| redefining the role of the quaternary shift in bacillus stearothermophilus phosphofructokinase. | bacillus stearothermophilus phosphofructokinase (bspfk) is a homotetramer that is allosterically inhibited by phosphoenolpyruvate (pep), which binds along one dimer-dimer interface. the substrate, fructose 6-phosphate (fru-6-p), binds along the other dimer-dimer interface. evans et al. observed that the structure with inhibitor (phosphoglycolate) bound, compared to the structure of wild-type bspfk with substrate and activator bound, exhibits a 7° rotation about the substrate-binding interface, t ... | 2013 | 23859543 |
| abiotic and microbiotic factors controlling biofilm formation by thermophilic sporeformers. | one of the major concerns in the production of dairy concentrates is the risk of contamination by heat-resistant spores from thermophilic bacteria. in order to acquire more insight in the composition of microbial communities occurring in the dairy concentrate industry, a bar-coded 16s amplicon sequencing analysis was carried out on milk, final products, and fouling samples taken from dairy concentrate production lines. the analysis of these samples revealed the presence of dna from a broad range ... | 2013 | 23851093 |
| genetic variants associated with the progression of hepatocellular carcinoma in hepatitis c egyptian patients. | hepatocellular carcinoma (hcc) associated to infection with hepatitis c virus (hcv) has become the fastest-rising cause of cancer-related deaths. genetic variations may play an important role in the development of hcc in hcv patients. ghrelin exerts anti-inflammatory, antifibrotic and hepatoprotective effects on chronically injured hepatic tissues. ghrelin gene shows several single nucleotide polymorphisms (snps) including -604g/a, arg51gln, and leu72met. hemochromatosis gene (hfe) mutations nam ... | 2013 | 23845776 |
| compact solar autoclave based on steam generation using broadband light-harvesting nanoparticles. | the lack of readily available sterilization processes for medicine and dentistry practices in the developing world is a major risk factor for the propagation of disease. modern medical facilities in the developed world often use autoclave systems to sterilize medical instruments and equipment and process waste that could contain harmful contagions. here, we show the use of broadband light-absorbing nanoparticles as solar photothermal heaters, which generate high-temperature steam for a standalon ... | 2013 | 23836642 |
| secretory expression of thermostable alkaline protease from bacillus stearothermophilus fi by using native signal peptide and α-factor secretion signal in pichia pastoris. | the thermostable alkaline protease from bacillus stearothermophilus f1 has high potential for industrial applications, and attempt to produce the enzyme in yeast for higher yield was undertaken. secretory expression of f1 protease through yeast system could improve enzyme's capability, thus simplifying the purification steps. mature and full genes of f1 protease were cloned into pichia pastoris expression vectors (pgapzαb and ppiczαb) and transformed into p. pastoris strains (gs115 and smd1168h) ... | 2013 | 23832300 |
| safety evaluation of a thermolysin enzyme produced from geobacillus stearothermophilus. | thermolysin is a zinc metalloprotease that has potential uses in the food industry. the safety of thermolysin has not been demonstrated before, and therefore a series of standard toxicological tests to assess its potential toxicity was undertaken. the thermolysin used in this study was derived from the thermophilic bacterium geobacillus stearothermophilus, which had undergone chemical mutagenesis to generate strains with increased thermolysin production. acute toxicity studies in rats and mice s ... | 2013 | 23831195 |
| thielavins a, j and k: α-glucosidase inhibitors from mexu 27095, an endophytic fungus from hintonia latiflora. | bioassay-guided fractionation of the bio-active organic extract obtained from solid-media culture of mexu 27095, an endophytic fungus isolated from the mexican medicinal plant hintonia latiflora (rubiaceae), led to separation of three tridepsides which were identified as thielavins a, j and k. all three compounds inhibited saccharomyces cerevisieae α-glucosidase (αghy) in a concentration-dependent manner with ic50 values of 23.8, 15.8, and 22.1μm, respectively. their inhibitory action was higher ... | 2013 | 23809634 |
| residues of a proposed gate region in type i atp-binding cassette import systems are crucial for function as revealed by mutational analysis. | the type i atp-binding cassette (abc) importer for positively charged amino acids of the thermophilic bacterium geobacillus stearothermophilus consists of the extracellular solute binding protein, artj, and a homodimer each of the transmembrane subunit, artm, and the nucleotide-binding and -hydrolyzing subunit, artp. we have investigated the functional consequences of mutations affecting conserved residues from two peptide regions in artm, recently proposed to form a 'gate' by which access of a ... | 2013 | 23747295 |
