DNA synapsis through transient tetramerization triggers cleavage by Ecl18kI restriction enzyme

NARCIS (Netherlands)

Zaremba, M.; Lyubchenko, Y.L.; Laurens, N.; van den Broek, B.; Wuite, G.J.L.; Siksnys, V.

2010-01-01

To cut DNA at their target sites, restriction enzymes assemble into different oligomeric structures. The Ecl18kI endonuclease in the crystal is arranged as a tetramer made of two dimers each bound to a DNA copy. However, free in solution Ecl18kI is a dimer. To find out whether the Ecl18kI dimer or

Correspondence between radioactive and functional methods in the quality control of DNA restriction and modifying enzymes

DEFF Research Database (Denmark)

Trujillo, L E; Pupo, E; Miranda, F

1996-01-01

We evaluated the use of two radiolabeled lambda DNA/Hpa II substrates to detect 5'-->3', 3'-->5' single and double stranded DNA dependent exonuclease and phosphatase activities found as contaminants in restriction and modifying enzyme preparations. Looking for the meaning of the radioactive assay...

ICRPfinder: a fast pattern design algorithm for coding sequences and its application in finding potential restriction enzyme recognition sites

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Stafford Phillip

2009-09-01

Full Text Available Abstract Background Restriction enzymes can produce easily definable segments from DNA sequences by using a variety of cut patterns. There are, however, no software tools that can aid in gene building -- that is, modifying wild-type DNA sequences to express the same wild-type amino acid sequences but with enhanced codons, specific cut sites, unique post-translational modifications, and other engineered-in components for recombinant applications. A fast DNA pattern design algorithm, ICRPfinder, is provided in this paper and applied to find or create potential recognition sites in target coding sequences. Results ICRPfinder is applied to find or create restriction enzyme recognition sites by introducing silent mutations. The algorithm is shown capable of mapping existing cut-sites but importantly it also can generate specified new unique cut-sites within a specified region that are guaranteed not to be present elsewhere in the DNA sequence. Conclusion ICRPfinder is a powerful tool for finding or creating specific DNA patterns in a given target coding sequence. ICRPfinder finds or creates patterns, which can include restriction enzyme recognition sites, without changing the translated protein sequence. ICRPfinder is a browser-based JavaScript application and it can run on any platform, in on-line or off-line mode.

Random Tagging Genotyping by Sequencing (rtGBS, an Unbiased Approach to Locate Restriction Enzyme Sites across the Target Genome.

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Elena Hilario

Full Text Available Genotyping by sequencing (GBS is a restriction enzyme based targeted approach developed to reduce the genome complexity and discover genetic markers when a priori sequence information is unavailable. Sufficient coverage at each locus is essential to distinguish heterozygous from homozygous sites accurately. The number of GBS samples able to be pooled in one sequencing lane is limited by the number of restriction sites present in the genome and the read depth required at each site per sample for accurate calling of single-nucleotide polymorphisms. Loci bias was observed using a slight modification of the Elshire et al.some restriction enzyme sites were represented in higher proportions while others were poorly represented or absent. This bias could be due to the quality of genomic DNA, the endonuclease and ligase reaction efficiency, the distance between restriction sites, the preferential amplification of small library restriction fragments, or bias towards cluster formation of small amplicons during the sequencing process. To overcome these issues, we have developed a GBS method based on randomly tagging genomic DNA (rtGBS. By randomly landing on the genome, we can, with less bias, find restriction sites that are far apart, and undetected by the standard GBS (stdGBS method. The study comprises two types of biological replicates: six different kiwifruit plants and two independent DNA extractions per plant; and three types of technical replicates: four samples of each DNA extraction, stdGBS vs. rtGBS methods, and two independent library amplifications, each sequenced in separate lanes. A statistically significant unbiased distribution of restriction fragment size by rtGBS showed that this method targeted 49% (39,145 of BamH I sites shared with the reference genome, compared to only 14% (11,513 by stdGBS.

Detection of the Single Nucleotide Polymorphism at Position rs2735940 in the Human Telomerase Reverse Transcriptase Gene by the Introduction of a New Restriction Enzyme Site for the PCR-RFLP Assay.

Science.gov (United States)

Wang, Sihua; Ding, Mingcui; Duan, Xiaoran; Wang, Tuanwei; Feng, Xiaolei; Wang, Pengpeng; Yao, Wu; Wu, Yongjun; Yan, Zhen; Feng, Feifei; Yu, Songcheng; Wang, Wei

2017-09-01

It has been shown that the single nucleotide polymorphism (SNP) of the rs2735940 site in the human telomerase reverse transcriptase ( hTERT ) gene is associated with increased cancer risk. The traditional method to detect SNP genotypes is polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). However, there is a limitation to utilizing PCR-RFLP due to a lack of proper restriction enzyme sites at many polymorphic loci. This study used an improved PCR-RFLP method with a mismatched base for detection of the SNP rs2735940. A new restriction enzyme cutting site was created by created restriction site PCR (CRS-PCR), and in addition, the restriction enzyme Msp I for CRS-PCR was cheaper than other enzymes. We used this novel assay to determine the allele frequencies in 552 healthy Chinese Han individuals, and found the allele frequencies to be 63% for allele C and 37% for allele T In summary, the modified PCR-RFLP can be used to detect the SNP of rs2735940 with low cost and high efficiency. © 2017 by the Association of Clinical Scientists, Inc.

Restriction enzyme cleavage of ultraviolet-damaged Simian virus 40 and pBR322 DNA

International Nuclear Information System (INIS)

Cleaver, J.E.

1983-01-01

Cleavage of specific DNA sequences by the restriction enzymes EcoRI, HindIII and TaqI was prevented when the DNA was irradiated with ultraviolet light. Most of the effects were attributed to cyclobutane pyrimidine dimers in the recognition sequences; the effectiveness of irradiation was directly proportional to the number of potential dimer sites in the DNA. Combining EcoRI with dimer-specific endonuclease digestion revealed that pyrimidine dimers blocked cleavage within one base-pair on the strand opposite to the dimer but did not block cleavage three to four base-pairs away on the same strand. These are the probable limits for the range of influence of pyrimidine dimers along the DNA, at least for this enzyme. The effect of irradiation on cleavage by TaqI seemed far greater than expected for the cyclobutane dimer yield, possibly because of effects from photoproducts flanking the tetranucleotide recognition sequence and the effect of non-cyclobutane (6-4)pyrimidine photoproducts involving adjacent T and C bases. (author)

Cloning and restriction enzyme mapping of ribosomal DNA of Giardia duodenalis, Giardia ardeae and Giardia muris.

Science.gov (United States)

van Keulen, H; Campbell, S R; Erlandsen, S L; Jarroll, E L

1991-06-01

In an attempt to study Giardia at the DNA sequence level, the rRNA genes of three species, Giardia duodenalis, Giardia ardeae and Giardia muris were cloned and restriction enzyme maps were constructed. The rDNA repeats of these Giardia show completely different restriction enzyme recognition patterns. The size of the rDNA repeat ranges from approximately 5.6 kb in G. duodenalis to 7.6 kb in both G. muris and G. ardeae. These size differences are mainly attributable to the variation in length of the spacer. Minor differences exist among these Giardia in the sizes of their small subunit rRNA and the internal transcribed spacer between small and large subunit rRNA. The genetic maps were constructed by sequence analysis of the DNA around the 5' and 3' ends of the mature rRNA genes and between the rRNA covering the 5.8S rRNA gene and internal transcribed spacer. Comparison of the 5.8S rDNA and 3' end of large subunit rDNA from these three Giardia species showed considerable sequence variation, but the rDNA sequences of G. duodenalis and G. ardeae appear more closely related to each other than to G. muris.

The effect of an angiotensin-converting enzyme inhibitor on water and electrolyte balance in water-restricted sheep

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R.A. Meintjies

1999-07-01

Full Text Available The importance of angiotensin II in the regulation of water and electrolyte balance in sheep is questionable. In this trial the effects of an angiotensin-converting enzyme (ACE inhibitor were quantified in sheep on restricted water intake. Comparing the phase of water restriction only with that of water restriction plus ACE inhibition, significant increases were observed during the latter phase in urine volume, sodium and potassium excretion via the urine, sodium concentration in the plasma and osmolar clearance. Urine osmolarity decreased with inhibition of angiotensin II formation while variables such as water, sodium and potassium loss via the faeces were unaffected. Most of the renal effects of ACE inhibition, except the increase in urinary potassium excretion, were explicable in terms of the established functions of angiotensin II. Furthermore, results of this trial indicate that angiotensin II has no significant effect on the intestine in regulating water and electrolyte excretion via the faeces.

Maternal protein restriction affects gene expression and enzyme activity of intestinal disaccharidases in adult rat offspring

International Nuclear Information System (INIS)

Pinheiro, D.F.; Pacheco, P.D.G.; Alvarenga, P.V.; Buratini, J. Jr; Castilho, A.C.S.; Lima, P.F.; Sartori, D.R.S.; Vicentini-Paulino, M.L.M.

2013-01-01

This study investigated the consequences of intrauterine protein restriction on the gastrointestinal tract and particularly on the gene expression and activity of intestinal disaccharidases in the adult offspring. Wistar rat dams were fed isocaloric diets containing 6% protein (restricted, n = 8) or 17% protein (control, n = 8) throughout gestation. Male offspring (n = 5-8 in each group) were evaluated at 3 or 16 weeks of age. Maternal protein restriction during pregnancy produced offspring with growth restriction from birth (5.7 ± 0.1 vs 6.3 ± 0.1 g; mean ± SE) to weaning (42.4 ± 1.3 vs 49.1 ± 1.6 g), although at 16 weeks of age their body weight was similar to control (421.7 ± 8.9 and 428.5 ± 8.5 g). Maternal protein restriction also increased lactase activity in the proximal (0.23 ± 0.02 vs 0.15 ± 0.02), medial (0.30 ± 0.06 vs 0.14 ± 0.01) and distal (0.43 ± 0.07 vs 0.07 ± 0.02 U·g -1 ·min -1 ) small intestine, and mRNA lactase abundance in the proximal intestine (7.96 ± 1.11 vs 2.38 ± 0.47 relative units) of 3-week-old offspring rats. In addition, maternal protein restriction increased sucrase activity (1.20 ± 0.02 vs 0.91 ± 0.02 U·g -1 ·min -1 ) and sucrase mRNA abundance (4.48 ± 0.51 vs 1.95 ± 0.17 relative units) in the duodenum of 16-week-old rats. In conclusion, the present study shows for the first time that intrauterine protein restriction affects gene expression of intestinal enzymes in offspring

Maternal protein restriction affects gene expression and enzyme activity of intestinal disaccharidases in adult rat offspring

Energy Technology Data Exchange (ETDEWEB)

Pinheiro, D.F.; Pacheco, P.D.G.; Alvarenga, P.V.; Buratini, J. Jr; Castilho, A.C.S.; Lima, P.F.; Sartori, D.R.S.; Vicentini-Paulino, M.L.M. [Departamento de Fisiologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP (Brazil)

2013-03-15

This study investigated the consequences of intrauterine protein restriction on the gastrointestinal tract and particularly on the gene expression and activity of intestinal disaccharidases in the adult offspring. Wistar rat dams were fed isocaloric diets containing 6% protein (restricted, n = 8) or 17% protein (control, n = 8) throughout gestation. Male offspring (n = 5-8 in each group) were evaluated at 3 or 16 weeks of age. Maternal protein restriction during pregnancy produced offspring with growth restriction from birth (5.7 ± 0.1 vs 6.3 ± 0.1 g; mean ± SE) to weaning (42.4 ± 1.3 vs 49.1 ± 1.6 g), although at 16 weeks of age their body weight was similar to control (421.7 ± 8.9 and 428.5 ± 8.5 g). Maternal protein restriction also increased lactase activity in the proximal (0.23 ± 0.02 vs 0.15 ± 0.02), medial (0.30 ± 0.06 vs 0.14 ± 0.01) and distal (0.43 ± 0.07 vs 0.07 ± 0.02 U·g{sup -1}·min{sup -1}) small intestine, and mRNA lactase abundance in the proximal intestine (7.96 ± 1.11 vs 2.38 ± 0.47 relative units) of 3-week-old offspring rats. In addition, maternal protein restriction increased sucrase activity (1.20 ± 0.02 vs 0.91 ± 0.02 U·g{sup -1}·min{sup -1}) and sucrase mRNA abundance (4.48 ± 0.51 vs 1.95 ± 0.17 relative units) in the duodenum of 16-week-old rats. In conclusion, the present study shows for the first time that intrauterine protein restriction affects gene expression of intestinal enzymes in offspring.

Re-evaluating the kinetics of ATP hydrolysis during initiation of DNA sliding by Type III restriction enzymes.

Science.gov (United States)

Tóth, Júlia; Bollins, Jack; Szczelkun, Mark D

2015-12-15

DNA cleavage by the Type III restriction enzymes requires long-range protein communication between recognition sites facilitated by thermally-driven 1D diffusion. This 'DNA sliding' is initiated by hydrolysis of multiple ATPs catalysed by a helicase-like domain. Two distinct ATPase phases were observed using short oligoduplex substrates; the rapid consumption of ∼10 ATPs coupled to a protein conformation switch followed by a slower phase, the duration of which was dictated by the rate of dissociation from the recognition site. Here, we show that the second ATPase phase is both variable and only observable when DNA ends are proximal to the recognition site. On DNA with sites more distant from the ends, a single ATPase phase coupled to the conformation switch was observed and subsequent site dissociation required little or no further ATP hydrolysis. The overall DNA dissociation kinetics (encompassing site release, DNA sliding and escape via a DNA end) were not influenced by the second phase. Although the data simplifies the ATP hydrolysis scheme for Type III restriction enzymes, questions remain as to why multiple ATPs are hydrolysed to prepare for DNA sliding. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Influence of nutrient restriction and melatonin supplementation of pregnant ewes on maternal and fetal pancreatic digestive enzymes and insulin-containing clusters.

Science.gov (United States)

Keomanivong, F E; Lemley, C O; Camacho, L E; Yunusova, R; Borowicz, P P; Caton, J S; Meyer, A M; Vonnahme, K A; Swanson, K C

2016-03-01

Primiparous ewes (n=32) were assigned to dietary treatments in a 2×2 factorial arrangement to determine effects of nutrient restriction and melatonin supplementation on maternal and fetal pancreatic weight, digestive enzyme activity, concentration of insulin-containing clusters and plasma insulin concentrations. Treatments consisted of nutrient intake with 60% (RES) or 100% (ADQ) of requirements and melatonin supplementation at 0 (CON) or 5 mg/day (MEL). Treatments began on day 50 of gestation and continued until day 130. On day 130, blood was collected under general anesthesia from the uterine artery, uterine vein, umbilical artery and umbilical vein for plasma insulin analysis. Ewes were then euthanized and the pancreas removed from the ewe and fetus, trimmed of mesentery and fat, weighed and snap-frozen until enzyme analysis. In addition, samples of pancreatic tissue were fixed in 10% formalin solution for histological examination including quantitative characterization of size and distribution of insulin-containing cell clusters. Nutrient restriction decreased (P⩽0.001) maternal pancreatic mass (g) and α-amylase activity (U/g, kU/pancreas, U/kg BW). Ewes supplemented with melatonin had increased pancreatic mass (P=0.03) and α-amylase content (kU/pancreas and U/kg BW). Melatonin supplementation decreased (P=0.002) maternal pancreatic insulin-positive tissue area (relative to section of tissue), and size of the largest insulin-containing cell cluster (P=0.04). Nutrient restriction decreased pancreatic insulin-positive tissue area (P=0.03) and percent of large (32 001 to 512 000 µm2) and giant (⩾512 001 µm2) insulin-containing cell clusters (P=0.04) in the fetus. Insulin concentrations in plasma from the uterine vein, umbilical artery and umbilical vein were greater (P⩽0.01) in animals receiving 100% requirements. When comparing ewes to fetuses, ewes had a greater percentage of medium insulin-containing cell clusters (2001 to 32 000 µm2) while fetuses

Caloric restriction counteracts age-related changes in the activities of sorbitol metabolizing enzymes from mouse liver

Science.gov (United States)

Hagopian, Kevork; Ramsey, Jon J.; Weindruch, Richard

2009-01-01

The influence of caloric restriction (CR) on hepatic sorbitol-metabolizing enzyme activities was investigated in young and old mice. Aldose reductase and sorbitol dehydrogenase activities were significantly lower in old CR mice than in old controls. Young CR mice showed decreased aldose reductase activity and a trend towards decreased sorbitol dehydrogenase when compared to controls. Metabolites of the pathway, namely sorbitol, glucose and fructose were decreased by CR in young and old mice. Pyruvate levels were decreased by CR in both young and old mice, while lactate decreased only in old CR. Malate levels increased in old CR but remained unchanged in young CR, when compared with controls. Accordingly, the lactae/pyruvate and malate/pyruvate ratios in young and old CR mice were increased, indicating increased NADH/NAD and NADPH/NADP redox couples, respectively. The results indicate that decreased glucose levels under CR conditions lead to decreased sorbitol pathway enzyme activities and metabolite levels, and could contribute to the beneficial effects of long-term CR through decreased sorbitol levels and NADPH sparing. PMID:18953666

Optimizing Restriction Site Placement for Synthetic Genomes

Science.gov (United States)

Montes, Pablo; Memelli, Heraldo; Ward, Charles; Kim, Joondong; Mitchell, Joseph S. B.; Skiena, Steven

Restriction enzymes are the workhorses of molecular biology. We introduce a new problem that arises in the course of our project to design virus variants to serve as potential vaccines: we wish to modify virus-length genomes to introduce large numbers of unique restriction enzyme recognition sites while preserving wild-type function by substitution of synonymous codons. We show that the resulting problem is NP-Complete, give an exponential-time algorithm, and propose effective heuristics, which we show give excellent results for five sample viral genomes. Our resulting modified genomes have several times more unique restriction sites and reduce the maximum gap between adjacent sites by three to nine-fold.

The Variants Within the COL5A1 Gene are Associated with Reduced Risk of Anterior Cruciate Ligament Injury in Skiers

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Stępień-Słodkowska Marta

2015-03-01

Full Text Available The purpose of this study was to examine the association of the BstUI RFLP C/T (rs 12722 and DpnII RFLP C/T (rs 13946 COL5A1 polymorphisms, individually and as haplotypes, with anterior cruciate ligament ruptures in recreational skiers. Subjects were 138 male recreational skiers with surgically diagnosed primary anterior cruciate ligament ruptures. The control group consisted of 183 apparently healthy male recreational skiers, who were without any self-reported history of ligament or tendon injury. DNA was extracted from buccal cells donated by the subjects and genotyping was carried out using real-time PCR. The genotype distributions for both polymorphisms met Hardy- Weinberg expectations in both groups. There were no significant differences in genotype distribution of allele frequencies of COL5A1 BstUI RFLP C/T and COL5A1 DpnII RFLP C/T polymorphisms between the ACL rupture and control groups. The T-T (BstUI RFLP T, DpnII RFLP T haplotype was the most common (55.6%. The haplotype T-C was not present in any of the subjects. There was an underrepresentation tendency of the C-T haplotype in the study group compared to controls under recessive mode of inheritance. Higher frequency of the COL5A1 BstUI RFLP C/T and COL5A1DpnII RFLP C/T polymorphisms haplotype is associated with reduced risk of anterior cruciate ligament injury in a group of apparently healthy male recreational skiers.

Mapping DNA cleavage by the Type ISP restriction-modification enzymes following long-range communication between DNA sites in different orientations

OpenAIRE

van Aelst, Kara; Saikrishnan, Kayarat; Szczelkun, Mark D

2015-01-01

The prokaryotic Type ISP restriction-modification enzymes are single-chain proteins comprising an Mrr-family nuclease, a superfamily 2 helicase-like ATPase, a coupler domain, a methyltransferase, and a DNA-recognition domain. Upon recognising an unmodified DNA target site, the helicase-like domain hydrolyzes ATP to cause site release (remodeling activity) and to then drive downstream translocation consuming 1-2 ATP per base pair (motor activity). On an invading foreign DNA, double-strand brea...

Pattern analysis approach reveals restriction enzyme cutting abnormalities and other cDNA library construction artifacts using raw EST data

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Zhou Sun

2012-05-01

Full Text Available Abstract Background Expressed Sequence Tag (EST sequences are widely used in applications such as genome annotation, gene discovery and gene expression studies. However, some of GenBank dbEST sequences have proven to be “unclean”. Identification of cDNA termini/ends and their structures in raw ESTs not only facilitates data quality control and accurate delineation of transcription ends, but also furthers our understanding of the potential sources of data abnormalities/errors present in the wet-lab procedures for cDNA library construction. Results After analyzing a total of 309,976 raw Pinus taeda ESTs, we uncovered many distinct variations of cDNA termini, some of which prove to be good indicators of wet-lab artifacts, and characterized each raw EST by its cDNA terminus structure patterns. In contrast to the expected patterns, many ESTs displayed complex and/or abnormal patterns that represent potential wet-lab errors such as: a failure of one or both of the restriction enzymes to cut the plasmid vector; a failure of the restriction enzymes to cut the vector at the correct positions; the insertion of two cDNA inserts into a single vector; the insertion of multiple and/or concatenated adapters/linkers; the presence of 3′-end terminal structures in designated 5′-end sequences or vice versa; and so on. With a close examination of these artifacts, many problematic ESTs that have been deposited into public databases by conventional bioinformatics pipelines or tools could be cleaned or filtered by our methodology. We developed a software tool for Abnormality Filtering and Sequence Trimming for ESTs (AFST, http://code.google.com/p/afst/ using a pattern analysis approach. To compare AFST with other pipelines that submitted ESTs into dbEST, we reprocessed 230,783 Pinus taeda and 38,709 Arachis hypogaea GenBank ESTs. We found 7.4% of Pinus taeda and 29.2% of Arachis hypogaea GenBank ESTs are “unclean” or abnormal, all of which could be cleaned

Fast conversion of scFv to Fab antibodies using type IIs restriction enzymes.

Science.gov (United States)

Sanmark, Hanna; Huovinen, Tuomas; Matikka, Tero; Pettersson, Tiina; Lahti, Maria; Lamminmäki, Urpo

2015-11-01

Single chain variable fragment (scFv) antibody libraries are widely used for developing novel bioaffinity reagents, although Fab or IgG molecules are the preferred antibody formats in many final applications. Therefore, rapid conversion methods for combining multiple DNA fragments are needed to attach constant domains to the scFv derived variable domains. In this study we describe a fast and easy cloning method for the conversion of single framework scFv fragments to Fab fragments using type IIS restriction enzymes. All cloning steps excluding plating of the Fab transformants can be done in 96 well plates and the procedure can be completed in one working day. The concept was tested by converting 69 scFv clones into Fab format on 96 well plates, which resulted in 93% success rate. The method is particularly useful as a high-throughput tool for the conversion of the chosen scFv clones into Fab molecules in order to analyze them as early as possible, as the conversion can significantly affect the binding properties of the chosen clones. Copyright © 2015 Elsevier B.V. All rights reserved.

Mutagenesis of the redox-active disulfide in mercuric ion reductase: Catalysis by mutant enzymes restricted to flavin redox chemistry

International Nuclear Information System (INIS)

Distefano, M.D.; Au, K.G.; Walsh, C.T.

1989-01-01

Mercuric reductase, a flavoenzyme that possesses a redox-active cystine, Cys 135 Cys 140 , catalyzes the reduction of Hg(II) to Hg(0) by NADPH. As a probe of mechanism, the authors have constructed mutants lacking a redox-active disulfide by eliminating Cys 135 (Ala 135 Cys 140 ), Cys 14 (Cys 135 Ala 140 ), or both (Ala 135 Ala 140 ). Additionally, they have made double mutants that lack Cys 135 (Ala 135 Cys 139 Cys 140 ) or Cys 140 (Cys 135 Cys 139 Ala 140 ) but introduce a new Cys in place of Gly 139 with the aim of constructing dithiol pairs in the active site that do not form a redox-active disulfide. The resulting mutant enzymes all lack redox-active disulfides and are hence restricted to FAD/FADH 2 redox chemistry. Each mutant enzyme possesses unique physical and spectroscopic properties that reflect subtle differences in the FAD microenvironment. Preliminary evidence for the Ala 135 Cys 139 Cys 14 mutant enzyme suggests that this protein forms a disulfide between the two adjacent Cys residues. Hg(II) titration experiments that correlate the extent of charge-transfer quenching with Hg(II) binding indicate that the Ala 135 Cys 140 protein binds Hg(II) with substantially less avidity than does the wild-type enzyme. All mutant mercuric reductases catalyze transhydrogenation and oxygen reduction reactions through obligatory reduced flavin intermediates at rates comparable to or greater than that of the wild-type enzyme. In multiple-turnover assays which monitored the production of Hg(0), two of the mutant enzymes were observed to proceed through at least 30 turnovers at rates ca. 1000-fold slower than that of wild-type mercuric reductase. They conclude that the Cys 135 and Cys 140 thiols serve as Hg(II) ligands that orient the Hg(II) for subsequent reduction by a reduced flavin intermediate

Characterization of Biomphalaria orbignyi, Biomphalaria peregrina and Biomphalaria oligoza by polymerase chain reaction and restriction enzyme digestion of the internal transcribed spacer region of the RNA ribosomal gene

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Spatz Linus

2000-01-01

Full Text Available The correct identification of Biomphalaria oligoza, B. orbignyi and B. peregrina species is difficult due to the morphological similarities among them. B. peregrina is widely distributed in South America and is considered a potential intermediate host of Schistosoma mansoni. We have reported the use of the polymerase chain reaction and restriction fragment length polymorphism analysis of the internal transcribed spacer region of the ribosomal DNA for the molecular identification of these snails. The snails were obtained from different localities of Argentina, Brazil and Uruguay. The restriction patterns obtained with MvaI enzyme presented the best profile to identify the three species. The profiles obtained with all enzymes were used to estimate genetic similarities among B. oligoza, B. peregrina and B. orbignyi. This is also the first report of B. orbignyi in Uruguay.

Fusion of GFP to the M.EcoKI DNA methyltransferase produces a new probe of Type I DNA restriction and modification enzymes

International Nuclear Information System (INIS)

Chen, Kai; Roberts, Gareth A.; Stephanou, Augoustinos S.; Cooper, Laurie P.; White, John H.; Dryden, David T.F.

2010-01-01

Research highlights: → Successful fusion of GFP to M.EcoKI DNA methyltransferase. → GFP located at C-terminal of sequence specificity subunit does not later enzyme activity. → FRET confirms structural model of M.EcoKI bound to DNA. -- Abstract: We describe the fusion of enhanced green fluorescent protein to the C-terminus of the HsdS DNA sequence-specificity subunit of the Type I DNA modification methyltransferase M.EcoKI. The fusion expresses well in vivo and assembles with the two HsdM modification subunits. The fusion protein functions as a sequence-specific DNA methyltransferase protecting DNA against digestion by the EcoKI restriction endonuclease. The purified enzyme shows Foerster resonance energy transfer to fluorescently-labelled DNA duplexes containing the target sequence and to fluorescently-labelled ocr protein, a DNA mimic that binds to the M.EcoKI enzyme. Distances determined from the energy transfer experiments corroborate the structural model of M.EcoKI.

The BsaHI restriction-modification system: Cloning, sequencing and analysis of conserved motifs

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Roberts Richard J

2008-05-01

Full Text Available Abstract Background Restriction and modification enzymes typically recognise short DNA sequences of between two and eight bases in length. Understanding the mechanism of this recognition represents a significant challenge that we begin to address for the BsaHI restriction-modification system, which recognises the six base sequence GRCGYC. Results The DNA sequences of the genes for the BsaHI methyltransferase, bsaHIM, and restriction endonuclease, bsaHIR, have been determined (GenBank accession #EU386360, cloned and expressed in E. coli. Both the restriction endonuclease and methyltransferase enzymes share significant similarity with a group of 6 other enzymes comprising the restriction-modification systems HgiDI and HgiGI and the putative HindVP, NlaCORFDP, NpuORFC228P and SplZORFNP restriction-modification systems. A sequence alignment of these homologues shows that their amino acid sequences are largely conserved and highlights several motifs of interest. We target one such conserved motif, reading SPERRFD, at the C-terminal end of the bsaHIR gene. A mutational analysis of these amino acids indicates that the motif is crucial for enzymatic activity. Sequence alignment of the methyltransferase gene reveals a short motif within the target recognition domain that is conserved among enzymes recognising the same sequences. Thus, this motif may be used as a diagnostic tool to define the recognition sequences of the cytosine C5 methyltransferases. Conclusion We have cloned and sequenced the BsaHI restriction and modification enzymes. We have identified a region of the R. BsaHI enzyme that is crucial for its activity. Analysis of the amino acid sequence of the BsaHI methyltransferase enzyme led us to propose two new motifs that can be used in the diagnosis of the recognition sequence of the cytosine C5-methyltransferases.

Comparison of time-restricted and ad libitum self-feeding on the growth, feeding behavior and daily digestive enzyme profiles of Atlantic salmon

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Shi, Ce; Liu, Ying; Yi, Mengmeng; Zheng, Jimeng; Tian, Huiqin; Du, Yishuai; Li, Xian; Sun, Guoxiang

2017-07-01

Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and, hence, better growth performance, the assumption has rarely been tested. This study compares the effects of time-restricted versus free access self-feeding on the growth, feeding behavior and daily digestive enzyme rhythms of Atlantic salmon ( Salmo salar). In an experiment that lasted 6 weeks, fish (109.9 g) were divided into two groups: group 1 had free access to a self-feeder (FA); group 2 received three meals per day (2 h per meal) at dawn, midday and dusk via a time-restricted self-feeder (TR). At the end of the experiment, the fish were sampled every 3 h over a 24-h period. The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase, while FA fish displayed no statistically significant rhythms ( P>0.05). Pepsin activity of TR fish also showed a significant daily rhythm ( P0.05). In conclusion, the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance, with the TR group showing comparatively poor blood glucose regulation.

Host Specificity of Salmonella typhimurium Deoxyribonucleic Acid Restriction and Modification

Science.gov (United States)

Slocum, Harvey; Boyer, Herbert W.

1973-01-01

The restriction and modification genes of Salmonella typhimurium which lie near the thr locus were transferred to a restrictionless mutant of Escherichia coli. These genes were found to be allelic to the E. coli K, B, and A restriction and modification genes. E. coli recombinants with the restriction and modification host specificity of S. typhimurium restricted phage λ that had been modified by each of the seven known host specificities of E. coli at efficiency of plating levels of about 10−2. Phage λ modified with the S. typhimurium host specificity was restricted by six of the seven E. coli host specificities but not by the RII (fi− R-factor controlled) host specificity. It is proposed that the restriction and modification enzymes of this S. typhimurium host specificity have two substrates, one of which is a substrate for the RII host specificity enzymes. PMID:4570605

Altering the selection capabilities of common cloning vectors via restriction enzyme mediated gene disruption

Science.gov (United States)

2013-01-01

Background The cloning of gene sequences forms the basis for many molecular biological studies. One important step in the cloning process is the isolation of bacterial transformants carrying vector DNA. This involves a vector-encoded selectable marker gene, which in most cases, confers resistance to an antibiotic. However, there are a number of circumstances in which a different selectable marker is required or may be preferable. Such situations can include restrictions to host strain choice, two phase cloning experiments and mutagenesis experiments, issues that result in additional unnecessary cloning steps, in which the DNA needs to be subcloned into a vector with a suitable selectable marker. Results We have used restriction enzyme mediated gene disruption to modify the selectable marker gene of a given vector by cloning a different selectable marker gene into the original marker present in that vector. Cloning a new selectable marker into a pre-existing marker was found to change the selection phenotype conferred by that vector, which we were able to demonstrate using multiple commonly used vectors and multiple resistance markers. This methodology was also successfully applied not only to cloning vectors, but also to expression vectors while keeping the expression characteristics of the vector unaltered. Conclusions Changing the selectable marker of a given vector has a number of advantages and applications. This rapid and efficient method could be used for co-expression of recombinant proteins, optimisation of two phase cloning procedures, as well as multiple genetic manipulations within the same host strain without the need to remove a pre-existing selectable marker in a previously genetically modified strain. PMID:23497512

Survival of Saccharomyces cerevisiae after treatment with the restriction endonuclease Alu I

International Nuclear Information System (INIS)

Winckler, K.; Bach, B.; Obe, G.

1988-01-01

Treatment of yeast cells proficient in the repair of radiation damage (Saccharomyces cervisiae) with the restriction endonuclease Alu I leads to a positive dose-effect relationship between inactivation level and enzyme concentration. The data suggest an uptake of the active restriction enzyme into the cells and a relationship between induction of DNA double-strand breaks and cell killing. (author)

DNA double-strand break measurement in mammalian cells by pulsed-field gel electrophoresis: an approach using restriction enzymes and gene probing

International Nuclear Information System (INIS)

Loebrich, M.; Ikpeme, S.; Kiefer, J.

1994-01-01

DNA samples prepared from human SP 3 cells, which had not been exposed to various doses of X-ray, were treated with NotI restriction endonuclease before being run in a contour-clamped homogeneous electrophoresis system. The restriction enzyme cuts the DNA at defined positions delivering DNA sizes which can be resolved by pulsed-field gel electrophoresis (PFGE). In order to investigate only one of the DNA fragments, a human lactoferrin cDNA, pHL-41, was hybridized to the DNA separated by PFGE. As a result, only the DNA fragment which contains the hybridized gene was detected resulting in a one-band pattern. The decrease of this band was found to be exponential with increasing radiation dose. From the slope, a double-strand break induction rate of (6.3±0.7) x 10 -3 /Mbp/Gy was deduced for 80 kV X-rays. (Author)

Exogenous DNA internalisation by sperm cells is improved by combining lipofection and restriction enzyme mediated integration.

Science.gov (United States)

Churchil, R R; Gupta, J; Singh, A; Sharma, D

2011-06-01

1. Three types of exogenous DNA inserts, i.e. complete linearised pVIVO2-GFP/LacZ vector (9620 bp), the LacZ gene (5317 bp) and the GFP gene (2152 bp) were used to transfect chicken spermatozoa through simple incubation of sperm cells with insert. 2. PCR assay, Dot Blot hybridisation and Southern hybridisation showed the successful internalisation of exogenous DNA by chicken sperm cells. 3. Lipofection and Restriction Enzyme Mediated Integration (REMI) were used to improve the rate of internalisation of exogenous DNA by sperm cells. 4. Results from dot blot as well as Southern hybridisation were semi-quantified and improved exogenous DNA uptake by sperm cells through lipofection and REMI. Stronger signals were observed from hybridisation of LacZ as well as GFP specific probe with the DNA from lipofected exogenous DNA transfected sperm DNA in comparison with those transfected with nude exogenous DNA.

Reference genome-independent assessment of mutation density using restriction enzyme-phased sequencing

Directory of Open Access Journals (Sweden)

Monson-Miller Jennifer

2012-02-01

Full Text Available Abstract Background The availability of low cost sequencing has spurred its application to discovery and typing of variation, including variation induced by mutagenesis. Mutation discovery is challenging as it requires a substantial amount of sequencing and analysis to detect very rare changes and distinguish them from noise. Also challenging are the cases when the organism of interest has not been sequenced or is highly divergent from the reference. Results We describe the development of a simple method for reduced representation sequencing. Input DNA was digested with a single restriction enzyme and ligated to Y adapters modified to contain a sequence barcode and to provide a compatible overhang for ligation. We demonstrated the efficiency of this method at SNP discovery using rice and arabidopsis. To test its suitability for the discovery of very rare SNP, one control and three mutagenized rice individuals (1, 5 and 10 mM sodium azide were used to prepare genomic libraries for Illumina sequencers by ligating barcoded adapters to NlaIII restriction sites. For genome-dependent discovery 15-30 million of 80 base reads per individual were aligned to the reference sequence achieving individual sequencing coverage from 7 to 15×. We identified high-confidence base changes by comparing sequences across individuals and identified instances consistent with mutations, i.e. changes that were found in a single treated individual and were solely GC to AT transitions. For genome-independent discovery 70-mers were extracted from the sequence of the control individual and single-copy sequence was identified by comparing the 70-mers across samples to evaluate copy number and variation. This de novo "genome" was used to align the reads and identify mutations as above. Covering approximately 1/5 of the 380 Mb genome of rice we detected mutation densities ranging from 0.6 to 4 per Mb of diploid DNA depending on the mutagenic treatment. Conclusions The

Short-term calorie restriction feminizes the mRNA profiles of drug metabolizing enzymes and transporters in livers of mice

International Nuclear Information System (INIS)

Fu, Zidong Donna; Klaassen, Curtis D.

2014-01-01

Calorie restriction (CR) is one of the most effective anti-aging interventions in mammals. A modern theory suggests that aging results from a decline in detoxification capabilities and thus accumulation of damaged macromolecules. The present study aimed to determine how short-term CR alters mRNA profiles of genes that encode metabolism and detoxification machinery in the liver. Male C57BL/6 mice were fed CR (0, 15, 30, or 40%) diets for one month, followed by mRNA quantification of 98 xenobiotic processing genes (XPGs) in the liver, including 7 uptake transporters, 39 phase-I enzymes, 37 phase-II enzymes, 10 efflux transporters, and 5 transcription factors. In general, 15% CR did not alter mRNAs of most XPGs, whereas 30 and 40% CR altered over half of the XPGs (32 increased and 29 decreased). CR up-regulated some phase-I enzymes (fold increase), such as Cyp4a14 (12), Por (2.3), Nqo1 (1.4), Fmo2 (5.4), and Fmo3 (346), and numerous number of phase-II enzymes, such as Sult1a1 (1.2), Sult1d1 (2.0), Sult1e1 (33), Sult3a1 (2.2), Gsta4 (1.3), Gstm2 (1.3), Gstm3 (1.7), and Mgst3 (2.2). CR feminized the mRNA profiles of 32 XPGs in livers of male mice. For instance, CR decreased the male-predominantly expressed Oatp1a1 (97%) and increased the female-predominantly expressed Oatp1a4 (11). In conclusion, short-term CR alters the mRNA levels of over half of the 98 XPGs quantified in livers of male mice, and over half of these alterations appear to be due to feminization of the liver. - Highlights: • Utilized a graded CR model in male mice • The mRNA profiles of xenobiotic processing genes (XPGs) in liver were investigated. • CR up-regulates many phase-II enzymes. • CR tends to feminize the mRNA profiles of XPGs

Short-term calorie restriction feminizes the mRNA profiles of drug metabolizing enzymes and transporters in livers of mice

Energy Technology Data Exchange (ETDEWEB)

Fu, Zidong Donna [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Klaassen, Curtis D., E-mail: cklaasse@kumc.edu [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66160 (United States)

2014-01-01

Calorie restriction (CR) is one of the most effective anti-aging interventions in mammals. A modern theory suggests that aging results from a decline in detoxification capabilities and thus accumulation of damaged macromolecules. The present study aimed to determine how short-term CR alters mRNA profiles of genes that encode metabolism and detoxification machinery in the liver. Male C57BL/6 mice were fed CR (0, 15, 30, or 40%) diets for one month, followed by mRNA quantification of 98 xenobiotic processing genes (XPGs) in the liver, including 7 uptake transporters, 39 phase-I enzymes, 37 phase-II enzymes, 10 efflux transporters, and 5 transcription factors. In general, 15% CR did not alter mRNAs of most XPGs, whereas 30 and 40% CR altered over half of the XPGs (32 increased and 29 decreased). CR up-regulated some phase-I enzymes (fold increase), such as Cyp4a14 (12), Por (2.3), Nqo1 (1.4), Fmo2 (5.4), and Fmo3 (346), and numerous number of phase-II enzymes, such as Sult1a1 (1.2), Sult1d1 (2.0), Sult1e1 (33), Sult3a1 (2.2), Gsta4 (1.3), Gstm2 (1.3), Gstm3 (1.7), and Mgst3 (2.2). CR feminized the mRNA profiles of 32 XPGs in livers of male mice. For instance, CR decreased the male-predominantly expressed Oatp1a1 (97%) and increased the female-predominantly expressed Oatp1a4 (11). In conclusion, short-term CR alters the mRNA levels of over half of the 98 XPGs quantified in livers of male mice, and over half of these alterations appear to be due to feminization of the liver. - Highlights: • Utilized a graded CR model in male mice • The mRNA profiles of xenobiotic processing genes (XPGs) in liver were investigated. • CR up-regulates many phase-II enzymes. • CR tends to feminize the mRNA profiles of XPGs.

Short-term calorie restriction feminizes the mRNA profiles of drug metabolizing enzymes and transporters in livers of mice.

Science.gov (United States)

Fu, Zidong Donna; Klaassen, Curtis D

2014-01-01

Calorie restriction (CR) is one of the most effective anti-aging interventions in mammals. A modern theory suggests that aging results from a decline in detoxification capabilities and thus accumulation of damaged macromolecules. The present study aimed to determine how short-term CR alters mRNA profiles of genes that encode metabolism and detoxification machinery in the liver. Male C57BL/6 mice were fed CR (0, 15, 30, or 40%) diets for one month, followed by mRNA quantification of 98 xenobiotic processing genes (XPGs) in the liver, including 7 uptake transporters, 39 phase-I enzymes, 37 phase-II enzymes, 10 efflux transporters, and 5 transcription factors. In general, 15% CR did not alter mRNAs of most XPGs, whereas 30 and 40% CR altered over half of the XPGs (32 increased and 29 decreased). CR up-regulated some phase-I enzymes (fold increase), such as Cyp4a14 (12), Por (2.3), Nqo1 (1.4), Fmo2 (5.4), and Fmo3 (346), and numerous number of phase-II enzymes, such as Sult1a1 (1.2), Sult1d1 (2.0), Sult1e1 (33), Sult3a1 (2.2), Gsta4 (1.3), Gstm2 (1.3), Gstm3 (1.7), and Mgst3 (2.2). CR feminized the mRNA profiles of 32 XPGs in livers of male mice. For instance, CR decreased the male-predominantly expressed Oatp1a1 (97%) and increased the female-predominantly expressed Oatp1a4 (11). In conclusion, short-term CR alters the mRNA levels of over half of the 98 XPGs quantified in livers of male mice, and over half of these alterations appear to be due to feminization of the liver. Copyright © 2013 Elsevier Inc. All rights reserved.

Maternal protein restriction induces alterations in insulin signaling and ATP sensitive potassium channel protein in hypothalami of intrauterine growth restriction fetal rats.

Science.gov (United States)

Liu, Xiaomei; Qi, Ying; Gao, Hong; Jiao, Yisheng; Gu, Hui; Miao, Jianing; Yuan, Zhengwei

2013-01-01

It is well recognized that intrauterine growth restriction leads to the development of insulin resistance and type 2 diabetes mellitus in adulthood. To investigate the mechanisms behind this "metabolic imprinting" phenomenon, we examined the impact of maternal undernutrition on insulin signaling pathway and the ATP sensitive potassium channel expression in the hypothalamus of intrauterine growth restriction fetus. Intrauterine growth restriction rat model was developed through maternal low protein diet. The expression and activated levels of insulin signaling molecules and K(ATP) protein in the hypothalami which were dissected at 20 days of gestation, were analyzed by western blot and real time PCR. The tyrosine phosphorylation levels of the insulin receptor substrate 2 and phosphatidylinositol 3'-kinase p85α in the hypothalami of intrauterine growth restriction fetus were markedly reduced. There was also a downregulation of the hypothalamic ATP sensitive potassium channel subunit, sulfonylurea receptor 1, which conveys the insulin signaling. Moreover, the abundances of gluconeogenesis enzymes were increased in the intrauterine growth restriction livers, though no correlation was observed between sulfonylurea receptor 1 and gluconeogenesis enzymes. Our data suggested that aberrant intrauterine milieu impaired insulin signaling in the hypothalamus, and these alterations early in life might contribute to the predisposition of the intrauterine growth restriction fetus toward the adult metabolic disorders.

Mapping DNA cleavage by the Type ISP restriction-modification enzymes following long-range communication between DNA sites in different orientations

Science.gov (United States)

van Aelst, Kara; Saikrishnan, Kayarat; Szczelkun, Mark D.

2015-01-01

The prokaryotic Type ISP restriction-modification enzymes are single-chain proteins comprising an Mrr-family nuclease, a superfamily 2 helicase-like ATPase, a coupler domain, a methyltransferase, and a DNA-recognition domain. Upon recognising an unmodified DNA target site, the helicase-like domain hydrolyzes ATP to cause site release (remodeling activity) and to then drive downstream translocation consuming 1–2 ATP per base pair (motor activity). On an invading foreign DNA, double-strand breaks are introduced at random wherever two translocating enzymes form a so-called collision complex following long-range communication between a pair of target sites in inverted (head-to-head) repeat. Paradoxically, structural models for collision suggest that the nuclease domains are too far apart (>30 bp) to dimerise and produce a double-strand DNA break using just two strand-cleavage events. Here, we examined the organisation of different collision complexes and how these lead to nuclease activation. We mapped DNA cleavage when a translocating enzyme collides with a static enzyme bound to its site. By following communication between sites in both head-to-head and head-to-tail orientations, we could show that motor activity leads to activation of the nuclease domains via distant interactions of the helicase or MTase-TRD. Direct nuclease dimerization is not required. To help explain the observed cleavage patterns, we also used exonuclease footprinting to demonstrate that individual Type ISP domains can swing off the DNA. This study lends further support to a model where DNA breaks are generated by multiple random nicks due to mobility of a collision complex with an overall DNA-binding footprint of ∼30 bp. PMID:26507855

Effect of dietary protein restriction on renal ammonia metabolism

Science.gov (United States)

Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E.; Guo, Hui; Verlander, Jill W.

2015-01-01

Dietary protein restriction has multiple benefits in kidney disease. Because protein intake is a major determinant of endogenous acid production, it is important that net acid excretion change in parallel during protein restriction. Ammonia is the primary component of net acid excretion, and inappropriate ammonia excretion can lead to negative nitrogen balance. Accordingly, we examined ammonia excretion in response to protein restriction and then we determined the molecular mechanism of the changes observed. Wild-type C57Bl/6 mice fed a 20% protein diet and then changed to 6% protein developed an 85% reduction in ammonia excretion within 2 days, which persisted during a 10-day study. The expression of multiple proteins involved in renal ammonia metabolism was altered, including the ammonia-generating enzymes phosphate-dependent glutaminase (PDG) and phosphoenolpyruvate carboxykinase (PEPCK) and the ammonia-metabolizing enzyme glutamine synthetase. Rhbg, an ammonia transporter, increased in expression in the inner stripe of outer medullary collecting duct intercalated cell (OMCDis-IC). However, collecting duct-specific Rhbg deletion did not alter the response to protein restriction. Rhcg deletion did not alter ammonia excretion in response to dietary protein restriction. These results indicate 1) dietary protein restriction decreases renal ammonia excretion through coordinated regulation of multiple components of ammonia metabolism; 2) increased Rhbg expression in the OMCDis-IC may indicate a biological role in addition to ammonia transport; and 3) Rhcg expression is not necessary to decrease ammonia excretion during dietary protein restriction. PMID:25925252

Suppression of APOBEC3-mediated restriction of HIV-1 by Vif

Directory of Open Access Journals (Sweden)

Yuqing eFeng

2014-08-01

Full Text Available The APOBEC3 restriction factors are a family of deoxycytidine deaminases that are able to suppress replication of viruses with a single-stranded DNA intermediate by inducing mutagenesis and functional inactivation of the virus. Of the seven human APOBEC3 enzymes, only APOBEC3-D, -F, -G, and -H appear relevant to restriction of HIV-1 in CD4+ T cells and will be the focus of this review. The restriction of HIV-1 occurs most potently in the absence of HIV-1 Vif that induces polyubiquitination and degradation of APOBEC3 enzymes through the proteasome pathway. To restrict HIV-1, APOBEC3 enzymes must be encapsidated into budding virions. Upon infection of the target cell during reverse transcription of the HIV-1 RNA into (-DNA APOBEC3 enzymes deaminate cytosines to forms uracils in single-stranded (- DNA regions. Upon replication of the (-DNA to (+DNA, the HIV-1 reverse transcriptase incorporates adenines opposite the uracils thereby inducing C/G to T/A mutations that can functionally inactivate HIV-1. APOBEC3G is the most studied APOBEC3 enzyme and it is known that Vif attempts to thwart APOBEC3 function not only by inducing its proteasomal degradation but by several degradation-independent mechanisms such as inhibiting APOBEC3G virion encapsidation, mRNA translation, and for those APOBEC3G molecules that still become virion encapsidated, Vif can inhibit APOBEC3G mutagenic activity. Although most Vif variants can induce efficient degradation of APOBEC3-D, -F, and -G, there appears to be differential sensitivity to Vif-mediated degradation for APOBEC3H. This review examines APOBEC3-mediated HIV restriction mechanisms, how Vif acts as a substrate receptor for a Cullin5 ubiquitin ligase complex to induce degradation of APOBEC3s, and the determinants and functional consequences of the APOBEC3 and Vif interaction from a biological and biochemical perspective.

Hemolysis, Elevated Liver Enzymes, and Low Platelets, Severe Fetal Growth Restriction, Postpartum Subarachnoid Hemorrhage, and Craniotomy: A Rare Case Report and Systematic Review

Directory of Open Access Journals (Sweden)

Shadi Rezai

2017-01-01

Full Text Available Introduction. Hemolysis, elevated liver enzymes, and low platelets (HELLP syndrome is a relatively uncommon but traumatic condition occurring in the later stage of pregnancy as a complication of severe preeclampsia or eclampsia. Prompt brain computed tomography (CT or magnetic resonance imaging (MRI and a multidisciplinary management approach are required to improve perinatal outcome. Case. A 37-year-old, Gravida 6, Para 1-0-4-1, Hispanic female with a history of chronic hypertension presented at 26 weeks and 6 days of gestational age. She was noted to have hemolysis, elevated liver enzymes, and low platelets (HELLP syndrome accompanied by fetal growth restriction (FGR, during ultrasound evaluation, warranting premature delivery. The infant was delivered in stable condition suffering no permanent neurological deficit. Conclusion. HELLP syndrome is an uncommon and traumatic obstetric event which can lead to neurological deficits if not managed in a responsive and rapid manner. The central aggravating factor seems to be hypertension induced preeclamptic or eclamptic episode and complications thereof. The syndrome itself is manifested by hemolytic anemia, increased liver enzymes, and decreasing platelet counts with a majority of neurological defects resulting from hemorrhagic stroke or subarachnoid hemorrhage (SAH. To minimize adverse perinatal outcomes, obstetric management of this medical complication must include rapid clinical assessment, diagnostic examination, and neurosurgery consultation.

