterium Pseudoalteromonas sp. 22b
PublikacjaAntarktyczny szczep, gram-ujemnych bakterii Pseudoalteromonas sp. 22b, wyizolowanych z przewodu pokarmowego kryla z gatunku Thyssanoessa macrura, jest producentem wewnątrzkomórkowej zimnolubnej beta-galaktozydazy. Białko to jest homotetramerem, w którym każda z jednostek monomeru zbudowana jest z 1028 reszt aminokwasowych. Gen kodujący ten enzym został sklonowany i eksprymowany w komórkach E. coli. Następnie z zastosowaniem procedury...
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Active Site Architecture and Reaction Mechanism Determination of Cold Adapted beta-D-galactosidase from Arthrobacter sp. 32cB
PublikacjaArthbetaDG is a dimeric, cold-adapted beta-D-galactosidase that exhibits high hydrolytic and transglycosylation activity. A series of crystal structures of its wild form, as well as its ArthbetaDG_E441Q mutein complexes with ligands were obtained in order to describe the mode of its action. The ArthbetaDG_E441Q mutein is an inactive form of the enzyme designed to enable observation of enzyme interaction with its substrate. The...
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THE GENE CLONING, OVEREXPRESSION, PURIFICATION AND BIOCHEMICAL CHARACTERISATION OF A NEW COLD-ADAPTED β–GALACTOSIDASE FROM ARTHROBACTER SP. VII-4
PublikacjaINTRODUCTION. β-Galactosidase [EC 3.2.1.23] is an enzyme that catalyzes the hydrolysis of O-glycosidic linkages in galactosides. It is commercially used in dairy industry for the production of milk with reduced lactose content. Potentially, the best method for lactose removal under cooling conditions should be carried out with a cold-adapted enzyme. AIM. The aim of this study was to determine the taxonomic affiliation of the isolate...
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A new cold-adapted beta-D-galactosidase from the Antarctic Arthrobacter sp. 32c - gene cloning, overexpression, purification and properties
PublikacjaThe development of a new cold-active β-D-galactosidases and microorganisms that efficiently ferment lactose is of high biotechnological interest, particularly for lactose removal in milk and dairy products at low temperatures and for cheese whey bioremediation processes with simultaneous bio-ethanol production. In this article, we present a new β-D-galactosidase as a candidate to be applied in the above mentioned biotechnological...
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Extracellular secretion of Pseudoalteromonas sp. cold-adapted esterase in Escherichia coli in the presence of Pseudoalteromonas sp. components of ABC transport system
PublikacjaEnzymy lipolityczne, głównie lipazy i esterazy, stanowią cenną grupę biokatalizatorów wykorzystywanych w przemyśle. Coraz większe zainteresowanie tą klasą enzymów sprawiło, że poszukuje się alternatywnych źródeł ich pozyskiwania. W celu zbadania wpływu białek transportu ABC Pseudoalteromonas sp. 643A na ekspresję genu, sekrecję i aktywność esterazy EstA z tego mikroorganizmu w systemie ekspresyjnym E. coli skonstruowano układ do...
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Cloning and characterization of a novel cold-active glycoside hydrolase family 1 enzyme with beta-glucosidase, beta-fucosidase and beta-galactosidase activities.
PublikacjaBackground: Cold-active enzymes, sourced from cold-adapted organisms, are characterized by high catalytic efficiencies at low temperatures compared with their mesophilic counterparts, which have poor activity. This property makes them advantageous for biotechnology applications as it: (i) saves energy costs, (ii) shortens the times for processes operated at low temperatures, (iii) protects thermosensitive substrates or products...
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In Situ Random Microseeding and Streak Seeding Used for Growth of Crystals of Cold-Adapted beta-D-Galactosidases: Crystal Structure of betaDG from Arthrobacter sp. 32cB
PublikacjaThere is an increasing demand for cold-adapted enzymes in a wide range of industrial branches. Nevertheless, structural information about them is still scarce. The knowledge of crystal structures is important to understand their mode of action and to design genetically engineered enzymes with enhanced activity. The most difficult task and the limiting step in structural studies of cold-adapted enzymes is their crystallization,...
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The psychrotrophic yeast Sporobolomyces roseus LOCK 1119 as a source of a highly active aspartic protease for the in vitro production of antioxidant peptides
PublikacjaA psychrotrophic yeast strain producing a cold-adapted protease at low temperature was classified as Sporobolomyces roseus. In standard YPG medium, S. roseus LOCK 1119 synthesized an extracellular protease with an activity of approximately 560 U/L. Optimization of medium composition and process temperature considerably enhanced enzyme biosynthesis; an approximate 70% increase in activity (2060 U/L). The native enzyme was purified...
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Structure of EstA esterase from psychrotrophic Pseudoalteromonas sp. 643A covalently inhibited by monoethylphosphonate.
PublikacjaThe crystal structure of the esterase EstA from the cold-adapted bacteriumPseudoalteromonas sp. 643A was determined in a covalently inhibited form at aresolution of 1.35 A˚. The enzyme has a typical SGNH hydrolase structureconsisting of a single domain containing a five-stranded beta-sheet, with threehelices at the convex side and two helices at the concave side of the sheet, and isornamented with a couple of very short helices...
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Cloning, expression, and biochemical characterization of a coldactive GDSL-esterase of a Pseudomonas sp. S9 isolated from Spitsbergen island soil
PublikacjaAn estS9 gene, encoding an esterase of the psychrotolerant bacterium Pseudomonas sp. S9 was cloned and sequenced. The deduced sequence revealed a protein of 636 amino acid residues with a molecular mass of 69 kDa.Further amino acid sequence analysis revealed that the EstS9 enzyme contained a G-D-S-L motif centered at a catalytic serine, an N-terminal catalytic domain and a C-terminal autotransporter domain. Two recombinant E. coli...
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A new B-D-galactosidase with a low temperature optimum isolated from the Antarctic Arthrobacter sp. 20B: gene cloning, purification and characterization.
PublikacjaA psychrotrophic bacterium producing a coldadaptedB-galactosidase upon growth at low temperatureswas classiWed as Arthrobacter sp. 20B. A genomic DNAlibrary of strain 20B introduced into Escherichia coliTOP10F' and screening on X-Gal (5-bromo-4-chloro-3-indolyl-B-D-galactopyranoside)-containing agar plates ledto the isolation of B-galactosidase gene. The B-galactosidasegene (bgaS) encoding a protein of 1,053 amino acids,with a...
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Purification and biochemical characteristic of a cold-active recombinant esterase from Pseudoalteromonas sp. 643A under denaturing conditions.
PublikacjaIn this paper production of a cold-active esterase EstA from the Antarctic bacterium Pseudoalteromonas sp. 643A in E. coli expression system was described. The purification and biochemical characteristic of EstA were performed in the presence of urea and then compared with results obtained for the esterase with no addition of urea and isolated from the native source. In both cases the cold-active enzyme displayed similar properties....
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A new cold-active β-galactosidase from Arthrobacter sp. S3* - gene cloning, overexpression, purification and properties
PublikacjaA psychrotrophic bacterium producing a cold-active β-galactosidase was isolated from Spitsbergen soil and classified as Arthrobacter sp. S3*. The gene encoding β-galactosidase was isolated from the genomic DNA library, sequenced, cloned, expressed in Escherichia coli, purified by ion exchange chromatography and characterized. The Arthrobaster sp. S3* β-galactosidase is a homotrimeric enzyme composed of 74,4 kDa subunits. It is...