| crystallization and preliminary crystallographic analysis of abp, a gh27 β-l-arabinopyranosidase from geobacillus stearothermophilus. | geobacillus stearothermophilus t-6 is a thermophilic soil bacterium that possesses an extensive system for the utilization of hemicellulose. the bacterium produces a small number of endo-acting extracellular enzymes that cleave high-molecular-weight hemicellulolytic polymers into short decorated oligosaccharides, which are further hydrolysed into the respective sugar monomers by a battery of intracellular glycoside hydrolases. one of these intracellular processing enzymes is β-l-arabinopyranosid ... | 2013 | 23722857 |
| sequence and structural investigation of a novel psychrophilic α-amylase from glaciozyma antarctica pi12 for cold-adaptation analysis. | a novel α-amylase was isolated successfully from glaciozyma antarctica pi12 using dna walking and reverse transcription-polymerase chain reaction (rt-pcr) methods. the structure of this psychrophilic α-amylase (amypi12) from g. antarctica pi12 has yet to be studied in detail. a 3d model of amypi12 was built using a homology modelling approach to search for a suitable template and to generate an optimum target-template alignment, followed by model building using modeller9.9. analysis of the amypi ... | 2013 | 23686283 |
| s-layer coated emulsomes as potential nanocarriers. | the present study introduces a novel nanocarrier system comprising lipidic emulsomes and s-layer (fusion) proteins as functionalizing tools coating the surface. emulsomes composed of a solid tripalmitin core and a phospholipid shell are created reproducibly with an average diameter of approximately 300 nm using temperature-controlled extrusion steps. both wildtype (wt) and recombinant (r) s-layer protein sbsb of geobacillus stearothermophilus pv72/p2 are capable of forming coherent crystalline e ... | 2013 | 23606662 |
| crystal structure and mode of helicase binding of the c-terminal domain of primase from helicobacter pylori. | to better understand the poor conservation of the helicase binding domain of primases (dnags) among the eubacteria, we determined the crystal structure of the helicobacter pylori dnag c-terminal domain (hpdnag-ctd) at 1.78 å. the structure has a globular subdomain connected to a helical hairpin. structural comparison has revealed that globular subdomains, despite the variation in number of helices, have broadly similar arrangements across the species, whereas helical hairpins show different orie ... | 2013 | 23585534 |
| optimizing lactose hydrolysis by computer-guided modification of the catalytic site of a wild-type enzyme. | lactose intolerance is a serious global health problem. a lactose hydrolysis enzyme, thermostable β-galactosidase, bgab (from geobacillus stearothermophilus) has attracted the attention of industrial biologists because of its potential application in processing lactose-containing products. however, this enzyme experiences galactose product inhibition. through homology modeling and molecular dynamics (md) simulation, we have identified the galactose binding sites in the thermostable β-galactosida ... | 2013 | 23585056 |
| combined impact of bacillus stearothermophilus maltogenic alpha-amylase and surfactants on starch pasting and gelation properties. | in baking applications involving starch gelatinisation, surfactants such as sodium stearoyl lactylate (ssl) and monoacylglycerols (mag) and bacillus stearothermophilus maltogenic alpha-amylase (bsta) can be used jointly. we here showed that ssl but not mag delays wheat starch hydrolysis by bsta. the effects were explained in terms of different degrees of adsorption of the surfactants on the starch granule surface, retarded and/or decreased water uptake and delayed availability of gelatinised sta ... | 2013 | 23561216 |
| "on-the-fly" kinetics of enzymatic racemization using deuterium nmr in dna-based chiral oriented media. | we report the in situ and real-time monitoring of the interconversion of l- and d-alanine-d3 by alanine racemase from bacillus stearothermophilus directly observed by (2)h nmr spectroscopy in anisotropic phase. the enantiomers are distinguished by the difference of their (2)h quadrupolar splittings in a chiral liquid crystal containing short dna fragments. the proof-of-principle, the reliability, and the robustness of this new method is demonstrated by the determination of the turnover rates of ... | 2013 | 23547756 |
| crystallization and preliminary crystallographic analysis of axe2, an acetylxylan esterase from geobacillus stearothermophilus. | acetylxylan esterases are part of the hemi-cellulolytic system of many microorganisms which utilize plant biomass for growth. xylans, which are polymeric sugars that constitute a significant part of the plant biomass, are usually substituted with acetyl side groups attached at position 2 or 3 of the xylose backbone units. acetylxylan esterases hydrolyse the ester linkages of the xylan acetyl groups and thus improve the ability of main-chain hydrolysing enzymes to break down the sugar backbone un ... | 2013 | 23545652 |