Human cellular restriction factors that target HIV-1 replication

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Jeang Kuan-Teh

2009-09-01

Full Text Available Abstract Recent findings have highlighted roles played by innate cellular factors in restricting intracellular viral replication. In this review, we discuss in brief the activities of apolipoprotein B mRNA-editing enzyme 3G (APOBEC3G, bone marrow stromal cell antigen 2 (BST-2, cyclophilin A, tripartite motif protein 5 alpha (Trim5α, and cellular microRNAs as examples of host restriction factors that target HIV-1. We point to countermeasures encoded by HIV-1 for moderating the potency of these cellular restriction functions.

A model for cell wall dissolution in mating yeast cells: polarized secretion and restricted diffusion of cell wall remodeling enzymes induces local dissolution.

Science.gov (United States)

Huberman, Lori B; Murray, Andrew W

2014-01-01

Mating of the budding yeast, Saccharomyces cerevisiae, occurs when two haploid cells of opposite mating types signal using reciprocal pheromones and receptors, grow towards each other, and fuse to form a single diploid cell. To fuse, both cells dissolve their cell walls at the point of contact. This event must be carefully controlled because the osmotic pressure differential between the cytoplasm and extracellular environment causes cells with unprotected plasma membranes to lyse. If the cell wall-degrading enzymes diffuse through the cell wall, their concentration would rise when two cells touched each other, such as when two pheromone-stimulated cells adhere to each other via mating agglutinins. At the surfaces that touch, the enzymes must diffuse laterally through the wall before they can escape into the medium, increasing the time the enzymes spend in the cell wall, and thus raising their concentration at the point of attachment and restricting cell wall dissolution to points where cells touch each other. We tested this hypothesis by studying pheromone treated cells confined between two solid, impermeable surfaces. This confinement increases the frequency of pheromone-induced cell death, and this effect is diminished by reducing the osmotic pressure difference across the cell wall or by deleting putative cell wall glucanases and other genes necessary for efficient cell wall fusion. Our results support the model that pheromone-induced cell death is the result of a contact-driven increase in the local concentration of cell wall remodeling enzymes and suggest that this process plays an important role in regulating cell wall dissolution and fusion in mating cells.

A Model for Cell Wall Dissolution in Mating Yeast Cells: Polarized Secretion and Restricted Diffusion of Cell Wall Remodeling Enzymes Induces Local Dissolution

Science.gov (United States)

Huberman, Lori B.; Murray, Andrew W.

2014-01-01

Mating of the budding yeast, Saccharomyces cerevisiae, occurs when two haploid cells of opposite mating types signal using reciprocal pheromones and receptors, grow towards each other, and fuse to form a single diploid cell. To fuse, both cells dissolve their cell walls at the point of contact. This event must be carefully controlled because the osmotic pressure differential between the cytoplasm and extracellular environment causes cells with unprotected plasma membranes to lyse. If the cell wall-degrading enzymes diffuse through the cell wall, their concentration would rise when two cells touched each other, such as when two pheromone-stimulated cells adhere to each other via mating agglutinins. At the surfaces that touch, the enzymes must diffuse laterally through the wall before they can escape into the medium, increasing the time the enzymes spend in the cell wall, and thus raising their concentration at the point of attachment and restricting cell wall dissolution to points where cells touch each other. We tested this hypothesis by studying pheromone treated cells confined between two solid, impermeable surfaces. This confinement increases the frequency of pheromone-induced cell death, and this effect is diminished by reducing the osmotic pressure difference across the cell wall or by deleting putative cell wall glucanases and other genes necessary for efficient cell wall fusion. Our results support the model that pheromone-induced cell death is the result of a contact-driven increase in the local concentration of cell wall remodeling enzymes and suggest that this process plays an important role in regulating cell wall dissolution and fusion in mating cells. PMID:25329559

A new restriction endonuclease from Citrobacter freundii

OpenAIRE

Janulaitis, A.A.; Stakenas, P.S.; Lebedenko, E.N.; Berlin, Yu.A.

1982-01-01

CfrI, a new restriction endonuclease of unique substrate specificity, has been isolated from a Citrobacter freundii strain. The enzyme recognizes a degenerated sequence PyGGCCPu in double-strand DNA and cleaves it between Py and G residues to yield 5′ -protruding tetranucleotide ends GGCC.

Determination of genotype differences through restriction ...

African Journals Online (AJOL)

Tyrosinase gene or C locus has long been implicated in the coat colour determination. This gene a copper-containing enzyme located on chromosome 11q14.3 is expressed in melanocytes and controls the major steps in pigment production. In camel, C locus a restriction site provoked by the T variant of the mutation was ...

A new restriction endonuclease from Citrobacter freundii

Science.gov (United States)

Janulaitis, A.A.; Stakenas, P.S.; Lebedenko, E.N.; Berlin, Yu.A.

1982-01-01

CfrI, a new restriction endonuclease of unique substrate specificity, has been isolated from a Citrobacter freundii strain. The enzyme recognizes a degenerated sequence PyGGCCPu in double-strand DNA and cleaves it between Py and G residues to yield 5′ -protruding tetranucleotide ends GGCC. Images PMID:6294607

Enzyme loading dependence of cellulose hydrolysis of sugarcane bagasse

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Carlos Martín

2012-01-01

Full Text Available The enzymatic hydrolysis of steam-pretreated sugarcane bagasse, either delignified or non-delignified, was studied as a function of enzyme loading. Hydrolysis experiments were carried out using five enzyme loadings (2.5 to 20 FPU/g cellulose and the concentration of solids was 2% for both materials. Alkaline delignification improved cellulose hydrolysis by increasing surface area. For both materials, glucose concentrations increased with enzyme loading. On the other hand, enzyme loadings higher than 15 FPU/g did not result in any increase in the initial rate, since the excess of enzyme adsorbed onto the substrate restricted the diffusion process through the structure.

Use of sperm plasmid DNA lipofection combined with REMI (restriction enzyme-mediated insertion) for production of transgenic chickens expressing eGFP (enhanced green fluorescent protein) or human follicle-stimulating hormone.

Science.gov (United States)

Harel-Markowitz, Eliane; Gurevich, Michael; Shore, Laurence S; Katz, Adi; Stram, Yehuda; Shemesh, Mordechai

2009-05-01

Linearized p-eGFP (plasmid-enhanced green fluorescent protein) or p-hFSH (plasmid human FSH) sequences with the corresponding restriction enzyme were lipofected into sperm genomic DNA. Sperm transfected with p-eGFP were used for artificial insemination in hens, and in 17 out of 19 of the resultant chicks, the exogenous DNA was detected in their lymphocytes as determined by PCR and expressed in tissues as determined by (a) PCR, (b) specific emission of green fluorescence by the eGFP, and (c) Southern blot analysis. A complete homology was found between the Aequorea Victoria eGFP DNA and a 313-bp PCR product of extracted DNA from chick blood cells. Following insemination with sperm lipofected with p-hFSH, transgenic offspring were obtained for two generations as determined by detection of the transgene for human FSH (PCR) and expression of the gene (RT-PCR and quantitative real-time PCR) and the presence of the protein in blood (radioimmunoassay). Data demonstrate that lipofection of plasmid DNA with restriction enzyme is a highly efficient method for the production of transfected sperm to produce transgenic offspring by direct artificial insemination.

Food restriction modulates β-adrenergic-sensitive adenylate cyclase in rat liver during aging

International Nuclear Information System (INIS)

Katz, M.S.

1988-01-01

Adenylate cyclase activities were studied in rat liver during postmaturational aging of male Fischer 344 rats fed ad libitum or restricted to 60% of the ad libitum intake. Catecholamine-stimulated adenylate cyclase activity increased by 200-300% between 6 and 24-27 mo of age in ad libitum-fed rats, whereas in food-restricted rats catecholamine response increased by only 58-84% between 6 and 30 mo. In ad libitum-fed rats, glucagon-stimulated enzyme activity also increased by 40% between 6 and 12 mo and in restricted rats a similar age-related increase was delayed until 18 mo. β-Adrenergic receptor density increased by 50% between 6 and 24 mo in livers from ad libitum-fed but not food-restricted rats and showed a highly significant correlation with maximal isoproterenol-stimulated adenylate cyclase activity over the postmaturational life span. Age-related increases in unstimulated (basal) adenylate cyclase activity and nonreceptor-mediated enzyme activation were retarded by food restriction. The results demonstrate that food restriction diminishes a marked age-related increase in β-adrenergic-sensitive adenylate cyclase activity of rat liver. Alterations of adrenergic-responsive adenylate cyclase with age and the modulatory effects of food restriction appear to be mediated by changes in both receptor and nonreceptor components of adenylate cyclase

Analysis of mutation/rearrangement frequencies and methylation patterns at a given DNA locus using restriction fragment length polymorphism.

Science.gov (United States)

Boyko, Alex; Kovalchuk, Igor

2010-01-01

Restriction fragment length polymorphism (RFLP) is a difference in DNA sequences of organisms belonging to the same species. RFLPs are typically detected as DNA fragments of different lengths after digestion with various restriction endonucleases. The comparison of RFLPs allows investigators to analyze the frequency of occurrence of mutations, such as point mutations, deletions, insertions, and gross chromosomal rearrangements, in the progeny of stressed plants. The assay involves restriction enzyme digestion of DNA followed by hybridization of digested DNA using a radioactively or enzymatically labeled probe. Since DNA can be digested with methylation sensitive enzymes, the assay can also be used to analyze a methylation pattern of a particular locus. Here, we describe RFLP analysis using methylation-insensitive and methylation-sensitive enzymes.

NAD+ metabolite levels as a function of vitamins and calorie restriction: evidence for different mechanisms of longevity

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Song Peng

2010-02-01

Full Text Available Abstract Background NAD+ is a coenzyme for hydride transfer enzymes and a substrate for sirtuins and other NAD+-dependent ADPribose transfer enzymes. In wild-type Saccharomyces cerevisiae, calorie restriction accomplished by glucose limitation extends replicative lifespan in a manner that depends on Sir2 and the NAD+ salvage enzymes, nicotinic acid phosphoribosyl transferase and nicotinamidase. Though alterations in the NAD+ to nicotinamide ratio and the NAD+ to NADH ratio are anticipated by models to account for the effects of calorie restriction, the nature of a putative change in NAD+ metabolism requires analytical definition and quantification of the key metabolites. Results Hydrophilic interaction chromatography followed by tandem electrospray mass spectrometry were used to identify the 12 compounds that constitute the core NAD+ metabolome and 6 related nucleosides and nucleotides. Whereas yeast extract and nicotinic acid increase net NAD+ synthesis in a manner that can account for extended lifespan, glucose restriction does not alter NAD+ or nicotinamide levels in ways that would increase Sir2 activity. Conclusions The results constrain the possible mechanisms by which calorie restriction may regulate Sir2 and suggest that provision of vitamins and calorie restriction extend lifespan by different mechanisms.

Rational Design of Thermally Stable Novel Biocatalytic Nanomaterials: Enzyme Stability in Restricted Spatial Dimensions

Science.gov (United States)

Mudhivarthi, Vamsi K.

Enzyme stability is of intense interest in bio-materials science as biocatalysts, and as sensing platforms. This is essentially because the unique properties of DNA, RNA, PAA can be coupled with the interesting and novel properties of proteins to produce systems with unprecedented control over their properties. In this article, the very first examples of enzyme/NA/inorganic hybrid nanomaterials and enzyme-Polyacrylic acid conjugates will be presented. The basic principles of design, synthesis and control of properties of these hybrid materials will be presented first, and this will be followed by a discussion of selected examples from our recent research findings. Data show that key properties of biological catalysts are improved by the inorganic framework especially when the catalyst is co-embedded with DNA. Several examples of such studies with various enzymes and proteins, including horseradish peroxidase (HRP), glucose oxidase (GO), cytochrome c (Cyt c), met-hemoglobin (Hb) and met-myoglobin (Mb) will be discussed. Additionally, key insights obtained by the standard methods of materials science including XRD, SEM and TEM as well as biochemical, calorimetric and spectroscopic methods will be discussed. Furthermore, improved structure and enhanced activities of the biocatalysts in specific cases will be demonstrated along with the potential stabilization mechanisms. Our hypothesis is that nucleic acids provide an excellent control over the enzyme-solid interactions as well as rational assembly of nanomaterials. These novel nanobiohybrid materials may aid in engineering more effective synthetic materials for gene-delivery, RNA-delivery and drug delivery applications.

NcoI restriction fragment length polymorphism (RFLP) of the tumour necrosis factor (TNF alpha) region in primary biliary cirrhosis and in healthy Danes

DEFF Research Database (Denmark)

Fugger, L; Morling, N; Ryder, L P

1989-01-01

The restriction fragment length polymorphism of the human tumour necrosis factor (TNF alpha) region was investigated by means of 20 different restriction enzymes and a human TNF alpha cDNA probe. Only one of the enzymes, NcoI, revealed a polymorphic pattern consisting of fragments of 10.5 and 5.5...

Facile synthesis of new carbon-11 labeled conformationally restricted rivastigmine analogues as potential PET agents for imaging AChE and BChE enzymes

International Nuclear Information System (INIS)

Wang Min; Wang Jiquan; Gao Mingzhang; Zheng Qihuang

2008-01-01

Rivastigmine is a newer-generation inhibitor with a dual inhibitory action on both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes, and is used for the treatment of AChE- and BChE-related diseases such as brain Alzheimer's disease and cardiovascular disease. New carbon-11 labeled conformationally restricted rivastigmine analogues radiolabeled quaternary ammonium triflate salts, (3aR,9bS)-1-[ 11 C]methyl-1-methyl-6-(methylcarbamoyloxy)-2,3,3a,4,5, 9b-hexahy dro-1H-benzo[g]indolium triflate ([ 11 C]8) and (3aR,9bS)-1-[ 11 C]methyl-1-methyl-6-(heptylcarbamoyloxy)-2,3,3a,4,5, 9b-hexahy dro-1H-benzo[g]indolium triflate ([ 11 C]9), were designed and synthesized as potential positron emission tomography (PET) agents for imaging AChE and BChE enzymes. The appropriate precursors were labeled with [ 11 C]CH 3 OTf through N-[ 11 C]methylation, and the target tracers were isolated by solid-phase extraction (SPE) using a cation-exchange CM Sep-Pak cartridge in 40-50% radiochemical yields decay corrected to end of bombardment (EOB), 15-20 min overall synthesis time, and 148-222 GBq/μmol specific activity at EOB

Study on detection of mutation DNA fragment in gastric cancer by restriction endonuclease fingerprinting with capillary electrophoresis.

Science.gov (United States)

Wang, Rong; Xie, Hua; Xu, Yue-Bing; Jia, Zheng-Ping; Meng, Xian-Dong; Zhang, Juan-Hong; Ma, Jun; Wang, Juan; Wang, Xian-Hua

2012-03-01

The DNA fragment detection focusing technique has further enhanced the sensitivity and information of DNA targets. The DNA fragment detection method was established by capillary electrophoresis with laser-induced fluorescence detection and restriction endonuclease chromatographic fingerprinting (CE-LIF-REF) in our experiment. The silica capillary column was coated with short linear polyarclarylamide (SLPA) using nongel sieving technology. The excision product of various restricted enzymes of DNA fragments was obtained by REF with the molecular biology software Primer Premier 5. The PBR322/BsuRI DNA marker was used to establish the optimization method. The markers were focused electrophoretically and detected by CE-LIF. The results demonstrate that the CE-LIF-REF with SLPA can improve separation, sensitivity and speed of analysis. This technique may be applied to analysis of the excision product of various restricted enzymes of prokaryotic plasmid (pIRES2), eukaryote plasmid (pcDNA3.1) and the PCR product of codon 248 region of gastric cancer tissue. The results suggest that this method could very sensitively separate the excision products of various restricted enzymes at a much better resolution than the traditional agarose electrophoresis. Copyright © 2011 John Wiley & Sons, Ltd.

CisSERS: Customizable In Silico Sequence Evaluation for Restriction Sites.

Science.gov (United States)

Sharpe, Richard M; Koepke, Tyson; Harper, Artemus; Grimes, John; Galli, Marco; Satoh-Cruz, Mio; Kalyanaraman, Ananth; Evans, Katherine; Kramer, David; Dhingra, Amit

2016-01-01

High-throughput sequencing continues to produce an immense volume of information that is processed and assembled into mature sequence data. Data analysis tools are urgently needed that leverage the embedded DNA sequence polymorphisms and consequent changes to restriction sites or sequence motifs in a high-throughput manner to enable biological experimentation. CisSERS was developed as a standalone open source tool to analyze sequence datasets and provide biologists with individual or comparative genome organization information in terms of presence and frequency of patterns or motifs such as restriction enzymes. Predicted agarose gel visualization of the custom analyses results was also integrated to enhance the usefulness of the software. CisSERS offers several novel functionalities, such as handling of large and multiple datasets in parallel, multiple restriction enzyme site detection and custom motif detection features, which are seamlessly integrated with real time agarose gel visualization. Using a simple fasta-formatted file as input, CisSERS utilizes the REBASE enzyme database. Results from CisSERS enable the user to make decisions for designing genotyping by sequencing experiments, reduced representation sequencing, 3'UTR sequencing, and cleaved amplified polymorphic sequence (CAPS) molecular markers for large sample sets. CisSERS is a java based graphical user interface built around a perl backbone. Several of the applications of CisSERS including CAPS molecular marker development were successfully validated using wet-lab experimentation. Here, we present the tool CisSERS and results from in-silico and corresponding wet-lab analyses demonstrating that CisSERS is a technology platform solution that facilitates efficient data utilization in genomics and genetics studies.

Genetic relationships between clinical and non-clinical strains of Yersinia enterocolitica biovar 1A as revealed by multilocus enzyme electrophoresis and multilocus restriction typing

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Virdi Jugsharan S

2010-05-01

Full Text Available Abstract Background Genetic relationships among 81 strains of Y. enterocolitica biovar 1A isolated from clinical and non-clinical sources were discerned by multilocus enzyme electrophoresis (MLEE and multilocus restriction typing (MLRT using six loci each. Such studies may reveal associations between the genotypes of the strains and their sources of isolation. Results All loci were polymorphic and generated 62 electrophoretic types (ETs and 12 restriction types (RTs. The mean genetic diversity (H of the strains by MLEE and MLRT was 0.566 and 0.441 respectively. MLEE (DI = 0.98 was more discriminatory and clustered Y. enterocolitica biovar 1A strains into four groups, while MLRT (DI = 0.77 identified two distinct groups. BURST (Based Upon Related Sequence Types analysis of the MLRT data suggested aquatic serotype O:6,30-6,31 isolates to be the ancestral strains from which, clinical O:6,30-6,31 strains might have originated by host adaptation and genetic change. Conclusion MLEE revealed greater genetic diversity among strains of Y. enterocolitica biovar 1A and clustered strains in four groups, while MLRT grouped the strains into two groups. BURST analysis of MLRT data nevertheless provided newer insights into the probable evolution of clinical strains from aquatic strains.

CisSERS: Customizable In Silico Sequence Evaluation for Restriction Sites.

Directory of Open Access Journals (Sweden)

Richard M Sharpe

Full Text Available High-throughput sequencing continues to produce an immense volume of information that is processed and assembled into mature sequence data. Data analysis tools are urgently needed that leverage the embedded DNA sequence polymorphisms and consequent changes to restriction sites or sequence motifs in a high-throughput manner to enable biological experimentation. CisSERS was developed as a standalone open source tool to analyze sequence datasets and provide biologists with individual or comparative genome organization information in terms of presence and frequency of patterns or motifs such as restriction enzymes. Predicted agarose gel visualization of the custom analyses results was also integrated to enhance the usefulness of the software. CisSERS offers several novel functionalities, such as handling of large and multiple datasets in parallel, multiple restriction enzyme site detection and custom motif detection features, which are seamlessly integrated with real time agarose gel visualization. Using a simple fasta-formatted file as input, CisSERS utilizes the REBASE enzyme database. Results from CisSERS enable the user to make decisions for designing genotyping by sequencing experiments, reduced representation sequencing, 3'UTR sequencing, and cleaved amplified polymorphic sequence (CAPS molecular markers for large sample sets. CisSERS is a java based graphical user interface built around a perl backbone. Several of the applications of CisSERS including CAPS molecular marker development were successfully validated using wet-lab experimentation. Here, we present the tool CisSERS and results from in-silico and corresponding wet-lab analyses demonstrating that CisSERS is a technology platform solution that facilitates efficient data utilization in genomics and genetics studies.

Restriction fragment length polymorphism (RFLP) of two HLA-B-associated transcripts (BATs) genes in healthy Danes

DEFF Research Database (Denmark)

Fugger, L; Morling, N; Ryder, L P

1990-01-01

The restriction fragment length polymorphism (RFLP) of the two human HLA-B-associated transcripts (BATs) genes, BAT1 and BAT2, was investigated using 5 different restriction enzymes and two human BAT1 and BAT2 cDNA probes. Two of the enzymes, NcoI and RsaI, revealed polymorphic patterns which were...... investigated in healthy Danes. The cDNA/restriction enzyme combination BAT1/NcoI identifies polymorphic bands at 12 kb, 8 kb, 2.5 kb, and 1.1 kb, while the BAT2/RsaI combination identifies polymorphic bands at 3.3 kb, 2.7 kb, 2.3 kb, and 0.9 kb. The frequencies of these markers were determined in 90 unrelated...... Danes. Co-dominant segregation and allelic behavior was seen for the BAT1/NcoI 12 kb and 8 kb bands and the BAT2/RsaI 2.7 kb and 2.3 kb bands, respectively. It is possible that the BAT2/RsaI 3.3 kb band represents a rare allele of the BAT2/RsaI system. The BAT2/RsaI 2.3 kb marker was strongly negatively...

Effect of ionizing radiation on the activity of restriction nucleases PvuII and HindIII

International Nuclear Information System (INIS)

Luzova, M.; Michaelidesova, A.; Davidkova, M.

2014-01-01

The research is focused on the influence of the ionizing radiation on the activity of the restriction enzymes PvuII and HindIII. Enzymes PvuII and HindIII are restriction endonucleases of type II. These enzymes can be found in bacteria and they have a significant role in defense mechanisms of bacteria against viruses. They cleave DNA double helix at specific recognition palindromic sequences in the presence of cofactor Mg 2+ . PvuII cleaves the sequence CAG↓CTG and HindIII cleaves the sequence A↓AGCTT in marked places. Plasmid pcDNA3 has been used as the DNA substrate for the whole experimental study. It is 5446 base pairs (bp) long, circular DNA molecule and it contains three recognition sites for enzyme PvuII and one recognition site for enzyme HindIII. After the correct interaction of pcDNA3 with PvuII, we thus have three plasmid fragments with lengths 1069, 1097 and 3280 bp. When HindIII is incubated with this plasmid, we shall obtain the linear form of the DNA plasmid.The method for processing the cleaved DNA samples is the agarose gel electrophoresis. The activity of the irradiated enzymes decreases with increasing dose of radiation, because a part of the enzymes is deactivated due to induced radiation damage. To determine effect of radiation quality, samples were irradiated using proton and gamma sources. The results of our experimental study will be presented and discussed with respect to molecular structure of both enzymes and particular sites of radical damage influencing their function. (authors)

Analytical workflow of double-digest restriction site-associated DNA sequencing based on empirical and in silico optimization in tomato.

Science.gov (United States)

Shirasawa, Kenta; Hirakawa, Hideki; Isobe, Sachiko

2016-04-01

Double-digest restriction site-associated DNA sequencing (ddRAD-Seq) enables high-throughput genome-wide genotyping with next-generation sequencing technology. Consequently, this method has become popular in plant genetics and breeding. Although computational in silico prediction of restriction sites from the genome sequence is recognized as an effective approach for choosing the restriction enzymes to be used, few reports have evaluated the in silico predictions in actual experimental data. In this study, we designed and demonstrated a workflow for in silico and empirical ddRAD-Seq analysis in tomato, as follows: (i)in silico prediction of optimum restriction enzymes from the reference genome, (ii) verification of the prediction by actual ddRAD-Seq data of four restriction enzyme combinations, (iii) establishment of a computational data processing pipeline for high-confidence single nucleotide polymorphism (SNP) calling, and (iv) validation of SNP accuracy by construction of genetic linkage maps. The quality of SNPs based on de novo assembly reference of the ddRAD-Seq reads was comparable with that of SNPs obtained using the published reference genome of tomato. Comparisons of SNP calls in diverse tomato lines revealed that SNP density in the genome influenced the detectability of SNPs by ddRAD-Seq. In silico prediction prior to actual analysis contributed to optimization of the experimental conditions for ddRAD-Seq, e.g. choices of enzymes and plant materials. Following optimization, this ddRAD-Seq pipeline could help accelerate genetics, genomics, and molecular breeding in both model and non-model plants, including crops. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

Telomere Restriction Fragment (TRF) Analysis.

Science.gov (United States)

Mender, Ilgen; Shay, Jerry W

2015-11-20

restriction enzyme recognition sites within TTAGGG tandem telomeric repeats, therefore digestion of genomic DNA, not telomeric DNA, with a combination of 6 base restriction endonucleases reduces genomic DNA size to less than 800 bp.

Overexpression of CYB5R3 and NQO1, two NAD+ -producing enzymes, mimics aspects of caloric restriction.

Science.gov (United States)

Diaz-Ruiz, Alberto; Lanasa, Michael; Garcia, Joseph; Mora, Hector; Fan, Frances; Martin-Montalvo, Alejandro; Di Francesco, Andrea; Calvo-Rubio, Miguel; Salvador-Pascual, Andrea; Aon, Miguel A; Fishbein, Kenneth W; Pearson, Kevin J; Villalba, Jose Manuel; Navas, Placido; Bernier, Michel; de Cabo, Rafael

2018-04-28

Calorie restriction (CR) is one of the most robust means to improve health and survival in model organisms. CR imposes a metabolic program that leads to increased stress resistance and delayed onset of chronic diseases, including cancer. In rodents, CR induces the upregulation of two NADH-dehydrogenases, namely NAD(P)H:quinone oxidoreductase 1 (Nqo1) and cytochrome b 5 reductase 3 (Cyb5r3), which provide electrons for energy metabolism. It has been proposed that this upregulation may be responsible for some of the beneficial effects of CR, and defects in their activity are linked to aging and several age-associated diseases. However, it is unclear whether changes in metabolic homeostasis solely through upregulation of these NADH-dehydrogenases have a positive impact on health and survival. We generated a mouse that overexpresses both metabolic enzymes leading to phenotypes that resemble aspects of CR including a modest increase in lifespan, greater physical performance, a decrease in chronic inflammation, and, importantly, protection against carcinogenesis, one of the main hallmarks of CR. Furthermore, these animals showed an enhancement of metabolic flexibility and a significant upregulation of the NAD + /sirtuin pathway. The results highlight the importance of these NAD + producers for the promotion of health and extended lifespan. © 2018 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Restriction fragment length polymorphism of the major histocompatibility complex of the dog.

Science.gov (United States)

Sarmiento, U M; Storb, R F

1988-01-01

Human major histocompatibility complex (HLA) cDNA probes were used to analyze the restriction fragment length polymorphism (RFLP) of the DLA-D region in dogs. Genomic DNA from peripheral blood leucocytes of 23 unrelated DLA-D-homozygous dogs representing nine DLA-D types (defined by mixed leucocyte reaction) was digested with restriction enzymes (Bam HI, Eco RI, Hind III, Pvu II, Taq I, Rsa I, Msp I, Pst I, and Bgl II), separated by agarose gel electrophoresis, and transferred onto Biotrace membrane. The Southern blots were successively hybridized with radiolabeled HLA cDNA probes corresponding to DR, DQ, DP, and DO beta genes. The autoradiograms for all nine enzyme digests displayed multiple bands with the DRb, DQb, and DPb probes while the DOb probe hybridized with one to two bands. The RFLP patterns were highly polymorphic but consistent within each DLA-D type. Standard RFLP patterns were established for nine DLA-D types which could be discriminated from each other by using two enzymes (Rsa I and Pst I) and the HLA-DPb probe. Cluster analysis of the polymorphic restriction fragments detected by the DRb probe revealed four closely related supertypic groups or DLA-DR families: Dw3 + Dw4 + D1, Dw8 + D10, D7 + D16 + D9, and Dw1. This study provides the basis for DLA-D genotyping at a population level by RFLP analysis. These results also suggest that the genetic organization of the DLA-D region may closely resemble that of the HLA complex.

Simple and sensitive fluorescence assay of restriction endonuclease on graphene oxide

International Nuclear Information System (INIS)

Gang, Jong Back

2015-01-01

Restriction endonucleases hydrolyze internal phosphodiester bonds at specific sites in a DNA sequence. These enzymes are essential in a variety of fields, such as biotechnology and clinical diagnostics. It is of great importance and necessity for the scientific and biomedical use of enzymes to measure endonuclease activity. In this study, graphene oxide (GO) has been used as a platform to measure enzyme activity with high sensitivity. To increase the detection sensitivity of Hinf I, the endonuclease-digested reaction was treated with exonuclease III (Exo III) and a fluorescence assay was conducted to measure the emission. Results showed that Exo III treatment enhanced 2.7-fold signal-to-background ratio for the detection of Hinf I compared with that done without Exo III in the presence of GO

Does feed restriction and re-alimentation differently affect lipid content and metabolism according to muscle type in pigs (Sus scrofa)?

Science.gov (United States)

Gondret, Florence; Lebret, Bénédicte

2007-06-01

This study aimed to investigate whether feed restriction and re-alimentation differently affect lipid content and activities of lipogenic or catabolic enzymes according to muscle types in pigs. At around 28 kg body mass (BW), sixty pigs (n=30 per group) were allocated to either ad libitum (AL) or restricted/re-feeding (RA) regimens. After feed restriction (80 kg BW), lipid content was reduced (P<0.01) in the oxidative rhomboideus (RH) as in the glycolytic biceps femoris (BF) muscles of RA pigs compared with AL pigs. Lower activities (P<0.05) of the lipogenic enzymes fatty acid synthase (FAS) and malic enzyme (ME) were observed in the RH but not in the BF of RA vs. AL pigs. After re-feeding (110 kg BW), lipid content was restored in the RH, but was still 12% lower (P<0.05) in the BF of RA compared with AL pigs. In the RH, the trend for an enhanced FAS activity and for a smaller weight-related decrease of ME activity in RA pigs than AL pigs during re-feeding, may have contributed to the muscle fat recovery observed in the RA pigs. In the BF, higher oxidative enzyme activities (P<0.10) in RA pigs compared to AL pigs might explain the incomplete lipid recovery observed after re-feeding in the former animals. In conclusion, metabolic activities in response to restriction and re-feeding differed according to muscle metabolic type.

A new restriction endonuclease-based method for highly-specific detection of DNA targets from methicillin-resistant Staphylococcus aureus.

Directory of Open Access Journals (Sweden)

Maria W Smith

Full Text Available PCR multiplexing has proven to be challenging, and thus has provided limited means for pathogen genotyping. We developed a new approach for analysis of PCR amplicons based on restriction endonuclease digestion. The first stage of the restriction enzyme assay is hybridization of a target DNA to immobilized complementary oligonucleotide probes that carry a molecular marker, horseradish peroxidase (HRP. At the second stage, a target-specific restriction enzyme is added, cleaving the target-probe duplex at the corresponding restriction site and releasing the HRP marker into solution, where it is quantified colorimetrically. The assay was tested for detection of the methicillin-resistant Staphylococcus aureus (MRSA pathogen, using the mecA gene as a target. Calibration curves indicated that the limit of detection for both target oligonucleotide and PCR amplicon was approximately 1 nM. Sequences of target oligonucleotides were altered to demonstrate that (i any mutation of the restriction site reduced the signal to zero; (ii double and triple point mutations of sequences flanking the restriction site reduced restriction to 50-80% of the positive control; and (iii a minimum of a 16-bp target-probe dsDNA hybrid was required for significant cleavage. Further experiments showed that the assay could detect the mecA amplicon from an unpurified PCR mixture with detection limits similar to those with standard fluorescence-based qPCR. Furthermore, addition of a large excess of heterologous genomic DNA did not affect amplicon detection. Specificity of the assay is very high because it involves two biorecognition steps. The proposed assay is low-cost and can be completed in less than 1 hour. Thus, we have demonstrated an efficient new approach for pathogen detection and amplicon genotyping in conjunction with various end-point and qPCR applications. The restriction enzyme assay may also be used for parallel analysis of multiple different amplicons from the same

Cleavage and protection of locked nucleic acid-modified DNA by restriction endonucleases

DEFF Research Database (Denmark)

Crouzier, Lucile; Dubois, Camille; Wengel, Jesper

2012-01-01

Locked nucleic acid (LNA) is one of the most prominent nucleic acid analogues reported so far. We herein for the first time report cleavage by restriction endonuclease of LNA-modified DNA oligonucleotides. The experiments revealed that RsaI is an efficient enzyme capable of recognizing and cleaving...

PCR-RFLP Using BseDI Enzyme for Pork Authentication in Sausage and Nugget Products

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Y. Erwanto

2011-04-01

Full Text Available A polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP using BseDI restriction enzyme had been applied for identifying the presence of pork in processed meat (beef sausage and chicken nugget including before and after frying. Pork sample in various levels (1%, 3%, 5%, 10%, and 25 % was prepared in a mixture with beef and chicken meats and processed for sausage and nugget. The primers CYTb1 and CYTb2 were designed in the mitochondrial cytochrome b (cyt b gene and PCR successfully amplified fragments of 359 bp. To distinguish existence of porcine species, the amplified PCR products of mitochondrial DNA were cut by BseDI restriction enzyme. The result showed pig mitochondrial DNA was cut into 131 and 228 bp fragments. The PCR-RFLP species identification assay yielded excellent results for identification of porcine species. It is a potentially reliable technique for pork detection in animal food processed products for Halal authentication.

Restriction fragment polymorphisms in the major histocompatibility complex of diabetic BB rats

DEFF Research Database (Denmark)

Kastern, W.; Dyrberg, T.; Scholler, J.

1984-01-01

DNA isolated from diabetic BB (BB/Hagedorn) rats was examined for restriction fragment length differences within the major histocompatibility complex (MHC) as compared with nondiabetic (W-subline) BB rats. Polymorphisms were detected using a mouse class I MHC gene as probe. Specifically, a 2-kb Bam......HI fragment was present in all the nondiabetic rats examined, but absent in the diabetic rats. Similar polymorphisms were observed with various other restriction enzymes, particularly XbaI, HindII, and SacI. There were no polymorphisms detected using either a human DR-alpha (class II antigen heavy chain...

Chondroitin / dermatan sulfate modification enzymes in zebrafish development.

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Judith Habicher

Full Text Available Chondroitin/dermatan sulfate (CS/DS proteoglycans consist of unbranched sulfated polysaccharide chains of repeating GalNAc-GlcA/IdoA disaccharide units, attached to serine residues on specific proteins. The CS/DS proteoglycans are abundant in the extracellular matrix where they have essential functions in tissue development and homeostasis. In this report a phylogenetic analysis of vertebrate genes coding for the enzymes that modify CS/DS is presented. We identify single orthologous genes in the zebrafish genome for the sulfotransferases chst7, chst11, chst13, chst14, chst15 and ust and the epimerase dse. In contrast, two copies were found for mammalian sulfotransferases CHST3 and CHST12 and the epimerase DSEL, named chst3a and chst3b, chst12a and chst12b, dsela and dselb, respectively. Expression of CS/DS modification enzymes is spatially and temporally regulated with a large variation between different genes. We found that CS/DS 4-O-sulfotransferases and 6-O-sulfotransferases as well as CS/DS epimerases show a strong and partly overlapping expression, whereas the expression is restricted for enzymes with ability to synthesize di-sulfated disaccharides. A structural analysis further showed that CS/DS sulfation increases during embryonic development mainly due to synthesis of 4-O-sulfated GalNAc while the proportion of 6-O-sulfated GalNAc increases in later developmental stages. Di-sulfated GalNAc synthesized by Chst15 and 2-O-sulfated GlcA/IdoA synthesized by Ust are rare, in accordance with the restricted expression of these enzymes. We also compared CS/DS composition with that of heparan sulfate (HS. Notably, CS/DS biosynthesis in early zebrafish development is more dynamic than HS biosynthesis. Furthermore, HS contains disaccharides with more than one sulfate group, which are virtually absent in CS/DS.

Development of Colletotrichum gloeosporioides Restriction Enzyme-Mediated Integration Mutants as Biocontrol Agents Against Anthracnose Disease in Avocado Fruits.

Science.gov (United States)

Yakoby, N; Zhou, R; Kobiler, I; Dinoor, A; Prusky, D

2001-02-01

ABSTRACT Reduced-pathogenicity mutants of the avocado fruit pathogen Colletotrichum gloeosporioides isolate Cg-14 (teleomorph: Glomerella cingulata) were generated by insertional mutagenesis by restriction enzyme-mediated integration (REMI) transformation. Following seven transformations, 3,500 hygromycin-resistant isolates were subjected to a virulence assay by inoculation on mesocarp and pericarp of cv. Fuerte avocado fruits. Fourteen isolates showed a reduced degree of virulence relative compared with wild-type Cg-14. Two isolates, Cg-M-142 and Cg-M-1150, were further characterized. Cg-M-142 produced appressoria on avocado pericarp similar to Cg-14, but caused reduced symptom development on the fruit's pericarp and mesocarp. Isolate Cg-M-1150 did not produce appressoria; it caused much reduced maceration on the mesocarp and no symptoms on the pericarp. Southern blot analysis of Cg-M-142 and Cg-M-1150 showed REMI at different XbaI sites of the fungal genome. Pre-inoculation of avocado fruit with Cg-M-142 delayed symptom development by the wild-type isolate. Induced resistance was accompanied by an increase in the levels of preformed antifungal diene, from 760 to 1,200 mug/g fresh weight 9 days after inoculation, whereas pre-inoculation with Cg-M-1150 did not affect the level of antifungal diene, nor did it delay the appearance of decay symptoms. The results presented here show that reduced-pathogenicity isolates can be used for the biological control of anthracnose caused by C. gloeosporioides attack.

Novel host restriction factors implicated in HIV-1 replication.

Science.gov (United States)

Ghimire, Dibya; Rai, Madhu; Gaur, Ritu

2018-04-01

Human immunodeficiency virus-1 (HIV-1) is known to interact with multiple host cellular proteins during its replication in the target cell. While many of these host cellular proteins facilitate viral replication, a number of them are reported to inhibit HIV-1 replication at various stages of its life cycle. These host cellular proteins, which are known as restriction factors, constitute an integral part of the host's first line of defence against the viral pathogen. Since the discovery of apolipoprotein B mRNA-editing enzyme 3G (APOBEC3G) as an HIV-1 restriction factor, several human proteins have been identified that exhibit anti-HIV-1 restriction. While each restriction factor employs a distinct mechanism of inhibition, the HIV-1 virus has equally evolved complex counter strategies to neutralize their inhibitory effect. APOBEC3G, tetherin, sterile alpha motif and histidine-aspartate domain 1 (SAMHD1), and trim-5α are some of the best known HIV-1 restriction factors that have been studied in great detail. Recently, six novel restriction factors were discovered that exhibit significant antiviral activity: endoplasmic reticulum α1,2-mannosidase I (ERManI), translocator protein (TSPO), guanylate-binding protein 5 (GBP5), serine incorporator (SERINC3/5) and zinc-finger antiviral protein (ZAP). The focus of this review is to discuss the antiviral mechanism of action of these six restriction factors and provide insights into the probable counter-evasion strategies employed by the HIV-1 virus. The recent discovery of new restriction factors substantiates the complex host-pathogen interactions occurring during HIV-1 pathogenesis and makes it imperative that further investigations are conducted to elucidate the molecular basis of HIV-1 replication.

Identification of Pork Contamination in Meatballs of Indonesia Local Market Using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP Analysis

Directory of Open Access Journals (Sweden)

Yuny Erwanto

2014-10-01

Full Text Available This research applied and evaluated a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP using cytochrome b gene to detect pork contamination in meatballs from local markets in Surabaya and Yogyakarta regions, Indonesia. To confirm the effectiveness and specificity of this fragment, thirty nine DNA samples from different meatball shops were isolated and amplified, and then the PCR amplicon was digested by BseDI restriction enzyme to detect the presence of pork in meatballs. BseDI restriction enzyme was able to cleave porcine cytochrome b gene into two fragments (131 bp and 228 bp. Testing the meatballs from the local market showed that nine of twenty meatball shops in Yogyakarta region were detected to have pork contamination, but there was no pork contamination in meatball shops in Surabaya region. In conclusion, specific PCR amplification of cytochrome b gen and cleaved by BseDI restriction enzymes seems to be a powerful technique for the identification of pork presence in meatball because of its simplicity, specificity and sensitivity. Furthermore, pork contamination intended for commercial products of sausage, nugget, steak and meat burger can be checked. The procedure is also much cheaper than other methods based on PCR, immunodiffusion and other techniques that need expensive equipment.

Identification of Pork Contamination in Meatballs of Indonesia Local Market Using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) Analysis.

Science.gov (United States)

Erwanto, Yuny; Abidin, Mohammad Zainal; Sugiyono, Eko Yasin Prasetyo Muslim; Rohman, Abdul

2014-10-01

This research applied and evaluated a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using cytochrome b gene to detect pork contamination in meatballs from local markets in Surabaya and Yogyakarta regions, Indonesia. To confirm the effectiveness and specificity of this fragment, thirty nine DNA samples from different meatball shops were isolated and amplified, and then the PCR amplicon was digested by BseDI restriction enzyme to detect the presence of pork in meatballs. BseDI restriction enzyme was able to cleave porcine cytochrome b gene into two fragments (131 bp and 228 bp). Testing the meatballs from the local market showed that nine of twenty meatball shops in Yogyakarta region were detected to have pork contamination, but there was no pork contamination in meatball shops in Surabaya region. In conclusion, specific PCR amplification of cytochrome b gen and cleaved by BseDI restriction enzymes seems to be a powerful technique for the identification of pork presence in meatball because of its simplicity, specificity and sensitivity. Furthermore, pork contamination intended for commercial products of sausage, nugget, steak and meat burger can be checked. The procedure is also much cheaper than other methods based on PCR, immunodiffusion and other techniques that need expensive equipment.

Molecular identification of similar species of the genus Biomphalaria (Mollusca: Planorbidae determined by a polymerase chain reaction-restriction fragment length polymorphism

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Caldeira Roberta Lima

1998-01-01

Full Text Available The freshwater snails Biomphalaria straminea, B. intermedia, B. kuhniana and B. peregrina, are morphologically similar; based on this similarity the first three species were therefore grouped in the complex B. straminea. The morphological identification of these species is based on characters such as vaginal wrinkling, relation between prepuce: penial sheath:deferens vas and number of muscle layers in the penis wall. In this study the polymerase chain reaction restriction fragment length polymorphism technique was used for molecular identification of these molluscs. This technique is based on the amplification of the internal transcribed spacer regions ITS1 e ITS2 of the ribosomal RNA gene and subsequent digestion of these fragments by restriction enzymes. Six enzymes were tested: Dde I, Mnl I, Hae III, Rsa I, Hpa II e Alu I. The restriction patterns obtained with DdeI presented the best profile for separation of the four species of Biomphalaria. The profiles obtained with all the enzymes were used to estimate the genetic distances among the species through analysis of common banding patterns.

HIV restriction by APOBEC3 in humanized mice.

Directory of Open Access Journals (Sweden)

John F Krisko

2013-03-01

Full Text Available Innate immune restriction factors represent important specialized barriers to zoonotic transmission of viruses. Significant consideration has been given to their possible use for therapeutic benefit. The apolipoprotein B mRNA editing enzyme catalytic polypeptide 3 (APOBEC3 family of cytidine deaminases are potent immune defense molecules capable of efficiently restricting endogenous retroelements as well as a broad range of viruses including Human Immunodeficiency virus (HIV, Hepatitis B virus (HBV, Human Papilloma virus (HPV, and Human T Cell Leukemia virus (HTLV. The best characterized members of this family are APOBEC3G (A3G and APOBEC3F (A3F and their restriction of HIV. HIV has evolved to counteract these powerful restriction factors by encoding an accessory gene designated viral infectivity factor (vif. Here we demonstrate that APOBEC3 efficiently restricts CCR5-tropic HIV in the absence of Vif. However, our results also show that CXCR4-tropic HIV can escape from APOBEC3 restriction and replicate in vivo independent of Vif. Molecular analysis identified thymocytes as cells with reduced A3G and A3F expression. Direct injection of vif-defective HIV into the thymus resulted in viral replication and dissemination detected by plasma viral load analysis; however, vif-defective viruses remained sensitive to APOBEC3 restriction as extensive G to A mutation was observed in proviral DNA recovered from other organs. Remarkably, HIV replication persisted despite the inability of HIV to develop resistance to APOBEC3 in the absence of Vif. Our results provide novel insight into a highly specific subset of cells that potentially circumvent the action of APOBEC3; however our results also demonstrate the massive inactivation of CCR5-tropic HIV in the absence of Vif.

THE HUMAN FUMARYLACETOACETATE GENE : CHARACTERIZATION OF RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS AND IDENTIFICATION OF HAPLOTYPES IN TYROSINEMIA TYPE-1 AND PSEUDODEFICIENCY

NARCIS (Netherlands)

ROOTWELT, H; KVITTINGEN, EA; HOIE, K; AGSTERIBBE, E; HARTOG, M; BERGER, R

Deficiency of human fumarylacetoacetase (FAH) activity results in hereditary tyrosinemia type I. Using the restriction enzymes BglII, KpnI and StuI and a 1.3-kb cDNA probe for the FAH gene, we have found 6 restriction fragment length polymorphisms (RFLPs). These RFLPs were utilised in 3 tyrosinemia

Physiological Responses, Growth Rate and Blood Metabolites Under Feed Restriction and Thermal Exposure in Kids

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O.K. Hooda

2014-05-01

Full Text Available The study was carried out to study the cumulative effect of thermal stress and feed restriction in kids. Twelve kids of Alpine x Beetle cross were divided into two groups. Group 1 served as control and group 2 was put on restricted feeding and exposed at 40, 42 and 44oC. Body weights of both groups were similar before thermal exposure and feed restriction. Body weight of group 1 increased significantly and were higher than group 2 throughout the experiment. Body weight gain, average daily gain and feed conversion efficiency were comparable in both groups after removal of thermal stress and switching over to ad libitum feeding (42-63 days. Body weights of group 2 remained lower than group 1, the losses in body weights of group 2 could not be compensated and there was approximately 25% loss in body weight at the end of experiment. Physiological responses of group 2 were significantly lower before exposure to high temperature but increased significantly after exposure at temperature 40, 42 and 44oC and the increase was in commensurate with the increase in exposure temperature. Blood glucose, total protein, albumin and serum enzymes decreased significantly on exposure at higher temperature and differences were higher in feed restricted group. T3, T4 and cortisol concentration were similar in both groups before feed restriction and thermal stress. T3, T4 concentration decreased while cortisol concentration increased significantly after exposure to high temperature. Variations in plasma enzymes, acid phosphatase, alkaline phosphatase, SGOT and SGPT were not significant before feed restriction and thermal stress. The activities of acid phosphatase and alkaline phosphatase decreased whereas that of SGOT and SGPT increased significantly on exposure at temperature 40oC and subsequent changes at temperature 42 and 44oC were not significant. The study indicated that animals of group 2 experienced more stress as observed by significant alteration in body

A whole genome screen for HIV restriction factors

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Liu Li

2011-11-01

Full Text Available Abstract Background Upon cellular entry retroviruses must avoid innate restriction factors produced by the host cell. For human immunodeficiency virus (HIV human restriction factors, APOBEC3 (apolipoprotein-B-mRNA-editing-enzyme, p21 and tetherin are well characterised. Results To identify intrinsic resistance factors to HIV-1 replication we screened 19,121 human genes and identified 114 factors with significant inhibition of infection. Those with a known function are involved in a broad spectrum of cellular processes including receptor signalling, vesicle trafficking, transcription, apoptosis, cross-nuclear membrane transport, meiosis, DNA damage repair, ubiquitination and RNA processing. We focused on the PAF1 complex which has been previously implicated in gene transcription, cell cycle control and mRNA surveillance. Knockdown of all members of the PAF1 family of proteins enhanced HIV-1 reverse transcription and integration of provirus. Over-expression of PAF1 in host cells renders them refractory to HIV-1. Simian Immunodeficiency Viruses and HIV-2 are also restricted in PAF1 expressing cells. PAF1 is expressed in primary monocytes, macrophages and T-lymphocytes and we demonstrate strong activity in MonoMac1, a monocyte cell line. Conclusions We propose that the PAF1c establishes an anti-viral state to prevent infection by incoming retroviruses. This previously unrecognised mechanism of restriction could have implications for invasion of cells by any pathogen.

Sequence-specific protection of duplex DNA against restriction and methylation enzymes by pseudocomplementary PNAs

DEFF Research Database (Denmark)

Izvolsky, K I; Demidov, V V; Nielsen, P E

2000-01-01

I restriction endonuclease and dam methylase. The pcPNA-assisted protection against enzymatic methylation is more efficient when the PNA-binding site embodies the methylase-recognition site rather than overlaps it. We conclude that pcPNAs may provide the robust tools allowing to sequence-specifically manipulate...... DNA duplexes in a virtually sequence-unrestricted manner....