| identification of a long-range protein network that modulates active site dynamics in extremophilic alcohol dehydrogenases. | a tetrameric thermophilic alcohol dehydrogenase from bacillus stearothermophilus (ht-adh) has been mutated at an aromatic side chain in the active site (trp-87). the ht-w87a mutation results in a loss of the arrhenius break seen at 30 °c for the wild-type enzyme and an increase in cold lability that is attributed to destabilization of the active tetrameric form. kinetic isotope effects (kies) are nearly temperature-independent over the experimental temperature range, and similar in magnitude to ... | 2013 | 23525111 |
| augmentation of pcr efficiency using highly thermostable gold nanoparticles synthesized from a thermophilic bacterium, geobacillus stearothermophilus. | biogenic gold nanoparticles were synthesized from the geobacillus stearothermophilus cell-free extract. these nanoparticles were characterized by uv-vis spectroscopy, ftir, tem, and xrd. the gold nanoparticles showed an absorption maximum at 522 nm. the tem micrograph revealed the formation of monodispersed particles. the high degree of stability of the nanoparticle solution could be attributed to the secretion of certain capping proteins by the bacterium in the reaction mixture which was confir ... | 2013 | 23434707 |
| specific contacts between protein s4 and ribosomal rna are required at multiple stages of ribosome assembly. | assembly of bacterial 30s ribosomal subunits requires structural rearrangements to both its 16s rrna and ribosomal protein components. ribosomal protein s4 nucleates 30s assembly and associates rapidly with the 5' domain of the 16s rrna. in vitro, transformation of initial s4-rrna complexes to long-lived, mature complexes involves refolding of 16s helix 18, which forms part of the decoding center. here we use targeted mutagenesis of geobacillus stearothermophilus s4 to show that remodeling of s4 ... | 2013 | 23431409 |
| large scale dynamics of the michaelis complex in bacillus stearothermophilus lactate dehydrogenase revealed by a single-tryptophan mutant study. | large scale dynamics within the michaelis complex mimic of bacillus stearothermophilus thermophilic lactate dehydrogenase, bsldh·nadh·oxamate, were studied with site specific resolution by laser-induced temperature jump relaxation spectroscopy with a time resolution of 20 ns. nadh emission and trp emission from the wild type and a series of single-tryptophan bsldh mutants, with the tryptophan positions different distances from the active site, were used as reporters of evolving structure in resp ... | 2013 | 23428201 |
| addressable self-immobilization of lactate dehydrogenase across multiple length scales. | successful nanobiotechnology implementation largely depends on control over the interfaces between inorganic materials and biological molecules. controlling the orientations of biomolecules and their spatial arrangements on the surface may transform many technologies including sensors, to energy. here, we demonstrate the self-organization of l-lactate dehydrogenase (ldh), which exhibits enhanced enzymatic activity and stability on a variety of gold surfaces ranging from nanoparticles to electrod ... | 2013 | 23386458 |
| heavy-enzyme kinetic isotope effects on proton transfer in alanine racemase. | the catalytic effects of perdeuterating the pyridoxal phosphate-dependent enzyme alanine racemase from geobacillus stearothermophilus are reported. the mass of the heavy perdeuterated form is ~5.5% greater than that of the protiated form, causing kinetic isotope effects (kies) of ~1.3 on k(cat) and k(cat)/k(m) for both l- and d-alanine. these values increase when cα-deuterated alanine is used as the substrate. the heavy-enzyme kies of ~3 on k(cat)/k(m) with deuterated substrates are greater than ... | 2013 | 23373756 |
| use of 'small but smart' libraries to enhance the enantioselectivity of an esterase from bacillus stearothermophilus towards tetrahydrofuran-3-yl acetate. | two libraries of simultaneous double mutations in the active site region of an esterase from bacillus stearothermophilus were constructed to improve the enantioselectivity in the hydrolysis of tetrahydrofuran-3-yl acetate. as screening of large mutant libraries is hampered by the necessity for gc/ms analysis, mutant libraries were designed according to a 'small but smart' concept. the design of focused libraries was based on data derived from a structural alignment of 3317 amino acid sequences o ... | 2013 | 23331978 |
| a survey of antimicrobial residues in table eggs in khartoum state, sudan, 2007-2008. | the risk to consumers of antimicrobial residues in table eggs produced in khartoum state, sudan, was studied. all producing layer farms (n = 175) in the state were sampled in april, june and august 2008. a total of 933 eggs from 335 layer houses were screened for antimicrobial residues by using the growth inhibition of geobacillus stearothermophilus var. calidolactis in-house test. a high proportion of layer farms (72% in april, 61% in june and 66% in august) and layer houses (63% april, 59% in ... | 2012 | 23327308 |
| a meta-analysis accounting for sources of variability to estimate heat resistance reference parameters of bacteria using hierarchical bayesian modeling: estimation of d at 121.1 °c and ph 7, zt and zph of geobacillus stearothermophilus. | predicting microbial survival requires reference parameters for each micro-organism of concern. when data are abundant and publicly available, a meta-analysis is a useful approach for assessment of these parameters, which can be performed with hierarchical bayesian modeling. geobacillus stearothermophilus is a major agent of microbial spoilage of canned foods and is therefore a persistent problem in the food industry. the thermal inactivation parameters of g. stearothermophilus (d(ref), i.e.the ... | 2013 | 23279820 |
| functional characterization of the galactan utilization system of geobacillus stearothermophilus. | type i galactan is a pectic polysaccharide composed of β-1,4 linked units of d-galactose and is part of the main plant cell wall polysaccharides, which are the most abundant sources of renewable carbon in the biosphere. the thermophilic bacterium geobacillus stearothermophilus t-6 possesses an extensive system for the utilization of plant cell wall polysaccharides, including a 9.4-kb gene cluster, ganrefgba, which encodes galactan-utilization elements. based on enzyme activity assays, the ganefg ... | 2013 | 23216604 |
| crystallization of domains involved in self-assembly of the s-layer protein sbsc. | the gram-positive bacterium geobacillus stearothermophilus atcc 12980 is completely covered with a two-dimensional crystalline monolayer composed of the s-layer protein sbsc. in order to complete the structure of the full-length protein, additional soluble constructs containing the crucial domains for self-assembly have been successfully cloned, expressed and purified. crystals obtained from three different recombinant constructs yielded diffraction to 3.4, 2.8 and 1.5 å resolution. native data ... | 2012 | 23192035 |
| construction of silica-enhanced s-layer protein cages. | the work presented here shows for the first time that it is possible to silicify s-layer coated liposomes and to obtain stable functionalized hollow nano-containers. for this purpose, the s-layer protein of geobacillus stearothermophilus pv72/p2 was recombinantly expressed and used for coating positively charged liposomes composed of dipalmitoylphosphatidylcholine, cholesterol and hexadecylamine in a molar ratio of 10:5:4. subsequently, plain (uncoated) liposomes and s-layer coated liposomes wer ... | 2013 | 23168223 |
| evaluation and validation of two microbiological tests for screening antibiotic residues in honey according to the european guideline for the validation of screening methods. | two microbiological kits based on bacillus stearothermophilus (eclipse 50® and premi®test) have been evaluated and validated according to the european guideline for the validation of screening methods (january 2010) and in relation to the concentrations recommended by the eu-rl in 2007. both tests are robust, a fast method and easy to implement. both tests are applicable to a very large variety of honeys from different floral and geographical origins (rosemary, lavender, scrub, heath, alder, for ... | 2013 | 23126529 |
| lysine racemase from a lactic acid bacterium, oenococcus oeni: structural basis of substrate specificity. | oenococcus oeni, a lactic acid bacterium, possesses a lysine racemase, which has a specific activity towards basic amino acids. a comparison of amino acid residues around the active site suggested that ile222 and tyr354 of the geobacillus stearothermophilus alanine racemase, which shares 60% sequence similarity with lysine racemase, were replaced by thr224 and trp355 in the o. oeni lysine racemase. t224i/w355y double mutations significantly decreased the activity of lysine racemase, whereas i222 ... | 2012 | 23035128 |
| dibenzocycloheptanoids from the leaves of cinnamomum subavenium. | five dibenzocycloheptatrienes (1-3, 5, and 6) and one dibenzocycloheptadiene (8) together with 16 known compounds were isolated from the leaves of cinnamomum subavenium. application of hplc-spe-nmr to a selected fraction afforded two additional dibenzocycloheptatrienes (4, 7). the glycosides 2-7 comprise two diastereomers because of the chiral glycosyl moiety and the axial chirality of the biphenyl system. their structures were elucidated via ecd and 2d nmr analyses and chemical degradation. sub ... | 2012 | 23025417 |
| zinc-binding domain of the bacteriophage t7 dna primase modulates binding to the dna template. | the zinc-binding domain (zbd) of prokaryotic dna primases has been postulated to be crucial for recognition of specific sequences in the single-stranded dna template. to determine the molecular basis for this role in recognition, we carried out homolog-scanning mutagenesis of the zinc-binding domain of dna primase of bacteriophage t7 using a bacterial homolog from geobacillus stearothermophilus. the ability of t7 dna primase to catalyze template-directed oligoribonucleotide synthesis is eliminat ... | 2012 | 23024359 |
| the molecular mechanism of thermostable α-galactosidases agaa and agab explained by x-ray crystallography and mutational studies. | the α-galactosidase agaa from the thermophilic microorganism geobacillus stearothermophilus has great industrial potential because it is fully active at 338 k against raffinose and can increase the yield of manufactured sucrose. agab has lower affinity for its natural substrates but is a powerful tool for the enzymatic synthesis of disaccharides by transglycosylation. these two enzymes have 97% identity and belong to the glycoside hydrolase (gh) family gh36 for which few structures are available ... | 2012 | 23012371 |