Combination of methylated-DNA precipitation and methylation-sensitive restriction enzymes (COMPARE-MS) for the rapid, sensitive and quantitative detection of DNA methylation.

Science.gov (United States)

Yegnasubramanian, Srinivasan; Lin, Xiaohui; Haffner, Michael C; DeMarzo, Angelo M; Nelson, William G

2006-02-09

Hypermethylation of CpG island (CGI) sequences is a nearly universal somatic genome alteration in cancer. Rapid and sensitive detection of DNA hypermethylation would aid in cancer diagnosis and risk stratification. We present a novel technique, called COMPARE-MS, that can rapidly and quantitatively detect CGI hypermethylation with high sensitivity and specificity in hundreds of samples simultaneously. To quantitate CGI hypermethylation, COMPARE-MS uses real-time PCR of DNA that was first digested by methylation-sensitive restriction enzymes and then precipitated by methyl-binding domain polypeptides immobilized on a magnetic solid matrix. We show that COMPARE-MS could detect five genome equivalents of methylated CGIs in a 1000- to 10,000-fold excess of unmethylated DNA. COMPARE-MS was used to rapidly quantitate hypermethylation at multiple CGIs in >155 prostate tissues, including benign and malignant prostate specimens, and prostate cell lines. This analysis showed that GSTP1, MDR1 and PTGS2 CGI hypermethylation as determined by COMPARE-MS could differentiate between malignant and benign prostate with sensitivities >95% and specificities approaching 100%. This novel technology could significantly improve our ability to detect CGI hypermethylation.

Cut-and-Paste of DNA Using an Artificial Restriction DNA Cutter

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Makoto Komiyama

2013-02-01

Full Text Available DNA manipulations using a completely chemistry-based DNA cutter (ARCUT have been reviewed. This cutter, recently developed by the authors, is composed of Ce(IV/EDTA complex and two strands of pseudo-complementary peptide nucleic acid. The site-selective scission proceeds via hydrolysis of targeted phosphodiester linkages, so that the resultant scission fragments can be easily ligated with other fragments by using DNA ligase. Importantly, scission-site and site-specificity of the cutter are freely tuned in terms of the Watson–Crick rule. Thus, when one should like to manipulate DNA according to the need, he or she does not have to think about (1 whether appropriate “restriction enzyme sites” exist near the manipulation site and (2 whether the site-specificity of the restriction enzymes, if any, are sufficient to cut only the aimed position without chopping the DNA at non-targeted sites. Even the human genome can be manipulated, since ARCUT can cut the genome at only one predetermined site. Furthermore, the cutter is useful to promote homologous recombination in human cells, converting a site to desired sequence. The ARCUT-based DNA manipulation should be promising for versatile applications.

Analysis of DNA restriction fragments greater than 5.7 Mb in size from the centromeric region of human chromosomes.

Science.gov (United States)

Arn, P H; Li, X; Smith, C; Hsu, M; Schwartz, D C; Jabs, E W

1991-01-01

Pulsed electrophoresis was used to study the organization of the human centromeric region. Genomic DNA was digested with rare-cutting enzymes. DNA fragments from 0.2 to greater than 5.7 Mb were separated by electrophoresis and hybridized with alphoid and simple DNA repeats. Rare-cutting enzymes (Mlu I, Nar I, Not I, Nru I, Sal I, Sfi I, Sst II) demonstrated fewer restriction sites at centromeric regions than elsewhere in the genome. The enzyme Not I had the fewest restriction sites at centromeric regions. As much as 70% of these sequences from the centromeric region are present in Not I DNA fragments greater than 5.7 and estimated to be as large as 10 Mb in size. Other repetitive sequences such as short interspersed repeated segments (SINEs), long interspersed repeated segments (LINEs), ribosomal DNA, and mini-satellite DNA that are not enriched at the centromeric region, are not enriched in Not I fragments of greater than 5.7 Mb in size.

Effect of Short-term Quercetin, Caloric Restriction and Combined Treatment on Age-related Oxidative Stress Markers in the Rat Cerebral Cortex

Science.gov (United States)

Alugoju, Phaniendra; Swamy, Vkd Krishan; Periyasamy, Latha

2018-03-14

Aging is characterized by gradual accumulation of macromolecular damage leading to progressive loss of physiological function and increased susceptibility to diverse diseases. Effective anti-aging strategies involving caloric restriction or antioxidant supplementation are receiving growing attention to attenuate macromolecular damage in age associated pathology. In the present study, we for the first time investigated the effect of quercetin, caloric restriction and combined treatment (caloric restriction with quercetin) on oxidative stress parameters, acetylcholinesterase and ATPases enzyme activities in the cerebral cortex of aged male Wistar rats. 21 months aged rats were divided into four groups (n=6-8) such as group 1-fed ad libitum (AL); group 2-quercetin supplementation of 50 mg/kg b.w/day for 45 days fed ad libitum (QUER); group 3: caloric restricted (CR) (fed 40% reduced AL for 45 days); group 4-fed 40% CR and 50 mg/kg b.w/day QUER for 45 days (CR + QUER). Group 5-three month age old rats served as young control (YOUNG). Our results demonstrate that combined treatment of caloric restriction and quercetin significantly improved the age associated decline in the activities of endogenous antioxidant enzymes [such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)] and glutathione (GSH) content and attenuated elevated levels of protein carbonyl content (PCC), lipid peroxidation, lipofuscin, reactive oxygen species (ROS), and nitric oxide (NO). Furthermore, it is also observed that combined treatment ameliorated age associated alterations in acetylcholine esterase (AChE) and adenosine triphosphatases (ATPases) such as Na+/K+-ATPase and Ca+2-ATPase (but not Mg+2- ATPase) enzyme activities. Finally, we conclude that combined treatment of caloric restriction and quercetin (but not either treatment alone) in late life is an effective anti-aging therapy to counteract the age related accumulation of oxidative macromolecular damage

Pst I restriction fragment length polymorphism of the human placental alkaline phosphatase gene in normal placentae and tumors

International Nuclear Information System (INIS)

Tsavaler, L.; Penhallow, R.C.; Kam, W.; Sussman, H.H.

1987-01-01

The structure of the human placental alkaline phosphatase gene from normal term placentae was studied by restriction enzyme digestion and Southern blot analysis using a cDNA probe to the gene for the placental enzyme. The DNA digests fall into three distinct patterns based on the presence and intensity of an extra 1.1-kilobase Pst I Band. The extra 1.1-kilobase band is present in 9 of 27 placenta samples, and in 1 of these samples the extra band is present at double intensity. No polymorphism was revealed by digestion with restriction enzymes EcoRI, Sma I, BamHI, or Sac I. The extra Pst I-digestion site may lie in a noncoding region of the gene because no correlation was observed between the restriction fragment length polymorphism and the common placental alkaline phosphatase alleles identified by starch gel electrophoresis. In addition, because placental alkaline phosphatase is frequently re-expressed in neoplasms, the authors examined tissue from ovarian, testicular, and endometrial tumors and from BeWo choriocarcinoma cells in culture. The Pst I-DNA digestion patterns from these cells and tissues were identical to those seen in the normal ovary and term placentae. The consistent reproducible digestion patterns seen in DNA from normal and tumor tissue indicate that a major gene rearrangement is not the basis for the ectopic expression of placental alkaline phosphatase in neoplasia

Functional Coupling of Duplex Translocation to DNA Cleavage in a Type I Restriction Enzyme

Czech Academy of Sciences Publication Activity Database

Cséfalvay, Eva; Lapkouski, Mikalai; Guzanová, Alena; Cséfalvay, Ladislav; Baikova, T.; Shevelev, Igor; Bialevich, V.; Shamayeva, Katerina; Janščák, Pavel; Kutá-Smatanová, Ivana; Panjikar, S.; Carey, J.; Weiserová, Marie; Ettrich, Rüdiger

2015-01-01

Roč. 10, č. 6 (2015), e0128700 E-ISSN 1932-6203 R&D Projects: GA ČR GAP207/12/2323; GA ČR GAP305/10/0281 Institutional support: RVO:67179843 ; RVO:61388971 ; RVO:68378050 Keywords : Escherichia-Coli * Endonuclease ecor1241 * HSDR subunit * RECBCD enzyme * proteins * genes * helicase * sequence * family * domain Subject RIV: CE - Biochemistry Impact factor: 3.057, year: 2015

Template-directed addition of nucleosides to DNA by the BfiI restriction enzyme

OpenAIRE

Sasnauskas, Giedrius; Connolly, Bernard A.; Halford, Stephen E.; Siksnys, Virginijus

2008-01-01

Restriction endonucleases catalyse DNA cleavage at specific sites. The BfiI endonuclease cuts DNA to give staggered ends with 1-nt 3′-extensions. We show here that BfiI can also fill in the staggered ends: while cleaving DNA, it can add a 2′-deoxynucleoside to the reaction product to yield directly a blunt-ended DNA. We propose that nucleoside incorporation proceeds through a two-step reaction, in which BfiI first cleaves the DNA to make a covalent enzyme–DNA intermediate and then resolves it...

Efficient, crosswise catalytic promiscuity among enzymes that catalyze phosphoryl transfer.

Science.gov (United States)

Mohamed, Mark F; Hollfelder, Florian

2013-01-01

The observation that one enzyme can accelerate several chemically distinct reactions was at one time surprising because the enormous efficiency of catalysis was often seen as inextricably linked to specialization for one reaction. Originally underreported, and considered a quirk rather than a fundamental property, enzyme promiscuity is now understood to be important as a springboard for adaptive evolution. Owing to the large number of promiscuous enzymes that have been identified over the last decade, and the increased appreciation for promiscuity's evolutionary importance, the focus of research has shifted to developing a better understanding of the mechanistic basis for promiscuity and the origins of tolerant or restrictive specificity. We review the evidence for widespread crosswise promiscuity amongst enzymes that catalyze phosphoryl transfer, including several members of the alkaline phosphatase superfamily, where large rate accelerations between 10(6) and 10(17) are observed for both native and multiple promiscuous reactions. This article is part of a Special Issue entitled: Chemistry and mechanism of phosphatases, diesterases and triesterases. Copyright © 2012 Elsevier B.V. All rights reserved.

Actinomycete enzymes and activities involved in straw saccharification

Energy Technology Data Exchange (ETDEWEB)

McCarthy, A J; Ball, A S [Liverpool Univ. (UK). Dept. of Genetics and Microbiology

1990-01-01

This research programme has been directed towards the analysis of actinomycete enzyme systems involved in the degradation of plant biomass (lignocellulose.) The programme was innovative in that a novel source of enzymes was systematically screened and wheat straw saccharifying activity was the test criterion. Over 200 actinomycete strains representing a broad taxonomic range were screened. A range of specific enzyme activities were involved and included cellulase, xylanase, arabinofuranosidase, acetylesterase, {beta}-xylosidase and {beta}-glucosidase. Since hemicellulose (arabinoxylan) was the primary source of sugar, xylanases were characterized. The xylan-degrading systems of actinomycetes were complex and nonuniform, with up to six separate endoxylanases identified in active strains. Except for microbispora bispora, actinomycetes were found to be a poor source of cellulase activity. Evidence for activity against the lignin fraction of straw was produced for a range of actinomycete strains. While modification reactions were common, cleavage of inter-monomer bonds, and utilization of complex polyphenolic compounds were restricted to two strains: Thermomonospora mesophila and Streptomyces badius. Crude enzyme preparations from actinomycetes can be used to generate sugar, particularly pentoses, directly from cereal straw. The potential for improvements in yield rests with the formulation to cooperative enzyme combinations from different strains. The stability properties of enzymes from thermophilic strains and the general neutral to alkali pH optima offer advantages in certain process situations. Actinomycetes are a particularly rich source of xylanases for commercial application and can rapidly solubilise a lignocarbohydrate fraction of straw which may have both product and pretreatment potential. 31 refs., 4 figs., 5 tabs.

Stock discrimination in Great Lakes Walleye using mitochondrial DNA restriction analysis

International Nuclear Information System (INIS)

Billington, N.; Hebert, P.D.N.

1986-01-01

Over the past two years it has become evident that because of its strict maternal inheritance and rapid rate of evolutionary differentiation, mitochondrial (mt) DNA diversity offers exceptional promise in the discrimination of fish stocks. The current project aims to determine the extent of mt DNA variation among stocks of walleye (Stizostedion vitreum) from the Great Lakes. At this point, mt DNA has been isolated from 68 walleye representing the Thames River stock and a reef breeding stock from western Lake Erie, as well as from individuals of S. canadense, a species which hybridizes with S. vitreum. Mitochondrial DNA was extracted from livers of these fish, purified by CsCl density gradient centrifugation and digested using 20 endonucleases. Polymorphisms were detected with 8 of the enzymes. There was a great deal of variation among fish from both spawning populations, so much so that individual fish could be identified by this technique. No single enzyme allowed discrimination of the two stocks, but restriction pattern variation following Dde I digestion permitted separation of 50% of Lake Erie fish from Thames River stock. Comparison of mt DNA restriction patterns of walleye and sauger showed that two species are easily separable, setting the stage for a more detailed study of hybridization between the taxa

Inhibition of a NEDD8 Cascade Restores Restriction of HIV by APOBEC3G.

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David J Stanley

2012-12-01

Full Text Available Cellular restriction factors help to defend humans against human immunodeficiency virus (HIV. HIV accessory proteins hijack at least three different Cullin-RING ubiquitin ligases, which must be activated by the small ubiquitin-like protein NEDD8, in order to counteract host cellular restriction factors. We found that conjugation of NEDD8 to Cullin-5 by the NEDD8-conjugating enzyme UBE2F is required for HIV Vif-mediated degradation of the host restriction factor APOBEC3G (A3G. Pharmacological inhibition of the NEDD8 E1 by MLN4924 or knockdown of either UBE2F or its RING-protein binding partner RBX2 bypasses the effect of Vif, restoring the restriction of HIV by A3G. NMR mapping and mutational analyses define specificity determinants of the UBE2F NEDD8 cascade. These studies demonstrate that disrupting host NEDD8 cascades presents a novel antiretroviral therapeutic approach enhancing the ability of the immune system to combat HIV.

EFFECT OF MARINATION WITH PROTEOLYTIC ENZYMES ON QUALITY OF BEEF MUSCLE

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Daniela Istrati

2012-03-01

Full Text Available During storage and thermal treatment meat suffers a number of biochemical and physical-chemical changes in the substrate protein, changes that take place with varying intensity depending on the method of preservation utilized and temperature of thermal treatment applied. Application of different treatments aimed to influence the proteolytic activity as is the case of enzymatic tenderization of beef.Improving the meat tenderness with proteolytic enzymes is promising, but current legislation restricting the use of proteolytic enzymes from bacterial origin and recommended tenderizers salts containing papain, ficin and bromelain. Recent research revealed that meat marinating before grilling results in a reduction of heterocyclic amine content after thermal treatment. Also, the addition of fruit pulp, garlic or other spices contributes to decreased production of heterocyclic amines because of their antioxidant activity. In the present study was aimed influence of exogenous proteolytic enzymes on adult beef tenderness. To increase the tenderness of adult beef were used exogenous enzymes preparations (papain and bromelain and natural sources of enzymes using pineapple and papaya fruit. It was intended to establish the correlation between enzymatic activity of enzymes used in the study, the processing technology and changes in the physical-chemical and biochemical characteristics that occur during storage in refrigerated conditions (evolution of the rigidity index and water holding capacity, cooking losses and cooking yield of the samples injected/marinated with enzymes.

Characterization and identification of enzyme-producing microflora isolated from the gut of sea cucumber Apostichopus japonicus

Science.gov (United States)

Li, Fenghui; Gao, Fei; Tan, Jie; Fan, Chaojing; Sun, Huiling; Yan, Jingping; Chen, Siqing; Wang, Xiaojun

2016-01-01

Gut microorganisms play an important role in the digestion of their host animals. The purpose of this research was to isolate and assess the enzyme-producing microbes from the Apostichopus japonicus gut. Thirty-nine strains that can produce at least one of the three digestive enzymes (protease, amylase, and cellulase) were qualitatively screened based on their extracellular enzyme-producing abilities. The enzyme-producing strains clustered into eight groups at the genetic similarity level of 100% by analyzing the restriction patterns of 16S rDNA amplified with Mbo I. Phylogenetic analysis revealed that 37 strains belonged to the genus Bacillus and two were members of the genus Virgibacillus. Enzyme-producing capability results indicate that the main enzyme-producing microflora in the A. japonicus gut was Bacillus, which can produce protease, amylase, and cellulase. Virgibacillus, however, can only produce protease. The high enzyme-producing capability of the isolates suggests that the gut microbiota play an important role in the sea cucumber digestive process.

On the distinction of the mechanisms of DNA cleavage by restriction enzymes—The I-, II-, and III-type molecular motors

Science.gov (United States)

Pikin, S. A.

2008-09-01

A comparative physical description is given for the functioning of various restriction enzymes and for their processes of DNA cleavage. The previously proposed model system of kinetic equations is applied to the I-and III-type enzymes, which use ATP molecules as an energy source, while the II-type enzymes work thanks to catalytic reactions with participation of an electric field. All the enzymes achieved bending and twisting DNA, providing for either the linear motion of the II-type enzyme along the DNA chain or the DNA translocation by the I-and III-type enzymes due to moving chiral kinks. A comparative estimation of the considered linear and angular velocities is performed. The role of stalling forces for enzyme-DNA complexes, which induce the observed cutting of the DNA either inside the enzyme (II) or in some “weak” places outside enzymes I and III, which results in the supercoiling of the DNA, is shown. The role of ionic screening for the described processes is discussed.

Restriction fragment length polymorphism (RFLP) analysis of PCR products amplified from 18S ribosomal RNA gene of Trypanosoma congolense

International Nuclear Information System (INIS)

Osanyo, A.; Majiwa, P.W.

2006-01-01

Oligonucleotide primers were designed from the conserved nucleotide sequences of 18S ribosomal RNA (18S rRNA) gene of protozoans: Trypanosoma brucei, Leishmania donovani, Triponema aequale and Lagenidium gigantum. The primers were used in polymerace chain reaction (PCR) to generate PCR products of approximately 1 Kb using genomic DNA from T. brucei and the four genotypic groups of T. congolense as template. The five PCR products so produced were digested with several restriction enzymes and hybridized to a DNA probe made from T. brucei PCR product of the same 18S rRNA gene region. Most restriction enzyme digests revealed polymorphism with respect to the location of their recognition sites on the five PCR products. The restriction fragment length polymorphism (RFLP) pattern observed indicate that the 18S rRNA gene sequences of trypanosomes: T. brucei and the four genotypes of T.congolence group are heterogeneous. The results further demonstrate that the region that was amplified can be used in specific identification of trypanosomes species and subspecies.(author)

Alignment of Escherichia coli K12 DNA sequences to a genomic restriction map.

Science.gov (United States)

Rudd, K E; Miller, W; Ostell, J; Benson, D A

1990-01-25

We use the extensive published information describing the genome of Escherichia coli and new restriction map alignment software to align DNA sequence, genetic, and physical maps. Restriction map alignment software is used which considers restriction maps as strings analogous to DNA or protein sequences except that two values, enzyme name and DNA base address, are associated with each position on the string. The resulting alignments reveal a nearly linear relationship between the physical and genetic maps of the E. coli chromosome. Physical map comparisons with the 1976, 1980, and 1983 genetic maps demonstrate a better fit with the more recent maps. The results of these alignments are genomic kilobase coordinates, orientation and rank of the alignment that best fits the genetic data. A statistical measure based on extreme value distribution is applied to the alignments. Additional computer analyses allow us to estimate the accuracy of the published E. coli genomic restriction map, simulate rearrangements of the bacterial chromosome, and search for repetitive DNA. The procedures we used are general enough to be applicable to other genome mapping projects.

Behavior of restriction-modification systems as selfish mobile elements and their impact on genome evolution.

Science.gov (United States)

Kobayashi, I

2001-09-15

Restriction-modification (RM) systems are composed of genes that encode a restriction enzyme and a modification methylase. RM systems sometimes behave as discrete units of life, like viruses and transposons. RM complexes attack invading DNA that has not been properly modified and thus may serve as a tool of defense for bacterial cells. However, any threat to their maintenance, such as a challenge by a competing genetic element (an incompatible plasmid or an allelic homologous stretch of DNA, for example) can lead to cell death through restriction breakage in the genome. This post-segregational or post-disturbance cell killing may provide the RM complexes (and any DNA linked with them) with a competitive advantage. There is evidence that they have undergone extensive horizontal transfer between genomes, as inferred from their sequence homology, codon usage bias and GC content difference. They are often linked with mobile genetic elements such as plasmids, viruses, transposons and integrons. The comparison of closely related bacterial genomes also suggests that, at times, RM genes themselves behave as mobile elements and cause genome rearrangements. Indeed some bacterial genomes that survived post-disturbance attack by an RM gene complex in the laboratory have experienced genome rearrangements. The avoidance of some restriction sites by bacterial genomes may result from selection by past restriction attacks. Both bacteriophages and bacteria also appear to use homologous recombination to cope with the selfish behavior of RM systems. RM systems compete with each other in several ways. One is competition for recognition sequences in post-segregational killing. Another is super-infection exclusion, that is, the killing of the cell carrying an RM system when it is infected with another RM system of the same regulatory specificity but of a different sequence specificity. The capacity of RM systems to act as selfish, mobile genetic elements may underlie the structure and

Enzyme Treatment-Free and Ligation-Independent Cloning Using Caged Primers in Polymerase Chain Reactions

Directory of Open Access Journals (Sweden)

Akinori Kuzuya

2011-12-01

Full Text Available A new simple scheme for constructing recombinant vectors that does not require any restriction enzyme, ligase, or any other special enzyme treatment has been developed. By using caged primers in PCR, unnatural sticky-ends of any sequence, which are sufficiently long for ligation-independent cloning (LIC, are directly prepared on the product after a brief UVA irradiation. Target genes and vectors amplified by this light-assisted cohesive-ending (LACE PCR join together in the desired arrangement in a simple mixture of them, tightly enough to be repaired and ligated in competent cells.

Restriction analysis of genetic variability of Polish isolates of Tomato black ring virus.

Science.gov (United States)

Jończyk, Magdalena; Borodynko, Natasza; Pospieszny, Henryk

2004-01-01

Several different isolates of Tomato black ring virus (TBRV) have been collected in Poland from cucumber, tomato, potato and black locust plants. Biological tests showed some differences in the range of infected plants and the type of symptoms, which was the basis for selection of seven the most biologically different TBRV isolates. According to the sequence of TBRV-MJ, several primer pairs were designed and almost the entire sequence of both genomic RNAs was amplified. The RT-PCR products derived from all tested TBRV isolates were digested by restriction enzymes. On the basis of the restriction patterns, the variable and the conserved regions of the TBRV genome were defined and the relationships between the Polish TBRV isolates established.

Asymmetric Stetter reactions catalyzed by thiamine diphosphate-dependent enzymes.

Science.gov (United States)

Kasparyan, Elena; Richter, Michael; Dresen, Carola; Walter, Lydia S; Fuchs, Georg; Leeper, Finian J; Wacker, Tobias; Andrade, Susana L A; Kolter, Geraldine; Pohl, Martina; Müller, Michael

2014-12-01

The intermolecular asymmetric Stetter reaction is an almost unexplored transformation for biocatalysts. Previously reported thiamine diphosphate (ThDP)-dependent PigD from Serratia marcescens is the first enzyme identified to catalyze the Stetter reaction of α,β-unsaturated ketones (Michael acceptor substrates) and α-keto acids. PigD is involved in the biosynthesis of the potent cytotoxic agent prodigiosin. Here, we describe the investigation of two new ThDP-dependent enzymes, SeAAS from Saccharopolyspora erythraea and HapD from Hahella chejuensis. Both show a high degree of homology to the amino acid sequence of PigD (39 and 51 %, respectively). The new enzymes were heterologously overproduced in Escherichia coli, and the yield of soluble protein was enhanced by co-expression of the chaperone genes groEL/ES. SeAAS and HapD catalyze intermolecular Stetter reactions in vitro with high enantioselectivity. The enzymes possess a characteristic substrate range with respect to Michael acceptor substrates. This provides support for a new type of ThDP-dependent enzymatic activity, which is abundant in various species and not restricted to prodigiosin biosynthesis in different strains. Moreover, PigD, SeAAS, and HapD are also able to catalyze asymmetric carbon-carbon bond formation reactions of aldehydes and α-keto acids, resulting in 2-hydroxy ketones.

Restriction-modification systems in Mycoplasma spp

Directory of Open Access Journals (Sweden)

Marcelo Brocchi

2007-01-01

Full Text Available Restriction and Modification (R-M systems are present in all Mycoplasma species sequenced so far. The presence of these genes poses barriers to gene transfer and could protect the cell against phage infections. The number and types of R-M genes between different Mycoplasma species are variable, which is characteristic of a polymorphism. The majority of the CDSs code for Type III R-M systems and particularly for methyltransferase enzymes, which suggests that functions other than the protection against the invasion of heterologous DNA may exist. A possible function of these enzymes could be the protection against the invasion of other but similar R-M systems. In Mycoplasma hyopneumoniae strain J, three of the putative methyltransferase genes were clustered in a region forming a genomic island. Many R-M CDSs were mapped in the vicinity of transposable elements suggesting an association between these genes and reinforcing the idea of R-M systems as mobile selfish DNA. Also, many R-M genes present repeats within their coding sequences, indicating that their expression is under the control of phase variation mechanisms. Altogether, these data suggest that R-M systems are a remarkable characteristic of Mycoplasma species and are probably involved in the adaptation of these bacteria to different environmental conditions.

How quantum entanglement in DNA synchronizes double-strand breakage by type II restriction endonucleases.

Science.gov (United States)

Kurian, P; Dunston, G; Lindesay, J

2016-02-21

Macroscopic quantum effects in living systems have been studied widely in pursuit of fundamental explanations for biological energy transport and sensing. While it is known that type II endonucleases, the largest class of restriction enzymes, induce DNA double-strand breaks by attacking phosphodiester bonds, the mechanism by which simultaneous cutting is coordinated between the catalytic centers remains unclear. We propose a quantum mechanical model for collective electronic behavior in the DNA helix, where dipole-dipole oscillations are quantized through boundary conditions imposed by the enzyme. Zero-point modes of coherent oscillations would provide the energy required for double-strand breakage. Such quanta may be preserved in the presence of thermal noise by the enzyme's displacement of water surrounding the DNA recognition sequence. The enzyme thus serves as a decoherence shield. Palindromic mirror symmetry of the enzyme-DNA complex should conserve parity, because symmetric bond-breaking ceases when the symmetry of the complex is violated or when physiological parameters are perturbed from optima. Persistent correlations in DNA across longer spatial separations-a possible signature of quantum entanglement-may be explained by such a mechanism. Copyright © 2015 Elsevier Ltd. All rights reserved.

Simultaneous and rapid differential diagnosis of Mycoplasma genitalium and Ureaplasma urealyticum based on a polymerase chain reaction-restriction fragment length polymorphism

Directory of Open Access Journals (Sweden)

R Mirnejad

2011-01-01

Full Text Available Objectives: The aim of this investigation was to simultaneously detect and differentiate Mycoplasma genitalium and Ureaplasma urealyticum in female patients suffering from genital complications by polymerase chain reaction (PCR-restriction fragment length polymorphism (RFLP. Materials and Methods : Genital swabs were taken from 210 patients. They were transported to the laboratory in phosphate-buffered saline. For PCR, samples were analysed with genus-specific MyUu-R and MyUu-F primers. This primer set, which was originally designed in our laboratory, amplified a 465 bp fragment (M. genitalium and a 559 bp fragment (U. urealyticum. Samples containing a band of the expected sizes for the Mycoplasma strains were subjected to digestion with a restriction endonuclease enzyme of TaqI and Cac8I. Results: Of the 210 samples, a total of 100 (47.6% samples were found to be positive for Mycoplasmas (seven M. genitalium isolates, 3.3%; and 89 U. urealyticum isolates, 42.4%, and coinfections with both species were detected in four samples (1.9%. The PCR-RFLP results showed that M. genitalium and U. urealyticum are different by enzyme patterns. Conclusion: PCR-RFLP offers a rapid and easily applicable protocol to simultaneous detection and differentiation of M. genitalium and U. urealyticum from clinical samples when specific primers and restriction enzymes are used.

Rapid intranasal delivery of chloramphenicol acetyltransferase in the active form to different brain regions as a model for enzyme therapy in the CNS.

Science.gov (United States)

Appu, Abhilash P; Arun, Peethambaran; Krishnan, Jishnu K S; Moffett, John R; Namboodiri, Aryan M A

2016-02-01

The blood brain barrier (BBB) is critical for maintaining central nervous system (CNS) homeostasis by restricting entry of potentially toxic substances. However, the BBB is a major obstacle in the treatment of neurotoxicity and neurological disorders due to the restrictive nature of the barrier to many medications. Intranasal delivery of active enzymes to the brain has therapeutic potential for the treatment of numerous CNS enzyme deficiency disorders and CNS toxicity caused by chemical threat agents. The aim of this work is to provide a sensitive model system for analyzing the rapid delivery of active enzymes into various regions of the brain with therapeutic bioavailability. We tested intranasal delivery of chloramphenicol acetyltransferase (CAT), a relatively large (75kD) enzyme, in its active form into different regions of the brain. CAT was delivered intranasally to anaesthetized rats and enzyme activity was measured in different regions using a highly specific High Performance Thin Layer Chromatography (HP-TLC)-radiometry coupled assay. Active enzyme reached all examined areas of the brain within 15min (the earliest time point tested). In addition, the yield of enzyme activity in the brain was almost doubled in the brains of rats pre-treated with matrix metalloproteinase-9 (MMP-9). Intranasal administration of active enzymes in conjunction with MMP-9 to the CNS is both rapid and effective. The present results suggest that intranasal enzyme therapy is a promising method for counteracting CNS chemical threat poisoning, as well as for treating CNS enzyme deficiency disorders. Published by Elsevier B.V.

Comparison of canine parvovirus with mink enteritis virus by restriction site mapping.

OpenAIRE

McMaster, G K; Tratschin, J D; Siegl, G

1981-01-01

The genomes of canine parvovirus and mink enteritis virus were compared by restriction enzyme analysis of their replicative-form DNAs. Of 79 mapped sites, 68, or 86%, were found to be common for both types of DNA, indicating that canine parvovirus and mink enteritis virus are closely related viruses. Whether they evolved from a common precursor or whether canine parvovirus is derived from mink enteritis virus, however, cannot be deduced from our present data.

Restriction map of the single-stranded DNA genome of Kilham rat virus strain 171, a nondefective parvovirus

International Nuclear Information System (INIS)

Banerjee, P.T.; Rathrock, R.; Mitra, S.

1981-01-01

A physical map of Kilham rat virus strain 171 DNA was constructed by analyzing the sizes and locations of restriction endonuclease-generated fragments of the replicative-form viral DNA synthesized in vitro. BglI, KpnI, BamHI, SmaI, XhoI, and XorII did not appear to have any cleavage sites, whereas 11 other enzymes cleaved the genome at one to eight sites, and AluI generated more than 12 distinct fragments. The 30 restriction sites that were mapped were distributed randomly in the viral genome. A comparison of the restriction fragments of in vivo- and in vitro-replicated replicative-form DNAs showed that these DNAs were identical except in the size or configuration of the terminal fragments

Nicotinamide and PNC1 govern lifespan extension by calorie restriction in Saccharomyces cerevisiae.

Science.gov (United States)

Anderson, Rozalyn M; Bitterman, Kevin J; Wood, Jason G; Medvedik, Oliver; Sinclair, David A

2003-05-08

Calorie restriction extends lifespan in a broad range of organisms, from yeasts to mammals. Numerous hypotheses have been proposed to explain this phenomenon, including decreased oxidative damage and altered energy metabolism. In Saccharomyces cerevisiae, lifespan extension by calorie restriction requires the NAD+-dependent histone deacetylase, Sir2 (ref. 1). We have recently shown that Sir2 and its closest human homologue SIRT1, a p53 deacetylase, are strongly inhibited by the vitamin B3 precursor nicotinamide. Here we show that increased expression of PNC1 (pyrazinamidase/nicotinamidase 1), which encodes an enzyme that deaminates nicotinamide, is both necessary and sufficient for lifespan extension by calorie restriction and low-intensity stress. We also identify PNC1 as a longevity gene that is responsive to all stimuli that extend lifespan. We provide evidence that nicotinamide depletion is sufficient to activate Sir2 and that this is the mechanism by which PNC1 regulates longevity. We conclude that yeast lifespan extension by calorie restriction is the consequence of an active cellular response to a low-intensity stress and speculate that nicotinamide might regulate critical cellular processes in higher organisms.

Marine Metagenome as A Resource for Novel Enzymes

KAUST Repository

Alma’abadi, Amani D.

2015-11-10

More than 99% of identified prokaryotes, including many from the marine environment, cannot be cultured in the laboratory. This lack of capability restricts our knowledge of microbial genetics and community ecology. Metagenomics, the culture-independent cloning of environmental DNAs that are isolated directly from an environmental sample, has already provided a wealth of information about the uncultured microbial world. It has also facilitated the discovery of novel biocatalysts by allowing researchers to probe directly into a huge diversity of enzymes within natural microbial communities. Recent advances in these studies have led to great interest in recruiting microbial enzymes for the development of environmentally-friendly industry. Although the metagenomics approach has many limitations, it is expected to provide not only scientific insights but also economic benefits, especially in industry. This review highlights the importance of metagenomics in mining microbial lipases, as an example, by using high-throughput techniques. In addition, we discuss challenges in the metagenomics as an important part of bioinformatics analysis in big data.

A Kinetic Modelling of Enzyme Inhibitions in the Central Metabolism of Yeast Cells

Science.gov (United States)

Kasbawati; Kalondeng, A.; Aris, N.; Erawaty, N.; Azis, M. I.

2018-03-01

Metabolic regulation plays an important role in the metabolic engineering of a cellular process. It is conducted to improve the productivity of a microbial process by identifying the important regulatory nodes of a metabolic pathway such as fermentation pathway. Regulation of enzymes involved in a particular pathway can be held to improve the productivity of the system. In the central metabolism of yeast cell, some enzymes are known as regulating enzymes that can be inhibited to increase the production of ethanol. In this research we study the kinetic modelling of the enzymes in the central pathway of yeast metabolism by taking into consideration the enzyme inhibition effects to the ethanol production. The existence of positive steady state solution and the stability of the system are also analysed to study the property and dynamical behaviour of the system. One stable steady state of the system is produced if some conditions are fulfilled. The conditions concern to the restriction of the maximum reactions of the enzymes in the pyruvate and acetaldehyde branch points. There exists a certain time of fermentation reaction at which a maximum and a minimum ethanol productions are attained after regulating the system. Optimal ethanol concentration is also produced for a certain initial concentration of inhibitor.

Exercise coupled with dietary restriction reduces oxidative stress in male adolescents with obesity.

Science.gov (United States)

Li, Chunyan; Feng, Feihu; Xiong, Xiaoling; Li, Rui; Chen, Ning

2017-04-01

The increased oxidative stress is usually observed in obese population, but the control of body weight by calorie restriction and/or exercise training can ameliorate oxidative stress. In order to evaluate oxidative stress in response to exercise and dietary restriction in obese adolescents, a total of 20 obese volunteers were enrolled in a 4-week intervention program including exercise training and dietary restriction. Body compositions and blood samples were analysed before and after 4-week intervention, and biomarkers associated with oxidative stress were examined. After 4-week exercise training coupled with dietary restriction, physical composition parameters including body mass, body mass index (BMI), lean body mass, body fat mass and fat mass ratio had obvious reduction by 12.43%, 13.51%, 5.83%, 25.05% and 14.52%, respectively. In addition, the activities of antioxidant enzymes, such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) revealed a remarkable enhancement. On the other hand, protein carbonyls (PC) exhibited an obvious reduction. Moreover, total thiols and nitrites with respect to baseline revealed a reducing trend although no significant difference was observed. Therefore, the 4-week exercise intervention coupled with dietary restriction is benefit for the loss of body weight and the mitigation of oxidative stress in obese population so that it can be a recommendable intervention prescription for the loss of body weight.

Enzyme

Science.gov (United States)

Enzymes are complex proteins that cause a specific chemical change in all parts of the body. For ... use them. Blood clotting is another example of enzymes at work. Enzymes are needed for all body ...

Enhanced resolution of DNA restriction fragments: A procedure by two-dimensional electrophoresis and double-labeling

International Nuclear Information System (INIS)

Yi, M.; Au, L.C.; Ichikawa, N.; Ts'o, P.O.

1990-01-01

A probe-free method was developed to detect DNA rearrangement in bacteria based on the electrophoretic separation of twice-digested restriction fragments of genomic DNA into a two-dimensional (2-D) pattern. The first restriction enzyme digestion was done in solution, followed by electrophoresis of the restriction fragments in one dimension. A second restriction enzyme digestion was carried out in situ in the gel, followed by electrophoresis in a second dimension perpendicular to the first electrophoresis. The 2-D pattern provides for the resolution of 300-400 spots, which are defined and indexed by an x,y coordinate system with size markers. This approach has greatly increased the resolution power over conventional one-dimensional (1-D) electrophoresis. To study DNA rearrangement, a 2-D pattern from a test strain was compared with the 2-D pattern from a reference strain. After the first digestion, genomic DNA fragments from the test strain were labeled with 35S, while those from the reference strain were labeled with 32P. This was done to utilize the difference in the energy emission of 35S and 32P isotopes for autoradiography when two x-ray films were exposed simultaneously on top of the gel after the 2-D electrophoresis. The irradiation from the decay of 35S exposed only the lower film, whereas the irradiation from the decay of 32P exposed both the lower and upper films. Different DNA fragments existed in the test DNA compared with the reference DNA can be identified unambiguously by the differential two 2-D patterns produced on two films upon exposure to the 35S and 32P fragments in the same gel. An appropriate photographic procedure further simplified the process, allowing only the difference in DNA fragments between these two patterns to be shown in the map

Mechanisms leading to increased risk of preterm birth in growth-restricted guinea pig pregnancies.

Science.gov (United States)

Palliser, Hannah K; Kelleher, Meredith A; Welsh, Toni N; Zakar, Tamas; Hirst, Jonathan J

2014-02-01

Intrauterine growth restriction (IUGR) is a risk factor for preterm labor; however, the mechanisms of the relationship remain unknown. Prostaglandin (PG), key stimulants of labor, availability is regulated by the synthetic enzymes, prostaglandin endoperoxidases 1 and 2 (PTGS1 and 2), and the metabolizing enzyme, 15-hydroxyprostaglandin dehydrogenase (HPGD). We hypothesized that IUGR increases susceptibility to preterm labor due to the changing balance of synthetic and metabolizing enzymes and hence greater PG availability. We have tested this hypothesis using a surgically induced IUGR model in guinea pigs, which results in significantly shorter gestation. Myometrium, amnion, chorion, and placentas were collected from sham operated or IUGR pregnancies, and PTGS1 and HPGD protein expression were quantified throughout late gestation (>62 days) and labor. The PTGS1 expression was significantly upregulated in the myometrium of IUGR animals, and chorionic HPGD expression was markedly decreased (P production over metabolism in IUGR pregnancies leads to a greater susceptibility to preterm birth.

Sirtuins as Mediator of the Anti-Ageing Effects of Calorie Restriction in Skeletal and Cardiac Muscle

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Alberto Zullo

2018-03-01

Full Text Available Fighting diseases and controlling the signs of ageing are the major goals of biomedicine. Sirtuins, enzymes with mainly deacetylating activity, could be pivotal targets of novel preventive and therapeutic strategies to reach such aims. Scientific proofs are accumulating in experimental models, but, to a minor extent, also in humans, that the ancient practice of calorie restriction could prove an effective way to prevent several degenerative diseases and to postpone the detrimental signs of ageing. In the present review, we summarize the evidence about the central role of sirtuins in mediating the beneficial effects of calorie restriction in skeletal and cardiac muscle since these tissues are greatly damaged by diseases and advancing years. Moreover, we entertain the possibility that the identification of sirtuin activators that mimic calorie restriction could provide the benefits without the inconvenience of this dietary style.

Restricted Interval Valued Neutrosophic Sets and Restricted Interval Valued Neutrosophic Topological Spaces

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Anjan Mukherjee

2016-08-01

Full Text Available In this paper we introduce the concept of restricted interval valued neutrosophic sets (RIVNS in short. Some basic operations and properties of RIVNS are discussed. The concept of restricted interval valued neutrosophic topology is also introduced together with restricted interval valued neutrosophic finer and restricted interval valued neutrosophic coarser topology. We also define restricted interval valued neutrosophic interior and closer of a restricted interval valued neutrosophic set. Some theorems and examples are cites. Restricted interval valued neutrosophic subspace topology is also studied.

The effects of beta-adrenergic blockade on body composition in free-fed and diet-restricted rats.

Science.gov (United States)

Ji, L L; Doan, T D; Lennon, D L; Nagle, F J; Lardy, H A

1987-04-01

The effects of the non-selective beta-adrenergic blocking agent propranolol (known for its anti-lipolytic activity) on body composition were investigated in growing male rats on normal unrestricted diet (N = 7) and on diet restriction (N = 7, 95% of controls). Three animals in each group were injected i.p. with 30 mg propranolol per kg body weight (bw) dissolved in saline, 5 days/week. This dose attenuates exercising heart rate by 25% and exercise training-induced enzyme activity. The remaining animals received saline. Fat, glycogen, moisture and non-ether extractable residue were determined in the homogenized residue of the whole animal. After 9 weeks on the experimental regimen, bw gain was significantly lower in the diet restricted rats, whereas propranolol had no effect on the bw gain. The percentage of fat, moisture and non-ether extractable residue were unchanged by either propranolol or diet restriction. However, glycogen content was significantly lower in the beta-blocked rats either with or without diet restriction. These data indicated that neither beta-adrenergic blockade nor minimal diet restriction influences the percentage body fat, whereas body glycogen content is decreased under both conditions.

Toxicokinetics of chloral hydrate in ad libitum-fed, dietary-controlled, and calorically restricted male B6C3F1 mice following short-term exposure

International Nuclear Information System (INIS)

Seng, John E.; Agrawal, Nalini; Horsley, Elizabeth T.M.; Leakey, Tatiana I.; Scherer, Erin M.; Xia, Shijun; Allaben, William T.; Leakey, Julian E.A.

2003-01-01

Chloral hydrate is widely used as a sedative in pediatric medicine and is a by-product of water chlorination and a metabolic intermediate in the biotransformation of trichloroethylene. Chloral hydrate and its major metabolite, trichloroacetic acid, induce liver tumors in B6C3F 1 mice, a strain that can exhibit high rates of background liver tumor incidence, which is associated with increased body weight. This report describes the influence of diet and body weight on the acute toxicity, hepatic enzyme response, and toxickinetics of chloral hydrate as part of a larger study investigating the carcinogenicity of chloral hydrate in ad libitum-fed and dietary controlled mice. Dietary control involves moderate food restriction to maintain the test animals at an idealized body weight. Mice were dosed with chloral hydrate at 0, 50, 100, 250, 500, and 1000 mg/kg daily, 5 days/week, by aqueous gavage for 2 weekly dosing cycles. Three diet groups were used: ad libitum, dietary control, and 40% caloric restriction. Both dietary control and caloric restriction slightly reduced acute toxicity of high doses of chloral hydrate and potentiated the induction of hepatic enzymes associated with peroxisome proliferation. Chloral hydrate toxicokinetics were investigated using blood samples obtained by sequential tail clipping and a microscale gas chromatography technique. It was rapidly cleared from serum within 3 h of dosing. Trichloroacetate was the major metabolite in serum in all three diet groups. Although the area under the curve values for serum trichloroacetate were slightly greater in the dietary controlled and calorically restricted groups than in the ad libitum-fed groups, this increase did not appear to completely account for the potentiation of hepatic enzyme induction by dietary restriction

Calorie Restriction-Mediated Replicative Lifespan Extension in Yeast Is Non-Cell Autonomous

Science.gov (United States)

Mei, Szu-Chieh; Brenner, Charles

2015-01-01

In laboratory yeast strains with Sir2 and Fob1 function, wild-type NAD+ salvage is required for calorie restriction (CR) to extend replicative lifespan. CR does not significantly alter steady state levels of intracellular NAD+ metabolites. However, levels of Sir2 and Pnc1, two enzymes that sequentially convert NAD+ to nicotinic acid (NA), are up-regulated during CR. To test whether factors such as NA might be exported by glucose-restricted mother cells to survive later generations, we developed a replicative longevity paradigm in which mother cells are moved after 15 generations on defined media. The experiment reveals that CR mother cells lose the longevity benefit of CR when evacuated from their local environment to fresh CR media. Addition of NA or nicotinamide riboside (NR) allows a moved mother to maintain replicative longevity despite the move. Moreover, conditioned medium from CR-treated cells transmits the longevity benefit of CR to moved mother cells. Evidence suggests the existence of a longevity factor that is dialyzable but is neither NA nor NR, and indicates that Sir2 is not required for the longevity factor to be produced or to act. Data indicate that the benefit of glucose-restriction is transmitted from cell to cell in budding yeast, suggesting that glucose restriction may benefit neighboring cells and not only an individual cell. PMID:25633578

Calorie restriction-mediated replicative lifespan extension in yeast is non-cell autonomous.

Directory of Open Access Journals (Sweden)

Szu-Chieh Mei

2015-01-01

Full Text Available In laboratory yeast strains with Sir2 and Fob1 function, wild-type NAD+ salvage is required for calorie restriction (CR to extend replicative lifespan. CR does not significantly alter steady state levels of intracellular NAD+ metabolites. However, levels of Sir2 and Pnc1, two enzymes that sequentially convert NAD+ to nicotinic acid (NA, are up-regulated during CR. To test whether factors such as NA might be exported by glucose-restricted mother cells to survive later generations, we developed a replicative longevity paradigm in which mother cells are moved after 15 generations on defined media. The experiment reveals that CR mother cells lose the longevity benefit of CR when evacuated from their local environment to fresh CR media. Addition of NA or nicotinamide riboside (NR allows a moved mother to maintain replicative longevity despite the move. Moreover, conditioned medium from CR-treated cells transmits the longevity benefit of CR to moved mother cells. Evidence suggests the existence of a longevity factor that is dialyzable but is neither NA nor NR, and indicates that Sir2 is not required for the longevity factor to be produced or to act. Data indicate that the benefit of glucose-restriction is transmitted from cell to cell in budding yeast, suggesting that glucose restriction may benefit neighboring cells and not only an individual cell.

Purification, crystallization, X-ray diffraction analysis and phasing of an engineered single-chain PvuII restriction endonuclease

International Nuclear Information System (INIS)

Meramveliotaki, Chrysi; Kotsifaki, Dina; Androulaki, Maria; Hountas, Athanasios; Eliopoulos, Elias; Kokkinidis, Michael

2007-01-01

PvuII is the first type II restriction endonuclease to be converted from its wild-type homodimeric form into an enzymatically active single-chain variant. The enzyme was crystallized and phasing was successfully performed by molecular replacement. The restriction endonuclease PvuII from Proteus vulgaris has been converted from its wild-type homodimeric form into the enzymatically active single-chain variant scPvuII by tandemly joining the two subunits through the peptide linker Gly-Ser-Gly-Gly. scPvuII, which is suitable for the development of programmed restriction endonucleases for highly specific DNA cleavage, was purified and crystallized. The crystals diffract to a resolution of 2.35 Å and belong to space group P4 2 , with unit-cell parameters a = b = 101.92, c = 100.28 Å and two molecules per asymmetric unit. Phasing was successfully performed by molecular replacement

Marine Metagenome as A Resource for Novel Enzymes

Directory of Open Access Journals (Sweden)

Amani D. Alma’abadi

2015-10-01

Full Text Available More than 99% of identified prokaryotes, including many from the marine environment, cannot be cultured in the laboratory. This lack of capability restricts our knowledge of microbial genetics and community ecology. Metagenomics, the culture-independent cloning of environmental DNAs that are isolated directly from an environmental sample, has already provided a wealth of information about the uncultured microbial world. It has also facilitated the discovery of novel biocatalysts by allowing researchers to probe directly into a huge diversity of enzymes within natural microbial communities. Recent advances in these studies have led to a great interest in recruiting microbial enzymes for the development of environmentally-friendly industry. Although the metagenomics approach has many limitations, it is expected to provide not only scientific insights but also economic benefits, especially in industry. This review highlights the importance of metagenomics in mining microbial lipases, as an example, by using high-throughput techniques. In addition, we discuss challenges in the metagenomics as an important part of bioinformatics analysis in big data.

Enzyme Informatics

Science.gov (United States)

Alderson, Rosanna G.; Ferrari, Luna De; Mavridis, Lazaros; McDonagh, James L.; Mitchell, John B. O.; Nath, Neetika

2012-01-01

Over the last 50 years, sequencing, structural biology and bioinformatics have completely revolutionised biomolecular science, with millions of sequences and tens of thousands of three dimensional structures becoming available. The bioinformatics of enzymes is well served by, mostly free, online databases. BRENDA describes the chemistry, substrate specificity, kinetics, preparation and biological sources of enzymes, while KEGG is valuable for understanding enzymes and metabolic pathways. EzCatDB, SFLD and MACiE are key repositories for data on the chemical mechanisms by which enzymes operate. At the current rate of genome sequencing and manual annotation, human curation will never finish the functional annotation of the ever-expanding list of known enzymes. Hence there is an increasing need for automated annotation, though it is not yet widespread for enzyme data. In contrast, functional ontologies such as the Gene Ontology already profit from automation. Despite our growing understanding of enzyme structure and dynamics, we are only beginning to be able to design novel enzymes. One can now begin to trace the functional evolution of enzymes using phylogenetics. The ability of enzymes to perform secondary functions, albeit relatively inefficiently, gives clues as to how enzyme function evolves. Substrate promiscuity in enzymes is one example of imperfect specificity in protein-ligand interactions. Similarly, most drugs bind to more than one protein target. This may sometimes result in helpful polypharmacology as a drug modulates plural targets, but also often leads to adverse side-effects. Many cheminformatics approaches can be used to model the interactions between druglike molecules and proteins in silico. We can even use quantum chemical techniques like DFT and QM/MM to compute the structural and energetic course of enzyme catalysed chemical reaction mechanisms, including a full description of bond making and breaking. PMID:23116471

On-Chip Evaluation of DNA Methylation with Electrochemical Combined Bisulfite Restriction Analysis Utilizing a Carbon Film Containing a Nanocrystalline Structure.