| physicochemical characterization of tensio-active produced by geobacillus stearothermophilus isolated from petroleum-contaminated soil. | biosurfactants are surface-active agents of microbial origin, and have a property of lowering the interfacial tension between two liquids. they act on the interface and are amphiphathic molecules; in with both hydrophilic and hydrophobic portions are present in the same molecule. however, the economics of producing biosurfactant has limited its commercial applications, and the costs can be reduced using cheap substrates or industrial waste. the present study showed the biosurfactant production u ... | 2013 | 23010035 |
| computational design of a diels-alderase from a thermophilic esterase: the importance of dynamics. | a novel computational diels-alderase design, based on a relatively rare form of carboxylesterase from geobacillus stearothermophilus, is presented and theoretically evaluated. the structure was found by mining the pdb for a suitable oxyanion hole-containing structure, followed by a combinatorial approach to find suitable substrates and rational mutations. four lead designs were selected and thoroughly modeled to obtain realistic estimates of substrate binding and prearrangement. molecular dynami ... | 2012 | 22983490 |
| biosynthesis of anti-hcv compounds using thermophilic microorganisms. | this work describes the application of thermophilic microorganisms for obtaining 6-halogenated purine nucleosides. biosynthesis of 6-chloropurine-2'-deoxyriboside and 6-chloropurine riboside was achieved by geobacillus stearothermophilus cect 43 with a conversion of 90% and 68%, respectively. furthermore, the selected microorganism was satisfactorily stabilized by immobilization in an agarose matrix. this biocatalyst can be reused at least 70 times without significant loss of activity, obtaining ... | 2012 | 22959520 |
| mutational and structural analysis of l-n-carbamoylase reveals new insights into a peptidase m20/m25/m40 family member. | n-carbamoyl-l-amino acid amidohydrolases (l-carbamoylases) are important industrial enzymes used in kinetic resolution of racemic mixtures of n-carbamoyl-amino acids due to their strict enantiospecificity. in this work, we report the first l-carbamoylase structure belonging to geobacillus stearothermophilus cect43 (bslcar), at a resolution of 2.7 å. structural analysis of bslcar and several members of the peptidase m20/m25/m40 family confirmed the expected conserved residues at the active site i ... | 2012 | 22904279 |
| study of the influence of sporulation conditions on heat resistance of geobacillus stearothermophilus used in the development of biological indicators for steam sterilization. | biological indicators are important tools in infection control via sterilization process monitoring. the use of a standardized spore crop with a well-defined heat resistance will guarantee the quality of a biological indicator. ambient factors during sporulation can affect spore characteristics and properties, including heat resistance. the aim of this study is to evaluate the main sporulation factors responsible for heat resistance in geobacillus stearothermophilus, a useful biological indicato ... | 2012 | 22872104 |
| characterisation of three starch degrading enzymes: thermostable β-amylase, maltotetraogenic and maltogenic α-amylases. | maltogenic α-amylase from bacillus stearothermophilus (bsta) is widely used as bread crumb anti-firming enzyme. a maltotetraose-forming α-amylase from pseudomonas saccharophila (psa) was recently proposed as alternative, hence the need to compare both exo-acting enzymes with some endo-action component. a purely exo-acting thermostable β-amylase from clostridium thermosulfurogenes (ctb) was included for reference purposes. under the experimental conditions used, temperature optima of the enzymes ... | 2012 | 22868150 |
| biotransformation of 2,6-diaminopurine nucleosides by immobilized geobacillus stearothermophilus. | an efficient and green bioprocess to obtain 2,6-diaminopurine nucleosides using thermophilic bacteria is herein reported. geobacillus stearothermophilus cect 43 showed a conversion rate of 90 and 83% at 2 h to obtain 2,6-diaminopurine-2'-deoxyriboside and 2,6-diaminopurine riboside, respectively. the selected biocatalyst was successfully stabilized in an agarose matrix and used to produce up to 23.4 g of 2,6-diaminopurine-2'-deoxyriboside in 240 h of process. these nucleoside analogues can be us ... | 2012 | 22837142 |
| spore germination based assay for monitoring antibiotic residues in milk at dairy farm. | spore germination based assay involves the transformation of dormant spores of bacillus stearothermophilus 953 into active vegetative cells. the inhibition of germination process specifically in presence of antibiotic residues was used as a novel approach for monitoring target contaminants in milk. the indicator organism i.e., b. stearothermophilus 953 was initially allowed to sporulate by seeding in sporulation medium and incubating at 55 °c for 18 ± 2 h. the spores exhibited a typical chain be ... | 2012 | 22806162 |
| tracking spore-forming bacteria in food: from natural biodiversity to selection by processes. | sporeforming bacteria are ubiquitous in the environment and exhibit a wide range of diversity leading to their natural prevalence in foodstuff. the state of the art of sporeformer prevalence in ingredients and food was investigated using a multiparametric pcr-based tool that enables simultaneous detection and identification of various genera and species mostly encountered in food, i.e., alicyclobacillus, anoxybacillus flavithermus, bacillus, b. cereus group, b. licheniformis, b. pumilus, b. spor ... | 2012 | 22795797 |
| a potent and safe h2o2 fumigation approach. | the control of microbial load on surfaces of research and animal labs as well as of hospital and production rooms is an everyday challenge. surface sanitization or disinfection of production equipments and rooms by wiping with chemicals is a time-consuming procedure. its validation is very intricate. alternatively, fumigation allows overcoming many critical aspects of wiping in both procedure and validation. moreover, the use of nebulized hydrogen peroxide (h(2)o(2)) of moderate concentration re ... | 2016 | 22767884 |
| sbsb structure and lattice reconstruction unveil ca2+ triggered s-layer assembly. | s-layers are regular two-dimensional semipermeable protein layers that constitute a major cell-wall component in archaea and many bacteria. the nanoscale repeat structure of the s-layer lattices and their self-assembly from s-layer proteins (slps) have sparked interest in their use as patterning and display scaffolds for a range of nano-biotechnological applications. despite their biological abundance and the technological interest in them, structural information about slps is limited to truncat ... | 2012 | 22722836 |
| [a new dna methyltransferase m.bstc8i forms 5'-g(m5c)nngc-3'. studying of restriction endonuclease sensitivity to m.bstc8i-methylation]. | bacillus stearothermophilus c8 was grown up on the luria agar at 37 degrees c. a new dna-methylase was determined in cellular lysate. the methylation of the dnas of bacteriophages lambda and t7 in the region of 5'-g(m5c)nngc-3' blocked the activity of bstc8i. specificity of m.bstc8i was analyzed on methylated lambda dna. for this purpose, we used computer modeling and the data on the sensitivity of restrictases bstc8i, bsuri, ajni, and pvuii to methylation. the sensitivity of some restrictases t ... | 2012 | 22702143 |
| the abp gene in geobacillus stearothermophilus t-6 encodes a gh27 β-l-arabinopyranosidase. | in this study we demonstrate that the abp gene in geobacillus stearothermophilus t-6 encodes a family 27 glycoside hydrolase β-l-arabinopyranosidase. the catalytic constants towards the chromogenic substrate pnp-β-l-arabinopyranoside were 0.8±0.1 mm, 6.6±0.3 s(-1), and 8.2±0.3 s(-1) mm(-1) for k(m), k(cat) and k(cat)/k(m), respectively. (13)c nmr spectroscopy unequivocally showed that abp is capable of removing β-l-arabinopyranose residues from the natural arabino-polysaccharide, larch arabinoga ... | 2012 | 22687242 |
| structure and characterization of rnase h3 from aquifex aeolicus. | the crystal structure of ribonuclease h3 from aquifex aeolicus (aae-rnase h3) was determined at 2.0 å resolution. aae-rnase h3 consists of an n-terminal tata box-binding protein (tbp)-like domain (n-domain) and a c-terminal rnase h domain (c-domain). the structure of the c-domain highly resembles that of bacillus stearothermophilus rnase h3 (bst-rnase h3), except that it contains three disulfide bonds, and the fourth conserved glutamate residue of the asp-glu-asp-glu active site motif (glu198) i ... | 2012 | 22686566 |
| application of pheb as a reporter gene for geobacillus spp., enabling qualitative colony screening and quantitative analysis of promoter strength. | the pheb gene from geobacillus stearothermophilus dsm6285 has been exploited as a reporter gene for geobacillus spp. the gene product, catechol 2,3-dioxygenase (c23o), catalyzes the formation of 2-hydroxymuconic semialdehyde, which can be readily assayed. the reporter was used to examine expression from the ldh promoter associated with fermentative metabolism. | 2012 | 22685159 |
| cloning and sequence analysis of the heat-stable acrylamidase from a newly isolated thermophilic bacterium, geobacillus thermoglucosidasius aut-01. | a thermophilic bacterium capable of degrading acrylamide, aut-01, was isolated from soil collected from a hot spring area in montana, usa. the thermophilic strain grew with 0.2 % glucose as the sole carbon source and 1.4 mm acrylamide as the sole nitrogen source. the isolate aut-01 was identified as geobacillus thermoglucosidasius based on 16s rdna sequence. an enzyme from the strain capable of transforming acrylamide to acrylic acid was purified by a series of chromatographic columns. the molec ... | 2013 | 22639115 |