Science.gov (United States)

Kurita, Ryoji; Yanagisawa, Hiroyuki; Kamata, Tomoyuki; Kato, Dai; Niwa, Osamu

2017-06-06

This paper reports an on-chip electrochemical assessment of the DNA methylation status in genomic DNA on a conductive nanocarbon film electrode realized with combined bisulfite restriction analysis (COBRA). The film electrode consists of sp 2 and sp 3 hybrid bonds and is fabricated with an unbalanced magnetron (UBM) sputtering method. First, we studied the effect of the sp 2 /sp 3 ratio of the UBM nanocarbon film electrode with p-aminophenol, which is a major electro-active product of the labeling enzyme from p-aminophenol phosphate. The signal current for p-aminophenol increases as the sp 2 content in the UBM nanocarbon film electrode increases because of the π-π interaction between aromatic p-aminophenol and the graphene-like sp 2 structure. Furthermore, the capacitative current at the UBM nanocarbon film electrode was successfully reduced by about 1 order of magnitude thanks to the angstrom-level surface flatness. Therefore, a high signal-to-noise ratio was achieved compared with that of conventional electrodes. Then, after performing an ELISA-like hybridization assay with a restriction enzyme, we undertook an electrochemical evaluation of the cytosine methylation status in DNA by measuring the oxidation current derived from p-aminophenol. When the target cytosine in the analyte sequence is methylated (unmethylated), the restriction enzyme of HpyCH4IV is able (unable) to cleave the sequence, that is, the detection probe cannot (can) hybridize. We succeeded in estimating the methylation ratio at a site-specific CpG site from the peak current of a cyclic voltammogram obtained from a PCR product solution ranging from 0.01 to 1 nM.

The elastic network model reveals a consistent picture on intrinsic functional dynamics of type II restriction endonucleases

International Nuclear Information System (INIS)

Uyar, A; Kurkcuoglu, O; Doruker, P; Nilsson, L

2011-01-01

The vibrational dynamics of various type II restriction endonucleases, in complex with cognate/non-cognate DNA and in the apo form, are investigated with the elastic network model in order to reveal common functional mechanisms in this enzyme family. Scissor-like and tong-like motions observed in the slowest modes of all enzymes and their complexes point to common DNA recognition and cleavage mechanisms. Normal mode analysis further points out that the scissor-like motion has an important role in differentiating between cognate and non-cognate sequences at the recognition site, thus implying its catalytic relevance. Flexible regions observed around the DNA-binding site of the enzyme usually concentrate on the highly conserved β-strands, especially after DNA binding. These β-strands may have a structurally stabilizing role in functional dynamics for target site recognition and cleavage. In addition, hot spot residues based on high-frequency modes reveal possible communication pathways between the two distant cleavage sites in the enzyme family. Some of these hot spots also exist on the shortest path between the catalytic sites and are highly conserved

Restrictions and Proportionality

DEFF Research Database (Denmark)

Werlauff, Erik

2009-01-01

The article discusses three central aspects of the freedoms under European Community law, namely 1) the prohibition against restrictions as an important extension of the prohibition against discrimination, 2) a prohibition against exit restrictions which is just as important as the prohibition...... against host country restrictions, but which is often not recognised to the same extent by national law, and 3) the importance of also identifying and recognising an exit restriction, so that it is possible to achieve the required test of appropriateness and proportionality in relation to the rule...

Identification of planorbids from Venezuela by polymerase chain reaction amplification and restriction fragment length polymorphism of internal transcriber spacer of the RNA ribosomal gene

Directory of Open Access Journals (Sweden)

Caldeira Roberta L

2000-01-01

Full Text Available Snails of the genus Biomphalaria from Venezuela were subjected to morphological assessment as well as polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP analysis. Morphological identification was carried out by comparison of characters of the shell and the male and female reproductive apparatus. The PCR-RFLP involved amplification of the internal spacer region ITS1 and ITS2 of the RNA ribosomal gene and subsequent digestion of this fragment by the restriction enzymes DdeI, MnlI, HaeIII and MspI. The planorbids were compared with snails of the same species and others reported from Venezuela and present in Brazil, Cuba and Mexico. All the enzymes showed a specific profile for each species, that of DdeI being the clearest. The snails were identified as B. glabrata, B. prona and B. kuhniana.

A Mimicking-of-DNA-Methylation-Patterns Pipeline for Overcoming the Restriction Barrier of Bacteria

Science.gov (United States)

Zhang, Guoqiang; Wang, Wenzhao; Deng, Aihua; Sun, Zhaopeng; Zhang, Yun; Liang, Yong; Che, Yongsheng; Wen, Tingyi

2012-01-01

Genetic transformation of bacteria harboring multiple Restriction-Modification (R-M) systems is often difficult using conventional methods. Here, we describe a mimicking-of-DNA-methylation-patterns (MoDMP) pipeline to address this problem in three difficult-to-transform bacterial strains. Twenty-four putative DNA methyltransferases (MTases) from these difficult-to-transform strains were cloned and expressed in an Escherichia coli strain lacking all of the known R-M systems and orphan MTases. Thirteen of these MTases exhibited DNA modification activity in Southwestern dot blot or Liquid Chromatography–Mass Spectrometry (LC–MS) assays. The active MTase genes were assembled into three operons using the Saccharomyces cerevisiae DNA assembler and were co-expressed in the E. coli strain lacking known R-M systems and orphan MTases. Thereafter, results from the dot blot and restriction enzyme digestion assays indicated that the DNA methylation patterns of the difficult-to-transform strains are mimicked in these E. coli hosts. The transformation of the Gram-positive Bacillus amyloliquefaciens TA208 and B. cereus ATCC 10987 strains with the shuttle plasmids prepared from MoDMP hosts showed increased efficiencies (up to four orders of magnitude) compared to those using the plasmids prepared from the E. coli strain lacking known R-M systems and orphan MTases or its parental strain. Additionally, the gene coding for uracil phosphoribosyltransferase (upp) was directly inactivated using non-replicative plasmids prepared from the MoDMP host in B. amyloliquefaciens TA208. Moreover, the Gram-negative chemoautotrophic Nitrobacter hamburgensis strain X14 was transformed and expressed Green Fluorescent Protein (GFP). Finally, the sequence specificities of active MTases were identified by restriction enzyme digestion, making the MoDMP system potentially useful for other strains. The effectiveness of the MoDMP pipeline in different bacterial groups suggests a universal potential

Pancreatic Enzymes

Science.gov (United States)

... Contact Us DONATE NOW GENERAL DONATION PURPLESTRIDE Pancreatic enzymes Home Facing Pancreatic Cancer Living with Pancreatic Cancer ... and see a registered dietitian. What are pancreatic enzymes? Pancreatic enzymes help break down fats, proteins and ...

Towards the molecular characterisation of parasitic nematode assemblages: an evaluation of terminal-restriction fragment length polymorphism (T-RFLP) analysis.

Science.gov (United States)

Lott, M J; Hose, G C; Power, M L

2014-09-01

Identifying factors which regulate temporal and regional structuring within parasite assemblages requires the development of non-invasive techniques which facilitate both the rapid discrimination of individual parasites and the capacity to monitor entire parasite communities across time and space. To this end, we have developed and evaluated a rapid fluorescence-based method, terminal restriction fragment length polymorphism (T-RFLP) analysis, for the characterisation of parasitic nematode assemblages in macropodid marsupials. The accuracy with which T-RFLP was capable of distinguishing between the constituent taxa of a parasite community was assessed by comparing sequence data from two loci (the ITS+ region of nuclear ribosomal DNA and the mitochondrial CO1) across ∼20 species of nematodes (suborder Strongylida). Our results demonstrate that with fluorescent labelling of the forward and reverse terminal restriction fragments (T-RFs) of the ITS+ region, the restriction enzyme Hinf1 was capable of generating species specific T-RFLP profiles. A notable exception was within the genus Cloacina, in which closely related species often shared identical T-RFs. This may be a consequence of the group's comparatively recent evolutionary radiation. While the CO1 displayed higher sequence diversity than the ITS+, the subsequent T-RFLP profiles were taxonomically inconsistent and could not be used to further differentiate species within Cloacina. Additionally, several of the ITS+ derived T-RFLP profiles exhibited unexpected secondary peaks, possibly as a consequence of the restriction enzymes inability to cleave partially single stranded amplicons. These data suggest that the question of T-RFLPs utility in monitoring parasite communities cannot be addressed without considering the ecology and unique evolutionary history of the constituent taxa. Copyright © 2014 Elsevier Inc. All rights reserved.

R Factor-Controlled Restriction and Modification of Deoxyribonucleic Acid: Restriction Mutants

Science.gov (United States)

Yoshimori, Robert; Roulland-Dussoix, Daisy; Boyer, Herbert W.

1972-01-01

Restriction mutants of two different R factor-controlled host specificities (RI and RII) were isolated. All of the restriction mutants examined had a normal modification phenotype. No complementation was observed between the RI and RII host specificities. It is concluded that for each host specificity no protein subunit is shared by the restriction endonuclease and modification methylase. PMID:4565538

Restriction digest screening facilitates efficient detection of site-directed mutations introduced by CRISPR in C. albicans UME6.

Science.gov (United States)

Evans, Ben A; Smith, Olivia L; Pickerill, Ethan S; York, Mary K; Buenconsejo, Kristen J P; Chambers, Antonio E; Bernstein, Douglas A

2018-01-01

Introduction of point mutations to a gene of interest is a powerful tool when determining protein function. CRISPR-mediated genome editing allows for more efficient transfer of a desired mutation into a wide range of model organisms. Traditionally, PCR amplification and DNA sequencing is used to determine if isolates contain the intended mutation. However, mutation efficiency is highly variable, potentially making sequencing costly and time consuming. To more efficiently screen for correct transformants, we have identified restriction enzymes sites that encode for two identical amino acids or one or two stop codons. We used CRISPR to introduce these restriction sites directly upstream of the Candida albicans UME6 Zn 2+ -binding domain, a known regulator of C. albicans filamentation. While repair templates coding for different restriction sites were not equally successful at introducing mutations, restriction digest screening enabled us to rapidly identify isolates with the intended mutation in a cost-efficient manner. In addition, mutated isolates have clear defects in filamentation and virulence compared to wild type C. albicans . Our data suggest restriction digestion screening efficiently identifies point mutations introduced by CRISPR and streamlines the process of identifying residues important for a phenotype of interest.

Calorie restriction increases muscle mitochondrial biogenesis in healthy humans.

Directory of Open Access Journals (Sweden)

Anthony E Civitarese

2007-03-01

Full Text Available Caloric restriction without malnutrition extends life span in a range of organisms including insects and mammals and lowers free radical production by the mitochondria. However, the mechanism responsible for this adaptation are poorly understood.The current study was undertaken to examine muscle mitochondrial bioenergetics in response to caloric restriction alone or in combination with exercise in 36 young (36.8 +/- 1.0 y, overweight (body mass index, 27.8 +/- 0.7 kg/m(2 individuals randomized into one of three groups for a 6-mo intervention: Control, 100% of energy requirements; CR, 25% caloric restriction; and CREX, caloric restriction with exercise (CREX, 12.5% CR + 12.5% increased energy expenditure (EE. In the controls, 24-h EE was unchanged, but in CR and CREX it was significantly reduced from baseline even after adjustment for the loss of metabolic mass (CR, -135 +/- 42 kcal/d, p = 0.002 and CREX, -117 +/- 52 kcal/d, p = 0.008. Participants in the CR and CREX groups had increased expression of genes encoding proteins involved in mitochondrial function such as PPARGC1A, TFAM, eNOS, SIRT1, and PARL (all, p < 0.05. In parallel, mitochondrial DNA content increased by 35% +/- 5% in the CR group (p = 0.005 and 21% +/- 4% in the CREX group (p < 0.004, with no change in the control group (2% +/- 2%. However, the activity of key mitochondrial enzymes of the TCA (tricarboxylic acid cycle (citrate synthase, beta-oxidation (beta-hydroxyacyl-CoA dehydrogenase, and electron transport chain (cytochrome C oxidase II was unchanged. DNA damage was reduced from baseline in the CR (-0.56 +/- 0.11 arbitrary units, p = 0.003 and CREX (-0.45 +/- 0.12 arbitrary units, p = 0.011, but not in the controls. In primary cultures of human myotubes, a nitric oxide donor (mimicking eNOS signaling induced mitochondrial biogenesis but failed to induce SIRT1 protein expression, suggesting that additional factors may regulate SIRT1 content during CR.The observed increase in

Measuring the Enzyme Activity of Arabidopsis Deubiquitylating Enzymes.

Science.gov (United States)

Kalinowska, Kamila; Nagel, Marie-Kristin; Isono, Erika

2016-01-01

Deubiquitylating enzymes, or DUBs, are important regulators of ubiquitin homeostasis and substrate stability, though the molecular mechanisms of most of the DUBs in plants are not yet understood. As different ubiquitin chain types are implicated in different biological pathways, it is important to analyze the enzyme characteristic for studying a DUB. Quantitative analysis of DUB activity is also important to determine enzyme kinetics and the influence of DUB binding proteins on the enzyme activity. Here, we show methods to analyze DUB activity using immunodetection, Coomassie Brilliant Blue staining, and fluorescence measurement that can be useful for understanding the basic characteristic of DUBs.

Direct 19F NMR observation of the conformational selection of optically active rotamers of the antifolate compound fluoronitropyrimethamine bound to enzyme dihydrofolate reductase

International Nuclear Information System (INIS)

Tendler, S.J.B.; Birdsall, B.; Feeney, J.; Griffin, R.J.; Stevens, M.F.G.; Roberts, G.C.K.

1988-01-01

The molucular basis of the binding of the lipophilic antifolate compound fluoronitropyrimethamine to its target enzyme dihydrofolate reductase has been investigated using a combination of 19 F NMR spectroscopy and molecular mechanical calculations 19 F NMR reveals the presence of two different conformational states for the fluoronitropyrimethamine-Lactobacillus casei enzyme complex. MM2 molecular mechanical calculations predict restricted rotation about the C5-C1 bond of the ligand and this give rise to two slowly interconverting rotamers which are an enantiomeric pair. The results of 19 F NMR spectroscopy reveal that both these isomers bind to the enzyme, with different affinities. There is no detectable interconversion of the bound rotamers themselves on the NMR timescale. The effect of the addition of co-enzyme to the sample is to reverse the preference the enzyme has for each rotamer. (author). 11 refs.; 3 figs

Nanomaterials with enzyme-like characteristics (nanozymes): next-generation artificial enzymes.

Science.gov (United States)

Wei, Hui; Wang, Erkang

2013-07-21

Over the past few decades, researchers have established artificial enzymes as highly stable and low-cost alternatives to natural enzymes in a wide range of applications. A variety of materials including cyclodextrins, metal complexes, porphyrins, polymers, dendrimers and biomolecules have been extensively explored to mimic the structures and functions of naturally occurring enzymes. Recently, some nanomaterials have been found to exhibit unexpected enzyme-like activities, and great advances have been made in this area due to the tremendous progress in nano-research and the unique characteristics of nanomaterials. To highlight the progress in the field of nanomaterial-based artificial enzymes (nanozymes), this review discusses various nanomaterials that have been explored to mimic different kinds of enzymes. We cover their kinetics, mechanisms and applications in numerous fields, from biosensing and immunoassays, to stem cell growth and pollutant removal. We also summarize several approaches to tune the activities of nanozymes. Finally, we make comparisons between nanozymes and other catalytic materials (other artificial enzymes, natural enzymes, organic catalysts and nanomaterial-based catalysts) and address the current challenges and future directions (302 references).

Measuring the Restrictiveness of Living Environments for Children and Youth: Reconceptualizing Restriction

Science.gov (United States)

Rauktis, Mary E.; Huefner, Jonathan C.; O'Brien, Kirk; Pecora, Peter J.; Doucette, Ann; Thompson, Ronald W.

2009-01-01

The "Restrictiveness of Living Environment Scale" has long been the primary way to conceptualize the "restrictiveness" of a child's living situation. However, changes in systems of care and other factors have created a need to revisit how restrictiveness is conceptualized and measured. A measure was created to assess an environment's level of…

[Advances on enzymes and enzyme inhibitors research based on microfluidic devices].

Science.gov (United States)

Hou, Feng-Hua; Ye, Jian-Qing; Chen, Zuan-Guang; Cheng, Zhi-Yi

2010-06-01

With the continuous development in microfluidic fabrication technology, microfluidic analysis has evolved from a concept to one of research frontiers in last twenty years. The research of enzymes and enzyme inhibitors based on microfluidic devices has also made great progress. Microfluidic technology improved greatly the analytical performance of the research of enzymes and enzyme inhibitors by reducing the consumption of reagents, decreasing the analysis time, and developing automation. This review focuses on the development and classification of enzymes and enzyme inhibitors research based on microfluidic devices.

Direct comparison of enzyme histochemical and immunohistochemical methods to localize an enzyme

NARCIS (Netherlands)

van Noorden, Cornelis J. F.

2002-01-01

Immunohistochemical localization of enzymes is compared directly with localization of enzyme activity with (catalytic) enzyme histochemical methods. The two approaches demonstrate principally different aspects of an enzyme. The immunohistochemical method localizes the enzyme protein whether it is

Computational enzyme design: transitioning from catalytic proteins to enzymes.

Science.gov (United States)

Mak, Wai Shun; Siegel, Justin B

2014-08-01

The widespread interest in enzymes stem from their ability to catalyze chemical reactions under mild and ecologically friendly conditions with unparalleled catalytic proficiencies. While thousands of naturally occurring enzymes have been identified and characterized, there are still numerous important applications for which there are no biological catalysts capable of performing the desired chemical transformation. In order to engineer enzymes for which there is no natural starting point, efforts using a combination of quantum chemistry and force-field based protein molecular modeling have led to the design of novel proteins capable of catalyzing chemical reactions not catalyzed by naturally occurring enzymes. Here we discuss the current status and potential avenues to pursue as the field of computational enzyme design moves forward. Published by Elsevier Ltd.

Treatment of PCR products with exonuclease I and heat-labile alkaline phosphatase improves the visibility of combined bisulfite restriction analysis

International Nuclear Information System (INIS)

Watanabe, Kousuke; Emoto, Noriko; Sunohara, Mitsuhiro; Kawakami, Masanori; Kage, Hidenori; Nagase, Takahide; Ohishi, Nobuya; Takai, Daiya

2010-01-01

Research highlights: → Incubating PCR products at a high temperature causes smears in gel electrophoresis. → Smears interfere with the interpretation of methylation analysis using COBRA. → Treatment with exonuclease I and heat-labile alkaline phosphatase eliminates smears. → The elimination of smears improves the visibility of COBRA. -- Abstract: DNA methylation plays a vital role in the regulation of gene expression. Abnormal promoter hypermethylation is an important mechanism of inactivating tumor suppressor genes in human cancers. Combined bisulfite restriction analysis (COBRA) is a widely used method for identifying the DNA methylation of specific CpG sites. Here, we report that exonuclease I and heat-labile alkaline phosphatase can be used for PCR purification for COBRA, improving the visibility of gel electrophoresis after restriction digestion. This improvement is observed when restriction digestion is performed at a high temperature, such as 60 o C or 65 o C, with BstUI and TaqI, respectively. This simple method can be applied instead of DNA purification using spin columns or phenol/chloroform extraction. It can also be applied to other situations when PCR products are digested by thermophile-derived restriction enzymes, such as PCR restriction fragment length polymorphism (RFLP) analysis.

Molecular mechanisms of intrauterine growth restriction.

Science.gov (United States)

Gurugubelli Krishna, Rao; Vishnu Bhat, B

2017-07-10

Intrauterine growth restriction (IUGR) is a pregnancy specific disease characterized by decreased growth rate of fetus than the normal growth potential at particular gestational age. In the current scenario it is a leading cause of fetal and neonatal morbidity and mortality. In the last decade exhilarating experimental studies from several laboratories have provided fascinating proof for comprehension of molecular basis of IUGR. Atypical expression of enzymes governed by TGFβ causes the placental apoptosis and altered expression of TGFβ due to hyper alimentation causes impairment of lung function. Crosstalk of cAMP with protein kinases plays a prominent role in the regulation of cortisol levels. Increasing levels of NOD1 proteins leads to development of IUGR by increasing the levels of inflammatory mediators. Increase in leptin synthesis in placental trophoblast cells is associated with IUGR. In this review, we emphasize on the regulatory mechanisms of IUGR and its associated diseases. They may help improve the in-utero fetal growth and provide a better therapeutic intervention for prevention and treatment of IUGR.

Stabilization of enzymes in ionic liquids via modification of enzyme charge.

Science.gov (United States)

Nordwald, Erik M; Kaar, Joel L

2013-09-01

Due to the propensity of ionic liquids (ILs) to inactivate enzymes, the development of strategies to improve enzyme utility in these solvents is critical to fully exploit ILs for biocatalysis. We have developed a strategy to broadly improve enzyme utility in ILs based on elucidating the effect of charge modifications on the function of enzymes in IL environments. Results of stability studies in aqueous-IL mixtures indicated a clear connection between the ratio of enzyme-containing positive-to-negative sites and enzyme stability in ILs. Stability studies of the effect of [BMIM][Cl] and [EMIM][EtSO4 ] on chymotrypsin specifically found an optimum ratio of positively-charged amine-to-negatively-charged acid groups (0.39). At this ratio, the half-life of chymotrypsin was increased 1.6- and 4.3-fold relative to wild-type chymotrypsin in [BMIM][Cl] and [EMIM][EtSO4 ], respectively. The half-lives of lipase and papain were similarly increased as much as 4.0 and 2.4-fold, respectively, in [BMIM][Cl] by modifying the ratio of positive-to-negative sites of each enzyme. More generally, the results of stability studies found that modifications that reduce the ratio of enzyme-containing positive-to-negative sites improve enzyme stability in ILs. Understanding the impact of charge modification on enzyme stability in ILs may ultimately be exploited to rationally engineer enzymes for improved function in IL environments. Copyright © 2013 Wiley Periodicals, Inc.

Artificial Enzymes, "Chemzymes"

DEFF Research Database (Denmark)

Bjerre, Jeannette; Rousseau, Cyril Andre Raphaël; Pedersen, Lavinia Georgeta M

2008-01-01

Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models that successf......Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models...... that successfully perform Michaelis-Menten catalysis under enzymatic conditions (i.e., aqueous medium, neutral pH, ambient temperature) and for those that do, very high rate accelerations are seldomly seen. This review will provide a brief summary of the recent developments in artificial enzymes, so called...... "Chemzymes", based on cyclodextrins and other molecules. Only the chemzymes that have shown enzyme-like activity that has been quantified by different methods will be mentioned. This review will summarize the work done in the field of artificial glycosidases, oxidases, epoxidases, and esterases, as well...

Enzyme detection by microfluidics

DEFF Research Database (Denmark)

2013-01-01

Microfluidic-implemented methods of detecting an enzyme, in particular a DNA-modifying enzyme, are provided, as well as methods for detecting a cell, or a microorganism expressing said enzyme. The enzyme is detected by providing a nucleic acid substrate, which is specifically targeted...... by that enzyme...

A systems biology framework for modeling metabolic enzyme inhibition of Mycobacterium tuberculosis

Directory of Open Access Journals (Sweden)

Reifman Jaques

2009-09-01

Full Text Available Abstract Background Because metabolism is fundamental in sustaining microbial life, drugs that target pathogen-specific metabolic enzymes and pathways can be very effective. In particular, the metabolic challenges faced by intracellular pathogens, such as Mycobacterium tuberculosis, residing in the infected host provide novel opportunities for therapeutic intervention. Results We developed a mathematical framework to simulate the effects on the growth of a pathogen when enzymes in its metabolic pathways are inhibited. Combining detailed models of enzyme kinetics, a complete metabolic network description as modeled by flux balance analysis, and a dynamic cell population growth model, we quantitatively modeled and predicted the dose-response of the 3-nitropropionate inhibitor on the growth of M. tuberculosis in a medium whose carbon source was restricted to fatty acids, and that of the 5'-O-(N-salicylsulfamoyl adenosine inhibitor in a medium with low-iron concentration. Conclusion The predicted results quantitatively reproduced the experimentally measured dose-response curves, ranging over three orders of magnitude in inhibitor concentration. Thus, by allowing for detailed specifications of the underlying enzymatic kinetics, metabolic reactions/constraints, and growth media, our model captured the essential chemical and biological factors that determine the effects of drug inhibition on in vitro growth of M. tuberculosis cells.

A20 restricts wnt signaling in intestinal epithelial cells and suppresses colon carcinogenesis.

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Ling Shao

Full Text Available Colon carcinogenesis consists of a multistep process during which a series of genetic and epigenetic adaptations occur that lead to malignant transformation. Here, we have studied the role of A20 (also known as TNFAIP3, a ubiquitin-editing enzyme that restricts NFκB and cell death signaling, in intestinal homeostasis and tumorigenesis. We have found that A20 expression is consistently reduced in human colonic adenomas than in normal colonic tissues. To further investigate A20's potential roles in regulating colon carcinogenesis, we have generated mice lacking A20 specifically in intestinal epithelial cells and interbred these with mice harboring a mutation in the adenomatous polyposis coli gene (APC(min. While A20(FL/FL villin-Cre mice exhibit uninflamed intestines without polyps, A20(FL/FL villin-Cre APC(min/+ mice contain far greater numbers and larger colonic polyps than control APC(min mice. We find that A20 binds to the β-catenin destruction complex and restricts canonical wnt signaling by supporting ubiquitination and degradation of β-catenin in intestinal epithelial cells. Moreover, acute deletion of A20 from intestinal epithelial cells in vivo leads to enhanced expression of the β-catenin dependent genes cyclinD1 and c-myc, known promoters of colon cancer. Taken together, these findings demonstrate new roles for A20 in restricting β-catenin signaling and preventing colon tumorigenesis.

Angiotensin converting enzyme inhibition induces alterations to hippuran renography despite unchanged ipsilateral renal blood flow in conscious two-kidney, one clip Goldblatt hypertensive dogs

NARCIS (Netherlands)

Jonker, G J; de Zeeuw, D; Huisman, R M; van der Hem, G K

1988-01-01

We performed experiments in the two-kidney, one clip Goldblatt hypertensive dog to see whether angiotensin converting enzyme (ACE) inhibition could improve the sensitivity of hippurate renography in detecting renal artery stenosis. Ten dogs on a sodium-restricted diet were studied before and after

7 CFR 58.436 - Rennet, pepsin, other milk clotting enzymes and flavor enzymes.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Rennet, pepsin, other milk clotting enzymes and flavor enzymes. 58.436 Section 58.436 Agriculture Regulations of the Department of Agriculture (Continued... clotting enzymes and flavor enzymes. Enzyme preparations used in the manufacture of cheese shall be safe...

Elevated Liver Enzymes

Science.gov (United States)

Symptoms Elevated liver enzymes By Mayo Clinic Staff Elevated liver enzymes may indicate inflammation or damage to cells in the liver. Inflamed or ... than normal amounts of certain chemicals, including liver enzymes, into the bloodstream, which can result in elevated ...

Stability of Enzymes in Granular Enzyme Products for Laundry Detergents

DEFF Research Database (Denmark)

Biran, Suzan; Bach, Poul; Simonsen, Ole

Enzymes have long been of interest to the detergent industry due to their ability to improve the cleaning efficiency of synthetic detergents, contribute to shortening washing times, and reduce energy and water consumption, provision of environmentally friendlier wash water effluents and fabric care....... However, incorporating enzymes in detergent formulations gives rise to numerous practical problems due to their incompatibility with and stability against various detergent components. In powdered detergent formulations, these issues can be partly overcome by physically isolating the enzymes in separate...... particles. However, enzymes may loose a significant part of their activity over a time period of several weeks. Possible causes of inactivation of enzymes in a granule may be related to the release of hydrogen peroxide from the bleaching chemicals in a moisture-containing atmosphere, humidity, autolysis...

Enzyme structure, enzyme function and allozyme diversity in ...

African Journals Online (AJOL)

In estimates of population genetic diversity based on allozyme heterozygosity, some enzymes are regularly more variable than others. Evolutionary theory suggests that functionally less important molecules, or parts of molecules, evolve more rapidly than more important ones; the latter enzymes should then theoretically be ...

Aging, adiposity, and calorie restriction.

Science.gov (United States)

Fontana, Luigi; Klein, Samuel

2007-03-07

Excessive calorie intake and subsequent obesity increases the risk of developing chronic disease and decreases life expectancy. In rodent models, calorie restriction with adequate nutrient intake decreases the risk of developing chronic disease and extends maximum life span. To evaluate the physiological and clinical implications of calorie restriction with adequate nutrient intake. Search of PubMed (1966-December 2006) using terms encompassing various aspects of calorie restriction, dietary restriction, aging, longevity, life span, adiposity, and obesity; hand search of journals that focus on obesity, geriatrics, or aging; and search of reference lists of pertinent research and review articles and books. Reviewed reports (both basic science and clinical) included epidemiologic studies, case-control studies, and randomized controlled trials, with quality of data assessed by taking into account publication in a peer-reviewed journal, number of animals or individuals studied, objectivity of measurements, and techniques used to minimize bias. It is not known whether calorie restriction extends maximum life span or life expectancy in lean humans. However, calorie restriction in adult men and women causes many of the same metabolic adaptations that occur in calorie-restricted rodents and monkeys, including decreased metabolic, hormonal, and inflammatory risk factors for diabetes, cardiovascular disease, and possibly cancer. Excessive calorie restriction causes malnutrition and has adverse clinical effects. Calorie restriction in adult men and women causes beneficial metabolic, hormonal, and functional changes, but the precise amount of calorie intake or body fat mass associated with optimal health and maximum longevity in humans is not known. In addition, it is possible that even moderate calorie restriction may be harmful in specific patient populations, such as lean persons who have minimal amounts of body fat.

PCR-restriction fragment length polymorphism analysis of indigenous nitrogen-fixing micro organisms lineages

International Nuclear Information System (INIS)

Liew Woan Ying Pauline; Jong Bor Chyan; Khairuddin Abdul Rahim

2006-01-01

The use of PCR-RFLP analysis as a useful microbial identification tool has been evaluated for years. This approach was verified effective worldwide, where differential DNA bands and sequence markers distinctive to specific microbes or microbial groups have been identified. In our study, PCR-RFLP technique has been adopted in the identification of our indigenous N 2 -fixing isolates obtained from several local environments. RFLP was carried out with suitable restriction enzymes and the patterns were documented. Representatives of the different patterns were selected and analysed with the 16S ribosomal DNA sequencing method. The results demonstrated correlation between the differential RFLP patterns and the 16S rDNA identities. (Author)

Sodium restriction potentiates the renoprotective effects of combined vitamin D receptor activation and angiotensin-converting enzyme inhibition in established proteinuric nephropathy.

NARCIS (Netherlands)

Mirkovic, K.; Frenay, A.S.; Born, J. van den; Goor, H van; Navis, G.; Borst, M.H. de; Bindels, R.J.M.; Hoenderop, J.G.J.; Hillebrands, J.L.

2017-01-01

BACKGROUND: Renin-angiotensin-aldosterone system (RAAS) blockade provides renoprotective effects in chronic kidney disease (CKD); yet progressive renal function loss remains common. Dietary sodium restriction potentiates the renoprotective effects of RAAS blockade. Vitamin D receptor activator

Angiogenic factors for prediction of preeclampsia and intrauterine growth restriction onset in high-risk women: AngioPred study.

Science.gov (United States)

Raia-Barjat, Tiphaine; Prieux, Carole; Gris, Jean-Christophe; Chapelle, Céline; Laporte, Silvy; Chauleur, Céline

2017-09-22

The study aimed to compare the level of two angiogenic factors, soluble fms-like tyrosine kinase-1 (sFlt1) and soluble endoglin (sEng), for the prediction of preeclampsia and intrauterine growth restriction in high-risk pregnant women. A prospective multicenter cohort study of 200 pregnant patients was conducted between June 2008 and October 2010. sFlt1 and sEng were measured by enzyme-linked immunosorbent assay. Forty-five patients developed a placenta-mediated adverse pregnancy outcome. Plasma levels of sFlt1 and sEng were higher in patients who will experience a preeclampsia at 28, 32, and 36 weeks compared with patients with no complication. The same results were observed for intrauterine growth restriction. Plasma levels of sFlt1 and sEng were not significantly different for patients with preeclampsia compare to patients with intrauterine growth restriction. Patients with early pre-eclampsia (PE) had very high rates of angiogenic factors at 20, 24, and 28 weeks. Patients with late PE and early and late intrauterine growth retardation (IUGR) had high rates at 32 and 36 weeks. In high-risk women, angiogenic factors are disturbed before the onset of preeclampsia and this is true for intrauterine growth restriction.

Dietary restriction with and without caloric restriction for healthy aging [version 1; referees: 3 approved

Directory of Open Access Journals (Sweden)

Changhan Lee

2016-01-01

Full Text Available Caloric restriction is the most effective and reproducible dietary intervention known to regulate aging and increase the healthy lifespan in various model organisms, ranging from the unicellular yeast to worms, flies, rodents, and primates. However, caloric restriction, which in most cases entails a 20–40% reduction of food consumption relative to normal intake, is a severe intervention that results in both beneficial and detrimental effects. Specific types of chronic, intermittent, or periodic dietary restrictions without chronic caloric restriction have instead the potential to provide a significant healthspan increase while minimizing adverse effects. Improved periodic or targeted dietary restriction regimens that uncouple the challenge of food deprivation from the beneficial effects will allow a safe intervention feasible for a major portion of the population. Here we focus on healthspan interventions that are not chronic or do not require calorie restriction.

B-cell responses to pregnancy-restricted and -unrestricted Plasmodium falciparum erythrocyte membrane protein 1 antigens in Ghanaian women naturally exposed to malaria parasites

DEFF Research Database (Denmark)

Ampomah, Paulina; Stevenson, Liz; Ofori, Michael F

2014-01-01

-linked immunosorbent assay (ELISA) and memory B-cell frequencies by enzyme-linked immunosorbent spot (ELISPOT) assay in a cohort of P. falciparum-exposed nonpregnant Ghanaian women. The antigens used were a VAR2CSA-type PfEMP1 (IT4VAR04) with expression restricted to parasites infecting the placenta, as well as two...... commonly recognized PfEMP1 proteins (HB3VAR06 and IT4VAR60) implicated in rosetting and not pregnancy restricted. This enabled, for the first time, a direct comparison in the same individuals of immune responses specific for a clinically important parasite antigen expressed only during well-defined periods...

Immobilized enzymes: understanding enzyme - surface interactions at the molecular level.

Science.gov (United States)

Hoarau, Marie; Badieyan, Somayesadat; Marsh, E Neil G

2017-11-22

Enzymes immobilized on solid supports have important and industrial and medical applications. However, their uses are limited by the significant reductions in activity and stability that often accompany the immobilization process. Here we review recent advances in our understanding of the molecular level interactions between proteins and supporting surfaces that contribute to changes in stability and activity. This understanding has been facilitated by the application of various surface-sensitive spectroscopic techniques that allow the structure and orientation of enzymes at the solid/liquid interface to be probed, often with monolayer sensitivity. An appreciation of the molecular interactions between enzyme and surface support has allowed the surface chemistry and method of enzyme attachement to be fine-tuned such that activity and stability can be greatly enhanced. These advances suggest that a much wider variety of enzymes may eventually be amenable to immobilization as green catalysts.

Restriction enzyme analysis of the chloroplast DNA of Phaseolus vulgaris L. vr. Rio Negro Análise de restrição do DNA cloroplástico de Phaseolus vulgaris vr. Rio Negro

Directory of Open Access Journals (Sweden)

Sergio Echeverrigaray

1996-12-01

Full Text Available The chloroplast DNA of Phaseolus vulgaris L. vr. Rio Negro was isola ted from chloroplasts obtained by descontiuous sucrose gradient centrifugation. The restriction analysis with the enzymes HindIII, EcoRI and BamHI and their combination, allowed to identified more than 20 fragments of 18 to 0.65kb. The size of Phaseolus vulgaris L. cp DNA was estimated in 140kb with the presence of a repeat sequence of about 22kb.O DNA cloroplástico do cultivar Rio Negro (Phaseolus vulgaris L. foi isolado a partir de cloroplastos obtidos por gradiente descontínuo de sacarose. A análise de restrição com as enzimas HindIII, EcoRI e BamHI e a combinação destas, permitiu a identificação de mais de 20 fragmentos na faixa de 18 a 0.65kb. O tamanho do cp DNA de Phaseolus vulgaris L. foi estimado em 140kb com a existência de sequências repetidas de aproximadamente 22kb.

Limiting Concentrate during Growing Period Affect Performance and Gene Expression of Hepatic Gluconeogenic Enzymes and Visfatin in Korean Native Beef Calves

Directory of Open Access Journals (Sweden)

S. S. Chang

2013-02-01

Full Text Available This study elucidated the effects of limited concentrate feeding on growth, plasma profile, and gene expression of gluconeogenic enzymes and visfatin in the liver of Hanwoo beef calves. The purpose of this study was to test that reducing the amount of concentrate would partially be compensated by increasing the intake of forage and by altering the metabolic status. The study utilized 20 Korean native beef calves (Hanwoo; 60 to 70 d of age divided into two groups of 10 calves each for 158 d. Control group calves received the amount of concentrate as per the established Korean feeding standards for Hanwoo, whereas calves in the restricted group only received half the amount of concentrate as per standard requirements. Good quality forage (Timothy hay was available for ad libitum consumption to both groups. Since calves were with their dam until 4 months of age in breeding pens before weaning, the intake of milk before weaning was not recorded, however, the concentrate and forage intakes were recorded daily. Body weights (BW were recorded at start and on 10 d interval. Blood samples were collected at start and at 50 d interval. On the final day of the experiment, liver biopsies were collected from all animals in each group. The BW was not different between the groups at all times, but tended to be higher (p = 0.061 only at final BW in control than restricted group. Total BW gain in the control group was 116.2 kg as opposed to 84.1 kg in restricted group that led to average BW gain of 736 g/d and 532 g/d in respective groups, and the differences were significant (p<0.01. As planned, the calves in the control group had higher concentrate and lower forage intake than the restricted group. The plasma variables like total protein and urea were higher (p<0.05 in control than restricted group. The mRNA expressions for the gluconeogenic enzymes such as cytosolic phosphoenol pyruvate carboxykinase (EC 4.1.1.32 and pyruvate carboxylase (EC 6.4.1.1, and

Limiting Concentrate during Growing Period Affect Performance and Gene Expression of Hepatic Gluconeogenic Enzymes and Visfatin in Korean Native Beef Calves.

Science.gov (United States)

Chang, S S; Lohakare, J D; Singh, N K; Kwon, E G; Nejad, J G; Sung, K I; Hong, S K

2013-02-01

This study elucidated the effects of limited concentrate feeding on growth, plasma profile, and gene expression of gluconeogenic enzymes and visfatin in the liver of Hanwoo beef calves. The purpose of this study was to test that reducing the amount of concentrate would partially be compensated by increasing the intake of forage and by altering the metabolic status. The study utilized 20 Korean native beef calves (Hanwoo; 60 to 70 d of age) divided into two groups of 10 calves each for 158 d. Control group calves received the amount of concentrate as per the established Korean feeding standards for Hanwoo, whereas calves in the restricted group only received half the amount of concentrate as per standard requirements. Good quality forage (Timothy hay) was available for ad libitum consumption to both groups. Since calves were with their dam until 4 months of age in breeding pens before weaning, the intake of milk before weaning was not recorded, however, the concentrate and forage intakes were recorded daily. Body weights (BW) were recorded at start and on 10 d interval. Blood samples were collected at start and at 50 d interval. On the final day of the experiment, liver biopsies were collected from all animals in each group. The BW was not different between the groups at all times, but tended to be higher (p = 0.061) only at final BW in control than restricted group. Total BW gain in the control group was 116.2 kg as opposed to 84.1 kg in restricted group that led to average BW gain of 736 g/d and 532 g/d in respective groups, and the differences were significant (pforage intake than the restricted group. The plasma variables like total protein and urea were higher (p<0.05) in control than restricted group. The mRNA expressions for the gluconeogenic enzymes such as cytosolic phosphoenol pyruvate carboxykinase (EC 4.1.1.32) and pyruvate carboxylase (EC 6.4.1.1), and visfatin measured by quantitative real-time PCR in liver biopsies showed higher expression (p<0.05) in

Expanding the Halohydrin Dehalogenase Enzyme Family: Identification of Novel Enzymes by Database Mining.

Science.gov (United States)

Schallmey, Marcus; Koopmeiners, Julia; Wells, Elizabeth; Wardenga, Rainer; Schallmey, Anett

2014-12-01

Halohydrin dehalogenases are very rare enzymes that are naturally involved in the mineralization of halogenated xenobiotics. Due to their catalytic potential and promiscuity, many biocatalytic reactions have been described that have led to several interesting and industrially important applications. Nevertheless, only a few of these enzymes have been made available through recombinant techniques; hence, it is of general interest to expand the repertoire of these enzymes so as to enable novel biocatalytic applications. After the identification of specific sequence motifs, 37 novel enzyme sequences were readily identified in public sequence databases. All enzymes that could be heterologously expressed also catalyzed typical halohydrin dehalogenase reactions. Phylogenetic inference for enzymes of the halohydrin dehalogenase enzyme family confirmed that all enzymes form a distinct monophyletic clade within the short-chain dehydrogenase/reductase superfamily. In addition, the majority of novel enzymes are substantially different from previously known phylogenetic subtypes. Consequently, four additional phylogenetic subtypes were defined, greatly expanding the halohydrin dehalogenase enzyme family. We show that the enormous wealth of environmental and genome sequences present in public databases can be tapped for in silico identification of very rare but biotechnologically important biocatalysts. Our findings help to readily identify halohydrin dehalogenases in ever-growing sequence databases and, as a consequence, make even more members of this interesting enzyme family available to the scientific and industrial community. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Enzyme replacement and substrate reduction therapy for Gaucher disease.

Science.gov (United States)

Shemesh, Elad; Deroma, Laura; Bembi, Bruno; Deegan, Patrick; Hollak, Carla; Weinreb, Neal J; Cox, Timothy M

2015-03-27

Gaucher disease, a rare disorder, is caused by inherited deficiency of the enzyme glucocerebrosidase. It is unique among the ultra-orphan disorders in that four treatments are currently approved by various regulatory authorities for use in routine clinical practice. Hitherto, because of the relatively few people affected worldwide, many of whom started therapy during a prolonged period when there were essentially no alternatives to imiglucerase, these treatments have not been systematically evaluated in studies such as randomized controlled trials now considered necessary to generate the highest level of clinical evidence. To summarize all available randomized controlled study data on the efficacy and safety of enzyme replacement therapies and substrate reduction therapy for treating Gaucher disease. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register. Additional searches were conducted on ClinicalTrials.gov for any ongoing studies with potential interim results, and through PubMed. We also searched the reference lists of relevant articles and reviews.Date of last search: 07 August 2014. All randomized and quasi-randomized controlled studies (including open-label studies and cross-over studies) assessing enzyme replacement therapy or substrate reduction therapy, or both, in all types of Gaucher disease were included. Two authors independently assessed the risk of bias in the included studies, and extracted relevant data. Of the 488 studies retrieved by the electronic searches, eight met the inclusion criteria and were analysed (300 participants). Response parameters were restricted to haemoglobin concentration, platelet count, spleen and liver volume and serum biomarkers (chitotriosidase and CCL18). Only one publication reported a 'low risk of bias' score in all parameters assessed, and all studies included were randomized.Four studies reported the responses to enzyme replacement therapy of previously

Metagenomics as a Tool for Enzyme Discovery: Hydrolytic Enzymes from Marine-Related Metagenomes.

Science.gov (United States)

Popovic, Ana; Tchigvintsev, Anatoly; Tran, Hai; Chernikova, Tatyana N; Golyshina, Olga V; Yakimov, Michail M; Golyshin, Peter N; Yakunin, Alexander F

2015-01-01

This chapter discusses metagenomics and its application for enzyme discovery, with a focus on hydrolytic enzymes from marine metagenomic libraries. With less than one percent of culturable microorganisms in the environment, metagenomics, or the collective study of community genetics, has opened up a rich pool of uncharacterized metabolic pathways, enzymes, and adaptations. This great untapped pool of genes provides the particularly exciting potential to mine for new biochemical activities or novel enzymes with activities tailored to peculiar sets of environmental conditions. Metagenomes also represent a huge reservoir of novel enzymes for applications in biocatalysis, biofuels, and bioremediation. Here we present the results of enzyme discovery for four enzyme activities, of particular industrial or environmental interest, including esterase/lipase, glycosyl hydrolase, protease and dehalogenase.

EFFECTS OF EXOGENOUS ENZYMES ON NUTRIENTS DIGESTIBILITY AND GROWTH PERFORMANCE IN SHEEP AND GOATS

Directory of Open Access Journals (Sweden)

Abdel-Fattah Z.M. Salem

2011-07-01

Full Text Available Six crossbred sheep (32.00±0.603 kg BW and 6 Baladi goats (18.00±0.703 kg BW were used in 2×2 factorial design to evaluate the effect of exogenous enzymes of ZADO® (i.e., ENZ and on digestibility and growth performance. Animals were fed on wheat straw ad libitum and restricted amount of commercial concentrate with (+ENZ or without (-ENZ 10 g/animal/day of ZADO to cover 120% of their maintenance requirements. Nutrients digestibilities were increased (P

49 CFR 215.203 - Restricted cars.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Restricted cars. 215.203 Section 215.203..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Restricted Equipment § 215.203 Restricted cars. (a) This section restricts the operation of any railroad freight car that is— (1) More than 50...

49 CFR 383.95 - Restrictions.

Science.gov (United States)

2010-10-01

... the skills test and the restriction, air brakes shall include any braking system operating fully or...; REQUIREMENTS AND PENALTIES Vehicle Groups and Endorsements § 383.95 Restrictions. (a) Air brake restrictions... skills test in a vehicle not equipped with air brakes, the State must indicate on the CDL, if issued...

Enzymes and Enzyme Activity Encoded by Nonenveloped Viruses.

Science.gov (United States)

Azad, Kimi; Banerjee, Manidipa; Johnson, John E

2017-09-29

Viruses are obligate intracellular parasites that rely on host cell machineries for their replication and survival. Although viruses tend to make optimal use of the host cell protein repertoire, they need to encode essential enzymatic or effector functions that may not be available or accessible in the host cellular milieu. The enzymes encoded by nonenveloped viruses-a group of viruses that lack any lipid coating or envelope-play vital roles in all the stages of the viral life cycle. This review summarizes the structural, biochemical, and mechanistic information available for several classes of enzymes and autocatalytic activity encoded by nonenveloped viruses. Advances in research and development of antiviral inhibitors targeting specific viral enzymes are also highlighted.

Molecular discrimination of lactobacilli used as starter and probiotic cultures by amplified ribosomal DNA restriction analysis.

Science.gov (United States)

Roy, D; Sirois, S; Vincent, D

2001-04-01

Lactic acid bacteria such as Lactobacillus helveticus, L. delbrueckii subsp. delbrueckii, L. delbrueckii subsp. lactis, L. delbrueckii subsp. bulgaricus, L. acidophilus, and L. casei related taxa which are widely used as starter or probiotic cultures can be identified by amplified ribosomal DNA restriction analysis (ARDRA). The genetic discrimination of the related species belonging to these groups was first obtained by PCR amplifications by using group-specific or species-specific 16S rDNA primers. The numerical analysis of the ARDRA patterns obtained by using CfoI, HinfI, Tru9I, and ScrFI was an efficient typing tool for identification of species of the L. acidophilus and L. casei complex. ARDRA by using CfoI was a reliable method for differentiation of L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis. Finally, strains ATCC 393 and ATCC 15820 exhibited unique ARDRA patterns with CfoI and Tru9I restriction enzymes as compared with the other strains of L. casei, L. paracasei, and L. rhamnosus.

Failure of lactose-restricted diets to prevent radiation-induced diarrhea in patients undergoing whole pelvis irradiation

International Nuclear Information System (INIS)

Stryker, J.A.; Bartholomew, M.

1986-01-01

Sixty-four patients were randomized prior to pelvic radiotherapy into one of three dietary groups: the control group maintained a regular diet except that they drank at least 480 cc of milk daily; the lactose-restricted group was placed on a lactose-restricted diet; and the lactase group drank at least 480 cc of milk with lactase enzyme added to hydrolyze 90% of the lactose. The patients kept records of their stool frequency and the number of diphenoxylate tablets required to control their diarrhea during a 5 week course of standard whole pelvis irradiation. The data does not support the concept that one of the mechanisms of radiation-induced diarrhea associated with pelvic irradiation is a reduction the ability of the intestine to hydrolyze ingested lactose due to the effect of the radiation on the small intestine. There was not a significant difference in stool frequency or diphenoxylate usage among the dietary groups

Impact of Autoantibodies against Glycolytic Enzymes on Pathogenicity of Autoimmune Retinopathy and Other Autoimmune Disorders

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Grazyna Adamus

2017-04-01

Full Text Available Autoantibodies (AAbs against glycolytic enzymes: aldolase, α-enolase, glyceraldehyde-3-phosphate dehydrogenase, and pyruvate kinase are prevalent in sera of patients with blinding retinal diseases, such as paraneoplastic [cancer-associated retinopathy (CAR] and non-paraneoplastic autoimmune retinopathies, as well as in many other autoimmune diseases. CAR is a degenerative disease of the retina characterized by sudden vision loss in patients with cancer and serum anti-retinal AAbs. In this review, we discuss the widespread serum presence of anti-glycolytic enzyme AAbs and their significance in autoimmune diseases. There are multiple mechanisms responsible for antibody generation, including the innate anti-microbial response, anti-tumor response, or autoimmune response against released self-antigens from damaged, inflamed tissue. AAbs against enolase, GADPH, and aldolase exist in a single patient in elevated titers, suggesting their participation in pathogenicity. The lack of restriction of AAbs to one disease may be related to an increased expression of glycolytic enzymes in various metabolically active tissues that triggers an autoimmune response and generation of AAbs with the same specificity in several chronic and autoimmune conditions. In CAR, the importance of serum anti-glycolytic enzyme AAbs had been previously dismissed, but the retina may be without pathological consequence until a failure of the blood–retinal barrier function, which would then allow pathogenic AAbs access to their retinal targets, ultimately leading to damaging effects.

The surface science of enzymes

DEFF Research Database (Denmark)

Rod, Thomas Holm; Nørskov, Jens Kehlet

2002-01-01

One of the largest challenges to science in the coming years is to find the relation between enzyme structure and function. Can we predict which reactions an enzyme catalyzes from knowledge of its structure-or from its amino acid sequence? Can we use that knowledge to modify enzyme function......? To solve these problems we must understand in some detail how enzymes interact with reactants from its surroundings. These interactions take place at the surface of the enzyme and the question of enzyme function can be viewed as the surface science of enzymes. In this article we discuss how to describe...... catalysis by enzymes, and in particular the analogies between enzyme catalyzed reactions and surface catalyzed reactions. We do this by discussing two concrete examples of reactions catalyzed both in nature (by enzymes) and in industrial reactors (by inorganic materials), and show that although analogies...

Magnetically responsive enzyme powders

Energy Technology Data Exchange (ETDEWEB)

Pospiskova, Kristyna, E-mail: kristyna.pospiskova@upol.cz [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

2015-04-15

Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction.

Enzymes in Fermented Fish.

Science.gov (United States)

Giyatmi; Irianto, H E

Fermented fish products are very popular particularly in Southeast Asian countries. These products have unique characteristics, especially in terms of aroma, flavor, and texture developing during fermentation process. Proteolytic enzymes have a main role in hydrolyzing protein into simpler compounds. Fermentation process of fish relies both on naturally occurring enzymes (in the muscle or the intestinal tract) as well as bacteria. Fermented fish products processed using the whole fish show a different characteristic compared to those prepared from headed and gutted fish. Endogenous enzymes like trypsin, chymotrypsin, elastase, and aminopeptidase are the most involved in the fermentation process. Muscle tissue enzymes like cathepsins, peptidases, transaminases, amidases, amino acid decarboxylases, glutamic dehydrogenases, and related enzymes may also play a role in fish fermentation. Due to the decreased bacterial number during fermentation, contribution of microbial enzymes to proteolysis may be expected prior to salting of fish. Commercial enzymes are supplemented during processing for specific purposes, such as quality improvement and process acceleration. In the case of fish sauce, efforts to accelerate fermentation process and to improve product quality have been studied by addition of enzymes such as papain, bromelain, trypsin, pepsin, and chymotrypsin. © 2017 Elsevier Inc. All rights reserved.

Thermodynamic activity-based intrinsic enzyme kinetic sheds light on enzyme-solvent interactions.

Science.gov (United States)

Grosch, Jan-Hendrik; Wagner, David; Nistelkas, Vasilios; Spieß, Antje C

2017-01-01

The reaction medium has major impact on biocatalytic reaction systems and on their economic significance. To allow for tailored medium engineering, thermodynamic phenomena, intrinsic enzyme kinetics, and enzyme-solvent interactions have to be discriminated. To this end, enzyme reaction kinetic modeling was coupled with thermodynamic calculations based on investigations of the alcohol dehydrogenase from Lactobacillus brevis (LbADH) in monophasic water/methyl tert-butyl ether (MTBE) mixtures as a model solvent. Substrate concentrations and substrate thermodynamic activities were varied separately to identify the individual thermodynamic and kinetic effects on the enzyme activity. Microkinetic parameters based on concentration and thermodynamic activity were derived to successfully identify a positive effect of MTBE on the availability of the substrate to the enzyme, but a negative effect on the enzyme performance. In conclusion, thermodynamic activity-based kinetic modeling might be a suitable tool to initially curtail the type of enzyme-solvent interactions and thus, a powerful first step to potentially understand the phenomena that occur in nonconventional media in more detail. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:96-103, 2017. © 2016 American Institute of Chemical Engineers.

Profiling the orphan enzymes

Science.gov (United States)

2014-01-01

The emergence of Next Generation Sequencing generates an incredible amount of sequence and great potential for new enzyme discovery. Despite this huge amount of data and the profusion of bioinformatic methods for function prediction, a large part of known enzyme activities is still lacking an associated protein sequence. These particular activities are called “orphan enzymes”. The present review proposes an update of previous surveys on orphan enzymes by mining the current content of public databases. While the percentage of orphan enzyme activities has decreased from 38% to 22% in ten years, there are still more than 1,000 orphans among the 5,000 entries of the Enzyme Commission (EC) classification. Taking into account all the reactions present in metabolic databases, this proportion dramatically increases to reach nearly 50% of orphans and many of them are not associated to a known pathway. We extended our survey to “local orphan enzymes” that are activities which have no representative sequence in a given clade, but have at least one in organisms belonging to other clades. We observe an important bias in Archaea and find that in general more than 30% of the EC activities have incomplete sequence information in at least one superkingdom. To estimate if candidate proteins for local orphans could be retrieved by homology search, we applied a simple strategy based on the PRIAM software and noticed that candidates may be proposed for an important fraction of local orphan enzymes. Finally, by studying relation between protein domains and catalyzed activities, it appears that newly discovered enzymes are mostly associated with already known enzyme domains. Thus, the exploration of the promiscuity and the multifunctional aspect of known enzyme families may solve part of the orphan enzyme issue. We conclude this review with a presentation of recent initiatives in finding proteins for orphan enzymes and in extending the enzyme world by the discovery of new

Urban water restrictions: Attitudes and avoidance

Science.gov (United States)

Cooper, Bethany; Burton, Michael; Crase, Lin

2011-12-01

In most urban cities across Australia, water restrictions remain the dominant policy mechanism to restrict urban water consumption. The extensive adoption of water restrictions as a means to limit demand, over several years, means that Australian urban water prices have consistently not reflected the opportunity cost of water. Given the generally strong political support for water restrictions and the likelihood that they will persist for some time, there is value in understanding households' attitudes in this context. More specifically, identifying the welfare gains associated with avoiding urban water restrictions entirely would be a nontrivial contribution to our knowledge and offer insights into the benefits of alternative policy responses. This paper describes the results from a contingent valuation study that investigates consumers' willingness to pay to avoid urban water restrictions. Importantly, the research also investigates the influence of cognitive and exogenous dimensions on the utility gain associated with avoiding water restrictions. The results provide insights into the impact of the current policy mechanism on economic welfare.

Effect of irradiation on immobilized enzymes compared with that on enzymes in solution

International Nuclear Information System (INIS)

Schachinger, L.; Schippel, C.; Altmann, E.; Diepold, B.; Yang, C.; Jaenike, M.; Hochhaeuser, E.

1985-01-01

Glucose oxidase and catalase were immobilized by attaching them to nylon fibers that had been treated with triethyloxonium-tetrafluoroborate, diaminohexane and glutaraldialdehyde according to Morris, Campell and Hornby (1975). This method assures that the enzymes are bound to a side chain of the polyamide structure. Enzyme activity (as measured by the O 2 -uptake and by microcalorimetry) was found to be unchanged after 2 years. The apparent Ksub(m)-constants of the immobilized enzymes with glucose were the same as those for enzymes in solution. GOD and catalase immobilized in poly(acrylamide) gel had the same Ksub(m)-value. Despite the high stability during storage, the radiation induced inactivation of enzymes immobilized on gel or chromosorb, an inorganic carrier, was of the same order of magnitude as that of the dissolved enzymes. The enzymes bound to nylon fibers showed a higher radiation sensitivity. This might have been caused by an additional attack on the binding site of the carrier. (orig.)

Direct Electron Transfer of Enzymes in a Biologically Assembled Conductive Nanomesh Enzyme Platform.

Science.gov (United States)

Lee, Seung-Woo; Lee, Ki-Young; Song, Yong-Won; Choi, Won Kook; Chang, Joonyeon; Yi, Hyunjung

2016-02-24

Nondestructive assembly of a nanostructured enzyme platform is developed in combination of the specific biomolecular attraction and electrostatic coupling for highly efficient direct electron transfer (DET) of enzymes with unprecedented applicability and versatility. The biologically assembled conductive nanomesh enzyme platform enables DET-based flexible integrated biosensors and DET of eight different enzyme with various catalytic activities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A new assay based on terminal restriction fragment length polymorphism of homocitrate synthase gene fragments for Candida species identification.

Science.gov (United States)

Szemiako, Kasjan; Śledzińska, Anna; Krawczyk, Beata

2017-08-01

Candida sp. have been responsible for an increasing number of infections, especially in patients with immunodeficiency. Species-specific differentiation of 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 the terminal restriction fragment length polymorphism (t-RFLP) method in the molecular identification of six species of Candida, which are the most common causes of fungal infections. Specific for fungi homocitrate synthase gene was chosen as a molecular target for amplification. The use of three restriction enzymes, DraI, RsaI, and BglII, for amplicon digestion can generate species-specific fluorescence labeled DNA fragment profiles, which can be used to determine the diagnostic algorithm. The designed method can be a cost-efficient high-throughput molecular technique for the identification of six clinically important Candida species.

Enzymes for improved biomass conversion

Science.gov (United States)

Brunecky, Roman; Himmel, Michael E.

2016-02-02

Disclosed herein are enzymes and combinations of the enzymes useful for the hydrolysis of cellulose and the conversion of biomass. Methods of degrading cellulose and biomass using enzymes and cocktails of enzymes are also disclosed.

Placental weight and birth weight to placental weight ratio in monochorionic and dichorionic growth-restricted and non-growth-restricted twins

Directory of Open Access Journals (Sweden)

Mariângela Alves Souza

Full Text Available OBJECTIVE: The aim of the present study was to compare the placental weight and birth weight/placental weight ratio for intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins. METHODS: This was a retrospective analysis of placentas from twin pregnancies. Placental weight and the birth weight/placental weight ratio were compared in intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins. The association between cord insertion type and placental lesions in intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins was also investigated. RESULTS: A total of 105 monochorionic (intrauterine growth restriction=40; non-intrauterine growth restriction=65 and 219 dichorionic (intrauterine growth restriction=57; non-intrauterine growth restriction=162 placentas were analyzed. A significantly lower placental weight was observed in intrauterine growth-restricted monochorionic (p=0.022 and dichorionic (p<0.001 twins compared to non-intrauterine growth-restricted twins. There was no difference in the birth weight/placental weight ratio between the intrauterine growth restriction and non-intrauterine growth restriction groups for either monochorionic (p=0.36 or dichorionic (p=0.68 twins. Placental weight and the birth weight/placental weight ratio were not associated with cord insertion type or with placental lesions. CONCLUSION: Low placental weight, and consequently reduced functional mass, appears to be involved in fetal growth restriction in monochorionic and dichorionic twins. The mechanism by which low placental weight influences the birth weight/placental weight ratio in intrauterine growth-restricted monochorionic and dichorionic twins needs to be determined in larger prospective studies.

Modified lingguizhugan decoction incorporated with dietary restriction and exercise ameliorates hyperglycemia, hyperlipidemia and hypertension in a rat model of the metabolic syndrome.

Science.gov (United States)

Yao, Limei; Wei, Jingjing; Shi, Si; Guo, Kunbin; Wang, Xiangyu; Wang, Qi; Chen, Dingsheng; Li, Weirong

2017-02-28

Modified Lingguizhugan Decoction (MLD) came from famous Chinese medicine Linggui Zhugan Decoction. The MLD is used for the treatment of metabolic syndrome in the clinical setting. Our study focuses on the comprehensive treatment of MLD incorporated with dietary restriction and exercise in a rat model of the metabolic syndrome (MS). Rats were divided into five groups: control group (Cont), high-fat diet group (HFD), high-fat diet incorporated with dietary restriction group (HFD-DR), exercise incorporated with dietary restriction group (HFD-DR-Ex) and MLD incorporated with dietary restriction and exercise group (HFD-DR-Ex-MLD). Treatments were conducted for 1 week after feeding high-fat diet for 12 weeks. The effects of treatments on high fat diet-induced obesity, hyperglycemia, hyperlipidemia, hypertension, hepatic injury and insulin resistance in rats of MS were examined. In addition, the tumor necrosis factor-α (TNF-α), leptin and protein kinase B (PKB) in rats serum and liver were also examined by enzyme-linked immunosorbent assay (ELISA). After a week's intervention by dietary restriction, dietary restriction incorporated with exercise or MLD, compared with HFD rats, the relative weight of liver and fat, levels of triglyceride, total cholesterol, low-density lipoprotein, free fatty acid, aspartate aminotransferase, glutamic-pyruvic transaminase and alkaline phosphatase, insulin, were significantly decreased (p exercise treatment exhibit effects in alleviating high-fat diet-induced obesity, hyperglycemia, hyperlipidemia, hypertension, hepatic injury and insulin resistance, which are possibly due to the down-regulation of TNF-α, leptin and PKB.

An overview of technologies for immobilization of enzymes and surface analysis techniques for immobilized enzymes

Science.gov (United States)

Mohamad, Nur Royhaila; Marzuki, Nur Haziqah Che; Buang, Nor Aziah; Huyop, Fahrul; Wahab, Roswanira Abdul

2015-01-01

The current demands of sustainable green methodologies have increased the use of enzymatic technology in industrial processes. Employment of enzyme as biocatalysts offers the benefits of mild reaction conditions, biodegradability and catalytic efficiency. The harsh conditions of industrial processes, however, increase propensity of enzyme destabilization, shortening their industrial lifespan. Consequently, the technology of enzyme immobilization provides an effective means to circumvent these concerns by enhancing enzyme catalytic properties and also simplify downstream processing and improve operational stability. There are several techniques used to immobilize the enzymes onto supports which range from reversible physical adsorption and ionic linkages, to the irreversible stable covalent bonds. Such techniques produce immobilized enzymes of varying stability due to changes in the surface microenvironment and degree of multipoint attachment. Hence, it is mandatory to obtain information about the structure of the enzyme protein following interaction with the support surface as well as interactions of the enzymes with other proteins. Characterization technologies at the nanoscale level to study enzymes immobilized on surfaces are crucial to obtain valuable qualitative and quantitative information, including morphological visualization of the immobilized enzymes. These technologies are pertinent to assess efficacy of an immobilization technique and development of future enzyme immobilization strategies. PMID:26019635

Enzyme inhibition by iminosugars

DEFF Research Database (Denmark)

López, Óscar; Qing, Feng-Ling; Pedersen, Christian Marcus

2013-01-01

Imino- and azasugar glycosidase inhibitors display pH dependant inhibition reflecting that both the inhibitor and the enzyme active site have groups that change protonation state with pH. With the enzyme having two acidic groups and the inhibitor one basic group, enzyme-inhibitor complexes...

Targeted enzyme prodrug therapies.

Science.gov (United States)

Schellmann, N; Deckert, P M; Bachran, D; Fuchs, H; Bachran, C

2010-09-01

The cure of cancer is still a formidable challenge in medical science. Long-known modalities including surgery, chemotherapy and radiotherapy are successful in a number of cases; however, invasive, metastasized and inaccessible tumors still pose an unresolved and ongoing problem. Targeted therapies designed to locate, detect and specifically kill tumor cells have been developed in the past three decades as an alternative to treat troublesome cancers. Most of these therapies are either based on antibody-dependent cellular cytotoxicity, targeted delivery of cytotoxic drugs or tumor site-specific activation of prodrugs. The latter is a two-step procedure. In the first step, a selected enzyme is accumulated in the tumor by guiding the enzyme or its gene to the neoplastic cells. In the second step, a harmless prodrug is applied and specifically converted by this enzyme into a cytotoxic drug only at the tumor site. A number of targeting systems, enzymes and prodrugs were investigated and improved since the concept was first envisioned in 1974. This review presents a concise overview on the history and latest developments in targeted therapies for cancer treatment. We cover the relevant technologies such as antibody-directed enzyme prodrug therapy (ADEPT), gene-directed enzyme prodrug therapy (GDEPT) as well as related therapies such as clostridial- (CDEPT) and polymer-directed enzyme prodrug therapy (PDEPT) with emphasis on prodrug-converting enzymes, prodrugs and drugs.

Enzyme-MOF (metal-organic framework) composites.

Science.gov (United States)

Lian, Xizhen; Fang, Yu; Joseph, Elizabeth; Wang, Qi; Li, Jialuo; Banerjee, Sayan; Lollar, Christina; Wang, Xuan; Zhou, Hong-Cai

2017-06-06

The ex vivo application of enzymes in various processes, especially via enzyme immobilization techniques, has been extensively studied in recent years in order to enhance the recyclability of enzymes, to minimize enzyme contamination in the product, and to explore novel horizons for enzymes in biomedical applications. Possessing remarkable amenability in structural design of the frameworks as well as almost unparalelled surface tunability, Metal-Organic Frameworks (MOFs) have been gaining popularity as candidates for enzyme immobilization platforms. Many MOF-enzyme composites have achieved unprecedented results, far outperforming free enzymes in many aspects. This review summarizes recent developments of MOF-enzyme composites with special emphasis on preparative techniques and the synergistic effects of enzymes and MOFs. The applications of MOF-enzyme composites, primarily in transferation, catalysis and sensing, are presented as well. The enhancement of enzymatic activity of the composites over free enzymes in biologically incompatible conditions is emphasized in many cases.

Restrictive annuloplasty to treat functional mitral regurgitation: optimize the restriction to improve the results?

Science.gov (United States)

Totaro, Pasquale; Adragna, Nicola; Argano, Vincenzo

2008-03-01

Today, the 'gold standard' treatment of functional mitral regurgitation (MR) is the subject of much discussion. Although restrictive annuloplasty is currently considered the most reproducible technique, the means by which the degree of annular restriction is optimized remains problematic. The study was designed in order to identify whether the degree of restriction of the mitral annulus could influence early and midterm results following the treatment of functional MR using restrictive annuloplasty. A total of 32 consecutive patients with functional MR grade > or = 3+ was enrolled, among whom the mean anterior-posterior (AP) mitral annulus diameter was 39 +/- 3 mm. Restrictive mitral annuloplasty (combined with coronary artery bypass grafting) was performed in all patients using a Carpentier-Edwards Classic or Physio ring (size 26 or 28). The degree of AP annular restriction was calculated for each patient, and correlated with early and mid-term residual MR and left ventricular (LV) reverse remodeling (in terms of LV end-diastolic diameter (LVEDD) and LV end-diastolic volume (LVEDV) reduction). All surviving patients were examined at a one-year follow up. The mean AP mitral annulus restriction achieved was 48 +/- 4%. Intraoperatively, transesophageal echocardiography showed no residual MR in any patient. Before discharge from hospital, transthoracic echocardiography confirmed an absence of residual MR and showed significant LV reverse remodeling (LVEDV from 121 +/- 25 ml to 97 +/- 26 ml; LVEDD from 55 +/- 6 mm to 47 +/- 8 mm). A significant correlation (r = 0.57, p 40% of preoperative) appears to have a favorable influence on early postoperative LV reverse remodeling, and also allows for complete resolution of functional MR. In addition, 'no tolerance' of early residual MR seems to have a favorable influence on mid-term results, leading to a reduction in the one-year recurrence of significant MR.

Protein restriction and cancer.

Science.gov (United States)

Yin, Jie; Ren, Wenkai; Huang, Xingguo; Li, Tiejun; Yin, Yulong

2018-03-26

Protein restriction without malnutrition is currently an effective nutritional intervention known to prevent diseases and promote health span from yeast to human. Recently, low protein diets are reported to be associated with lowered cancer incidence and mortality risk of cancers in human. In murine models, protein restriction inhibits tumor growth via mTOR signaling pathway. IGF-1, amino acid metabolic programing, FGF21, and autophagy may also serve as potential mechanisms of protein restriction mediated cancer prevention. Together, dietary intervention aimed at reducing protein intake can be beneficial and has the potential to be widely adopted and effective in preventing and treating cancers. Copyright © 2018 Elsevier B.V. All rights reserved.

Property Rights, Restrictions and Responsibilities

DEFF Research Database (Denmark)

Enemark, Stig

more to a social, ethical commitment or attitude to environmental sustainability and good husbandry. This paper provides an overall understanding of the concept of land administration systems for dealing with rights, restrictions and responsibilities in future spatially enabled government. Finally......Land Administration Systems are the basis for conceptualizing rights, restrictions and responsibilities related to people, policies and places. Property rights are normally concerned with ownership and tenure whereas restrictions usually control use and activities on land. Responsibilities relate...

Restricting wolves risks escape

Science.gov (United States)

Mech, L. David; Ballard, Warren; Bangs, Ed; Ream, Bob

2010-01-01

Implementing the proposal set forth by Licht and colleagues (BioScience 60: 147–153) requires restricting wolves to tiny "islands," areas that are magnitudes smaller than the ranges of most wolf populations. Wolves naturally have large ranges; restricting their spatial needs increases the risk of wolves escaping, exacerbating public relations and political and legal problems.

Differences in the association between maternal serum homocysteine and ADMA levels in women with pregnancies complicated by preeclampsia and/or intrauterine growth restriction.

Science.gov (United States)

Laskowska, Marzena; Laskowska, Katarzyna; Oleszczuk, Jan

2013-01-01

The aim of our study was to investigate the association between homocysteine and asymmetric dimethylarginine in preeclamptic women with and without intrauterine growth restriction compared with normal healthy uncomplicated pregnancies and normotensive pregnancies complicated by idiopathic isolated intrauterine fetal growth restriction. The maternal serum homocysteine and asymmetric dimethylarginine concentrations were determined using a sandwich enzyme-linked immunosorbent assays. A statistically significant positive correlation of maternal serum homocysteine levels with the serum asymmetric dimethylarginine levels was observed in healthy normotensive uncomplicated pregnant women from the control group and in preeclamptic patients with appropriate-for-gestational-age fetuses (R = 0.380079, p-value = 0.002311* and R = 0.455797, p-value = 0.004030* for the control and the P groups, respectively). However, this correlation was not significant in women with pregnancy complicated by intrauterine growth restriction, both isolated and in the course of severe preeclampsia. These findings provide support for the hypothesis that elevated levels of asymmetric dimethylarginine in pregnancy complicated by preeclampsia are associated with elevated homocysteine levels. But our results also demonstrate that in pregnancies complicated by intrauterine growth restriction, this mechanism is important, although not the only one.

Enzyme recycling in lignocellulosic biorefineries

DEFF Research Database (Denmark)

Jørgensen, Henning; Pinelo, Manuel

2017-01-01

platform. Cellulases are the most important enzymes required in this process, but the complex nature of lignocellulose requires several other enzymes (hemicellulases and auxiliary enzymes) for efficient hydrolysis. Enzyme recycling increases the catalytic productivity of the enzymes by reusing them...... for several batches of hydrolysis, and thereby reduces the overall cost associated with the hydrolysis. Research on this subject has been ongoing for many years and several promising technologies and methods have been developed and demonstrated. But only in a very few cases have these technologies been...... upscaled and tested in industrial settings, mainly because of many difficulties with recycling of enzymes from the complex lignocellulose hydrolyzate at industrially relevant conditions, i.e., high solids loadings. The challenges are associated with the large number of different enzymes required...

Translocation, switching and gating: potential roles for ATP in long-range communication on DNA by Type III restriction endonucleases.

Science.gov (United States)

Szczelkun, Mark D

2011-04-01

To cleave DNA, the Type III RM (restriction-modification) enzymes must communicate the relative orientation of two recognition sequences, which may be separated by many thousands of base pairs. This long-range interaction requires ATP hydrolysis by a helicase domain, and both active (DNA translocation) and passive (DNA sliding) modes of motion along DNA have been proposed. Potential roles for ATP binding and hydrolysis by the helicase domains are discussed, with a focus on bipartite ATPases that act as molecular switches.

9 CFR 92.3 - Movement restrictions.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Movement restrictions. 92.3 Section 92... ANIMAL PRODUCTS: PROCEDURES FOR REQUESTING RECOGNITION OF REGIONS § 92.3 Movement restrictions. Whenever... exist and the EC imposes prohibitions or other restrictions on the movement of animals or animal...

Enzymes of industrial purpose - review of the market of enzyme preparations and prospects for its development

Directory of Open Access Journals (Sweden)

A. A. Tolkacheva

2017-01-01

Full Text Available Microbial enzyme preparations are increasingly replacing conventional chemical catalysts in a number of industrial processes. Such drugs, in addition to environmental friendliness and high activity, have a number of advantages over enzyme preparations of vegetable and animal origin, namely: the production of microbial enzymes in bioreactors is easily controlled and predictable; excreted microbiological enzymes are more stable than intracellular animals and plant enzymes; the genetic diversity of microorganisms makes it possible to produce enzyme preparations with a wide range of specificity; microbiological enzymes can be synthesized year-round, in contrast to the production of plant enzymes, which is often seasonal. The leaders of the world market of enzymes are proteases and amylases, which account for 25% and 15%, respectively. Over the past five years, the world market for carbohydrases, including mainly amylases, cellulases and xylanases, has been the fastest growing segment of the enzyme market with an aggregate annual growth rate of more than 7.0%. Another major product of the industrial enzyme market, which has a great potential for growth, is lipases. From the point of view of designation, the main part is represented by food and food enzymes. The Russian market continues to be unsaturated - the current supply is not able to meet the needs of the Russian feed and food industry in enzyme preparations. Enzyme preparations of domestic producers are in demand in forage production, while food industrial enterprises prefer imported products. The most significant enterprises in the enzymatic industry in Russia at the moment are Sibbiofarm, AgroSistema, Agroferment. In the light of the Russian policy of increasing food security, the development of the domestic enzyme industry is an extremely topical task.

Continuous enzyme reactions with immobilized enzyme tubes prepared by radiation cast-polymerization

International Nuclear Information System (INIS)

Kumakura, Minoru; Kaetsu, Isao

1986-01-01

Immobilized glucose oxidase tubes were prepared by radiation cast-polymerization of 2-hydroxyethyl methacrylate and tetraethyleneglycol diacrylate monomer at low temperatures. The immobilized enzyme tubes which were spirally set in a water bath were used as reactor, in which the enzyme activity varied with tube size and flow rate of the substrate. The conversion yield of the substrate in continuous enzyme reaction was about 80%. (author)

About 'restriction', 'justified' and 'necessary'

DEFF Research Database (Denmark)

Werlauff, Erik

2016-01-01

The article is an academic fairy tale about why and how all national corporate tax protection legislation should undergo a 3-part test to ensure its consistency with EU law. Each Member State introduce a compulsory 3-step test for each new (corporate) tax provision. The test is simple: (1) Does...... the tax provision constitute a restriction in the sense of EU law? (2) If the answer is yes: Is the restriction justified? (3) If the answer is yes: Is the restriction necessary?"...

Non-homologous isofunctional enzymes: a systematic analysis of alternative solutions in enzyme evolution.

Science.gov (United States)

Omelchenko, Marina V; Galperin, Michael Y; Wolf, Yuri I; Koonin, Eugene V

2010-04-30

Evolutionarily unrelated proteins that catalyze the same biochemical reactions are often referred to as analogous - as opposed to homologous - enzymes. The existence of numerous alternative, non-homologous enzyme isoforms presents an interesting evolutionary problem; it also complicates genome-based reconstruction of the metabolic pathways in a variety of organisms. In 1998, a systematic search for analogous enzymes resulted in the identification of 105 Enzyme Commission (EC) numbers that included two or more proteins without detectable sequence similarity to each other, including 34 EC nodes where proteins were known (or predicted) to have distinct structural folds, indicating independent evolutionary origins. In the past 12 years, many putative non-homologous isofunctional enzymes were identified in newly sequenced genomes. In addition, efforts in structural genomics resulted in a vastly improved structural coverage of proteomes, providing for definitive assessment of (non)homologous relationships between proteins. We report the results of a comprehensive search for non-homologous isofunctional enzymes (NISE) that yielded 185 EC nodes with two or more experimentally characterized - or predicted - structurally unrelated proteins. Of these NISE sets, only 74 were from the original 1998 list. Structural assignments of the NISE show over-representation of proteins with the TIM barrel fold and the nucleotide-binding Rossmann fold. From the functional perspective, the set of NISE is enriched in hydrolases, particularly carbohydrate hydrolases, and in enzymes involved in defense against oxidative stress. These results indicate that at least some of the non-homologous isofunctional enzymes were recruited relatively recently from enzyme families that are active against related substrates and are sufficiently flexible to accommodate changes in substrate specificity.

Epitopes associated with MHC restriction site of T cells. III. I-J epitope on MHC-restricted T helper cells

International Nuclear Information System (INIS)

Asano, Y.; Nakayama, T.; Kubo, M.; Yagi, J.; Tada, T.

1987-01-01

I-J epitopes were found to be associated with the functional site of the class II MHC-restricted helper T (Th) cells: Virtually all of the H-2k-restricted Th cell function of H-2kxbF1 T cells was inhibited by the anti-I-Jk mAb, leaving the H-2b-restricted function unaffected. The I-Jk epitope was inducible in Th cells of different genotype origin according to the environmental class II antigens present in the early ontogeny of T cells. Although above results suggested that I-J is the structure reflecting the inducible MHC restriction specificity, further studies revealed some interesting controversies: First, the I-J phenotype did not always correlate with the class II restriction specificity, e.g., I-Ab-restricted Th from 5R was I-Jk-positive, whereas I-Ak-restricted Th of 4R was not. Second, there was no trans expression of parental I-J phenotypes and restriction specificities in F1 Th, e.g., the I-J phenotype was detected only on I-Ab-restricted Th of (4R X 5R)F1, whereas it was absent on I-Ak-restricted Th. This strict linkage between the restriction specificity and I-J phenotype was also found on Th cells developed in bone marrow chimera constructed with intra-H-2-recombinant mice. The expression of I-Jk was always associated with the restriction specificity of the relevant host. Thus, the restriction specificity of Th cells followed the host type, and the I-J expression on Th was exactly the same as that expressed by the host haplotype. These results indicate that I-J is an isomorphic structure adaptively expressed on Th cells that is involved in the unidirectional regulatory cell interactions, and that the polymorphism cannot be explained merely by the restriction specificity of the conventional T cell receptor heterodimer

Restrictive cardiomyopathy

Science.gov (United States)

... People with restrictive cardiomyopathy may be heart transplant candidates. The outlook depends on the cause of the ... www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. ...

21 CFR 203.20 - Sales restrictions.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Sales restrictions. 203.20 Section 203.20 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL PRESCRIPTION DRUG MARKETING Sales Restrictions § 203.20 Sales restrictions. Except as provided in § 203.22 or...

Enzyme activity assay of glycoprotein enzymes based on a boronate affinity molecularly imprinted 96-well microplate.

Science.gov (United States)

Bi, Xiaodong; Liu, Zhen

2014-12-16

Enzyme activity assay is an important method in clinical diagnostics. However, conventional enzyme activity assay suffers from apparent interference from the sample matrix. Herein, we present a new format of enzyme activity assay that can effectively eliminate the effects of the sample matrix. The key is a 96-well microplate modified with molecularly imprinted polymer (MIP) prepared according to a newly proposed method called boronate affinity-based oriented surface imprinting. Alkaline phosphatase (ALP), a glycoprotein enzyme that has been routinely used as an indicator for several diseases in clinical tests, was taken as a representative target enzyme. The prepared MIP exhibited strong affinity toward the template enzyme (with a dissociation constant of 10(-10) M) as well as superb tolerance for interference. Thus, the enzyme molecules in a complicated sample matrix could be specifically captured and cleaned up for enzyme activity assay, which eliminated the interference from the sample matrix. On the other hand, because the boronate affinity MIP could well retain the enzymatic activity of glycoprotein enzymes, the enzyme captured by the MIP was directly used for activity assay. Thus, additional assay time and possible enzyme or activity loss due to an enzyme release step required by other methods were avoided. Assay of ALP in human serum was successfully demonstrated, suggesting a promising prospect of the proposed method in real-world applications.

Novel Biocatalysts Combining the Special Assembly Properties of S-Layer Proteins and the Functionality of Enzymes of Extremophiles (BIOCAT)

Science.gov (United States)

2010-04-14

recrystallization properties of rSbpA/LamAAs shown by transmission electron microscopy of negatively stained preparations. rSbpA/LamA had the capability...the restriction sites BamHl and Noll were introduced at the 5’ and 3’ ends, respectively. For expression, all recombinant plasm ids were established...Laccase oxidizes hydroquinone to quinone by releasing two protons and two electrons . In the presence of oxygen, the enzyme forms water. First of all the

Enzymic lactose hydrolysis

Energy Technology Data Exchange (ETDEWEB)

Miller, J J; Brand, J C

1980-01-01

Acid or enzymic hydrolysis can be used to hydrolyze lactose. Advantages of both are compared and details of enzymic hydrolysis using yeast or fungal enzymes given. The new scheme outlined involves recycling lactase. Because lactose and lactase react to ultrafiltration (UF) membranes differently separation is possible. Milk or milk products are ultrafiltered to separate a concentrate from a lactose-rich permeate which is treated with lactase in a reactor until hydrolysis reaches a required level. The lactase can be removed by UF as it does not permeate the membrane, and it is recycled back to the reactor. Permeate from the second UF stage may or may not be recombined with the concentrate from the first stage to produce a low lactose product (analysis of a typical low-lactose dried whole milk is given). Batch or continuous processes are explained and a batch process without enzyme recovery is discussed. (Refs. 4).

Enzyme Mimics: Advances and Applications.

Science.gov (United States)

Kuah, Evelyn; Toh, Seraphina; Yee, Jessica; Ma, Qian; Gao, Zhiqiang

2016-06-13

Enzyme mimics or artificial enzymes are a class of catalysts that have been actively pursued for decades and have heralded much interest as potentially viable alternatives to natural enzymes. Aside from having catalytic activities similar to their natural counterparts, enzyme mimics have the desired advantages of tunable structures and catalytic efficiencies, excellent tolerance to experimental conditions, lower cost, and purely synthetic routes to their preparation. Although still in the midst of development, impressive advances have already been made. Enzyme mimics have shown immense potential in the catalysis of a wide range of chemical and biological reactions, the development of chemical and biological sensing and anti-biofouling systems, and the production of pharmaceuticals and clean fuels. This Review concerns the development of various types of enzyme mimics, namely polymeric and dendrimeric, supramolecular, nanoparticulate and proteinic enzyme mimics, with an emphasis on their synthesis, catalytic properties and technical applications. It provides an introduction to enzyme mimics and a comprehensive summary of the advances and current standings of their applications, and seeks to inspire researchers to perfect the design and synthesis of enzyme mimics and to tailor their functionality for a much wider range of applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Adsorption of monocomponent enzymes in enzyme mixture analyzed quantitatively during hydrolysis of lignocellulose substrates.

Science.gov (United States)

Várnai, Anikó; Viikari, Liisa; Marjamaa, Kaisa; Siika-aho, Matti

2011-01-01

The adsorption of purified Trichoderma reesei cellulases (TrCel7A, TrCel6A and TrCel5A) and xylanase TrXyn11 and Aspergillus niger β-glucosidase AnCel3A was studied in enzyme mixture during hydrolysis of two pretreated lignocellulosic materials, steam pretreated and catalytically delignified spruce, along with microcrystalline cellulose (Avicel). The enzyme mixture was compiled to resemble the composition of commercial cellulase preparations. The hydrolysis was carried out at 35 °C to mimic the temperature of the simultaneous saccharification and fermentation (SSF). Enzyme adsorption was followed by analyzing the activity and the protein amount of the individual free enzymes in the hydrolysis supernatant. Most enzymes adsorbed quickly at early stages of the hydrolysis and remained bound throughout the hydrolysis, although the conversion reached was fairly high. Only with the catalytically oxidized spruce samples, the bound enzymes started to be released as the hydrolysis degree reached 80%. The results based on enzyme activities and protein assay were in good accordance. Copyright © 2010 Elsevier Ltd. All rights reserved.

Characterising Complex Enzyme Reaction Data.

Directory of Open Access Journals (Sweden)

Handan Melike Dönertaş

Full Text Available The relationship between enzyme-catalysed reactions and the Enzyme Commission (EC number, the widely accepted classification scheme used to characterise enzyme activity, is complex and with the rapid increase in our knowledge of the reactions catalysed by enzymes needs revisiting. We present a manual and computational analysis to investigate this complexity and found that almost one-third of all known EC numbers are linked to more than one reaction in the secondary reaction databases (e.g., KEGG. Although this complexity is often resolved by defining generic, alternative and partial reactions, we have also found individual EC numbers with more than one reaction catalysing different types of bond changes. This analysis adds a new dimension to our understanding of enzyme function and might be useful for the accurate annotation of the function of enzymes and to study the changes in enzyme function during evolution.

Enzyme Immobilization: An Overview on Methods, Support Material, and Applications of Immobilized Enzymes.

Science.gov (United States)

Sirisha, V L; Jain, Ankita; Jain, Amita

Immobilized enzymes can be used in a wide range of processes. In recent years, a variety of new approaches have emerged for the immobilization of enzymes that have greater efficiency and wider usage. During the course of the last two decades, this area has rapidly expanded into a multidisciplinary field. This current study is a comprehensive review of a variety of literature produced on the different enzymes that have been immobilized on various supporting materials. These immobilized enzymes have a wide range of applications. These include applications in the sugar, fish, and wine industries, where they are used for removing organic compounds from waste water. This study also reviews their use in sophisticated biosensors for metabolite control and in situ measurements of environmental pollutants. Immobilized enzymes also find significant application in drug metabolism, biodiesel and antibiotic production, bioremediation, and the food industry. The widespread usage of immobilized enzymes is largely due to the fact that they are cheaper, environment friendly, and much easier to use when compared to equivalent technologies. © 2016 Elsevier Inc. All rights reserved.

Random-walk enzymes

Science.gov (United States)

Mak, Chi H.; Pham, Phuong; Afif, Samir A.; Goodman, Myron F.

2015-09-01

Enzymes that rely on random walk to search for substrate targets in a heterogeneously dispersed medium can leave behind complex spatial profiles of their catalyzed conversions. The catalytic signatures of these random-walk enzymes are the result of two coupled stochastic processes: scanning and catalysis. Here we develop analytical models to understand the conversion profiles produced by these enzymes, comparing an intrusive model, in which scanning and catalysis are tightly coupled, against a loosely coupled passive model. Diagrammatic theory and path-integral solutions of these models revealed clearly distinct predictions. Comparison to experimental data from catalyzed deaminations deposited on single-stranded DNA by the enzyme activation-induced deoxycytidine deaminase (AID) demonstrates that catalysis and diffusion are strongly intertwined, where the chemical conversions give rise to new stochastic trajectories that were absent if the substrate DNA was homogeneous. The C →U deamination profiles in both analytical predictions and experiments exhibit a strong contextual dependence, where the conversion rate of each target site is strongly contingent on the identities of other surrounding targets, with the intrusive model showing an excellent fit to the data. These methods can be applied to deduce sequence-dependent catalytic signatures of other DNA modification enzymes, with potential applications to cancer, gene regulation, and epigenetics.

Cloning and analysis of the genes encoding the type IIS restriction-modification system HphI from Haemophilus parahaemolyticus.

Science.gov (United States)

Lubys, A; Lubienè, J; Kulakauskas, S; Stankevicius, K; Timinskas, A; Janulaitis, A

1996-07-15

The genomic region encoding the type IIS restriction-modification (R-M) system HphI (enzymes recognizing the asymmetric sequence 5'-GGTGA-3'/5'-TCACC-3') from Haemophilus parahaemolyticus were cloned into Escherichia coli and sequenced. Sequence analysis of the R-M HphI system revealed three adjacent genes aligned in the same orientation: a cytosine 5 methyltransferase (gene hphIMC), an adenine N6 methyltransferase (hphIMA) and the HphI restriction endonuclease (gene hphIR). Either methyltransferase is capable of protecting plasmid DNA in vivo against the action of the cognate restriction endonuclease. hphIMA methylation renders plasmid DNA resistant to R.Hindill at overlapping sites, suggesting that the adenine methyltransferase modifies the 3'-terminal A residue on the GGTGA strand. Strong homology was found between the N-terminal part of the m6A methyltransferasease and an unidentified reading frame interrupted by an incomplete gaIE gene of Neisseria meningitidis. The HphI R-M genes are flanked by a copy of a 56 bp direct nucleotide repeat on each side. Similar sequences have also been identified in the non-coding regions of H.influenzae Rd DNA. Possible involvement of the repeat sequences in the mobility of the HphI R-M system is discussed.

Enzyme stabilization for pesticide degradation

Energy Technology Data Exchange (ETDEWEB)

Rivers, D.B.; Frazer, F.R. III; Mason, D.W.; Tice, T.R.

1988-01-01

Enzymes offer inherent advantages and limitations as active components of formulations used to decontaminate soil and equipment contaminated with toxic materials such as pesticides. Because of the catalytic nature of enzymes, each molecule of enzyme has the potential to destroy countless molecules of a contaminating toxic compound. This degradation takes place under mild environmental conditions of pH, temperature, pressure, and solvent. The basic limitation of enzymes is their degree of stability during storage and application conditions. Stabilizing methods such as the use of additives, covalent crosslinking, covalent attachment, gel entrapment, and microencapsulation have been directed developing an enzyme preparation that is stable under extremes of pH, temperature, and exposure to organic solvents. Initial studies were conducted using the model enzymes subtilisin and horseradish peroxidase.

Enzyme Molecules in Solitary Confinement

Directory of Open Access Journals (Sweden)

Raphaela B. Liebherr

2014-09-01

Full Text Available Large arrays of homogeneous microwells each defining a femtoliter volume are a versatile platform for monitoring the substrate turnover of many individual enzyme molecules in parallel. The high degree of parallelization enables the analysis of a statistically representative enzyme population. Enclosing individual enzyme molecules in microwells does not require any surface immobilization step and enables the kinetic investigation of enzymes free in solution. This review describes various microwell array formats and explores their applications for the detection and investigation of single enzyme molecules. The development of new fabrication techniques and sensitive detection methods drives the field of single molecule enzymology. Here, we introduce recent progress in single enzyme molecule analysis in microwell arrays and discuss the challenges and opportunities.

A Traffic Restriction Scheme for Enhancing Carpooling

Directory of Open Access Journals (Sweden)

Dong Ding

2017-01-01

Full Text Available For the purpose of alleviating traffic congestion, this paper proposes a scheme to encourage travelers to carpool by traffic restriction. By a variational inequity we describe travelers’ mode (solo driving and carpooling and route choice under user equilibrium principle in the context of fixed demand and detect the performance of a simple network with various restriction links, restriction proportions, and carpooling costs. Then the optimal traffic restriction scheme aiming at minimal total travel cost is designed through a bilevel program and applied to a Sioux Fall network example with genetic algorithm. According to various requirements, optimal restriction regions and proportions for restricted automobiles are captured. From the results it is found that traffic restriction scheme is possible to enhance carpooling and alleviate congestion. However, higher carpooling demand is not always helpful to the whole network. The topology of network, OD demand, and carpooling cost are included in the factors influencing the performance of the traffic system.

Enzyme technology: Key to selective biorefining

DEFF Research Database (Denmark)

Meyer, Anne S.

2014-01-01

to the reaction is a unique trait of enzyme catalysis. Since enzyme selectivity means that a specific reaction is catalysed between particular species to produce definite products, enzymes are particularly fit for converting specific compounds in mixed biomass streams. Since enzymes are protein molecules...... their rational use in biorefinery processes requires an understanding of the basic features of enzymes and reaction traits with respect to specificity, kinetics, reaction optima, stability and structure-function relations – we are now at a stage where it is possible to use nature’s enzyme structures as starting...... point and then improve the functional traits by targeted mutation of the protein. The talk will display some of our recent hypotheses related to enzyme action, recently obtained results within knowledge-based enzyme improvements as well as cast light on research methods used in optimizing enzyme...

Phage lytic enzymes: a history.

Science.gov (United States)

Trudil, David

2015-02-01

There are many recent studies regarding the efficacy of bacteriophage-related lytic enzymes: the enzymes of 'bacteria-eaters' or viruses that infect bacteria. By degrading the cell wall of the targeted bacteria, these lytic enzymes have been shown to efficiently lyse Gram-positive bacteria without affecting normal flora and non-related bacteria. Recent studies have suggested approaches for lysing Gram-negative bacteria as well (Briersa Y, et al., 2014). These enzymes include: phage-lysozyme, endolysin, lysozyme, lysin, phage lysin, phage lytic enzymes, phageassociated enzymes, enzybiotics, muralysin, muramidase, virolysin and designations such as Ply, PAE and others. Bacteriophages are viruses that kill bacteria, do not contribute to antimicrobial resistance, are easy to develop, inexpensive to manufacture and safe for humans, animals and the environment. The current focus on lytic enzymes has been on their use as anti-infectives in humans and more recently in agricultural research models. The initial translational application of lytic enzymes, however, was not associated with treating or preventing a specific disease but rather as an extraction method to be incorporated in a rapid bacterial detection assay (Bernstein D, 1997).The current review traces the translational history of phage lytic enzymes-from their initial discovery in 1986 for the rapid detection of group A streptococcus in clinical specimens to evolving applications in the detection and prevention of disease in humans and in agriculture.

Molecular motion in restricted geometries

Indian Academy of Sciences (India)

Molecular dynamics in restricted geometries is known to exhibit anomalous behaviour. Diffusion, translational or rotational, of molecules is altered significantly on confinement in restricted geometries. Quasielastic neutron scattering (QENS) offers a unique possibility of studying molecular motion in such systems. Both time ...

Identification of a DNA restriction-modification system in Pectobacterium carotovorum strains isolated from Poland.

Science.gov (United States)

Waleron, K; Waleron, M; Osipiuk, J; Podhajska, A J; Lojkowska, E

2006-02-01

Polish isolates of pectinolytic bacteria from the species Pectobacterium carotovorum were screened for the presence of a DNA restriction-modification (R-M) system. Eighty-nine strains of P. carotovorum were isolated from infected potato plants. Sixty-six strains belonged to P. carotovorum ssp. atrosepticum and 23 to P. carotovorum ssp. carotovorum. The presence of restriction enzyme Pca17AI, which is an isoschizomer of EcoRII endonuclease, was observed in all isolates of P. c. atrosepticum but not in P. c. carotovorum. The biochemical properties, PCR amplification, and sequences of the Pca17AI restriction endonuclease and methyltransferase genes were compared with the prototype EcoRII R-M system genes. Only when DNA isolated from cells of P. c. atrosepticum was used as a template, amplification of a 680 bp homologous to the gene coding EcoRII endonuclease. Endonuclease Pca17AI, having a relatively low temperature optimum, was identified. PCR amplification revealed that the nucleotide sequence of genes for EcoRII and Pca17AI R-M are different. Dcm methylation was observed in all strains of Pectobacterium and other Erwinia species tested. The sequence of a DNA fragment coding Dcm methylase in P. carotovorum was different from that of Escherichia coli. Pca17AI is the first psychrophilic isoschizomer of EcoRII endonuclease. The presence of specific Dcm methylation in chromosomal DNA isolated from P. carotovorum is described for the first time. A 680 bp PCR product, unique for P. c. atrosepticum strains, could serve as a molecular marker for detection of these bacteria in environmental samples.

Nanoarmored Enzymes for Organic Enzymology: Synthesis and Characterization of Poly(2-Alkyloxazoline)-Enzyme Conjugates.

Science.gov (United States)

Leurs, Melanie; Tiller, Joerg C

2017-01-01

The properties of enzymes can be altered significantly by modification with polymers. Numerous different methods are known to obtain such polymer-enzyme conjugates (PECs). However, there is no universal method to render enzymes into PECs that are fully soluble in organic solvents. Here, we present a method, which achieves such high degree of modification of proteins that the majority of modified enzymes will be soluble in organic solvents. This is achieved by preparing poly(2-alkyloxazoline)s (POx) with an NH 2 end group and coupling this functional polymer via pyromellitic acid dianhydride onto the amino groups of the respective protein. The resulting PECs are capable of serving as surfactants for unmodified proteins, rendering the whole mixture organosoluble. Depending on the nature of the POx and the molecular weight and the nature of the enzyme, the PECs are soluble in chloroform or even toluene. Another advantage of this method is that the poly(2-alkyloxazoline) can be activated with the coupling agent and used for the enzyme conjugation without further purification. The POx-enzyme conjugates generated by this modification strategy show modulated catalytic activity in both, aqueous and organic, systems. © 2017 Elsevier Inc. All rights reserved.

Engineering Cellulase Enzymes for Bioenergy

Science.gov (United States)

Atreya, Meera Elizabeth

Sustainable energy sources, such as biofuels, offer increasingly important alternatives to fossil fuels that contribute less to global climate change. The energy contained within cellulosic biofuels derives from sunlight energy stored in the form of carbon-carbon bonds comprising sugars such as glucose. Second-generation biofuels are produced from lignocellulosic biomass feedstocks, including agricultural waste products and non-food crops like Miscanthus, that contain lignin and the polysaccharides hemicellulose and cellulose. Cellulose is the most abundant biological material on Earth; it is a polymer of glucose and a structural component of plant cell walls. Accessing the sugar is challenging, as the crystalline structure of cellulose resists degradation; biochemical and thermochemical means can be used to depolymerize cellulose. Cellulase enzymes catalyze the biochemical depolymerization of cellulose into glucose. Glucose can be used as a carbon source for growth of a biofuel-producing microorganism. When it converts glucose to a hydrocarbon fuel, this microbe completes the biofuels process of transforming sunlight energy into accessible, chemical energy capable of replacing non-renewable transportation fuels. Due to strong intermolecular interactions between polymer chains, cellulose is significantly more challenging to depolymerize than starch, a more accessible polymer of glucose utilized in first-generation biofuels processes (often derived from corn). While most mammals cannot digest cellulose (dietary fiber), certain fungi and bacteria produce cellulase enzymes capable of hydrolyzing it. These organisms secrete a wide variety of glycoside hydrolase and other classes of enzymes that work in concert. Because cellulase enzymes are slow-acting and expensive to produce, my aim has been to improve the properties of these enzymes as a means to make a cellulosic biofuels process possible that is more efficient and, consequently, more economical than current

Impact of enzyme loading on the efficacy and recovery of cellulolytic enzymes immobilized on enzymogel nanoparticles.