| back to natural fiber: wool color influences its sensitivity to enzymatic treatment. | there are many missed biotechnological opportunities in the developmental countries. wool quality improvement is one of them. this study is concerning with improving the wool quality using technical enzymes. white wool proves to be more susceptible to the enzymatic treatment than blackish brown wool. this proves that the enzymatic reaction is sensitive to the natural color differences between wool fibers. a simple enzymatic method has been used to improve the wool quality as well as to investiga ... | 2012 | 22629141 |
| proton transfer in the quinol-dependent nitric oxide reductase from geobacillus stearothermophilus during reduction of oxygen. | bacterial nitric oxide reductases (nor) are integral membrane proteins that catalyse the reduction of nitric oxide to nitrous oxide, often as a step in the process of denitrification. most functional data has been obtained with nors that receive their electrons from a soluble cytochrome c in the periplasm and are hence termed cnor. very recently, the structure of a different type of nor, the quinol-dependent (q)-nor from the thermophilic bacterium geobacillus stearothermophilus was solved to ato ... | 2012 | 22538294 |
| structure and function of bacterial nitric oxide reductases: nitric oxide reductase, anaerobic enzymes. | the crystal structures of bacterial nitric oxide reductases (nor) from pseudomonas aeruginosa and geobacillus stearothermophilus were reported. the structural characteristics of these enzymes, especially at the catalytic site and on the pathway that catalytic protons are delivered, are compared, and the corresponding regions of aerobic and micro-aerobic cytochrome oxidases, o(2) reducing enzymes, which are evolutionarily related to nor are discussed. on the basis of these structural comparisons, ... | 2012 | 22425814 |
| two unsaturated fatty acids with potent α-glucosidase inhibitory activity purified from the body wall of sea cucumber (stichopus japonicus). | one therapeutic approach for preventing diabetes mellitus and obesity is to retard the absorption of glucose via inhibition of α-glucosidase. two unsaturated fatty acids with strong α-glucosidase inhibitory activity, 7(z)-octadecenoic acid (1) and 7(z),10(z)-octadecadienoic acid (2), were purified from the body wall of stichopus japonicus. ic(50) values of compounds 1 and 2 were 0.51 and 0.67 μg/ml against saccharomyces cerevisiae α-glucosidase and 0.49 and 0.60 μg/ml against bacillus stearother ... | 2014 | 22416705 |
| delivery strategies for novel vaccine formulations. | a major challenge in vaccine design is to identify antigen presentation and delivery systems capable of rapidly stimulating both the humoral and cellular components of the immune system to elicit a strong and sustained immunity against different viral isolates. approaches to achieve this end involve live attenuated and inactivated virions, viral vectors, dna, and protein subunits. this review reports the state of current antigen delivery, and focuses on two innovative systems recently establishe ... | 2012 | 24175206 |
| isolating a trimer intermediate in the self-assembly of e2 protein cage. | understanding the self-assembly mechanism of caged proteins provides clues to develop their potential applications in nanotechnology, such as a nanoscale drug delivery system. the e2 protein from bacillus stearothermophilus , with a virus-like caged structure, has drawn much attention for its potential application as a nanocapsule. to investigate its self-assembly process from subunits to a spherical protein cage, we truncate the c-terminus of the e2 subunit. the redesigned protein subunit shows ... | 2012 | 22320400 |
| cooperation between catalytic and dna binding domains enhances thermostability and supports dna synthesis at higher temperatures by thermostable dna polymerases. | we have previously introduced a general kinetic approach for comparative study of processivity, thermostability, and resistance to inhibitors of dna polymerases [pavlov, a. r., et al. (2002) proc. natl. acad. sci. u.s.a.99, 13510-13515]. the proposed method was successfully applied to characterize hybrid dna polymerases created by fusing catalytic dna polymerase domains with various sequence-nonspecific dna binding domains. here we use the developed kinetic analysis to assess basic parameters of ... | 2012 | 22320201 |
| crystal structures of glycoside hydrolase family 51 α-l-arabinofuranosidase from thermotoga maritima. | α-l-arabinofuranosidase from the hyperthermophilic bacterium thermotoga maritima (tm-afase) is an extremely thermophilic enzyme belonging to glycoside hydrolase family 51. it can catalyze the transglycosylation of a novel glycosyl donor, 4,6-dimethoxy-1,3,5-triazin-2-yl (dmt)-β-d-xylopyranoside. in this study we determined the crystal structures of tm-afase in substrate-free and complex forms with arabinose and xylose at 1.8-2.3 å resolution to determine the architecture of the substrate binding ... | 2012 | 22313787 |
| structural dynamics of bacterial translation initiation factor if2. | bacterial translation initiation factor if2 promotes ribosomal subunit association, recruitment, and binding of fmet-trna to the ribosomal p-site and initiation dipeptide formation. here, we present the solution structures of gdp-bound and apo-if2-g2 of bacillus stearothermophilus and provide evidence that this isolated domain binds the 50 s ribosomal subunit and hydrolyzes gtp. differences between the free and gdp-bound structures of if2-g2 suggest that domain reorganization within the g2-g3-c1 ... | 2012 | 22308033 |