Science.gov (United States)

Samaratunga, Ashani; Kudina, Olena; Nahar, Nurun; Zakharchenko, Andrey; Minko, Sergiy; Voronov, Andriy; Pryor, Scott W

2015-03-01

Cellulase and β-glucosidase were adsorbed on a polyacrylic acid polymer brush grafted on silica nanoparticles to produce enzymogels as a form of enzyme immobilization. Enzyme loading on the enzymogels was increased to a saturation level of approximately 110 μg (protein) mg(-1) (particle) for each enzyme. Enzymogels with varied enzyme loadings were then used to determine the impact on hydrolysis rate and enzyme recovery. Soluble sugar concentrations during the hydrolysis of filter paper and Solka-Floc with the enzymogels were 45 and 53%, respectively, of concentrations when using free cellulase. β-Glucosidase enzymogels showed lower performance; hydrolyzate glucose concentrations were just 38% of those using free enzymes. Increasing enzyme loading on the enzymogels did not reduce net efficacy for cellulase and improved efficacy for β-glucosidase. The use of free cellulases and cellulase enzymogels resulted in hydrolyzates with different proportions of cellobiose and glucose, suggesting differential attachment or efficacy of endoglucanases, exoglucanases, and β-glucosidases present in cellulase mixtures. When loading β-glucosidase individually, higher enzyme loadings on the enzymogels produced higher hydrolyzate glucose concentrations. Approximately 96% of cellulase and 66 % of β-glucosidase were recovered on the enzymogels, while enzyme loading level did not impact recovery for either enzyme.

Use of restriction fragment length polymorphisms to investigate strain variation within Neisseria meningitidis

Energy Technology Data Exchange (ETDEWEB)

Williams, S.D.

1989-01-01

Similarity within bacterial populations is difficult to assess due to the limited number of characters available for evaluation and the heterogeneity of bacterial species. Currently, the preferred method used to evaluate the structure of bacterial populations is multilocus enzyme electrophoresis. However, this method is extremely cumbersome and only offers an indirect measure of genetic similarities. The development of a more direct and less cumbersome method for this purpose is warranted. Restriction fragment length polymorphism analysis was evaluated as a tool for use in the study of bacterial population structures and in the epidemiology and surveillance of infectious disease. A collection of Neisseria meningitidis was available for use in the investigation of this technique. Neisseria meningitidis is the causative agent of epidemic cerebrospinal meningitis and septicemia as well as a variety of other clinical manifestations. Each isolate in the collection was defined in terms of serogroup specificity, clinical history, geographic source, and date of isolation. Forty-six strains were chosen for this study. The DNA from each strain was restricted with Pst1 and EcoR1 and electrophoresed on agarose gels. The DNA was transferred to nylon filters and hybridized with P{sup 32} labeled DNA probes. Two randomly generated probes and a gene-specific probe were used to estimate the genetic similarities between and among the strains in the study population. A total of 28 different restriction fragment migration types were detected by the probes used. Data obtained from the RFLP analysis was analyzed by cluster analysis and multivariate statistical methods. A total of 7 clones groups were detected. Two of these appear to be major clones that comprise 35% of the population.

Use of restriction fragment length polymorphisms to investigate strain variation within Neisseria meningitidis

International Nuclear Information System (INIS)

Williams, S.D.

1989-01-01

Similarity within bacterial populations is difficult to assess due to the limited number of characters available for evaluation and the heterogeneity of bacterial species. Currently, the preferred method used to evaluate the structure of bacterial populations is multilocus enzyme electrophoresis. However, this method is extremely cumbersome and only offers an indirect measure of genetic similarities. The development of a more direct and less cumbersome method for this purpose is warranted. Restriction fragment length polymorphism analysis was evaluated as a tool for use in the study of bacterial population structures and in the epidemiology and surveillance of infectious disease. A collection of Neisseria meningitidis was available for use in the investigation of this technique. Neisseria meningitidis is the causative agent of epidemic cerebrospinal meningitis and septicemia as well as a variety of other clinical manifestations. Each isolate in the collection was defined in terms of serogroup specificity, clinical history, geographic source, and date of isolation. Forty-six strains were chosen for this study. The DNA from each strain was restricted with Pst1 and EcoR1 and electrophoresed on agarose gels. The DNA was transferred to nylon filters and hybridized with P 32 labeled DNA probes. Two randomly generated probes and a gene-specific probe were used to estimate the genetic similarities between and among the strains in the study population. A total of 28 different restriction fragment migration types were detected by the probes used. Data obtained from the RFLP analysis was analyzed by cluster analysis and multivariate statistical methods. A total of 7 clones groups were detected. Two of these appear to be major clones that comprise 35% of the population

[Interaction between CYP450 enzymes and metabolism of traditional Chinese medicine as well as enzyme activity assay].

Science.gov (United States)

Lu, Tu-lin; Su, Lian-lin; Ji, De; Gu, Wei; Mao, Chun-qin

2015-09-01

Drugs are exogenous compounds for human bodies, and will be metabolized by many enzymes after administration. CYP450 enzyme, as a major metabolic enzyme, is an important phase I drug metabolizing enzyme. In human bodies, about 75% of drug metabolism is conducted by CYP450 enzymes, and CYP450 enzymes is the key factor for drug interactions between traditional Chinese medicine( TCM) -TCM, TCM-medicine and other drug combination. In order to make clear the interaction between metabolic enzymes and TCM metabolism, we generally chose the enzymatic activity as an evaluation index. That is to say, the enhancement or reduction of CYP450 enzyme activity was used to infer the inducing or inhibitory effect of active ingredients and extracts of traditional Chinese medicine on enzymes. At present, the common method for measuring metabolic enzyme activity is Cocktail probe drugs, and it is the key to select the suitable probe substrates. This is of great significance for study drug's absorption, distribution, metabolism and excretion (ADME) process in organisms. The study focuses on the interaction between TCMs, active ingredients, herbal extracts, cocktail probe substrates as well as CYP450 enzymes, in order to guide future studies.

BAKERY ENZYMES IN CEREAL TECHNOLOGIES

Directory of Open Access Journals (Sweden)

Václav Koman

2012-10-01

Full Text Available Normal 0 21 false false false SK X-NONE X-NONE Bread is the most common and traditional food in the world. For years, enzymes such as malt and fungal alpha-amylase have been used in bread making. Due to the changes in the baking industry and the ever-increasing demand for more natural products, enzymes have gained real importance in bread-making. If an enzyme is added, it is often destroyed by the heat during the baking process. For generations, enzymes have been used for the improvement of texture and appearance, enhancement of nutritional values and generation of appealing flavours and aromas. Enzymes used in bakery industry constitute nearly one third of the market. The bakery products have undergone radical improvements in quality over the past years in terms of flavour, texture and shelf-life. The the biggest contributor for these improvementsis the usage of enzymes. Present work seeks to systematically describe bakery enzymes, their classification, benefits, usage and chemical reactions in the bread making process.doi:10.5219/193

Crosslinked Enzyme Aggregates in Hierarchically-Ordered Mesoporous Silica: A Simple and Effective Method for Enzyme Stabilization

Energy Technology Data Exchange (ETDEWEB)

Kim, Moon Il; Kim, Jungbae; Lee, Jinwoo; Jia, Hongfei; Na, Hyon Bin; Youn, Jongkyu; Kwak, Ja Hun; Dohnalkova, Alice; Grate, Jay W.; Wang, Ping; Hyeon, Taeghwan; Park, Hyun-Gyu; Chang, Ho Nam

2007-02-01

alpha-chymotrypsin (CT) and lipase (LP) were immobilized in hierarchically-ordered mesocellular mesoporous silica (HMMS) in a simple but effective way for the enzyme stabilization, which was achieved by the enzyme adsorption followed by glutaraldehyde (GA) crosslinking. This resulted in the formation of nanometer scale crosslinked enzyme aggregates (CLEAs) entrapped in the mesocellular pores of HMMS (37 nm), which did not leach out of HMMS through narrow mesoporous channels (13 nm). CLEA of alpha-chymotrypsin (CLEA-CT) in HMMS showed a high enzyme loading capacity and significantly increased enzyme stability. No activity decrease of CLEA-CT was observed for two weeks under even rigorously shaking condition, while adsorbed CT in HMMS and free CT showed a rapid inactivation due to the enzyme leaching and presumably autolysis, respectively. With the CLEA-CT in HMMS, however, there was no tryptic digestion observed suggesting that the CLEA-CT is not susceptible to autolysis. Moreover, CLEA of lipase (CLEA-LP) in HMMS retained 30% specific activity of free lipase with greatly enhanced stability. This work demonstrates that HMMS can be efficiently employed as host materials for enzyme immobilization leading to highly enhanced stability of the immobilized enzymes with high enzyme loading and activity.

Immobilized enzymes and cells

Energy Technology Data Exchange (ETDEWEB)

Bucke, C; Wiseman, A

1981-04-04

This article reviews the current state of the art of enzyme and cell immobilization and suggests advances which might be made during the 1980's. Current uses of immobilized enzymes include the use of glucoamylase in the production of glucose syrups from starch and glucose isomerase in the production of high fructose corn syrup. Possibilities for future uses of immobilized enzymes and cells include the utilization of whey and the production of ethanol.

28 CFR 804.3 - Restrictions.

Science.gov (United States)

2010-07-01

... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Restrictions. 804.3 Section 804.3 Judicial Administration COURT SERVICES AND OFFENDER SUPERVISION AGENCY FOR THE DISTRICT OF COLUMBIA ACCEPTANCE OF GIFTS § 804.3 Restrictions. (a) The Agency is not authorized to accept gifts of money, stock...

5 CFR 1304.4605 - Post-employment restrictions.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Post-employment restrictions. 1304.4605 Section 1304.4605 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET ADMINISTRATIVE PROCEDURES POST EMPLOYMENT CONFLICT OF INTEREST § 1304.4605 Post-employment restrictions. (a) General Restrictions Applicable...

Restrictive Cardiomyopathy

Science.gov (United States)

... up in the circulatory system. In time, the heart fails. What causes it? Restrictive cardiomyopathy is often caused by diseases in other parts of the body. One known cause is cardiac ... build up in the heart tissue, making the tissue stiff and thickened. Cardiac ...

Mammary sensitivity to protein restriction and re-alimentation.

Science.gov (United States)

Goodwill, M G; Jessop, N S; Oldham, J D

1996-09-01

The present study tested the influence of protein undernutrition and re-alimentation on mammary gland size and secretory cell activity in lactating rats. During gestation, female Sprague-Dawley rats were offered a high-protein diet (215 g crude protein (N x 6.25; CP)/kg DM; H); litters were standardized to twelve pups at parturition. During lactation, two diets were offered ad libitum, diet H and a low-protein diet (90 g CP/kg DM; L). Lactational dietary treatments were the supply ad libitum of either diet H (HHH) or diet L (LLL) for the first 12 d of lactation, or diet L transferring to diet H on either day 6 (LHH) or 9 (LLH) of lactation. On days 1, 6, 9 and 12 of lactation, rats from each group (n > or = 6) were used to estimate mammary dry mass, fat, protein, DNA and RNA; the activities of lactose synthetase (EC 2.4.1.22) enzyme and Na+,K(+)-ATPase (EC 3.6.1.37) were also measured. Rats offered a diet considered protein sufficient (H) from day 1 of lactation showed a decrease in mammary dry mass and fat but an increase in DNA, RNA and protein on day 6, after which there was no further change, except for mammary protein which continued to increase. However, rats offered diet L showed a steady loss in mammary mass and fat throughout the 12 d lactation period and no change in mammary DNA, RNA or protein. Rats previously protein restricted for either the first 6 or 9 d of lactation had their mammary dry mass and mammary fat loss halted and showed a rapid increase in mammary DNA, RNA and protein on re-alimentation. Lactose production in group HHH, as measured by lactose synthetase activity, was similar on days 1 and 6 of lactation, after which a significant increase was seen. Protein-restricted rats showed no change in lactose synthetase activity during the 12 d experimental period. Changing from diet L to diet H led to a significant increase in lactose synthetase activity to levels comparable with those offered diet H from day 1. These results show that rats

7 CFR 322.28 - General requirements; restricted articles.

Science.gov (United States)

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false General requirements; restricted articles. 322.28... EQUIPMENT Importation and Transit of Restricted Articles § 322.28 General requirements; restricted articles. (a) The following articles from any region are restricted articles: (1) Dead bees of any genus; (2...

Acute intermittent porphyria: A single-base deletion and a nonsense mutation in the human hydroxymethylbilane synthase gene, predicting truncations of the enzyme polypeptide

Energy Technology Data Exchange (ETDEWEB)

Lee, G.L.; Astrin, K.H.; Desnick, R.J. [Mount Sinai School of Medicine, New York, NY (United States)

1995-08-28

Acute intermittent porphyria (AIP) is an autosomal-dominant inborn error of metabolism that results from the half-normal activity of the third enzyme in the heme biosynthetic pathway, hydroxymethylbilane synthase (HMB-synthase). AIP is an ecogenetic condition, since the life-threatening acute attacks are precipitated by various factors, including drugs, alcohol, fasting, and certain hormones. Biochemical diagnosis is problematic, and the identification of mutations in the HMB-synthase gene provides accurate detection of presymptomatic heterozygotes, permitting avoidance of the acute precipitating factors. By direct solid-phase sequencing, two mutations causing AIP were identified, an adenine deletion at position 629 in exon 11(629delA), which alters the reading frame and predicts premature truncation of the enzyme protein after amino acid 255, and a nonsense mutation in exon 12 (R225X). These mutations were confirmed by either restriction enzyme analysis or family studies of symptomatic patients, permitting accurate presymptomatic diagnosis of affected relatives. 29 refs., 2 figs.

Imbalance between pulmonary angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity in acute respiratory distress syndrome

NARCIS (Netherlands)

Wösten-van Asperen, Roelie M.; Bos, Albert P.; Bem, Reinout A.; Dierdorp, Barbara S.; Dekker, Tamara; van Goor, Harry; Kamilic, Jelena; van der Loos, Chris M.; van den Berg, Elske; Bruijn, Martijn; van Woensel, Job B.; Lutter, René

2013-01-01

Angiotensin-converting enzyme and its effector peptide angiotensin II have been implicated in the pathogenesis of acute respiratory distress syndrome. Recently, angiotensin-converting enzyme 2 was identified as the counter-regulatory enzyme of angiotensin-converting enzyme that converts angiotensin

Imbalance between pulmonary angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity in acute respiratory distress syndrome

NARCIS (Netherlands)

Wosten-van Asperen, Roelie M.; Bos, Albert; Bem, Reinout A.; Dierdorp, Barbara S.; Dekker, Tamara; van Goor, Harry; Kamilic, Jelena; van der Loos, Chris M.; van den Berg, Elske; Bruijn, Martijn; van Woensel, Job B.; Lutter, Rene

2013-01-01

Objective: Angiotensin-converting enzyme and its effector peptide angiotensin II have been implicated in the pathogenesis of acute respiratory distress syndrome. Recently, angiotensin-converting enzyme 2 was identified as the counter-regulatory enzyme of angiotensin-converting enzyme that converts

Immobilization of enzymes using non-ionic colloidal liquid aphrons (CLAs): Surface and enzyme effects.

Science.gov (United States)

Ward, Keeran; Xi, Jingshu; Stuckey, David C

2015-12-01

The use of non-ionic colloidal liquid aphrons (CLAs) as a support for enzyme immobilisation was investigated. Formulation required the mixing of an aqueous-surfactant solution with a relatively non-polar solvent-surfactant solution, forming a solvent droplet surrounded by a thin stabilised aqueous film (soapy shell). Studies utilising anionic surfactants have showed increased retention, however, very little have been understood about the forces governing immobilisation. This study seeks to determine the effects of enzyme properties on CLA immobilisation by examining a non-ionic/non-polar solvent system comprised of two non-ionic surfactants, Tween 20 and 80, mineral oil and the enzymes lipase, aprotinin and α-chymotrypsin. From these results it was deduced that hydrophobic interactions strongly governed immobilisation. Confocal Scanning Laser Microscopy (CSLM) revealed that immobilisation was predominantly achieved by surface adsorption attributed to hydrophobic interactions between the enzyme and the CLA surface. Enzyme surface affinity was found to increase when added directly to the formulation (pre-manufacture addition), as opposed to the bulk continuous phase (post-manufacture addition), with α-chymotrypsin and aprotinin being the most perturbed, while lipase was relatively unaffected. The effect of zeta potential on immobilisation showed that enzymes adsorbed better closer to their pI, indicating that charge minimisation was necessary for immobilisation. Finally, the effect of increasing enzyme concentration in the aqueous phase resulted in an increase in adsorption for all enzymes due to cooperativity between protein molecules, with saturation occurring faster at higher adsorption rates. Copyright © 2015 Elsevier B.V. All rights reserved.

Allosteric regulation of epigenetic modifying enzymes.

Science.gov (United States)

Zucconi, Beth E; Cole, Philip A

2017-08-01

Epigenetic enzymes including histone modifying enzymes are key regulators of gene expression in normal and disease processes. Many drug development strategies to target histone modifying enzymes have focused on ligands that bind to enzyme active sites, but allosteric pockets offer potentially attractive opportunities for therapeutic development. Recent biochemical studies have revealed roles for small molecule and peptide ligands binding outside of the active sites in modulating the catalytic activities of histone modifying enzymes. Here we highlight several examples of allosteric regulation of epigenetic enzymes and discuss the biological significance of these findings. Copyright © 2017 Elsevier Ltd. All rights reserved.

Frequent and recent retrotransposition of orthologous genes plays a role in the evolution of sperm glycolytic enzymes

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de Villena Fernando

2010-05-01

Full Text Available Abstract Background The central metabolic pathway of glycolysis converts glucose to pyruvate, with the net production of 2 ATP and 2 NADH per glucose molecule. Each of the ten reactions in this pathway is typically catalyzed by multiple isozymes encoded by a multigene family. Several isozymes in this pathway are expressed only during spermatogenesis, and gene targeting studies indicate that they are essential for sperm function and male fertility in mouse. At least three of the novel glycolytic isozymes are encoded by retrogenes (Pgk2, Aldoart1, and Aldoart2. Their restricted expression profile suggests that retrotransposition may play a significant role in the evolution of sperm glycolytic enzymes. Results We conducted a comprehensive genomic analysis of glycolytic enzymes in the human and mouse genomes and identified several intronless copies for all enzymes in the pathway, except Pfk. Within each gene family, a single orthologous gene was typically retrotransposed frequently and independently in both species. Several retroposed sequences maintained open reading frames (ORFs and/or provided evidence of alternatively spliced exons. We analyzed expression of sequences with ORFs and Gpi1 transcript in mouse spermatogenic cells. Conclusions Our analysis detected frequent, recent, and lineage-specific retrotransposition of orthologous glycolytic enzymes in the human and mouse genomes. Retrotransposition events are associated with LINE/LTR and genomic integration is random. We found evidence for the alternative splicing of parent genes. Many retroposed sequences have maintained ORFs, suggesting a functional role for these genes.

DGAT enzymes and triacylglycerol biosynthesis

Science.gov (United States)

Yen, Chi-Liang Eric; Stone, Scot J.; Koliwad, Suneil; Harris, Charles; Farese, Robert V.

2008-01-01

Triacylglycerols (triglycerides) (TGs) are the major storage molecules of metabolic energy and FAs in most living organisms. Excessive accumulation of TGs, however, is associated with human diseases, such as obesity, diabetes mellitus, and steatohepatitis. The final and the only committed step in the biosynthesis of TGs is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes. The genes encoding two DGAT enzymes, DGAT1 and DGAT2, were identified in the past decade, and the use of molecular tools, including mice deficient in either enzyme, has shed light on their functions. Although DGAT enzymes are involved in TG synthesis, they have distinct protein sequences and differ in their biochemical, cellular, and physiological functions. Both enzymes may be useful as therapeutic targets for diseases. Here we review the current knowledge of DGAT enzymes, focusing on new advances since the cloning of their genes, including possible roles in human health and diseases. PMID:18757836

de novo computational enzyme design.

Science.gov (United States)

Zanghellini, Alexandre

2014-10-01

Recent advances in systems and synthetic biology as well as metabolic engineering are poised to transform industrial biotechnology by allowing us to design cell factories for the sustainable production of valuable fuels and chemicals. To deliver on their promises, such cell factories, as much as their brick-and-mortar counterparts, will require appropriate catalysts, especially for classes of reactions that are not known to be catalyzed by enzymes in natural organisms. A recently developed methodology, de novo computational enzyme design can be used to create enzymes catalyzing novel reactions. Here we review the different classes of chemical reactions for which active protein catalysts have been designed as well as the results of detailed biochemical and structural characterization studies. We also discuss how combining de novo computational enzyme design with more traditional protein engineering techniques can alleviate the shortcomings of state-of-the-art computational design techniques and create novel enzymes with catalytic proficiencies on par with natural enzymes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Measurement of enzyme activity.

Science.gov (United States)

Harris, T K; Keshwani, M M

2009-01-01

To study and understand the nature of living cells, scientists have continually employed traditional biochemical techniques aimed to fractionate and characterize a designated network of macromolecular components required to carry out a particular cellular function. At the most rudimentary level, cellular functions ultimately entail rapid chemical transformations that otherwise would not occur in the physiological environment of the cell. The term enzyme is used to singularly designate a macromolecular gene product that specifically and greatly enhances the rate of a chemical transformation. Purification and characterization of individual and collective groups of enzymes has been and will remain essential toward advancement of the molecular biological sciences; and developing and utilizing enzyme reaction assays is central to this mission. First, basic kinetic principles are described for understanding chemical reaction rates and the catalytic effects of enzymes on such rates. Then, a number of methods are described for measuring enzyme-catalyzed reaction rates, which mainly differ with regard to techniques used to detect and quantify concentration changes of given reactants or products. Finally, short commentary is given toward formulation of reaction mixtures used to measure enzyme activity. Whereas a comprehensive treatment of enzymatic reaction assays is not within the scope of this chapter, the very core principles that are presented should enable new researchers to better understand the logic and utility of any given enzymatic assay that becomes of interest.

Assessing restrictiveness of national alcohol marketing policies.

Science.gov (United States)

Esser, Marissa B; Jernigan, David H

2014-01-01

To develop an approach for monitoring national alcohol marketing policies globally, an area of the World Health Organization's (WHO) Global Alcohol Strategy. Data on restrictiveness of alcohol marketing policies came from the 2002 and 2008 WHO Global Surveys on Alcohol and Health. We included four scales in a sensitivity analysis to determine optimal weights to score countries on their marketing policies and applied the selected scale to assess national marketing policy restrictiveness. Nearly, 36% of countries had no marketing restrictions. The overall restrictiveness levels were not significantly different between 2002 and 2008. The number of countries with strict marketing regulations did not differ across years. This method of monitoring alcohol marketing restrictiveness helps track progress towards implementing WHO'S Global Alcohol Strategy. Findings indicate a consistent lack of restrictive policies over time, making this a priority area for national and global action. © The Author 2014. Medical Council on Alcohol and Oxford University Press. All rights reserved.

Complementary specificity of restriction endonucleases of Diplococcus pneumoniae with respect to DNA methylation. [Haemophilus influenzae, Escherichia coli, Paramecium aurelia

Energy Technology Data Exchange (ETDEWEB)

Lacks, S.; Greenberg, B.

1977-01-01

Restriction endonucleases Dpn I and Dpn II are produced by two distinct strains of Diplococcus pneumoniae. The two enzymes show complementary specificity with respect to methylation of sites in DNA. From the identity of its cleavage site with that of Mbo I, it appears that Dpn II cleaves at the unmodified sequence 5'-G-A-T-C-3'. Dpn I cleaves at the same sequence when the adenine residue is methylated. Both enzymes produce only double-strand breaks in susceptible DNA. Their susceptibility to Dpn I and not Dpn II shows that essentially all the G-A-T-C sequences are methylated in DNA from the pneumococcal strain that produces Dpn II as well as in DNA from Hemophilus influenzae and Escherichia coli. In the dam-3 mutant of E. coli none of these sequences appear to be methylated. Residual adenine methylation in the dam-3 mutant DNA most likely occurs at different sites. Different but characteristic degrees of methylation at G-A-T-C sites are found in the DNA of bacterial viruses grown in E. coli. DNAs from mammalian cells and viruses are not methylated at this sequence. Mitochondrial DNA from Paramecium aurelia is not methylated, but a small proportion of G-A-T-C sequences in the macronuclear DNA of this eukaryote appear to be methylated. Possible roles of sequence-specific methylation in the accommodation of plasmids, in the replication of DNA, in the regulation of gene function and in the restriction of viral infection are discussed.

7 CFR 319.75-2 - Restricted articles. 1

Science.gov (United States)

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Restricted articles. 1 319.75-2 Section 319.75-2... SERVICE, DEPARTMENT OF AGRICULTURE FOREIGN QUARANTINE NOTICES Khapra Beetle § 319.75-2 Restricted articles. 1 1 The importation of restricted articles may be subject to prohibitions or restrictions under...

Restricted gravity: Abelian projection of Einstein's theory

International Nuclear Information System (INIS)

Cho, Y.M.

2013-01-01

Treating Einstein's theory as a gauge theory of Lorentz group, we decompose the gravitational connection Γμ into the restricted connection made of the potential of the maximal Abelian subgroup H of Lorentz group G and the valence connection made of G/H part of the potential which transforms covariantly under Lorentz gauge transformation. With this we show that Einstein's theory can be decomposed into the restricted gravity made of the restricted connection which has the full Lorentz gauge invariance which has the valence connection as gravitational source. The decomposition shows the existence of a restricted theory of gravitation which has the full general invariance but is much simpler than Einstein's theory. Moreover, it tells that the restricted gravity can be written as an Abelian gauge theory,

Thermodynamics of Enzyme-Catalyzed Reactions Database

Science.gov (United States)

SRD 74 Thermodynamics of Enzyme-Catalyzed Reactions Database (Web, free access)   The Thermodynamics of Enzyme-Catalyzed Reactions Database contains thermodynamic data on enzyme-catalyzed reactions that have been recently published in the Journal of Physical and Chemical Reference Data (JPCRD). For each reaction the following information is provided: the reference for the data, the reaction studied, the name of the enzyme used and its Enzyme Commission number, the method of measurement, the data and an evaluation thereof.

Highly efficient enzyme encapsulation in a protein nanocage: towards enzyme catalysis in a cellular nanocompartment mimic

Science.gov (United States)

Schoonen, Lise; Nolte, Roeland J. M.; van Hest, Jan C. M.

2016-07-01

The study of enzyme behavior in small nanocompartments is crucial for the understanding of biocatalytic processes in the cellular environment. We have developed an enzymatic conjugation strategy to attach a model enzyme to the interior of a cowpea chlorotic mottle virus capsid. It is shown that with this methodology high encapsulation efficiencies can be achieved. Additionally, we demonstrate that the encapsulation does not affect the enzyme performance in terms of a decreased activity or a hampered substrate diffusion. Finally, it is shown that the encapsulated enzymes are protected against proteases. We believe that our strategy can be used to study enzyme kinetics in an environment that approaches physiological conditions.The study of enzyme behavior in small nanocompartments is crucial for the understanding of biocatalytic processes in the cellular environment. We have developed an enzymatic conjugation strategy to attach a model enzyme to the interior of a cowpea chlorotic mottle virus capsid. It is shown that with this methodology high encapsulation efficiencies can be achieved. Additionally, we demonstrate that the encapsulation does not affect the enzyme performance in terms of a decreased activity or a hampered substrate diffusion. Finally, it is shown that the encapsulated enzymes are protected against proteases. We believe that our strategy can be used to study enzyme kinetics in an environment that approaches physiological conditions. Electronic supplementary information (ESI) available: Experimental procedures for the cloning, expression, and purification of all proteins, as well as supplementary figures and calculations. See DOI: 10.1039/c6nr04181g

Enzymes in biogenesis of plant cell wall polysaccharides. Enzyme characterization using tracer techniques

International Nuclear Information System (INIS)

Dickinson, D.B.

1975-01-01

Enzymes and metabolic pathways, by which starch and cell wall polysaccharides are formed, were investigated in order to learn how these processes are regulated and to identify the enzymatic regulatory mechanisms involved. Germinating lily pollen was used for studies of cell wall formation, and pollen and maize endosperm for studies of starch biosynthesis. Hexokinase being the first step in conversion of hexoses to starch, wall polysaccharides and respiratory substrates, maize endosperm enzyme was assayed by its conversion of 14 C-hexose to 14 C-hexose-6-P, and rapid separation of the two labelled compounds on anion-exchange paper. This enzyme did not appear to be under tight regulation by feed-back inhibition or activation, nor to be severely inhibited by glucose-6-P or activated by citrate. ADP-glucose pyrophosphorylase and other pyrophosphorylases were assayed radiochemically with 14 C-glucose-1-P (forward direction) or 32-PPsub(i) (reverse direction). They showed that the maize endosperm enzyme was activated by the glycolytic intermediates fructose-6-P and 3-phosphoglycerate, and that low levels of the enzyme were present in the high sucrose-low starch mutant named shrunken-2. Under optimal in-vitro assay conditions, the pollen enzyme reacted four times faster than the observed in-vivo rate of starch accumulation. Biogenesis of plant cell wall polysaccharides requires the conversion of hexose phosphates to various sugar nucleotides and utilization of the latter by the appropriate polysaccharide synthetases. Lily pollen possesses a β-1,3-glucan synthetase which is activated up to six-fold by β-linked oligosaccharides. Hence, the in-vivo activity of this enzyme may be modulated by such effector molecules

Curves of restricted type in euclidean spaces

Directory of Open Access Journals (Sweden)

Bengü Kılıç Bayram

2014-01-01

Full Text Available Submanifolds of restricted type were introduced in [7]. In the present study we consider restricted type of curves in Em. We give some special examples. We also show that spherical curve in S2(r C E3 is of restricted type if and only if either ƒ(s is constant or a linear function of s of the form ƒ(s = ±s + b and every closed W - curve of rank k and of length 2(r in E2k is of restricted type.

DNA-Based Enzyme Reactors and Systems

Directory of Open Access Journals (Sweden)

Veikko Linko

2016-07-01

Full Text Available During recent years, the possibility to create custom biocompatible nanoshapes using DNA as a building material has rapidly emerged. Further, these rationally designed DNA structures could be exploited in positioning pivotal molecules, such as enzymes, with nanometer-level precision. This feature could be used in the fabrication of artificial biochemical machinery that is able to mimic the complex reactions found in living cells. Currently, DNA-enzyme hybrids can be used to control (multi-enzyme cascade reactions and to regulate the enzyme functions and the reaction pathways. Moreover, sophisticated DNA structures can be utilized in encapsulating active enzymes and delivering the molecular cargo into cells. In this review, we focus on the latest enzyme systems based on novel DNA nanostructures: enzyme reactors, regulatory devices and carriers that can find uses in various biotechnological and nanomedical applications.

Cold-Adapted Enzymes

Science.gov (United States)

Georlette, D.; Bentahir, M.; Claverie, P.; Collins, T.; D'amico, S.; Delille, D.; Feller, G.; Gratia, E.; Hoyoux, A.; Lonhienne, T.; Meuwis, M.-a.; Zecchinon, L.; Gerday, Ch.

In the last few years, increased attention has been focused on enzymes produced by cold-adapted micro-organisms. It has emerged that psychrophilic enzymes represent an extremely powerful tool in both protein folding investigations and for biotechnological purposes. Such enzymes are characterised by an increased thermosensitivity and, most of them, by a higher catalytic efficiency at low and moderate temperatures, when compared to their mesophilic counterparts. The high thermosensitivity probably originates from an increased flexibility of either a selected area of the molecular edifice or the overall protein structure, providing enhanced abilities to undergo conformational changes during catalysis at low temperatures. Structure modelling and recent crystallographic data have allowed to elucidate the structural parameters that could be involved in this higher resilience. It was demonstrated that each psychrophilic enzyme adopts its own adaptive strategy. It appears, moreover, that there is a continuum in the strategy of protein adaptation to temperature, as the previously mentioned structural parameters are implicated in the stability of thermophilic proteins. Additional 3D crystal structures, site-directed and random mutagenesis experiments should now be undertaken to further investigate the stability-flexibility-activity relationship.

Molecular bass for a malic enzyme null mutation

International Nuclear Information System (INIS)

Brown, M.L.; Wise, L.S.; Rubin, C.S.

1987-01-01

Many tissues from normal (wt) mice have cytosolic malic enzyme (ME) activity and express two mRNAs (2 and 3.1 kb) that code for a single ME polypeptide. Mod-1 null (M-n) mice lack cytosolic ME activity, but express 2.5 and 3.6 kb mRNAs that hybridize with wt ME cDNAs. To investigate the basis for the ME deficiency cDNAs corresponding to M-n ME RNA were cloned. A λgt11 library was prepared using M-n liver mRNA as a template. Wt ME cDNA probes hybridized with several recombinant phages and a 2kb insert with an atypical (non-wt) restriction pattern was subcloned in pGEM 1 and sequenced. The M-n ME cDNA contains an internal directly repeated sequence that corresponds to nts 1109-1617 in the coding region of wt ME cDNA. A restriction fragment from M-n ME cDNA that includes the first 204 bp of repeated sequence and 306 bp of contiguous 5' sequence was subcloned into pGEM 1 and used as a template for synthesizing 32 P-labeled anti-sense RNA. After hybridization with M-n liver RNA the 510 nt transcript was resistant to RNA digestion; after hybridization with wt RNA only fragments corresponding to the normally non-contiguous 204 bp and 306 bp segments of the insert were protected. Thus the partial duplication of coding sequence in M-n ME mRNA is confirmed. Analyses of intron-exon organization in the relevant regions of the wt and M-n ME genes will provide further insights into the mechanism underlying the ME null mutation

36 CFR 13.1174 - Whale water restrictions.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Whale water restrictions. 13... Vessel Operating Restrictions § 13.1174 Whale water restrictions. (a) May 15 through September 30, the following waters are designated as whale waters. (1) Waters north of a line drawn from Point Carolus to...

Enzyme Engineering for In Situ Immobilization.

Science.gov (United States)

Rehm, Fabian B H; Chen, Shuxiong; Rehm, Bernd H A

2016-10-14

Enzymes are used as biocatalysts in a vast range of industrial applications. Immobilization of enzymes to solid supports or their self-assembly into insoluble particles enhances their applicability by strongly improving properties such as stability in changing environments, re-usability and applicability in continuous biocatalytic processes. The possibility of co-immobilizing various functionally related enzymes involved in multistep synthesis, conversion or degradation reactions enables the design of multifunctional biocatalyst with enhanced performance compared to their soluble counterparts. This review provides a brief overview of up-to-date in vitro immobilization strategies while focusing on recent advances in enzyme engineering towards in situ self-assembly into insoluble particles. In situ self-assembly approaches include the bioengineering of bacteria to abundantly form enzymatically active inclusion bodies such as enzyme inclusions or enzyme-coated polyhydroxyalkanoate granules. These one-step production strategies for immobilized enzymes avoid prefabrication of the carrier as well as chemical cross-linking or attachment to a support material while the controlled oriented display strongly enhances the fraction of accessible catalytic sites and hence functional enzymes.

[The rise of enzyme engineering in China].

Science.gov (United States)

Li, Gaoxiang

2015-06-01

Enzyme engineering is an important part of the modern biotechnology. Industrial biocatalysis is considered the third wave of biotechnology following pharmaceutical and agricultural waves. In 25 years, China has made a mighty advances in enzyme engineering research. This review focuses on enzyme genomics, enzyme proteomics, biosynthesis, microbial conversion and biosensors in the Chinese enzyme engineering symposiums and advances in enzyme preparation industry in China.

Dietary Sodium Restriction and Association with Urinary Marinobufagenin, Blood Pressure, and Aortic Stiffness

Science.gov (United States)

Fedorova, Olga V.; Racine, Matthew L.; Geolfos, Candace J.; Gates, Phillip E.; Chonchol, Michel; Fleenor, Bradley S.; Lakatta, Edward G.; Bagrov, Alexei Y.; Seals, Douglas R.

2013-01-01

Summary Background and objectives Systolic BP and large elastic artery stiffness both increase with age and are reduced by dietary sodium restriction. Production of the natriuretic hormone marinobufagenin, an endogenous α1 Na+,K+-ATPase inhibitor, is increased in salt-sensitive hypertension and contributes to the rise in systolic BP during sodium loading. Design, setting, participants, & measurements The hypothesis was that dietary sodium restriction performed in middle-aged/older adults (eight men and three women; 60±2 years) with moderately elevated systolic BP (139±2/83±2 mmHg) would reduce urinary marinobufagenin excretion as well as systolic BP and aortic pulse-wave velocity (randomized, placebo-controlled, and crossover design). This study also explored the associations among marinobufagenin excretion with systolic BP and aortic pulse-wave velocity across conditions of 5 weeks of a low-sodium (77±9 mmol/d) and 5 weeks of a normal-sodium (144±7 mmol/d) diet. Results Urinary marinobufagenin excretion (weekly measurements; 25.4±1.8 versus 30.7±2.1 pmol/kg per day), systolic BP (127±3 versus 138±5 mmHg), and aortic pulse-wave velocity (700±40 versus 843±36 cm/s) were lower during the low- versus normal-sodium condition (all Psodium excretion (slope=0.46, Psodium condition (both Psodium restriction reduces urinary marinobufagenin excretion and that urinary marinobufagenin excretion is positively associated with systolic BP, aortic stiffness (aortic pulse-wave velocity), and endothelial cell expression of the oxidant enzyme NAD(P)H oxidase. Importantly, marinobufagenin excretion is positively related to systolic BP over ranges of sodium intake typical of an American diet, extending previous observations in rodents and humans fed experimentally high-sodium diets. PMID:23929930

50 CFR 697.23 - Restricted gear areas.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Restricted gear areas. 697.23 Section 697... Measures § 697.23 Restricted gear areas. (a) Resolution of lobster gear conflicts with fisheries managed...) Restricted Gear Area I—(1) Duration—(i) Mobile Gear. From October 1 through June 15 of each fishing year, no...

Efficient immobilization of AGE and NAL enzymes onto functional amino resin as recyclable and high-performance biocatalyst.

Science.gov (United States)

Cheng, Jian; Zhuang, Wei; Tang, Chenglun; Chen, Yong; Wu, Jinglan; Guo, Ting; Ying, Hanjie

2017-03-01

N-Acetylglucosamine-2-epimerase (AGE) and N-acetylneuraminic acid lyase (NAL) were immobilized for synthesis of N-acetylneuraminic acid (Neu5Ac) on three resins: Amberzyme oxirane resin (AOR), poly (styrene-co-DVB)-Br resin (PBR) and amino resin (AR). The loading capacity and immobilized enzyme activity showed that AR was the best carrier. Three methods of glutaraldehyde cross-linking were tested and simultaneous cross-linking and immobilization was demonstrated to be the best method. The functional properties of immobilized AGE and NAL were studied and compared to those of the free enzyme. The highest enzyme activities of free and immobilized AGE were obtained in 0.1 M potassium phosphate buffer at pH 7.5 and a temperature of 37 °C. Comparatively, the highest NAL activities were at pH 8.5. Meanwhile, an increase in K m (from 1.14 to 1.31 mg·mL -1 for AGE and from 1.05 to 1.25 mg·mL -1 for NAL) and a decrease in V max (from 177.53 to 106.37 µg·min -1 mL -1 for AGE and from 126.41 to 95.96 µg·min -1 mL -1 for NAL) were recorded after immobilization. The AR-glutaraldehyde-enzyme system exhibited better thermal stability than the free enzyme, and retained 72% of its initial activity even after eight repeated runs. The apparent activation energy (E a ) of the free and immobilized AGE (NAL) was 117.14 kJ·mol -1 (124.21 kJ·mol -1 ) and 78.45 kJ·mol -1 (66.64 kJ·mol -1 ), respectively, implying that the catalytic efficiency of the immobilized enzyme was restricted by mass-transfer rather than kinetic limit. Subsequently, Neu5Ac production from GlcNAc using immobilized enzymes in one reactor was carried out resulting 101.45 g·L -1 of Neu5Ac and the highest conversion ratio of 82%. This method of enzyme immobilization may have a promising future for Neu5Ac production in industry.

Conjugative transfer of clostridial shuttle vectors from Escherichia coli to Clostridium difficile through circumvention of the restriction barrier.

Science.gov (United States)

Purdy, Des; O'Keeffe, Triona A T; Elmore, Michael; Herbert, Mike; McLeod, Anne; Bokori-Brown, Monika; Ostrowski, Anna; Minton, Nigel P

2002-10-01

Progress towards understanding the molecular basis of virulence in Clostridium difficile has been hindered by the lack of effective gene transfer systems. We have now, for the first time, developed procedures that may be used to introduce autonomously replicating vectors into this organism through their conjugative, oriT-based mobilization from Escherichia coli donors. Successful transfer was achieved through the use of a plasmid replicon isolated from an indigenous C. difficile plasmid, pCD6, and through the characterization and subsequent circumvention of host restriction/modification (RM) systems. The characterized replicon is the first C. difficile plasmid replicon to be sequenced and encodes a large replication protein (RepA) and a repetitive region composed of a 35 bp iteron sequence repeated seven times. Strain CD6 has two RM systems, CdiCD6I/M.CdiCD6I and CdiCD6II/M. CdiCD6II, with equivalent specificities to Sau96I/M. Sau96I (5'-GGNMCC-3') and MboI/M. MboI (5'-GMATC-3') respectively. A second strain (CD3) possesses a type IIs restriction enzyme, Cdi I, which cleaves the sequence 5'-CATCG-3' between the fourth and fifth nucleotide to give a blunt-ended fragment. This is the first time that an enzyme with this specificity has been reported. The sequential addition of this site to vectors showed that each site caused between a five- and 16-fold reduction in transfer efficiency. The transfer efficiencies achieved with both strains equated to between 1.0 x 10-6 and 5.5 x 10-5 transconjugants per donor.

Inhibition of Neuroblastoma Tumor Growth by Ketogenic Diet and/or Calorie Restriction in a CD1-Nu Mouse Model.

Directory of Open Access Journals (Sweden)

Raphael Johannes Morscher

Full Text Available Neuroblastoma is a malignant pediatric cancer derived from neural crest cells. It is characterized by a generalized reduction of mitochondrial oxidative phosphorylation. The goal of the present study was to investigate the effects of calorie restriction and ketogenic diet on neuroblastoma tumor growth and monitor potential adaptive mechanisms of the cancer's oxidative phosphorylation system.Xenografts were established in CD-1 nude mice by subcutaneous injection of two neuroblastoma cell lines having distinct genetic characteristics and therapeutic sensitivity [SH-SY5Y and SK-N-BE(2]. Mice were randomized to four treatment groups receiving standard diet, calorie-restricted standard diet, long chain fatty acid based ketogenic diet or calorie-restricted ketogenic diet. Tumor growth, survival, metabolic parameters and weight of the mice were monitored. Cancer tissue was evaluated for diet-induced changes of proliferation indices and multiple oxidative phosphorylation system parameters (respiratory chain enzyme activities, western blot analysis, immunohistochemistry and mitochondrial DNA content.Ketogenic diet and/or calorie restriction significantly reduced tumor growth and prolonged survival in the xenograft model. Neuroblastoma growth reduction correlated with decreased blood glucose concentrations and was characterized by a significant decrease in Ki-67 and phospho-histone H3 levels in the diet groups with low tumor growth. As in human tumor tissue, neuroblastoma xenografts showed distinctly low mitochondrial complex II activity in combination with a generalized low level of mitochondrial oxidative phosphorylation, validating the tumor model. Neuroblastoma showed no ability to adapt its mitochondrial oxidative phosphorylation activity to the change in nutrient supply induced by dietary intervention.Our data suggest that targeting the metabolic characteristics of neuroblastoma could open a new front in supporting standard therapy regimens

Inhibition of Neuroblastoma Tumor Growth by Ketogenic Diet and/or Calorie Restriction in a CD1-Nu Mouse Model.

Science.gov (United States)

Morscher, Raphael Johannes; Aminzadeh-Gohari, Sepideh; Feichtinger, René Gunther; Mayr, Johannes Adalbert; Lang, Roland; Neureiter, Daniel; Sperl, Wolfgang; Kofler, Barbara

2015-01-01

Neuroblastoma is a malignant pediatric cancer derived from neural crest cells. It is characterized by a generalized reduction of mitochondrial oxidative phosphorylation. The goal of the present study was to investigate the effects of calorie restriction and ketogenic diet on neuroblastoma tumor growth and monitor potential adaptive mechanisms of the cancer's oxidative phosphorylation system. Xenografts were established in CD-1 nude mice by subcutaneous injection of two neuroblastoma cell lines having distinct genetic characteristics and therapeutic sensitivity [SH-SY5Y and SK-N-BE(2)]. Mice were randomized to four treatment groups receiving standard diet, calorie-restricted standard diet, long chain fatty acid based ketogenic diet or calorie-restricted ketogenic diet. Tumor growth, survival, metabolic parameters and weight of the mice were monitored. Cancer tissue was evaluated for diet-induced changes of proliferation indices and multiple oxidative phosphorylation system parameters (respiratory chain enzyme activities, western blot analysis, immunohistochemistry and mitochondrial DNA content). Ketogenic diet and/or calorie restriction significantly reduced tumor growth and prolonged survival in the xenograft model. Neuroblastoma growth reduction correlated with decreased blood glucose concentrations and was characterized by a significant decrease in Ki-67 and phospho-histone H3 levels in the diet groups with low tumor growth. As in human tumor tissue, neuroblastoma xenografts showed distinctly low mitochondrial complex II activity in combination with a generalized low level of mitochondrial oxidative phosphorylation, validating the tumor model. Neuroblastoma showed no ability to adapt its mitochondrial oxidative phosphorylation activity to the change in nutrient supply induced by dietary intervention. Our data suggest that targeting the metabolic characteristics of neuroblastoma could open a new front in supporting standard therapy regimens. Therefore, we propose

Parenting and restrictions in childhood epilepsy

NARCIS (Netherlands)

Rodenburg, R.; Meijer, A.M.; Scherphof, C.; Carpay, J.A.; Augustijn, P.; Aldenkamp, A.P.; Deković, M.

2013-01-01

Purpose: From the overprotection literature, the predictive and interactional (moderation) effects of controlling and indulgent parenting on restrictions in children with epilepsy were examined. Methods: Parents of 73 children with epilepsy completed questionnaires on parenting, restrictions, and

Enzyme structure and interaction with inhibitors

International Nuclear Information System (INIS)

London, R.E.

1983-01-01

This article reviews some of the results of studies on the 13 C-labeled enzyme dihydrofolate reductase (DHFR). Nuclear magnetic resonance (NMR) techniques are used in combination with isotopic labeling to learn about the structure and dynamics of this enzyme. 13 C-labeling is used for the purpose of studying enzyme/substrate and enzyme/inhibitor interactions. A second set of studies with DHFR was designed to investigate the basis for the high affinity between the inhibitor methotrexate and DHFR. The label was placed on the inhibitor, rather than the enzyme

Genotype of metabolic enzymes and the benefit of tamoxifen in postmenopausal breast cancer patients

International Nuclear Information System (INIS)

Wegman, Pia; Vainikka, Linda; Stål, Olle; Nordenskjöld, Bo; Skoog, Lambert; Rutqvist, Lars-Erik; Wingren, Sten

2005-01-01

Tamoxifen is widely used as endocrine therapy for oestrogen-receptor-positive breast cancer. However, many of these patients experience recurrence despite tamoxifen therapy by incompletely understood mechanisms. In the present report we propose that tamoxifen resistance may be due to differences in activity of metabolic enzymes as a result of genetic polymorphism. Cytochrome P450 2D6 (CYP2D6) and sulfotransferase 1A1 (SULT1A1) are polymorphic and are involved in the metabolism of tamoxifen. The CYP2D6*4 and SULT1A1*2 genotypes result in decreased enzyme activity. We therefore investigated the genotypes of CYP2D6 and SULT1A1 in 226 breast cancer patients participating in a trial of adjuvant tamoxifen treatment in order to validate the benefit from the therapy. The patients were genotyped using PCR followed by cleavage with restriction enzymes. Carriers of the CYP2D6*4 allele demonstrated a decreased risk of recurrence when treated with tamoxifen (relative risk = 0.28, 95% confidence interval = 0.11–0.74, P = 0.0089). A similar pattern was seen among the SULT1A1*1 homozygotes (relative risk = 0.48, 95% confidence interval = 0.21–1.12, P = 0.074). The combination of CYP2D6*4 and/or SULT1A1*1/*1 genotypes comprised 60% of the patients and showed a 62% decreased risk of distant recurrence with tamoxifen (relative risk = 0.38, 95% confidence interval = 0.19–0.74, P = 0.0041). The present study suggests that genotype of metabolic enzymes might be useful as a guide for adjuvant endocrine treatment of postmenopausal breast cancer patients. However, results are in contradiction to prior hypotheses and the present sample size is relatively small. Findings therefore need to be confirmed in a larger cohort

Positron emitter labeled enzyme inhibitors

International Nuclear Information System (INIS)

Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.; Langstrom, B.

1990-01-01

This invention involves a new strategy for imagining and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography

Paper sludge (PS) to bioethanol: Evaluation of virgin and recycle mill sludge for low enzyme, high-solids fermentation.

Science.gov (United States)

Boshoff, Sonja; Gottumukkala, Lalitha Devi; van Rensburg, Eugéne; Görgens, Johann

2016-03-01

Paper sludge (PS) from the paper and pulp industry consists primarily of cellulose and ash and has significant potential for ethanol production. Thirty-seven PS samples from 11 South African paper and pulp mills exhibited large variation in chemical composition and resulting ethanol production. Simultaneous saccharification and fermentation (SSF) of PS in fed-batch culture was investigated at high solid loadings and low enzyme dosages. Water holding capacity and viscosity of the PS influenced ethanol production at elevated solid loadings of PS. High viscosity of PS from virgin pulp mills restricted the solid loading to 18% (w/w) at an enzyme dosage of 20 FPU/gram dry PS (gdPS), whereas an optimal solid loading of 27% (w/w) was achieved with corrugated recycle mill PS at 11 FPU/gdPS. Ethanol concentration and yield of virgin pulp and corrugated recycle PS were 34.2g/L at 66.9% and 45.5 g/L at 78.2%, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Compounds from silicones alter enzyme activity in curing barnacle glue and model enzymes.

Science.gov (United States)

Rittschof, Daniel; Orihuela, Beatriz; Harder, Tilmann; Stafslien, Shane; Chisholm, Bret; Dickinson, Gary H

2011-02-17

Attachment strength of fouling organisms on silicone coatings is low. We hypothesized that low attachment strength on silicones is, in part, due to the interaction of surface available components with natural glues. Components could alter curing of glues through bulk changes or specifically through altered enzyme activity. GC-MS analysis of silicone coatings showed surface-available siloxanes when the coatings were gently rubbed with a cotton swab for 15 seconds or given a 30 second rinse with methanol. Mixtures of compounds were found on 2 commercial and 8 model silicone coatings. The hypothesis that silicone components alter glue curing enzymes was tested with curing barnacle glue and with commercial enzymes. In our model, barnacle glue curing involves trypsin-like serine protease(s), which activate enzymes and structural proteins, and a transglutaminase which cross-links glue proteins. Transglutaminase activity was significantly altered upon exposure of curing glue from individual barnacles to silicone eluates. Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents. Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties. Altered curing of natural glues has potential in fouling management.

Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction in People with Obesity.

Science.gov (United States)

Hall, Kevin D; Bemis, Thomas; Brychta, Robert; Chen, Kong Y; Courville, Amber; Crayner, Emma J; Goodwin, Stephanie; Guo, Juen; Howard, Lilian; Knuth, Nicolas D; Miller, Bernard V; Prado, Carla M; Siervo, Mario; Skarulis, Monica C; Walter, Mary; Walter, Peter J; Yannai, Laura

2015-09-01

Dietary carbohydrate restriction has been purported to cause endocrine adaptations that promote body fat loss more than dietary fat restriction. We selectively restricted dietary carbohydrate versus fat for 6 days following a 5-day baseline diet in 19 adults with obesity confined to a metabolic ward where they exercised daily. Subjects received both isocaloric diets in random order during each of two inpatient stays. Body fat loss was calculated as the difference between daily fat intake and net fat oxidation measured while residing in a metabolic chamber. Whereas carbohydrate restriction led to sustained increases in fat oxidation and loss of 53 ± 6 g/day of body fat, fat oxidation was unchanged by fat restriction, leading to 89 ± 6 g/day of fat loss, and was significantly greater than carbohydrate restriction (p = 0.002). Mathematical model simulations agreed with these data, but predicted that the body acts to minimize body fat differences with prolonged isocaloric diets varying in carbohydrate and fat. Copyright © 2015 Elsevier Inc. All rights reserved.

Prediction of Wild-type Enzyme Characteristics

DEFF Research Database (Denmark)

Geertz-Hansen, Henrik Marcus

of biotechnology, including enzyme discovery and characterization. This work presents two articles on sequence-based discovery and functional annotation of enzymes in environmental samples, and two articles on analysis and prediction of enzyme thermostability and cofactor requirements. The first article presents...... a sequence-based approach to discovery of proteolytic enzymes in metagenomes obtained from the Polar oceans. We show that microorganisms living in these extreme environments of constant low temperature harbour genes encoding novel proteolytic enzymes with potential industrial relevance. The second article...... presents a web server for the processing and annotation of functional metagenomics sequencing data, tailored to meet the requirements of non-bioinformaticians. The third article presents analyses of the molecular determinants of enzyme thermostability, and a feature-based prediction method of the melting...

Therapeutic Enzymes: Applications and Approaches to Pharmacological Improvement.

Science.gov (United States)

Yari, Maryam; Ghoshoon, Mohammad B; Vakili, Bahareh; Ghasemi, Younes

2017-01-01

Among therapeutic proteins, enzymes represent small and of course profitable market. They can be used to treat important, rare, and deadly diseases. Enzyme therapy is the only available treatment for certain disorders. Here, pharmaceutical enzymes are reviewed. They are categorized in four main groups, enzymes in replacement therapy, enzymes in cancer treatment, enzymes for fibrinolysis, and finally enzymes that are used topically for various treatments. Furthermore, enzyme gene therapy and future perspective of therapeutic enzymes are mentioned in brief. There are many important approved enzymes in pharmaceutical market. Several approaches such as point mutation, fusion protein designing, glycoengineering, and PEGylation were used to achieve improved enzymes. Although sometimes enzymes were engineered to facilitate production and purification process, appropriate delivery to target sites, extending half-life, and reducing immunogenicity are among the main goals of engineering approaches. Overall, enzymes play a critical role in treatment of common and rare diseases. Evaluation of new enzymes as well as improvement of approved enzymes are of the most important challenges in biotechnology. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Immobilized enzyme reactor chromatography: Optimization of protein retention and enzyme activity in monolithic silica stationary phases

International Nuclear Information System (INIS)

Besanger, Travis R.; Hodgson, Richard J.; Green, James R.A.; Brennan, John D.

2006-01-01

Our group recently reported on the application of protein-doped monolithic silica columns for immobilized enzyme reactor chromatography, which allowed screening of enzyme inhibitors present in mixtures using mass spectrometry for detection. The enzyme was immobilized by entrapment within a bimodal meso/macroporous silica material prepared by a biocompatible sol-gel processing route. While such columns proved to be useful for applications such as screening of protein-ligand interactions, significant amounts of entrapped proteins leached from the columns owing to the high proportion of macropores within the materials. Herein, we describe a detailed study of factors affecting the morphology of protein-doped bioaffinity columns and demonstrate that specific pH values and concentrations of poly(ethylene glycol) can be used to prepare essentially mesoporous columns that retain over 80% of initially loaded enzyme in an active and accessible form and yet still retain sufficient porosity to allow pressure-driven flow in the low μL/min range. Using the enzyme γ-glutamyl transpeptidase (γ-GT), we further evaluated the catalytic constants of the enzyme entrapped in capillary columns with different silica morphologies as a function of flowrate and backpressure using the enzyme reactor assay mode. It was found that the apparent activity of the enzyme was highest in mesoporous columns that retained high levels of enzyme. In such columns, enzyme activity increased by ∼2-fold with increases in both flowrate (from 250 to 1000 nL/min) and backpressure generated (from 500 to 2100 psi) during the chromatographic activity assay owing to increases in k cat and decreases in K M , switching from diffusion controlled to reaction controlled conditions at ca. 2000 psi. These results suggest that columns with minimal macropore volumes (<5%) are advantageous for the entrapment of soluble proteins for bioaffinity and bioreactor chromatography

Association of maternal and umbilical cord blood leptin concentrations and abnormal color Doppler indices of umbilical artery with fetal growth restriction

Directory of Open Access Journals (Sweden)

Elahe Zareaan

2017-08-01

Full Text Available Background: Fetal growth restriction (FGR is a condition with heterogeneous pathophysiology which characterized by fetal weight less than the tenth percentile for gestational age. Several factors have impact on maternal, placental and fetal due to growth restriction. Objective: The aim of this study was to investigate the relationship between levels of leptin in the cord, and serum leptin of mothers also abnormal color Doppler indices of umbilical artery with fetal growth restriction. Materials and Methods: This is a cross sectional study conducted in Isfahan, Iran, 2015-2016. We recruited 40 women with singleton pregnancies complicated by fetal growth restriction (Group I and 40 pregnant women with normal fetal growth (Group II with matched age. Maternal serum and umbilical artery leptin levels were determined with Enzyme-Linked immunosorben method. Also, color Doppler ultrasound of umbilical artery was performed. Results: Mean maternal and fetal leptin levels were lower in the FGR group compared to the normal group (36.58±(20.99 and 7.42 ±(4.08vs. 47.32±(22.50 and 30.49±(14.50 respectively. Also, mean fetal leptin level was lower in the group with abnormal color Doppler sonographic indices compared to the normal group (7. 40 ±(4.10vs 27.06±(15.80, respectively. Conclusion: This study indicated that maternal and fetal leptin levels are correlated with FGR originating from damaged placental function; also fetal leptin level can indicate changes in color Doppler sonographic indices.

Toward mechanistic classification of enzyme functions.

Science.gov (United States)

Almonacid, Daniel E; Babbitt, Patricia C

2011-06-01

Classification of enzyme function should be quantitative, computationally accessible, and informed by sequences and structures to enable use of genomic information for functional inference and other applications. Large-scale studies have established that divergently evolved enzymes share conserved elements of structure and common mechanistic steps and that convergently evolved enzymes often converge to similar mechanisms too, suggesting that reaction mechanisms could be used to develop finer-grained functional descriptions than provided by the Enzyme Commission (EC) system currently in use. Here we describe how evolution informs these structure-function mappings and review the databases that store mechanisms of enzyme reactions along with recent developments to measure ligand and mechanistic similarities. Together, these provide a foundation for new classifications of enzyme function. Copyright © 2011 Elsevier Ltd. All rights reserved.

Production of Enzymes from Marine Actinobacteria.

Science.gov (United States)

Zhao, X Q; Xu, X N; Chen, L Y

Marine actinobacteria are well recognized for their capabilities to produce valuable natural products, which have great potential for applications in medical, agricultural, and fine chemical industries. In addition to producing unique enzymes responsible for biosynthesis of natural products, many marine actinobacteria also produce hydrolytic enzymes which are able to degrade various biopolymers, such as cellulose, xylan, and chitin. These enzymes are important to produce biofuels and biochemicals of interest from renewable biomass. In this chapter, the recent reports of novel enzymes produced by marine actinobacteria are reviewed, and advanced technologies that can be applied to search for novel marine enzymes as well as for improved enzyme production by marine actinobacteria are summarized, which include ribosome engineering, genome mining, as well as synthetic biology studies. © 2016 Elsevier Inc. All rights reserved.

Evolutionary genomics and HIV restriction factors.

Science.gov (United States)

Pyndiah, Nitisha; Telenti, Amalio; Rausell, Antonio

2015-03-01

To provide updated insights into innate antiviral immunity and highlight prototypical evolutionary features of well characterized HIV restriction factors. Recently, a new HIV restriction factor, Myxovirus resistance 2, has been discovered and the region/residue responsible for its activity identified using an evolutionary approach. Furthermore, IFI16, an innate immunity protein known to sense several viruses, has been shown to contribute to the defense to HIV-1 by causing cell death upon sensing HIV-1 DNA. Restriction factors against HIV show characteristic signatures of positive selection. Different patterns of accelerated sequence evolution can distinguish antiviral strategies--offense or defence--as well as the level of specificity of the antiviral properties. Sequence analysis of primate orthologs of restriction factors serves to localize functional domains and sites responsible for antiviral action. We use recent discoveries to illustrate how evolutionary genomic analyses help identify new antiviral genes and their mechanisms of action.

Activity restriction among women with a short cervix.

Science.gov (United States)

Grobman, William A; Gilbert, Sharon A; Iams, Jay D; Spong, Catherine Y; Saade, George; Mercer, Brian M; Tita, Alan T N; Rouse, Dwight J; Sorokin, Yoram; Leveno, Kenneth J; Tolosa, Jorge E; Thorp, John M; Caritis, Steve N; Van Dorsten, J Peter

2013-06-01

To estimate determinants of and outcomes associated with activity restriction among women with a short cervix. This was a secondary analysis of a randomized trial of 17-α hydroxyprogesterone caproate for prevention of preterm birth among nulliparous women with singleton gestations and cervices less than 30 mm by midtrimester ultrasonography. Women were asked weekly whether they had been placed on pelvic, work, or nonwork rest. "Any activity restriction" was defined as being placed on any type of rest. Factors associated with any activity restriction were determined and the association between preterm birth and activity restriction was estimated with multivariable logistic regression. Of the 657 women in the trial, 646 (98%) responded to questions regarding activity restriction. Two hundred fifty-two (39.0%) were placed on any activity restriction at a median of 23.9 weeks (interquartile range 22.6-27.9 weeks). Women on activity restriction were older, more likely to have private insurance, less likely to be Hispanic, had a shorter cervical length, and were more likely to have funneling and intra-amniotic debris. Preterm birth at less than 37 weeks of gestation was more common among women placed on activity restriction (37% compared with 17%, Prestriction (adjusted odds ratio 2.37, 95% confidence interval 1.60-3.53). Results were similar for preterm birth at less than 34 weeks of gestation. Activity restriction did not reduce the rate of preterm birth in asymptomatic nulliparous women with a short cervix.

Restriction fragment length polymorphism of the HLA-DP subregion and correlations to HLA-DP phenotypes

International Nuclear Information System (INIS)

Hyldig-Nielsen, J.J.; Morling, N.; Oedum, N.; Ryder, L.P.; Platz, P.; Jakobsen, B.; Svejgaard, A.

1987-01-01

The restriction fragment length polymorphism (RFLP) of the class II HLA-DP subregion of the major histocompatibility complex (MHC) of humans has been unraveled by Southern blotting using DP/sub α/ and DP/sub β/ probes in a study of 46 unrelated individuals with known HLA-DP types. Contrary to earlier preliminary findings with a limited number of enzymes, the RFLP appears to be quite extensive both with the DP/sub β/ (14 different DNA markers defined by individual fragments or clusters thereof) and the DP/sub α/ (8 markers) probes, especially when enzyme recognizing only four base pairs were used. A few markers were absolutely or strongly associated with individual DP antigens, whereas most were associated with two or more DP antigens as defined by primed lymphocyte typing. Thus, Southern blotting seems feasible for typing for most DP determinants by specific fragments or subtraction between the various more broadly reactive DNA markers, and the RFLP provides further information on the DP subregion in addition to that provided by primed lymphocyte typing. In two recombinant families, the DP/sub β/ and DP/sub α/ DNA markers segregated with DP antigens, whereas the DR/sub β/, DQ/sub β/, DQ/sub α/, and DX/sub α/ markers followed the DR and DQ antigens

Zymography methods for visualizing hydrolytic enzymes

OpenAIRE

Vandooren, Jennifer; Geurts, Nathalie; Martens, Erik; Van den Steen, Philippe E.; Opdenakker, Ghislain

2013-01-01

Zymography is a technique for studying hydrolytic enzymes on the basis of substrate degradation. It is a powerful., but often misinterpreted, tool. yielding information on potential. hydrolytic activities, enzyme forms and the locations of active enzymes. In this Review, zymography techniques are compared in terms of advantages, limitations and interpretations. With in gel zymography, enzyme forms are visualized according to their molecular weights. Proteolytic activities are localized in tis...

Analysis of soil microbial community structure and enzyme activities associated with negative effects of pseudostellaria heterophylla consecutive monoculture on yield

International Nuclear Information System (INIS)

Lin, S.; Lin, W.X.

2015-01-01

Pseudostellaria heterophylla is an important medicinal plant in China. However, cultivation of P. heterophylla using consecutive monoculture results in significant reductions in yield and quality. In this study, terminal-restriction fragment length polymorphism (T-RFLP) analysis and measurement of soil enzyme activities were used to investigate the regulation of soil micro-ecology to identify ways to overcome the negative effects of P. heterophylla consecutive monoculture. T-RFLP analysis showed that rice/P. heterophylla (RP) and bean/P. heterophylla (BP) crop rotation systems increased the number and diversity of microbial groups in P. heterophylla rhizosphere soil. In particular, the RP and BP crop rotations increased the number and abundance of beneficial bacterial species compared with two-year consecutive monoculture of P. heterophylla. The presence of these beneficial bacteria was positively correlated with soil enzyme activities which increased in rhizosphere soils of the RP and BP crop rotation systems. The results indicated that crop rotation systems could increase activities of key soil enzymes and beneficial microbial groups and improve soil health. This study could provide a theoretical basis to resolve the problems associated with P. heterophylla consecutive monoculture. (author)

Studies on the enzymes produced by Basidiomycetes. Part 1. The production of crude enzymes

Energy Technology Data Exchange (ETDEWEB)

Hong, J. S.; Kim, D.H.

1981-01-01

Cellulase, protease, and xylanase, formation by the basidiomycetes, Pleurotus ostreatus 301 and Lentinus edodes 3-1 in growth on rice straw medium were studied. Cultural conditions adequate for enzyme production and effects of various materials and inorganic salts added to the rice straw media were investigated. Lentinus edodes 3-1 was an excellent producer of cellulase and xylanase, and Pleurotus ostreatus 301 of protease. The optimum conditions for enzyme production were 30 degrees for cellulase production and at 25 degrees for xylanase and protease production, with 75% moisture content and initial pH of 5.0-6.0. The appropriate incubation times for enzyme production were 30 days and 35 days for Pleurotus ostreatus 301 and Lentinus edodes 3-1, respectively. Among the various materials added, defatted soybean, defatted rape seed, or defatted sesame were all effective in enzyme production but reduced mycelial growth. Rice bran was also effective, particularly at a 30% concentration. The addition of inorganic salts enhanced enzyme production. Among inorganic salts, the optimum concentration of CaCO3 was 5%, and that of CaSO4 was 2%.

Multi-enzyme Process Modeling

DEFF Research Database (Denmark)

Andrade Santacoloma, Paloma de Gracia

are affected (in a positive or negative way) by the presence of the other enzymes and compounds in the media. In this thesis the concept of multi-enzyme in-pot term is adopted for processes that are carried out by the combination of enzymes in a single reactor and implemented at pilot or industrial scale...... features of the process and provides the information required to structure the process model by using a step-by-step procedure with the required tools and methods. In this way, this framework increases efficiency of the model development process with respect to time and resources needed (fast and effective....... In this way the model parameters that drives the main dynamic behavior can be identified and thus a better understanding of this type of processes. In order to develop, test and verify the methodology, three case studies were selected, specifically the bi-enzyme process for the production of lactobionic acid...

Photoperiodism and Enzyme Activity

Science.gov (United States)

Queiroz, Orlando; Morel, Claudine

1974-01-01

Metabolic readjustments after a change from long days to short days appear, in Kalanchoe blossfeldiana, to be achieved through the operation of two main mechanisms: variation in enzyme capacity, and circadian rhythmicity. After a lag time, capacity in phosphoenolpyruvate carboxylase and capacity in aspartate aminotransferase increase exponentially and appear to be allometrically linked during 50 to 60 short days; then a sudden fall takes place in the activity of the former. Malic enzyme and alanine aminotransferase behave differently. Thus, the operation of the two sections of the pathway (before and after the malate step) give rise to a continuously changing functional compartmentation in the pathway. Circadian rhythmicity, on the other hand, produces time compartmentation through phase shifts and variation in amplitude, independently for each enzyme. These characteristics suggest that the operation of a so-called biological clock would be involved. We propose the hypothesis that feedback regulation would be more accurate and efficient when applied to an already oscillating, clock-controlled enzyme system. PMID:16658749

Descriptive and predictive assessment of enzyme activity and enzyme related processes in biorefinery using IR spectroscopy and chemometrics

DEFF Research Database (Denmark)

Baum, Andreas

the understanding of the structural properties of the extracted pectin. Secondly, enzyme kinetics of biomass converting enzymes was examined in terms of measuring enzyme activity by spectral evolution profiling utilizing FTIR. Chemometric multiway methods were used to analyze the tensor datasets enabling the second......-order calibration advantage (reference Theory of Analytical chemistry). As PAPER 3 illustrates the method is universally applicable without the need of any external standards and was exemplified by performing quantitative enzyme activity determinations for glucose oxidase, pectin lyase and a cellolytic enzyme blend...... (Celluclast 1.5L). In PAPER 4, the concept is extended to quantify enzyme activity of two simultaneously acting enzymes, namely pectin lyase and pectin methyl esterase. By doing so the multiway methods PARAFAC, TUCKER3 and NPLS were compared and evaluated towards accuracy and precision....

Engineering of GlcNAc-1-Phosphotransferase for Production of Highly Phosphorylated Lysosomal Enzymes for Enzyme Replacement Therapy.

Science.gov (United States)

Liu, Lin; Lee, Wang-Sik; Doray, Balraj; Kornfeld, Stuart

2017-06-16

Several lysosomal enzymes currently used for enzyme replacement therapy in patients with lysosomal storage diseases contain very low levels of mannose 6-phosphate, limiting their uptake via mannose 6-phosphate receptors on the surface of the deficient cells. These enzymes are produced at high levels by mammalian cells and depend on endogenous GlcNAc-1-phosphotransferase α/β precursor to phosphorylate the mannose residues on their glycan chains. We show that co-expression of an engineered truncated GlcNAc-1-phosphotransferase α/β precursor and the lysosomal enzyme of interest in the producing cells resulted in markedly increased phosphorylation and cellular uptake of the secreted lysosomal enzyme. This method also results in the production of highly phosphorylated acid β-glucocerebrosidase, a lysosomal enzyme that normally has just trace amounts of this modification.

Evaluation of pressure tuning of enzymes

DEFF Research Database (Denmark)

Naghshineh, Mahsa

and high energy consumption. Therefore, searching for an environmentally friendly method of pectin extraction is a task for science and industry. Employment of hydrolytic enzymes may represent a green approach to obtain intact pectin polymer. However, the low stability/activity of enzymes, and low polymer...... yield of enzymatic extraction limits the application of enzyme in pectin production. There is evidence that emerging technology of high hydrostatic pressure processing can result in stabilization and activation of some enzymes. Therefore, the use of high hydrostatic pressure in combination with enzyme...... (cellulase/xylanase: 50/0, 50/25, 50/50, 25/50, and 0/50 U/g lime peel) at ambient pressure, 100 and 200 MPa were used to extract pectin from dried lime peel waste. It was found that pressure level, type and concentration of enzyme significantly influenced pectin yield and degree of esterification (DE...

Photoreactivating enzyme from Escherichia coli

International Nuclear Information System (INIS)

Snapka, R.M.; Fuselier, C.O.

1977-01-01

Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm. (author)

Practical steady-state enzyme kinetics.

Science.gov (United States)

Lorsch, Jon R

2014-01-01

Enzymes are key components of most biological processes. Characterization of enzymes is therefore frequently required during the study of biological systems. Steady-state kinetics provides a simple and rapid means of assessing the substrate specificity of an enzyme. When combined with site-directed mutagenesis (see Site-Directed Mutagenesis), it can be used to probe the roles of particular amino acids in the enzyme in substrate recognition and catalysis. Effects of interaction partners and posttranslational modifications can also be assessed using steady-state kinetics. This overview explains the general principles of steady-state enzyme kinetics experiments in a practical, rather than theoretical, way. Any biochemistry textbook will have a section on the theory of Michaelis-Menten kinetics, including derivations of the relevant equations. No specific enzymatic assay is described here, although a method for monitoring product formation or substrate consumption over time (an assay) is required to perform the experiments described. © 2014 Elsevier Inc. All rights reserved.

Photoreactivating enzyme from Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Snapka, R M; Fuselier, C O [California Univ., Irvine (USA)

1977-05-01

Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm.

Enzymes for Enhanced Oil Recovery (EOR)

Energy Technology Data Exchange (ETDEWEB)

Nasiri, Hamidreza

2011-04-15

Primary oil recovery by reservoir pressure depletion and secondary oil recovery by waterflooding usually result in poor displacement efficiency. As a consequence there is always some trapped oil remaining in oil reservoirs. Oil entrapment is a result of complex interactions between viscous, gravity and capillary forces. Improving recovery from hydrocarbon fields typically involves altering the relative importance of the viscous and capillary forces. The potential of many EOR methods depends on their influence on fluid/rock interactions related to wettability and fluid/fluid interactions reflected in IFT. If the method has the potential to change the interactions favorably, it may be considered for further investigation, i.e. core flooding experiment, pilot and reservoir implementation. Enzyme-proteins can be introduced as an enhanced oil recovery method to improve waterflood performance by affecting interactions at the oil-water-rock interfaces. An important part of this thesis was to investigate how selected enzymes may influence wettability and capillary forces in a crude oil-brine-rock system, and thus possibly contribute to enhanced oil recovery. To investigate further by which mechanisms selected enzyme-proteins may contribute to enhance oil recovery, groups of enzymes with different properties and catalytic functions, known to be interfacially active, were chosen to cover a wide range of possible effects. These groups include (1) Greenzyme (GZ) which is a commercial EOR enzyme and consists of enzymes and stabilizers (surfactants), (2) The Zonase group consists of two types of pure enzyme, Zonase1 and Zonase2 which are protease enzymes and whose catalytic functions are to hydrolyze (breakdown) peptide bonds, (3) The Novozyme (NZ) group consists of three types of pure enzyme, NZ2, NZ3 and NZ6 which are esterase enzymes and whose catalytic functions are to hydrolyze ester bonds, and (4) Alpha-Lactalbumin ( -La) which is an important whey protein. The effect of

Cellular Restriction Factors of Feline Immunodeficiency Virus

Science.gov (United States)

Zielonka, Jörg; Münk, Carsten

2011-01-01

Lentiviruses are known for their narrow cell- and species-tropisms, which are determined by cellular proteins whose absence or presence either support viral replication (dependency factors, cofactors) or inhibit viral replication (restriction factors). Similar to Human immunodeficiency virus type 1 (HIV-1), the cat lentivirus Feline immunodeficiency virus (FIV) is sensitive to recently discovered cellular restriction factors from non-host species that are able to stop viruses from replicating. Of particular importance are the cellular proteins APOBEC3, TRIM5α and tetherin/BST-2. In general, lentiviruses counteract or escape their species’ own variant of the restriction factor, but are targeted by the orthologous proteins of distantly related species. Most of the knowledge regarding lentiviral restriction factors has been obtained in the HIV-1 system; however, much less is known about their effects on other lentiviruses. We describe here the molecular mechanisms that explain how FIV maintains its replication in feline cells, but is largely prevented from cross-species infections by cellular restriction factors. PMID:22069525

HIV-related travel restrictions: trends and country characteristics.

Science.gov (United States)

Chang, Felicia; Prytherch, Helen; Nesbitt, Robin C; Wilder-Smith, Annelies

2013-06-03

Increasingly, HIV-seropositive individuals cross international borders. HIV-related restrictions on entry, stay, and residence imposed by countries have important consequences for this mobile population. Our aim was to describe the geographical distribution of countries with travel restrictions and to examine the trends and characteristics of countries with such restrictions. In 2011, data presented to UNAIDS were used to establish a list of countries with and without HIV restrictions on entry, stay, and residence and to describe their geographical distribution. The following indicators were investigated to describe the country characteristics: population at mid-year, international migrants as a percentage of the population, Human Development Index, estimated HIV prevalence (age: 15-49), presence of a policy prohibiting HIV screening for general employment purposes, government and civil society responses to having non-discrimination laws/regulations which specify migrants/mobile populations, government and civil society responses to having laws/regulations/policies that present obstacles to effective HIV prevention, treatment, care, and support for migrants/mobile populations, Corruption Perception Index, and gross national income per capita. HIV-related restrictions exist in 45 out of 193 WHO countries (23%) in all regions of the world. We found that the Eastern Mediterranean and Western Pacific Regions have the highest proportions of countries with these restrictions. Our analyses showed that countries that have opted for restrictions have the following characteristics: smaller populations, higher proportions of migrants in the population, lower HIV prevalence rates, and lack of legislation protecting people living with HIV from screening for employment purposes, compared with countries without restrictions. Countries with a high proportion of international migrants tend to have travel restrictions - a finding that is relevant to migrant populations and travel

Eclampsia despite strict dietary sodium restriction.

NARCIS (Netherlands)

Delemarre, F.M.C.; Steegers, E.A.P.; Berendes, J.N.

2001-01-01

The classic indication for prescribing dietary sodium restriction in pregnancy has been the prevention of eclampsia. We describe a case of intrapartum eclampsia in a 24-year-old nulliparous woman. A strongly sodium restricted diet was prescribed because of pre-eclampsia. Compliance to the diet was

7 CFR 3430.205 - Funding restrictions.

Science.gov (United States)

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Funding restrictions. 3430.205 Section 3430.205... Funding restrictions. (a) Prohibition against construction. Funds made available under this subpart shall not be used for the construction of a new building or facility or the acquisition, expansion...

A statistical mechanical approach to restricted integer partition functions

Science.gov (United States)

Zhou, Chi-Chun; Dai, Wu-Sheng

2018-05-01

The main aim of this paper is twofold: (1) suggesting a statistical mechanical approach to the calculation of the generating function of restricted integer partition functions which count the number of partitions—a way of writing an integer as a sum of other integers under certain restrictions. In this approach, the generating function of restricted integer partition functions is constructed from the canonical partition functions of various quantum gases. (2) Introducing a new type of restricted integer partition functions corresponding to general statistics which is a generalization of Gentile statistics in statistical mechanics; many kinds of restricted integer partition functions are special cases of this restricted integer partition function. Moreover, with statistical mechanics as a bridge, we reveal a mathematical fact: the generating function of restricted integer partition function is just the symmetric function which is a class of functions being invariant under the action of permutation groups. Using this approach, we provide some expressions of restricted integer partition functions as examples.

Study of vitamin D serum level in patients with epilepsy treated with enzyme-inducing and non enzyme-inducing medications

Directory of Open Access Journals (Sweden)

sima Hashemipour

2014-01-01

Full Text Available Background : Changes of serum minerals and vitamin D have been reported in anticonvulsant drugs user patients. The present study aimed at comparing the changes of serum minerals and vitamin D among two groups of enzyme-inducing and non enzyme-inducing anticonvulsant drug users. Methods: In this study 22 patients treated with enzyme-inducing drugs (carbamazepin, phenytoin, phenobarbital were compared to 25 patients of matched sex, age, and BMI treated with non enzyme-inducing drugs (sodium evaporate, lamotrigine. Serum calcium, phosphate, parathormone, and 25-hydroxy vitamin D were calculated in both groups. Calcium was measured by Calorimetery method. Parathormone and vitamin D were measured using ELISA method. Results: The mean serum vitamin D level was lower in enzyme-inducing than non enzyme-inducing drugs users (15.9±8.3 and 24.2±14.8, P=0.02. Frequency of vitamin D deficiency was higher in enzyme-inducing compared to non enzyme-inducing drugs users, 84% and 48% , respectively (P=0.016. The mean serum calcium level was significantly lower in enzyme-inducing drugs users. (8.7±0.2 vs. 9.0± 0.7, p= 0.05. Four percent in enzyme-inducing group compared to twenty four percent of non enzyme-inducing group had secondary hyperparathyroidism (P=0.016. Conclusion: While vitamin D deficiency is more frequent in enzyme-inducing drug users, secondary hyperparathyroidism is less frequent.

Molecular determinants of enzyme cold adaptation: comparative structural and computational studies of cold- and warm-adapted enzymes.

Science.gov (United States)

Papaleo, Elena; Tiberti, Matteo; Invernizzi, Gaetano; Pasi, Marco; Ranzani, Valeria

2011-11-01

The identification of molecular mechanisms underlying enzyme cold adaptation is a hot-topic both for fundamental research and industrial applications. In the present contribution, we review the last decades of structural computational investigations on cold-adapted enzymes in comparison to their warm-adapted counterparts. Comparative sequence and structural studies allow the definition of a multitude of adaptation strategies. Different enzymes carried out diverse mechanisms to adapt to low temperatures, so that a general theory for enzyme cold adaptation cannot be formulated. However, some common features can be traced in dynamic and flexibility properties of these enzymes, as well as in their intra- and inter-molecular interaction networks. Interestingly, the current data suggest that a family-centered point of view is necessary in the comparative analyses of cold- and warm-adapted enzymes. In fact, enzymes belonging to the same family or superfamily, thus sharing at least the three-dimensional fold and common features of the functional sites, have evolved similar structural and dynamic patterns to overcome the detrimental effects of low temperatures.

Flavourzyme, an Enzyme Preparation with Industrial Relevance: Automated Nine-Step Purification and Partial Characterization of Eight Enzymes.

Science.gov (United States)

Merz, Michael; Eisele, Thomas; Berends, Pieter; Appel, Daniel; Rabe, Swen; Blank, Imre; Stressler, Timo; Fischer, Lutz

2015-06-17

Flavourzyme is sold as a peptidase preparation from Aspergillus oryzae. The enzyme preparation is widely and diversely used for protein hydrolysis in industrial and research applications. However, detailed information about the composition of this mixture is still missing due to the complexity. The present study identified eight key enzymes by mass spectrometry and partially by activity staining on native polyacrylamide gels or gel zymography. The eight enzymes identified were two aminopeptidases, two dipeptidyl peptidases, three endopeptidases, and one α-amylase from the A. oryzae strain ATCC 42149/RIB 40 (yellow koji mold). Various specific marker substrates for these Flavourzyme enzymes were ascertained. An automated, time-saving nine-step protocol for the purification of all eight enzymes within 7 h was designed. Finally, the purified Flavourzyme enzymes were biochemically characterized with regard to pH and temperature profiles and molecular sizes.

How Harmful are Adaptation Restrictions

OpenAIRE

Bruin, de, K.C.; Dellink, R.B.

2009-01-01

The dominant assumption in economic models of climate policy remains that adaptation will be implemented in an optimal manner. There are, however, several reasons why optimal levels of adaptation may not be attainable. This paper investigates the effects of suboptimal levels of adaptation, i.e. adaptation restrictions, on the composition and level of climate change costs and on welfare. Several adaptation restrictions are identified and then simulated in a revised DICE model, extended with ad...

Monovalent Cation Activation of the Radical SAM Enzyme Pyruvate Formate-Lyase Activating Enzyme.

Science.gov (United States)

Shisler, Krista A; Hutcheson, Rachel U; Horitani, Masaki; Duschene, Kaitlin S; Crain, Adam V; Byer, Amanda S; Shepard, Eric M; Rasmussen, Ashley; Yang, Jian; Broderick, William E; Vey, Jessica L; Drennan, Catherine L; Hoffman, Brian M; Broderick, Joan B

2017-08-30

Pyruvate formate-lyase activating enzyme (PFL-AE) is a radical S-adenosyl-l-methionine (SAM) enzyme that installs a catalytically essential glycyl radical on pyruvate formate-lyase. We show that PFL-AE binds a catalytically essential monovalent cation at its active site, yet another parallel with B 12 enzymes, and we characterize this cation site by a combination of structural, biochemical, and spectroscopic approaches. Refinement of the PFL-AE crystal structure reveals Na + as the most likely ion present in the solved structures, and pulsed electron nuclear double resonance (ENDOR) demonstrates that the same cation site is occupied by 23 Na in the solution state of the as-isolated enzyme. A SAM carboxylate-oxygen is an M + ligand, and EPR and circular dichroism spectroscopies reveal that both the site occupancy and the identity of the cation perturb the electronic properties of the SAM-chelated iron-sulfur cluster. ENDOR studies of the PFL-AE/[ 13 C-methyl]-SAM complex show that the target sulfonium positioning varies with the cation, while the observation of an isotropic hyperfine coupling to the cation by ENDOR measurements establishes its intimate, SAM-mediated interaction with the cluster. This monovalent cation site controls enzyme activity: (i) PFL-AE in the absence of any simple monovalent cations has little-no activity; and (ii) among monocations, going down Group 1 of the periodic table from Li + to Cs + , PFL-AE activity sharply maximizes at K + , with NH 4 + closely matching the efficacy of K + . PFL-AE is thus a type I M + -activated enzyme whose M + controls reactivity by interactions with the cosubstrate, SAM, which is bound to the catalytic iron-sulfur cluster.

48 CFR 552.203-71 - Restriction on Advertising.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Restriction on Advertising... Restriction on Advertising. As prescribed in 503.570-2, insert the following clause: Restriction on Advertising (SEP 1999) The Contractor shall not refer to this contract in commercial advertising or similar...

Magnetic cross-linked enzyme aggregates (CLEAs): a novel concept towards carrier free immobilization of lignocellulolytic enzymes.

Science.gov (United States)

Bhattacharya, Abhishek; Pletschke, Brett I

2014-01-01

The enzymatic conversion of lignocellulosic biomass into biofuels has been identified as an excellent strategy to generate clean energy. However, the current process is cost-intensive as an effective immobilization approach to reuse the enzyme(s) has been a major challenge. The present study introduces the concept and application of novel magnetic cross-linked enzyme aggregates (mag-CLEAs). Both mag-CLEAs and calcium-mag-CLEAs (Ca-mag-CLEAs) exhibited a 1.35 fold higher xylanase activity compared to the free enzyme and retained more than 80.0% and 90.0% activity, respectively, after 136h of incubation at 50°C, compared to 50% activity retained by CLEAs. A 7.4 and 9.0 fold higher sugar release from lime-pretreated and NH4OH pre-treated sugar bagasse, respectively, was achieved with Ca-mag-CLEAs compared to the free enzymes. The present study promotes the successful application of mag-CLEAs and Ca-mag-CLEAs as carrier free immobilized enzymes for the effective hydrolysis of lignocellulolytic biomass and associated biofuel feedstocks. Copyright © 2014 Elsevier Inc. All rights reserved.

Investigation of restricted baby Skyrme models

International Nuclear Information System (INIS)

Adam, C.; Romanczukiewicz, T.; Wereszczynski, A.; Sanchez-Guillen, J.

2010-01-01

A restriction of the baby Skyrme model consisting of the quartic and potential terms only is investigated in detail for a wide range of potentials. Further, its properties are compared with those of the corresponding full baby Skyrme models. We find that topological (charge) as well as geometrical (nucleus/shell shape) features of baby Skyrmions are captured already by the soliton solutions of the restricted model. Further, we find a coincidence between the compact or noncompact nature of solitons in the restricted model, on the one hand, and the existence or nonexistence of multi-Skyrmions in the full baby Skyrme model, on the other hand.

21 CFR 864.9400 - Stabilized enzyme solution.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stabilized enzyme solution. 864.9400 Section 864... and Blood Products § 864.9400 Stabilized enzyme solution. (a) Identification. A stabilized enzyme... enzyme solutions include papain, bromelin, ficin, and trypsin. (b) Classification. Class II (performance...

Castor Oil Transesterification Catalysed by Liquid Enzymes

DEFF Research Database (Denmark)

Andrade, Thalles; Errico, Massimiliano; Christensen, Knud Villy

2017-01-01

In the present work, biodiesel production by reaction of non-edible castor oil with methanol under enzymatic catalysis is investigated. Two liquid enzymes were tested: Eversa Transform and Resinase HT. Reactions were performed at 35 °C and with a molar ratio of methanol to oil of 6:1. The reaction...... time was 8 hours. Stepwise addition of methanol was necessary to avoid enzyme inhibition by methanol. In order to minimize the enzyme costs, the influence of enzyme activity loss during reuse of both enzymes was evaluated under two distinct conditions. In the former, the enzymes were recovered...... and fully reused; in the latter, a mixture of 50 % reused and 50 % fresh enzymes was tested. In the case of total reuse after three cycles, both enzymes achieved only low conversions. The biodiesel content in the oil-phase using Eversa Transform was 94.21 % for the first cycle, 68.39 % in the second, and 33...

A virus-based single-enzyme nanoreactor

NARCIS (Netherlands)

Comellas Aragones, M.; Engelkamp, H.; Claessen, V.I.; Sommerdijk, N.A.J.M.; Rowan, A.E.; Christianen, P.C.M.; Maan, J.C.; Verduin, B.J.M.; Cornelissen, J.J.L.M.; Nolte, R.J.M.

2007-01-01

Most enzyme studies are carried out in bulk aqueous solution, at the so-called ensemble level, but more recently studies have appeared in which enzyme activity is measured at the level of a single molecule, revealing previously unseen properties. To this end, enzymes have been chemically or

PROCESS FOR DUST-FREE ENZYME MANUFACTURE

NARCIS (Netherlands)

Andela, C.; Feijen, Jan; Dillissen, Marc

1994-01-01

New enzyme granules are provided with improved properties. The granules are based on core particles having a good pore size and pore size distribution to allow an enzyme solution to enter into the particle. Accordingly, the core material comprises the enzyme in liquid form, thus eliminating the

Applications of Microbial Enzymes in Food Industry

Directory of Open Access Journals (Sweden)

Binod Parameswaran

2018-01-01

Full Text Available The use of enzymes or microorganisms in food preparations is an age-old process. With the advancement of technology, novel enzymes with wide range of applications and specificity have been developed and new application areas are still being explored. Microorganisms such as bacteria, yeast and fungi and their enzymes are widely used in several food preparations for improving the taste and texture and they offer huge economic benefits to industries. Microbial enzymes are the preferred source to plants or animals due to several advantages such as easy, cost-effective and consistent production. The present review discusses the recent advancement in enzyme technology for food industries. A comprehensive list of enzymes used in food processing, the microbial source of these enzymes and the wide range of their application are discussed.

Targeted quantification of functional enzyme dynamics in environmental samples for microbially mediated biogeochemical processes: Targeted quantification of functional enzyme dynamics

Energy Technology Data Exchange (ETDEWEB)

Li, Minjing [School of Environmental Studies, China University of Geosciences, Wuhan 430074 People' s Republic of China; Gao, Yuqian [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Qian, Wei-Jun [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Shi, Liang [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Liu, Yuanyuan [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Nelson, William C. [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Nicora, Carrie D. [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Resch, Charles T. [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Thompson, Christopher [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Yan, Sen [School of Environmental Studies, China University of Geosciences, Wuhan 430074 People' s Republic of China; Fredrickson, James K. [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Zachara, John M. [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Liu, Chongxuan [Pacific Northwest National Laboratory, Richland, WA 99354 USA; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055 People' s Republic of China

2017-07-13

Microbially mediated biogeochemical processes are catalyzed by enzymes that control the transformation of carbon, nitrogen, and other elements in environment. The dynamic linkage between enzymes and biogeochemical species transformation has, however, rarely been investigated because of the lack of analytical approaches to efficiently and reliably quantify enzymes and their dynamics in soils and sediments. Herein, we developed a signature peptide-based technique for sensitively quantifying dissimilatory and assimilatory enzymes using nitrate-reducing enzymes in a hyporheic zone sediment as an example. Moreover, the measured changes in enzyme concentration were found to correlate with the nitrate reduction rate in a way different from that inferred from biogeochemical models based on biomass or functional genes as surrogates for functional enzymes. This phenomenon has important implications for understanding and modeling the dynamics of microbial community functions and biogeochemical processes in environments. Our results also demonstrate the importance of enzyme quantification for the identification and interrogation of those biogeochemical processes with low metabolite concentrations as a result of faster enzyme-catalyzed consumption of metabolites than their production. The dynamic enzyme behaviors provide a basis for the development of enzyme-based models to describe the relationship between the microbial community and biogeochemical processes.

NRSA enzyme decomposition model data

Data.gov (United States)

U.S. Environmental Protection Agency — Microbial enzyme activities measured at more than 2000 US streams and rivers. These enzyme data were then used to predict organic matter decomposition and microbial...

Angiotensin-converting enzyme gene 2350 G/A polymorphism and susceptibility to atrial fibrillation in Han Chinese patients with essential hypertension

Directory of Open Access Journals (Sweden)

Min-Hui Jiang

2013-11-01

Full Text Available OBJECTIVE: The angiotensin-converting enzyme gene is one of the most studied candidate genes related to atrial fibrillation. Among the polymorphisms of the angiotensin-converting enzyme gene, the 2350 G/A polymorphism (rs4343 is known to have the most significant effects on the plasma angiotensin-converting enzyme concentration. The aim of the present study was to investigate the association of the angiotensin-converting enzyme 2350 G/A polymorphism with atrial fibrillation in Han Chinese patients with essential hypertension. METHODS: A total of 169 hypertensive patients were eligible for this study. Patients with atrial fibrillation (n = 75 were allocated to the atrial fibrillation group, and 94 subjects without atrial fibrillation were allocated to the control group. The PCR-based restriction fragment length polymorphism technique was used to assess the genotype frequencies. RESULTS: The distributions of the angiotensin-converting enzyme 2350 G/A genotypes (GG, GA, and AA, respectively were 40.43%, 41.49%, and 18.08% in the controls and 18.67%, 46.67%, and 34.66% in the atrial fibrillation subjects (p = 0.037. The frequency of the A allele in the atrial fibrillation group was significantly greater than in the control group (58.00% vs. 38.83%, p = 0.0007. Compared with the wild-type GG genotype, the GA and AA genotypes had an increased risk for atrial fibrillation. Additionally, atrial fibrillation patients with the AA genotype had greater left atrial dimensions than the patients with the GG or GA genotypes (p<0.01 and p<0.05, respectively. CONCLUSIONS: The results obtained in this study indicate that the angiotensin-converting enzyme 2350 G/A polymorphism is associated with atrial fibrillation and that the A allele shows an increased risk for atrial fibrillation in Han Chinese patients with essential hypertension.

Electricity system planning under the CO2 emission restriction

International Nuclear Information System (INIS)

Lim, Chae Young; Lee, Man Ki; Roh, Jae Hyung; Kim, Eun Hwan

2004-01-01

Objective of this study is to analyze how the restriction of CO 2 emission from power generation will affect the national electricity supply system. The role of nuclear power is investigated under the restriction of CO 2 emission in Korea. A simplified electricity system was modeled for the analysis. To analyze the impact of CO 2 emission restriction, 2 different scenarios were established and compared with the base scenario. The first scenario was 'CO 2 emission restriction with new nuclear power installation'. In this scenario, a CO 2 emission restriction of 0.11kg-C/kWh was imposed and there was no restriction on the nuclear power construction. While, in the second scenario, 'CO 2 emission restriction without new nuclear power installation' the same amount of CO 2 restriction was imposed with no consideration of nuclear power installation. It is found out that the current national emission target(0.11kg- C/kWh) in the electricity sector can not be achieved without nuclear and renewable(wind power) options considered

Heavy enzymes--experimental and computational insights in enzyme dynamics.

Science.gov (United States)

Swiderek, Katarzyna; Ruiz-Pernía, J Javier; Moliner, Vicent; Tuñón, Iñaki

2014-08-01

The role of protein motions in the chemical step of enzyme-catalyzed reactions is the subject of an open debate in the scientific literature. The systematic use of isotopically substituted enzymes has been revealed as a useful tool to quantify the role of these motions. According to the Born-Oppenheimer approximation, changing the mass of the protein does not change the forces acting on the system but alters the frequencies of the protein motions, which in turn can affect the rate constant. Experimental and theoretical studies carried out in this field are presented in this article and discussed in the framework of Transition State Theory. Copyright © 2014 Elsevier Ltd. All rights reserved.

Consumer attitudes to enzymes in food production

DEFF Research Database (Denmark)

Søndergaard, Helle Alsted; Grunert, Klaus G.; Scholderer, Joachim

2005-01-01

The use of enzymes in food production has potential benefits for both food manufacturers and consumers. A central question is how consumers react to new ways of producing foods with enzymes. This study investigates the formation of consumer attitudes to different enzyme production methods in three...... European countries. Results show that consumers are most positive towards non-GM enzyme production methods. The enzyme production method is by far the most important factor for the formation of buying intentions compared to price and benefits. Results also show that environmental concern and attitudes...... to technological progress are the socio-political attitudes that have the highest predictive value regarding attitudes to enzyme production methods....

Protein restriction in chronic renal failure

NARCIS (Netherlands)

ECHTEN, JEKT; NAUTA, J; HOP, WCJ; de Jong, MCJ; REITSMABIERENS, WCC; VANAMSTEL, SLBP; VANACKER, KJ; NOORDZIJ, CM; WOLFF, ED

The aim of the study was to investigate the effect of a protein restricted diet on renal function and growth of children with chronic renal failure. In a multicentre prospective study 56 children (aged 2-18 years) with chronic renal failure were randomly assigned to the protein restricted (0.8-1.1

49 CFR 215.303 - Stenciling of restricted cars.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Stenciling of restricted cars. 215.303 Section 215... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Stenciling § 215.303 Stenciling of restricted cars. (a) Each restricted railroad freight car that is described in § 215.205(a) of...

Immobilization of Enzymes in Polymer Supports.

Science.gov (United States)

Conlon, Hugh D.; Walt, David R.

1986-01-01

Two experiments in which an enzyme is immobilized onto a polymeric support are described. The experiments (which also demonstrate two different polymer preparations) involve: (1) entrapping an enzyme in an acrylamide polymer; and (2) reacting the amino groups on the enzyme's (esterase) lysine residues with an activated polymer. (JN)

Cellular Restriction Factors of Feline Immunodeficiency Virus

Directory of Open Access Journals (Sweden)

Carsten Münk

2011-10-01

Full Text Available Lentiviruses are known for their narrow cell- and species-tropisms, which are determined by cellular proteins whose absence or presence either support viral replication (dependency factors, cofactors or inhibit viral replication (restriction factors. Similar to Human immunodeficiency virus type 1 (HIV-1, the cat lentivirus Feline immunodeficiency virus (FIV is sensitive to recently discovered cellular restriction factors from non-host species that are able to stop viruses from replicating. Of particular importance are the cellular proteins APOBEC3, TRIM5α and tetherin/BST-2. In general, lentiviruses counteract or escape their species’ own variant of the restriction factor, but are targeted by the orthologous proteins of distantly related species. Most of the knowledge regarding lentiviral restriction factors has been obtained in the HIV-1 system; however, much less is known about their effects on other lentiviruses. We describe here the molecular mechanisms that explain how FIV maintains its replication in feline cells, but is largely prevented from cross-species infections by cellular restriction factors.