| structure and mechanism of the uvra-uvrb dna damage sensor. | nucleotide excision repair (ner) is used by all organisms to eliminate dna lesions. we determined the structure of the geobacillus stearothermophilus uvra-uvrb complex, the damage-sensor in bacterial ner and a new structure of uvra. we observe that the dna binding surface of uvra, previously found in an open shape that binds damaged dna, also exists in a closed groove shape compatible with native dna only. the sensor contains two uvrb molecules that flank the uvra dimer along the predicted path ... | 2012 | 22307053 |
| effect of ion pair on thermostability of f1 protease: integration of computational and experimental approaches. | a thermophilic bacillus stearothermophilus f1 produces an extremely thermostable serine protease. the f1 protease sequence was used to predict its three-dimensional (3d) structure to provide better insights into the relationship between the protein structure and biological function and to identify opportunities for protein engineering. the final model was evaluated to ensure its accuracy using three independent methods: procheck, verify3d, and errat. the predicted 3d structure of f1 protease was ... | 2012 | 22297217 |
| are commercially available geobacillus stearothermophilus biological indicators an appropriate standard for hydrogen peroxide vapour systems in hospitals? | | 2012 | 22297170 |
| potassium iodide-induced changes in pyruvate dehydrogenase complex from bacillus stearothermophilus. | treatment with ki and its subsequent removal induced disassembly of bacillus stearothermophilus pyruvate dehydrogenase complex (pdc) and association of disassembly products, respectively. the disassembly yielded neither completely dissociated components nor aggregate, but did yield a few molecular forms smaller than pdc. depending on the ki concentration, these changes were of three phases: k-1, below 0.6 m; k-2, 1.0-1.5 m; k-3, above 1.8 m. pdc was disassembled in k-1 to c1 comprising pyruvate ... | 1998 | 27393359 |
| role of divalent metal ions on activity and stability of thermostable dipeptidase from bacillus stearothermophilus. | thermostable dipeptidase from bacillus stearothermophilus, a typical metalloenzyme containing 1.0g atom of zn per mole of subunit of the dimeric enzyme was markedly activated by exogenous divalent metal ions such as mn(2+), co(2+), and cd(2+) . in contrast, several others including ba(2+), hg(2+), and cu(2+) considerably inhibited the enzyme, even the inherent metal, zn(2+), being slightly inhibitory. to study the metal-binding properties of this dipeptidase, the enzyme was completely resolved t ... | 1997 | 27393165 |
| thermostable extracellular protease of bacillus stearothermophilus: factors affecting its production. | a strain of protease-producing bacillus stearothermophilus has been isolated. glycerol was the best carbon source for production whereas yeast extract was the best nitrogen source. the bacterium could grow up to 70°c but optimum protease production was at 60°c. best initial ph for protease production was 5. alkaline ph inhibited production. the enzyme was stable at 60°c for 18 h and was inhibited by edta, pmsf and hgcl2. | 1994 | 24421006 |
| production of a thermophilic, extracellular alkaline protease by bacillus stearothermophilus ap-4. | a thermophilic bacillus stearothermophilus strain ap-4 excreting a thermostable alkaline protease, was isolated from a local compost. maximum activity of protease (250 u/ml) was after 36 h growth in broth at ph 9.0 and at 55°c. the protease was optimally active at ph 9.0 and 55°c and was stable in 5 mm cacl2. the enzyme was completely inactivated by pmsf, edta and β-mercaptoethanol. it is therefore a metal ion-dependent, alkaline, serine protease. | 1994 | 24420882 |
| purification of pyruvate dehydrogenase complex from an extreme thermophile, bacillus caldolyticus, and its thermal stability. | pyruvate dehydrogenase multienzyme complex was purified from bacillus caldolyticus. the complex was composed of four polypeptides with molecular masses of 39.8, 41.7, 53.7, and 57.5kda estimated by sds-page and they were presumed to be pyruvate decarboxylase (e1, dimeric), lipoate acetyltransferase (e2), and lipoamide dehydrogenase (e3) on the analogy of those from bacillus stearothermophilus. e1 and e3 were stable at ph 5.7-10.2 and 4.5-11.3, respectively. halves of e1 and e3 activity were abol ... | 1993 | 27280986 |
| [a microbiological method for the rapid determination of antibiotic concentrations during therapy]. | the assay described is an agar diffusion test using bacillus stearothermophilus as test organism. incubation is at 62° c; results can be obtained rapidly within 2 to 3 hours. the test was developed for the determination of gentamicin concentrations in serum and other body fluids. because of its high sensitivity the test strain is also suitable for the determination of other antibiotics. the test is designed primarily for the determination of concentrations in individual samples and thus for moni ... | 1977 | 27723000 |