Enzymic oxidation of carbon monoxide. II

Energy Technology Data Exchange (ETDEWEB)

Yagi, T

1959-01-01

An enzyme which catalyzes the oxidation of carbon monoxide into carbon dioxide was obtained in a cell free state from Desulfovibrio desulfuricans. The enzyme activity was assayed manometrically by measuring the rate of gas uptake under the atmosphere of carbon monoxide in the presence of benzyl-viologen as an oxidant. The optimum pH range was 7 to 8. The activity was slightly suppressed by illumination. The enzyme was more stable than hydrogenase or formate dehydrogenase against the heat treatment, suggesting that it is a different entity from these enzymes. In the absence of an added oxidant, the enzyme preparation produced hydrogen gas under the atmosphere of carbon monoxide. The phenomenon can be explained assuming the reductive decomposition of water. 17 references, 4 figures, 2 tables.

Production of cellulolytic enzymes from ascomycetes

DEFF Research Database (Denmark)

Hansen, Gustav Hammerich; Lübeck, Mette; Frisvad, Jens Christian

2015-01-01

Optimizing production of cellulose degrading enzymes is of great interest in order to increase the feasibility of constructing biorefinery facilities for a sustainable supply of energy and chemical products. The ascomycete phylum has a large potential for the production of cellulolytic enzymes....... Although numerous enzymatic profiles have already been unraveled, the research has been covering only a limited number of species and genera, thus leaving many ascomycetes to be analyzed. Such analysis requires choosing appropriate media and cultivation methods that ensure enzyme profiles with high...... specificities and activities. However, the choice of media, cultivation methods and enzyme assays highly affect the enzyme activity profile observed. This review provides an overview of enzymatic profiles for several ascomycetes covering phylogenetically distinct genera and species. The profiles of cellulose...

Computational Biochemistry-Enzyme Mechanisms Explored.

Science.gov (United States)

Culka, Martin; Gisdon, Florian J; Ullmann, G Matthias

2017-01-01

Understanding enzyme mechanisms is a major task to achieve in order to comprehend how living cells work. Recent advances in biomolecular research provide huge amount of data on enzyme kinetics and structure. The analysis of diverse experimental results and their combination into an overall picture is, however, often challenging. Microscopic details of the enzymatic processes are often anticipated based on several hints from macroscopic experimental data. Computational biochemistry aims at creation of a computational model of an enzyme in order to explain microscopic details of the catalytic process and reproduce or predict macroscopic experimental findings. Results of such computations are in part complementary to experimental data and provide an explanation of a biochemical process at the microscopic level. In order to evaluate the mechanism of an enzyme, a structural model is constructed which can be analyzed by several theoretical approaches. Several simulation methods can and should be combined to get a reliable picture of the process of interest. Furthermore, abstract models of biological systems can be constructed combining computational and experimental data. In this review, we discuss structural computational models of enzymatic systems. We first discuss various models to simulate enzyme catalysis. Furthermore, we review various approaches how to characterize the enzyme mechanism both qualitatively and quantitatively using different modeling approaches. © 2017 Elsevier Inc. All rights reserved.

The enzyme lecithin-cholesterol acyltransferase esterifies cerebrosterol and limits the toxic effect of this oxysterol on SH-SY5Y cells.

Science.gov (United States)

La Marca, Valeria; Spagnuolo, Maria Stefania; Cigliano, Luisa; Marasco, Daniela; Abrescia, Paolo

2014-07-01

Cholesterol is mostly removed from the CNS by its conversion to cerebrosterol (24(S)-hydroxycholesterol, 24(S)OH-C), which is transported to the circulation for bile formation in liver. A neurotoxic role of this oxysterol was previously demonstrated in cell culture. Here, we provide evidence that the enzyme lecithin-cholesterol acyltransferase, long known to esterify cholesterol, also produces monoesters of 24(S)OH-C. Proteoliposomes containing apolipoprotein A-I or apolipoprotein E were used to stimulate the enzyme activity and entrap the formed esters. Proteoliposomes with apolipoprotein A-I were found to be more active than those with apolipoprotein E in stimulating the production of oxysteryl esters. Cholesterol and 24(S)OH-C were found to compete for enzyme activity. High levels of haptoglobin, as those circulating during the acute inflammatory phase, inhibited 24(S)OH-C esterification. When highly neurotoxic 24(S)OH-C was treated with enzyme and proteoliposomes before incubation with differentiated SH-SY5Y cells, the neuron survival improved. The esters of 24(S)OH-C, embedded into proteoliposomes by the enzyme and isolated from unesterified 24(S)OH-C by gel filtration chromatography, did not enter the neurons in culture. These results suggest that the enzyme, in the presence of the apolipoproteins, converts 24(S)OH-C into esters restricted to the extracellular environment, thus preventing or limiting oxysterol-induced neurotoxic injuries to neurons in culture. 24-hydroxycholesterol (24(S)OH-C) is neurotoxic. The enzyme lecithin-cholesterol acyltransferase (LCAT) synthesizes monoesters of 24(S)OH-C in reaction mixtures with proteoliposomes containing phospholipids and apolipoprotein A-I or apolipoprotein E. The esters, also produced by incubation of cerebrospinal fluid only with tritiated 24(S)OH-C, are embedded into lipoproteins that do not enter neurons in culture. The enzyme activity limits the toxicity of 24-hydroxycholesterol in neuron culture. © 2014

36 CFR 1275.58 - Deletion of restricted portions.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Deletion of restricted... HISTORICAL MATERIALS OF THE NIXON ADMINISTRATION Access by the Public § 1275.58 Deletion of restricted... materials after the deletion of the portions which are restricted under this § 1275.50 or § 1275.52. ...

Cellulolytic enzyme compositions and uses thereof

Energy Technology Data Exchange (ETDEWEB)

Iyer, Prashant; Gaspar, Armindo Ribiero; Croonenberghs, James; Binder, Thomas P.

2017-07-25

The present invention relates enzyme composition comprising a cellulolytic preparation and an acetylxylan esterase (AXE); and the used of cellulolytic enzyme compositions for hydrolyzing acetylated cellulosic material. Finally the invention also relates to processes of producing fermentation products from acetylated cellulosic materials using a cellulolytic enzyme composition of the invention.

Strategies for enzyme saving during saccharification of pretreated lignocellulo-starch biomass: effect of enzyme dosage and detoxification chemicals

Directory of Open Access Journals (Sweden)

M.G. Mithra

2017-08-01

Full Text Available Two strategies leading to enzyme saving during saccharification of pretreated lignocellulo-starch biomass (LCSB was investigated which included reducing enzyme dosage by varying their levels in enzyme cocktails and enhancing the fermentable sugar yield in enzyme-reduced systems using detoxification chemicals. Time course release of reducing sugars (RS during 24–120 h was significantly higher when an enzyme cocktail containing full dose of cellulase (16 FPU/g cellulose along with half dose each of xylanase (1.5 mg protein/g hemicelluloses and Stargen (12.5 μl/g biomass was used to saccharify conventional dilute sulphuric acid (DSA pretreated biomass compared to a parallel system where only one-fourth the dose of the latter two enzymes was used. The reduction in RS content in the 120 h saccharified mash to the extent of 3–4 g/L compared to the system saccharified with full complement of the three enzymes could be overcome considerably by supplementing the system (half dose of two enzymes with detoxification chemical mix incorporating Tween 20, PEG 4000 and sodium borohydride. Microwave (MW-assisted DSA pretreated biomass on saccharification with enzyme cocktail having full dose of cellulase and half dose of Stargen along with detoxification chemicals gave significantly higher RS yield than DSA pretreated system saccharified using three enzymes. The study showed that xylanase could be eliminated during saccharification of MW-assisted DSA pretreated biomass without affecting RS yield when detoxification chemicals were also supplemented. The Saccharification Efficiency and Overall Conversion Efficiency were also high for the MW-assisted DSA pretreated biomass. Since whole slurry saccharifcation of pretreated biomass is essential to conserve fermentable sugars in LCSB saccharification, detoxification of soluble inhibitors is equally important as channelling out of insoluble lignin remaining in the residue. As one of the major factors contributing

Freedom and Restrictions in Language Use.

Science.gov (United States)

O'Donnell, Roy C.

Since freedom of thought and expression is essential in a democracy, censorship of language is rightly regarded as a threat to all other freedoms. Still, it is inevitable that certain restrictions will occasionally be imposed on language in America and in other societies. Restrictions on language date back to the Ten Commandments, which condemned…

Comparative analysis of human cytomegalovirus a-sequence in multiple clinical isolates by using polymerase chain reaction and restriction fragment length polymorphism assays.

Science.gov (United States)

Zaia, J A; Gallez-Hawkins, G; Churchill, M A; Morton-Blackshere, A; Pande, H; Adler, S P; Schmidt, G M; Forman, S J

1990-01-01

The human cytomegalovirus (HCMV) a-sequence (a-seq) is located in the joining region between the long (L) and short (S) unique sequences of the virus (L-S junction), and this hypervariable junction has been used to differentiate HCMV strains. The purpose of this study was to investigate whether there are differences among strains of human cytomegalovirus which could be characterized by polymerase chain reaction (PCR) amplification of the a-seq of HCMV DNA and to compare a PCR method of strain differentiation with conventional restriction fragment length polymorphism (RFLP) methodology by using HCMV junction probes. Laboratory strains of HCMV and viral isolates from individuals with HCMV infection were characterized by using both RFLPs and PCR. The PCR assay amplified regions in the major immediate-early gene (IE-1), the 64/65-kDa matrix phosphoprotein (pp65), and the a-seq of the L-S junction region. HCMV laboratory strains Towne, AD169, and Davis were distinguishable, in terms of size of the amplified product, when analyzed by PCR with primers specific for the a-seq but were indistinguishable by using PCR targeted to IE-1 and pp65 sequences. When this technique was applied to a characterization of isolates from individuals with HCMV infection, selected isolates could be readily distinguished. In addition, when the a-seq PCR product was analyzed with restriction enzyme digestion for the presence of specific sequences, these DNA differences were confirmed. PCR analysis across the variable a-seq of HCMV demonstrated differences among strains which were confirmed by RFLP in 38 of 40 isolates analyzed. The most informative restriction enzyme sites in the a-seq for distinguishing HCMV isolates were those of MnlI and BssHII. This indicates that the a-seq of HCMV is heterogeneous among wild strains, and PCR of the a-seq of HCMV is a practical way to characterize differences in strains of HCMV. Images PMID:1980680

Cellulase enzyme and biomass utilization

African Journals Online (AJOL)

STORAGESEVER

2009-06-03

Jun 3, 2009 ... human population grows and economic development. However, the current .... conditions and the production cost of the related enzyme system. Therefore ... Given the importance of this enzyme to these so many industries,.

Review: Neuroinflammation in intrauterine growth restriction.

Science.gov (United States)

Wixey, Julie A; Chand, Kirat K; Colditz, Paul B; Bjorkman, S Tracey

2017-06-01

Disruption to the maternal environment during pregnancy from events such as hypoxia, stress, toxins, inflammation, and reduced placental blood flow can affect fetal development. Intrauterine growth restriction (IUGR) is commonly caused by chronic placental insufficiency, interrupting supply of oxygen and nutrients to the fetus resulting in abnormal fetal growth. IUGR is a major cause of perinatal morbidity and mortality, occurring in approximately 5-10% of pregnancies. The fetal brain is particularly vulnerable in IUGR and there is an increased risk of long-term neurological disorders including cerebral palsy, epilepsy, learning difficulties, behavioural difficulties and psychiatric diagnoses. Few studies have focused on how growth restriction interferes with normal brain development in the IUGR neonate but recent studies in growth restricted animal models demonstrate increased neuroinflammation. This review describes the role of neuroinflammation in the progression of brain injury in growth restricted neonates. Identifying the mediators responsible for alterations in brain development in the IUGR infant is key to prevention and treatment of brain injury in these infants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nutrigenetics and nutrigenomics of caloric restriction.

Science.gov (United States)

Abete, Itziar; Navas-Carretero, Santiago; Marti, Amelia; Martinez, J Alfredo

2012-01-01

Obesity is a complex disease resulting from a chronic and long-term positive energy balance in which both genetic and environmental factors are involved. Weight-reduction methods are mainly focused on dietary changes and increased physical activity. However, responses to nutritional intervention programs show a wide range of interindividual variation, which is importantly influenced by genetic determinants. In this sense, subjects carrying several obesity-related single-nucleotide polymorphisms (SNPs) show differences in the response to calorie-restriction programs. Furthermore, there is evidence indicating that dietary components not only fuel the body but also participate in the modulation of gene expression. Thus, the expression pattern and nutritional regulation of several obesity-related genes have been studied, as well as those that are differentially expressed by caloric restriction. The responses to caloric restriction linked to the presence of SNPs in obesity-related genes are reviewed in this chapter. Also, the influence of energy restriction on gene expression pattern in different tissues is addressed. Copyright © 2012 Elsevier Inc. All rights reserved.

Reduced Insulin/Insulin-like Growth Factor-1 Signaling and Dietary Restriction Inhibit Translation but Preserve Muscle Mass in Caenorhabditis elegans

Energy Technology Data Exchange (ETDEWEB)

Depuydt, Geert; Xie, Fang; Petyuk, Vladislav A.; Shanmugam, Nilesh; Smolders, Arne; Dhondt, Ineke; Brewer, Heather M.; Camp, David G.; Smith, Richard D.; Braeckman, Bart P.

2013-09-03

Reduced signaling through the C. elegans insulin/IGF1 like tyrosine kinase receptor daf2 and dietary restriction via bacterial dilution are two well-characterized lifespan-extending interventions that operate in parallel or through (partially) independent mechanisms. Using accurate mass and time tag LCMS/MS quantitative proteomics we detected that the abundance of a large number of ribosomal subunits is decreased in response to dietary restriction as well as in the daf2(e1370) insulin/IGF1 receptor mutant. In addition, general protein synthesis levels in these long-lived worms are repressed. Surprisingly, ribosomal transcript levels were not correlated to actual protein abundance, suggesting that posttranscriptional regulation determines ribosome content. Proteomics also revealed increased presence of many structural muscle cell components in long-lived worms, which appears to result from prioritized preservation of muscle cell volume in nutrient-poor conditions or low insulin-like signaling. Activation of DAF16, but not diet-restriction, stimulates mRNA expression of muscle-related genes to prevent muscle atrophy. Important daf2 specific proteome changes include overexpression of aerobic metabolism enzymes and a general activation of stress responsive and immune defense systems, while increased abundance of many protein subunits of the proteasome core complex is a DR-specific characteristic.

Photosynthetic fuel for heterologous enzymes

DEFF Research Database (Denmark)

Mellor, Silas Busck; Vavitsas, Konstantinos; Nielsen, Agnieszka Janina Zygadlo

2017-01-01

of reducing power. Recent work on the metabolic engineering of photosynthetic organisms has shown that the electron carriers such as ferredoxin and flavodoxin can be used to couple heterologous enzymes to photosynthetic reducing power. Because these proteins have a plethora of interaction partners and rely...... on electrostatically steered complex formation, they form productive electron transfer complexes with non-native enzymes. A handful of examples demonstrate channeling of photosynthetic electrons to drive the activity of heterologous enzymes, and these focus mainly on hydrogenases and cytochrome P450s. However......, competition from native pathways and inefficient electron transfer rates present major obstacles, which limit the productivity of heterologous reactions coupled to photosynthesis. We discuss specific approaches to address these bottlenecks and ensure high productivity of such enzymes in a photosynthetic...

Sight Restrictions in Maghrib Muslim Architecture

Directory of Open Access Journals (Sweden)

Mustapha Ben Hamouche

1999-12-01

Full Text Available Sight in Islamic culture is subject to legal restrictions that aim at preserving moral consciousness in Muslim societies. These restrictions have a direct impact on architecture in traditional Muslim cities. Details such as placement of doors and windows, the use of balconies and rooftops, and building heights were shaped by legal reasoning based on sight restrictions. The present study aims at highlighting this legal reasoning system by analyzing legal opinions that were continuously advocated by jurists in response to daily practices, and the legal principles on which these opinions were based. This is expected to contribute in developing a new intellectual discourse on Muslim architecture that could go beyond the present design theories.

Recommendations of activity restriction in high-risk pregnancy scenarios

DEFF Research Database (Denmark)

Bendix, Jane; Hegaard, Hanne Kristine; Bergholt, Thomas

2015-01-01

activity restriction more often than obstetricians in five of the nine scenarios, in women with preterm premature rupture of membranes, preterm labour, cervical ripening, total placenta praevia, and intrauterine growth restriction, whereas no differences were found in the remaining scenarios. Compared...... to the obstetricians, the midwives also reported that they expected the recommendation to be more effective. Most midwives and obstetricians reported that they thought strict activity restriction was associated with severe or moderate adverse effect, and recommended antithrombotic prophylaxis. Conclusions: Danish...... obstetricians and midwives prescribe activity restriction in most high-risk pregnancies. The degree of activity restriction and the presumed effect vary between clinicians. This may reflect different attitudes and lack of guidelines based on clinical studies of a possible benefit of activity restriction....

Research progress of nanoparticles as enzyme mimetics

Science.gov (United States)

Hu, XiaoNa; Liu, JianBo; Hou, Shuai; Wen, Tao; Liu, WenQi; Zhang, Ke; He, WeiWei; Ji, YingLu; Ren, HongXuan; Wang, Qi; Wu, XiaoChun

2011-10-01

Natural enzymes as biological catalysts possess remarkable advantages, especially their highly efficient and selective catalysis under mild conditions. However, most natural enzymes are proteins, thus exhibiting an inherent low durability to harsh reaction conditions. Artificial enzyme mimetics have been pursued extensively to avoid this drawback. Quite recently, some inorganic nanoparticles (NPs) have been found to exhibit unique enzyme mimetics. In addition, their much higher stability overcomes the inherent disadvantage of natural enzymes. Furthermore, easy mass-production and low cost endow them more benefits. As a new member of artificial enzyme mimetics, they have received intense attention. In this review article, major progress in this field is summarized and future perspectives are highlighted.

Health Benefits of Fasting and Caloric Restriction.

Science.gov (United States)

Golbidi, Saeid; Daiber, Andreas; Korac, Bato; Li, Huige; Essop, M Faadiel; Laher, Ismail

2017-10-23

Obesity and obesity-related diseases, largely resulting from urbanization and behavioral changes, are now of global importance. Energy restriction, though, is associated with health improvements and increased longevity. We review some important mechanisms related to calorie limitation aimed at controlling of metabolic diseases, particularly diabetes. Calorie restriction triggers a complex series of intricate events, including activation of cellular stress response elements, improved autophagy, modification of apoptosis, and alteration in hormonal balance. Intermittent fasting is not only more acceptable to patients, but it also prevents some of the adverse effects of chronic calorie restriction, especially malnutrition. There are many somatic and potentially psychologic benefits of fasting or intermittent calorie restriction. However, some behavioral modifications related to abstinence of binge eating following a fasting period are crucial in maintaining the desired favorable outcomes.

Relationship Between Calorie Restriction, Lipid Peroxidation ...

African Journals Online (AJOL)

In the brain of the caloric restricted rats, there was little or no change in the tGSH and GSH, although the GSSG and GSSG/GSH% ratio were increased significantly. These results suggest that aging of rats had been decelerated by caloric restriction due to the decrease in the peroxidative damage in the lungs and brain.

78 FR 40958 - Amendment of Restricted Areas R-2504A & R-2504B; Camp Roberts, CA, and Restricted Area R-2530...

Science.gov (United States)

2013-07-09

...-0515; Airspace Docket No. 13-AWP-8] RIN 2120-AA66 Amendment of Restricted Areas R-2504A & R-2504B; Camp Roberts, CA, and Restricted Area R-2530; Sierra Army Depot, CA AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action amends the descriptions of restricted areas R...

Restrictive Dermopathy: Molecular diagnosis of restrictive dermopathy in a stillborn fetus from a consanguineous Iranian family

International Nuclear Information System (INIS)

Karaminejad, A.; Goodarzi, P.; Huong, Le Thi Thanh; Wehnert, Manfred S.

2009-01-01

Restrictive dermopathy (RD) is an autosomal recessive lethal human genetic disorder. It is characterized by intrauterine growth retardation, tight and rigid skin with erosions, multiple joint contractures, lung hypoplasia, prominent superficial vasculature and epidermal hyperkeratosis. In the present report, we describe the first case of restrictive dermopathy in a stillborn fetus of Iranian origin, confirmed by molecular genetic diagnosis. In the index case (G-30159), a homozygous one base insertion in ZMPSTE24exon 9 (c.1085-1086insT) was identified. We believe that by increasing awareness of this disease in clinicians, gynecologists and pathologists, we may be able to help families who have had suspected cases of restrictive dermopathy be diagnosed and offer molecular testing in carriers and prenatal diagnosis to prevent the occurrence of further affected cases. (author)

Improvement in Saccharification Yield of Mixed Rumen Enzymes by Identification of Recalcitrant Cell Wall Constituents Using Enzyme Fingerprinting.

Science.gov (United States)

Badhan, Ajay; Wang, Yu-Xi; Gruninger, Robert; Patton, Donald; Powlowski, Justin; Tsang, Adrian; McAllister, Tim A

2015-01-01

Identification of recalcitrant factors that limit digestion of forages and the development of enzymatic approaches that improve hydrolysis could play a key role in improving the efficiency of meat and milk production in ruminants. Enzyme fingerprinting of barley silage fed to heifers and total tract indigestible fibre residue (TIFR) collected from feces was used to identify cell wall components resistant to total tract digestion. Enzyme fingerprinting results identified acetyl xylan esterases as key to the enhanced ruminal digestion. FTIR analysis also suggested cross-link cell wall polymers as principal components of indigested fiber residues in feces. Based on structural information from enzymatic fingerprinting and FTIR, enzyme pretreatment to enhance glucose yield from barley straw and alfalfa hay upon exposure to mixed rumen-enzymes was developed. Prehydrolysis effects of recombinant fungal fibrolytic hydrolases were analyzed using microassay in combination with statistical experimental design. Recombinant hemicellulases and auxiliary enzymes initiated degradation of plant structural polysaccharides upon application and improved the in vitro saccharification of alfalfa and barley straw by mixed rumen enzymes. The validation results showed that microassay in combination with statistical experimental design can be successfully used to predict effective enzyme pretreatments that can enhance plant cell wall digestion by mixed rumen enzymes.

Short-Term Vitamin B-6 Restriction Does Not Affect Plasma Concentrations of Hydrogen Sulfide Biomarkers Lanthionine and Homolanthionine in Healthy Men and Women.

Science.gov (United States)

DeRatt, Barbara N; Ralat, Maria A; Gregory, Jesse F

2016-03-09

Suboptimal vitamin B-6 status is associated with increased cardiovascular disease risk, although the mechanism is unknown. The synthesis of the vasodilator hydrogen sulfide occurs through side reactions of the transsulfuration enzymes cystathionine β-synthase and cystathionine γ-lyase, with pyridoxal 5'-phosphate as a coenzyme. Two proposed hydrogen sulfide biomarkers, lanthionine and homolanthionine, are produced concurrently. To determine whether hydrogen sulfide production is reduced by vitamin B-6 deficiency, we examined the relations between plasma concentrations of lanthionine and homolanthionine, along with other components of the transsulfuration pathway (homocysteine, cystathionine, and Cys), in a secondary analysis of samples from 2 vitamin B-6 restriction studies in healthy men and women. Metabolite concentrations were measured in plasma from 23 healthy adults (12 men and 11 women) before and after 28-d controlled dietary vitamin B-6 restriction (0.37 ± 0.04 mg/d). Vitamin B-6 restriction effects on lanthionine and homolanthionine concentrations were assessed. Associations between hydrogen sulfide biomarkers, transsulfuration metabolites, and functional indicators of vitamin B-6 deficiency were analyzed by linear regression. Preprandial plasma lanthionine and homolanthionine concentrations ranged from 89.0 to 372 nmol/L and 5.75 to 32.3 nmol/L, respectively, in healthy adults. Mean lanthionine and homolanthionine concentrations were not affected by vitamin B-6 restriction (P restriction, homolanthionine was positively associated with functional indicators of vitamin B-6 deficiency, which differed from hypothesized negative associations. Plasma lanthionine was positively correlated with the concentration of its precursor, Cys, before (R 2 = 0.36; P = 0.002) and after (R 2 = 0.37; P = 0.002) restriction. Likewise, homolanthionine concentration was positively correlated with its precursor homocysteine, but only in vitamin B-6 adequacy (R 2 = 0.41; P

Challenges in nourishing the intrauterine growth-restricted foetus - Lessons learned from studies in the intrauterine growth-restricted foetal sheep.

Science.gov (United States)

Hay, William W; Brown, Laura D; Rozance, Paul J; Wesolowski, Stephanie R; Limesand, Sean W

2016-08-01

Previous attempts to improve growth and development of the intrauterine growth-restricted (IUGR) foetus during pregnancy have not worked or caused harm. Our research identifies tissue-specific mechanisms underlying foetal growth restriction and then tests strategies to improve growth and ameliorate many of the metabolic problems before the infant is born. The goal of our studies is to reduce the impact of foetal growth restriction at critical stages of development on the lifelong complications of IUGR offspring. Defining specific mechanisms that cause growth restriction in the foetus might identify specific nutrients and hormones that could be given to the mother to improve foetal growth and reduce metabolic complications, using strategies first tested in our IUGR animal model. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Development of enzymes and enzyme systems by genetic engineering to convert biomass to sugars

Science.gov (United States)

TITLE Development of Enzymes and Enzyme Systems by Genetic Engineering to Convert Biomass to Sugars ABSTRACT Plant cellulosic material is one of the most viable renewable resources for the world’s fuel and chemical feedstock needs. Currently ethanol derived from corn starch is the most common li...

Restrictions in Availability of Drugs Used for Suicide

DEFF Research Database (Denmark)

Nordentoft, Merete

2007-01-01

Availability of drugs with high lethality has been hypothesized to increase the risk of self-poisoning suicides. A literature search concerning deliberate self-poisoning and the effect of restricting access to drugs was conducted, and the effect of restrictions in availability of barbiturates, tr...... in availability of drugs with high case fatality should be a part of suicide prevention strategies.......Availability of drugs with high lethality has been hypothesized to increase the risk of self-poisoning suicides. A literature search concerning deliberate self-poisoning and the effect of restricting access to drugs was conducted, and the effect of restrictions in availability of barbiturates......, tricyclic antidepressants, dextropropoxyphene, and weak analgesics was reviewed. The correlations between method-specific and overall suicide rates and sales figures for barbiturates, dextropropoxyphene, weak analgesics, and tricyclic antidepressants were reviewed. It is concluded that restriction...

How Do Enzymes 'Meet' Nanoparticles and Nanomaterials?

Science.gov (United States)

Chen, Ming; Zeng, Guangming; Xu, Piao; Lai, Cui; Tang, Lin

2017-11-01

Enzymes are fundamental biological catalysts responsible for biological regulation and metabolism. The opportunity for enzymes to 'meet' nanoparticles and nanomaterials is rapidly increasing due to growing demands for applications in nanomaterial design, environmental monitoring, biochemical engineering, and biomedicine. Therefore, understanding the nature of nanomaterial-enzyme interactions is becoming important. Since 2014, enzymes have been used to modify, degrade, or make nanoparticles/nanomaterials, while numerous nanoparticles/nanomaterials have been used as materials for enzymatic immobilization and biosensors and as enzyme mimicry. Among the various nanoparticles and nanomaterials, metal nanoparticles and carbon nanomaterials have received extensive attention due to their fascinating properties. This review provides an overview about how enzymes meet nanoparticles and nanomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Watching Individual Enzymes at Work

Science.gov (United States)

Blank, Kerstin; Rocha, Susana; De Cremer, Gert; Roeffaers, Maarten B. J.; Uji-i, Hiroshi; Hofkens, Johan

Single-molecule fluorescence experiments are a powerful tool to analyze reaction mechanisms of enzymes. Because of their unique potential to detect heterogeneities in space and time, they have provided unprecedented insights into the nature and mechanisms of conformational changes related to the catalytic reaction. The most important finding from experiments with single enzymes is the generally observed phenomenon that the catalytic rate constants fluctuate over time (dynamic disorder). These fluctuations originate from conformational changes occurring on time scales, which are similar to or slower than that of the catalytic reaction. Here, we summarize experiments with enzymes that show dynamic disorder and introduce new experimental strategies showing how single-molecule fluorescence experiments can be applied to address other open questions in medical and industrial enzymology, such as enzyme inactivation processes, reactant transfer in cascade reactions, and the mechanisms of interfacial catalysis.

Advances in enzyme bioelectrochemistry

Directory of Open Access Journals (Sweden)

ANDRESSA R. PEREIRA

Full Text Available ABSTRACT Bioelectrochemistry can be defined as a branch of Chemical Science concerned with electron-proton transfer and transport involving biomolecules, as well as electrode reactions of redox enzymes. The bioelectrochemical reactions and system have direct impact in biotechnological development, in medical devices designing, in the behavior of DNA-protein complexes, in green-energy and bioenergy concepts, and make it possible an understanding of metabolism of all living organisms (e.g. humans where biomolecules are integral to health and proper functioning. In the last years, many researchers have dedicated itself to study different redox enzymes by using electrochemistry, aiming to understand their mechanisms and to develop promising bioanodes and biocathodes for biofuel cells as well as to develop biosensors and implantable bioelectronics devices. Inside this scope, this review try to introduce and contemplate some relevant topics for enzyme bioelectrochemistry, such as the immobilization of the enzymes at electrode surfaces, the electron transfer, the bioelectrocatalysis, and new techniques conjugated with electrochemistry vising understand the kinetics and thermodynamics of redox proteins. Furthermore, examples of recent approaches in designing biosensors and biofuel developed are presented.

Thermometric enzyme linked immunosorbent assay: TELISA.

Science.gov (United States)

Mattiasson, B; Borrebaeck, C; Sanfridson, B; Mosbach, K

1977-08-11

A new method, thermometric enzyme linked immunosorbent assay (TELISA), for the assay of endogenous and exogenous compounds in biological fluids is described. It is based on the previously described enzyme linked immunosorbent assay technique, ELISA, but utilizes enzymic heat formation which is measured in an enzyme thermistor unit. In the model system studied determination of human serum albumin down to a concentration of 10(-10) M (5 ng/ml) was achieved, with both normal and catalase labelled human serum albumin competing for the binding sites on the immunosorbent, which was rabbit antihuman serum albumin immobilized onto Sepharose CL-4B.

Newer antidiabetic drugs and calorie restriction mimicry

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Sanjay Kalra

2016-01-01

Full Text Available De-acceleration of aging and delayed development of age-related morbidity accompanies the restriction of calories (without malnutrition in laboratory mice, nematodes, yeast, fish, and dogs. Recent results from long-term longitudinal studies conducted on primates have suggested longevity benefits of a 30% restriction of calories in rhesus monkeys as well. Among calorie restricted rhesus monkeys one of the mechanisms for the improvement in lifespan was the reduction in the development of glucose intolerance and cardiovascular disease. Although there are no comparable human studies, it is likely that metabolic and longevity benefits will accompany a reduction in calories in humans as well. However, considering the difficulties in getting healthy adults to limit food intake science has focused on understanding the biochemical processes that accompany calorie restriction (CR to formulate drugs that would mimic the effects of CR without the need to actually restrict calories. Drugs in this emerging therapeutic field are called CR mimetics. Some of the currently used anti-diabetic agents may have some CR mimetic like effects. This review focuses on the CR mimetic properties of the currently available anti-diabetic agents.

Compensatory mechanisms activated with intermittent energy restriction

DEFF Research Database (Denmark)

Coutinho, Sílvia Ribeiro; Halset, Eline Holli; Gåsbakk, Sigrid

2018-01-01

Background & aims: Strong compensatory responses, with reduced resting metabolic rate (RMR), increased exercise efficiency (ExEff) and appetite, are activated when weight loss (WL) is achieved with continuous energy restriction (CER), which try to restore energy balance. Intermittent energy...... restriction (IER), where short spells of energy restriction are interspaced by periods of habitual energy intake, may offer some protection in minimizing those responses. We aimed to compare the effect of IER versus CER on body composition and the compensatory responses induced by WL. Methods: 35 adults (age......: 39 ± 9 y) with obesity (BMI: 36 ± 4 kg/m2) were randomized to lose a similar weight with an IER (N = 18) or a CER (N = 17) diet over a 12 week period. Macronutrient composition and overall energy restriction (33% reduction) were similar between groups. Body weight/composition, RMR, fasting...

Restriction fragment length polymorphism (RFLP) of two HLA-B-associated transcripts (BATs) genes in healthy Danes

DEFF Research Database (Denmark)

Fugger, L; Morling, N; Ryder, L P

1990-01-01

investigated in healthy Danes. The cDNA/restriction enzyme combination BAT1/NcoI identifies polymorphic bands at 12 kb, 8 kb, 2.5 kb, and 1.1 kb, while the BAT2/RsaI combination identifies polymorphic bands at 3.3 kb, 2.7 kb, 2.3 kb, and 0.9 kb. The frequencies of these markers were determined in 90 unrelated...... Danes. Co-dominant segregation and allelic behavior was seen for the BAT1/NcoI 12 kb and 8 kb bands and the BAT2/RsaI 2.7 kb and 2.3 kb bands, respectively. It is possible that the BAT2/RsaI 3.3 kb band represents a rare allele of the BAT2/RsaI system. The BAT2/RsaI 2.3 kb marker was strongly negatively...

Decoding restricted participation in sequential electricity markets

Energy Technology Data Exchange (ETDEWEB)

Knaut, Andreas; Paschmann, Martin

2017-06-15

Restricted participation in sequential markets may cause high price volatility and welfare losses. In this paper we therefore analyze the drivers of restricted participation in the German intraday auction which is a short-term electricity market with quarter-hourly products. Applying a fundamental electricity market model with 15-minute temporal resolution, we identify the lack of sub-hourly market coupling being the most relevant driver of restricted participation. We derive a proxy for price volatility and find that full market coupling may trigger quarter-hourly price volatility to decrease by a factor close to four.

Effects of protease and non-starch polysaccharide enzyme on performance, digestive function, activity and gene expression of endogenous enzyme of broilers.

Directory of Open Access Journals (Sweden)

Lin Yuan

Full Text Available Three hundred one-day-old male broiler chickens (Ross-308 were fed corn-soybean basal diets containing non-starch polysaccharide (NSP enzyme and different levels of acid protease from 1 to 42 days of age to investigate the effects of exogenous enzymes on growth performance, digestive function, activity of endogenous digestive enzymes in the pancreas and mRNA expression of pancreatic digestive enzymes. For days 1-42, compared to the control chickens, average daily feed intake (ADFI and average daily gain (ADG were significantly enhanced by the addition of NSP enzyme in combination with protease supplementation at 40 or 80 mg/kg (p<0.05. Feed-to-gain ratio (FGR was significantly improved by supplementation with NSP enzymes or NSP enzyme combined with 40 or 80 mg/kg protease compared to the control diet (p<0.05. Apparent digestibility of crude protein (ADCP was significantly enhanced by the addition of NSP enzyme or NSP enzyme combined with 40 or 80 mg/kg protease (p<0.05. Cholecystokinin (CCK level in serum was reduced by 31.39% with NSP enzyme combined with protease supplementation at 160 mg/kg (p<0.05, but the CCK level in serum was increased by 26.51% with NSP enzyme supplementation alone. After 21 days, supplementation with NSP enzyme and NSP enzyme combined with 40 or 80 mg/kg protease increased the activity of pancreatic trypsin by 74.13%, 70.66% and 42.59% (p<0.05, respectively. After 42 days, supplementation with NSP enzyme and NSP enzyme combined with 40 mg/kg protease increased the activity of pancreatic trypsin by 32.45% and 27.41%, respectively (p<0.05. However, supplementation with NSP enzyme and 80 or 160 mg/kg protease decreased the activity of pancreatic trypsin by 10.75% and 25.88%, respectively (p<0.05. The activities of pancreatic lipase and amylase were significantly higher in treated animals than they were in the control group (p<0.05. Supplementation with NSP enzyme, NSP enzyme combined with 40 or 80 mg/kg protease increased

Mesoscopic dynamics of diffusion-influenced enzyme kinetics.

Science.gov (United States)

Chen, Jiang-Xing; Kapral, Raymond

2011-01-28

A particle-based mesoscopic model for enzyme kinetics is constructed and used to investigate the influence of diffusion on the reactive dynamics. Enzymes and enzyme-substrate complexes are modeled as finite-size soft spherical particles, while substrate, product, and solvent molecules are point particles. The system is evolved using a hybrid molecular dynamics-multiparticle collision dynamics scheme. Both the nonreactive and reactive dynamics are constructed to satisfy mass, momentum, and energy conservation laws, and reversible reaction steps satisfy detailed balance. Hydrodynamic interactions among the enzymes and complexes are automatically accounted for in the dynamics. Diffusion manifests itself in various ways, notably in power-law behavior in the evolution of the species concentrations. In accord with earlier investigations, regimes where the product production rate exhibits either monotonic or nonmonotonic behavior as a function of time are found. In addition, the species concentrations display both t(-1/2) and t(-3/2) power-law behavior, depending on the dynamical regime under investigation. For high enzyme volume fractions, cooperative effects influence the enzyme kinetics. The time dependent rate coefficient determined from the mass action rate law is computed and shown to depend on the enzyme concentration. Lifetime distributions of substrate molecules newly released in complex dissociation events are determined and shown to have either a power-law form for rebinding to the same enzyme from which they were released or an exponential form for rebinding to different enzymes. The model can be used and extended to explore a variety of issues related concentration effects and diffusion on enzyme kinetics.

Mesoscopic dynamics of diffusion-influenced enzyme kinetics

Science.gov (United States)

Chen, Jiang-Xing; Kapral, Raymond

2011-01-01

A particle-based mesoscopic model for enzyme kinetics is constructed and used to investigate the influence of diffusion on the reactive dynamics. Enzymes and enzyme-substrate complexes are modeled as finite-size soft spherical particles, while substrate, product, and solvent molecules are point particles. The system is evolved using a hybrid molecular dynamics-multiparticle collision dynamics scheme. Both the nonreactive and reactive dynamics are constructed to satisfy mass, momentum, and energy conservation laws, and reversible reaction steps satisfy detailed balance. Hydrodynamic interactions among the enzymes and complexes are automatically accounted for in the dynamics. Diffusion manifests itself in various ways, notably in power-law behavior in the evolution of the species concentrations. In accord with earlier investigations, regimes where the product production rate exhibits either monotonic or nonmonotonic behavior as a function of time are found. In addition, the species concentrations display both t^{-1/2} and t^{-3/2} power-law behavior, depending on the dynamical regime under investigation. For high enzyme volume fractions, cooperative effects influence the enzyme kinetics. The time dependent rate coefficient determined from the mass action rate law is computed and shown to depend on the enzyme concentration. Lifetime distributions of substrate molecules newly released in complex dissociation events are determined and shown to have either a power-law form for rebinding to the same enzyme from which they were released or an exponential form for rebinding to different enzymes. The model can be used and extended to explore a variety of issues related concentration effects and diffusion on enzyme kinetics.

High throughput, high resolution enzymatic lithography process: effect of crystallite size, moisture, and enzyme concentration.

Science.gov (United States)

Mao, Zhantong; Ganesh, Manoj; Bucaro, Michael; Smolianski, Igor; Gross, Richard A; Lyons, Alan M

2014-12-08

By bringing enzymes into contact with predefined regions of a surface, a polymer film can be selectively degraded to form desired patterns that find a variety of applications in biotechnology and electronics. This so-called "enzymatic lithography" is an environmentally friendly process as it does not require actinic radiation or synthetic chemicals to develop the patterns. A significant challenge to using enzymatic lithography has been the need to restrict the mobility of the enzyme in order to maintain control of feature sizes. Previous approaches have resulted in low throughput and were limited to polymer films only a few nanometers thick. In this paper, we demonstrate an enzymatic lithography system based on Candida antartica lipase B (CALB) and poly(ε-caprolactone) (PCL) that can resolve fine-scale features, (<1 μm across) in thick (0.1-2.0 μm) polymer films. A Polymer Pen Lithography (PPL) tool was developed to deposit an aqueous solution of CALB onto a spin-cast PCL film. Immobilization of the enzyme on the polymer surface was monitored using fluorescence microscopy by labeling CALB with FITC. The crystallite size in the PCL films was systematically varied; small crystallites resulted in significantly faster etch rates (20 nm/min) and the ability to resolve smaller features (as fine as 1 μm). The effect of printing conditions and relative humidity during incubation is also presented. Patterns formed in the PCL film were transferred to an underlying copper foil demonstrating a "Green" approach to the fabrication of printed circuit boards.

Discovering novel enzymes by functional screening of plurigenomic libraries from alga-associated Flavobacteriia and Gammaproteobacteria.

Science.gov (United States)

Martin, Marjolaine; Vandermies, Marie; Joyeux, Coline; Martin, Renée; Barbeyron, Tristan; Michel, Gurvan; Vandenbol, Micheline

2016-01-01

Alga-associated microorganisms, in the context of their numerous interactions with the host and the complexity of the marine environment, are known to produce diverse hydrolytic enzymes with original biochemistry. We recently isolated several macroalgal-polysaccharide-degrading bacteria from the surface of the brown alga Ascophyllum nodosum. These active isolates belong to two classes: the Flavobacteriia and the Gammaproteobacteria. In the present study, we constructed two "plurigenomic" (with multiple bacterial genomes) libraries with the 5 most interesting isolates (regarding their phylogeny and their enzymatic activities) of each class (Fv and Gm libraries). Both libraries were screened for diverse hydrolytic activities. Five activities, out of the 48 previously identified in the natural polysaccharolytic isolates, were recovered by functional screening: a xylanase (GmXyl7), a beta-glucosidase (GmBg1), an esterase (GmEst7) and two iota-carrageenases (Fvi2.5 and Gmi1.3). We discuss here the potential role of the used host-cell, the average DNA insert-sizes and the used restriction enzymes on the divergent screening yields obtained for both libraries and get deeper inside the "great screen anomaly". Interestingly, the discovered esterase probably stands for a novel family of homoserine o-acetyltransferase-like-esterases, while the two iota-carrageenases represent new members of the poorly known GH82 family (containing only 19 proteins since its description in 2000). These original results demonstrate the efficiency of our uncommon "plurigenomic" library approach and the underexplored potential of alga-associated cultivable microbiota for the identification of novel and algal-specific enzymes. Copyright © 2016 Elsevier GmbH. All rights reserved.

Co-immobilization of multiple enzymes by metal coordinated nucleotide hydrogel nanofibers: improved stability and an enzyme cascade for glucose detection.

Science.gov (United States)

Liang, Hao; Jiang, Shuhui; Yuan, Qipeng; Li, Guofeng; Wang, Feng; Zhang, Zijie; Liu, Juewen

2016-03-21

Preserving enzyme activity and promoting synergistic activity via co-localization of multiple enzymes are key topics in bionanotechnology, materials science, and analytical chemistry. This study reports a facile method for co-immobilizing multiple enzymes in metal coordinated hydrogel nanofibers. Specifically, four types of protein enzymes, including glucose oxidase, Candida rugosa lipase, α-amylase, and horseradish peroxidase, were respectively encapsulated in a gel nanofiber made of Zn(2+) and adenosine monophosphate (AMP) with a simple mixing step. Most enzymes achieved quantitative loading and retained full activity. At the same time, the entrapped enzymes were more stable against temperature variation (by 7.5 °C), protease attack, extreme pH (by 2-fold), and organic solvents. After storing for 15 days, the entrapped enzyme still retained 70% activity while the free enzyme nearly completely lost its activity. Compared to nanoparticles formed with AMP and lanthanide ions, the nanofiber gels allowed much higher enzyme activity. Finally, a highly sensitive and selective biosensor for glucose was prepared using the gel nanofiber to co-immobilize glucose oxidase and horseradish peroxidase for an enzyme cascade system. A detection limit of 0.3 μM glucose with excellent selectivity was achieved. This work indicates that metal coordinated materials using nucleotides are highly useful for interfacing with biomolecules.

ENZYME RESISTANCE OF GENETICALLY MODIFIED STARCH POTATOES

Directory of Open Access Journals (Sweden)

A. Sh. Mannapova

2015-01-01

Full Text Available Here in this article the justification of expediency of enzyme resistant starch use in therapeutic food products is presented . Enzyme resistant starch is capable to resist to enzymatic hydrolysis in a small intestine of a person, has a low glycemic index, leads to decrease of postprandial concentration of glucose, cholesterol, triglycerides in blood and insulin reaction, to improvement of sensitivity of all organism to insulin, to increase in sense of fulness and to reduction of adjournment of fats. Resistant starch makes bifidogenшс impact on microflora of a intestine of the person, leads to increase of a quantity of lactobacillus and bifidobacterium and to increased production of butyric acid in a large intestine. In this regard the enzyme resistant starch is an important component in food for prevention and curing of human diseases such as diabetes, obesity, colitis, a cancer of large and direct intestine. One method is specified by authors for imitation of starch digestion in a human body. This method is based on the definition of an enzyme resistance of starch in vitro by its hydrolysis to glucose with application of a glucoamylase and digestive enzyme preparation Pancreatin. This method is used in researches of an enzyme resistance of starch, of genetically modified potato, high amylose corn starch Hi-Maize 1043 and HYLON VII (National Starch Food Innovation, USA, amylopectin and amylose. It is shown that the enzyme resistance of the starch emitted from genetically modified potatoes conforms to the enzyme resistance of the high amylose corn starch “Hi-Maize 1043 and HYLON VII starch”, (National Starch Food Innovation, the USA relating to the II type of enzyme resistant starch. It is established that amylopectin doesn't have the enzyme resistant properties. The results of researches are presented. They allow us to make the following conclusion: amylose in comparison with amylopectin possesses higher enzyme resistance and gives to

Structure and function of α-glucan debranching enzymes

DEFF Research Database (Denmark)

Møller, Marie Sofie; Henriksen, Anette; Svensson, Birte

2016-01-01

α-Glucan debranching enzymes hydrolyse α-1,6-linkages in starch/glycogen, thereby, playing a central role in energy metabolism in all living organisms. They belong to glycoside hydrolase families GH13 and GH57 and several of these enzymes are industrially important. Nine GH13 subfamilies include α......-glucan debranching enzymes; isoamylase and glycogen debranching enzymes (GH13_11); pullulanase type I/limit dextrinase (GH13_12–14); pullulan hydrolase (GH13_20); bifunctional glycogen debranching enzyme (GH13_25); oligo-1 and glucan-1,6-α-glucosidases (GH13_31); pullulanase type II (GH13_39); and α-amylase domains......_39 enzymes could represent a “missing link” between the strictly α-1,6-specific debranching enzymes and the enzymes with dual specificity and α-1,4-linkage preference....

Superimposition of postnatal calorie restriction protects the aging male intrauterine growth- restricted offspring from metabolic maladaptations.

Science.gov (United States)

Dai, Yun; Thamotharan, Shanthie; Garg, Meena; Shin, Bo-Chul; Devaskar, Sherin U

2012-09-01

Intrauterine growth restriction (IUGR) results in dysregulated glucose homeostasis and adiposity in the adult. We hypothesized that with aging, these perturbations will wane, and superimposition of postnatal growth restriction (PNGR) on IUGR [intrauterine and postnatal growth restriction (IPGR)] will reverse the residual IUGR phenotype. We therefore undertook hyperinsulinemic-euglycemic clamp, energy balance, and physical activity studies during fed, fasted, and refed states, in light and dark cycles, on postweaned chow diet-fed more than 17-month aging male IUGR, PNGR, and IPGR vs. control (CON) rat offspring. Hyperinsulinemic-euglycemic clamp revealed similar whole-body insulin sensitivity and physical activity in the nonobese IUGR vs. CON, despite reduced heat production and energy expenditure. Compared with CON and IUGR, IPGR mimicking PNGR was lean and growth restricted with increased physical activity, O(2) consumption (VO(2)), energy intake, and expenditure. Although insulin sensitivity was no different in IPGR and PNGR, skeletal muscle insulin-induced glucose uptake was enhanced. This presentation proved protective against the chronologically earlier (5.5 months) development of obesity and dysregulated energy homeostasis after 19 wk on a postweaned high-fat diet. This protective role of PNGR on the metabolic IUGR phenotype needs future fine tuning aimed at minimizing unintended consequences.

Geographically diverse Australian isolates of Melissococcus pluton exhibit minimal genotypic diversity by restriction endonuclease analysis.

Science.gov (United States)

Djordjevic, S P; Smith, L A; Forbes, W A; Hornitzky, M A

1999-04-15

Melissococcus pluton, the causative agent of European foulbrood is an economically significant disease of honey bees (Apis mellifera) across most regions of the world and is prevalent throughout most states of Australia. 49 Isolates of M. pluton recovered from diseased colonies or honey samples in New South Wales, Queensland, South Australia, Tasmania and Victoria were compared using SDS-PAGE, Western immunoblotting and restriction endonuclease analyses. DNA profiles of all 49 geographically diverse isolates showed remarkably similar AluI profiles although four isolates (one each from Queensland, South Australia, New South Wales and Victoria) displayed minor profile variations compared to AluI patterns of all other isolates. DNA from a subset of the 49 Australian and three isolates from the United Kingdom were digested separately with the restriction endonucleases CfoI, RsaI and DraI. Restriction endonuclease fragment patterns generated using these enzymes were also similar although minor variations were noted. SDS-PAGE of whole cell proteins from 13 of the 49 isolates from different states of Australia, including the four isolates which displayed minor profile variations (AluI) produced indistinguishable patterns. Major immunoreactive proteins of approximate molecular masses of 21, 24, 28, 30, 36, 40, 44, 56, 60, 71, 79 and 95 kDa were observed in immunoblots of whole cell lysates of 22 of the 49 isolates and reacted with rabbit hyperimmune antibodies raised against M. pluton whole cells. Neither SDS-PAGE or immunoblotting was capable of distinguishing differences between geographically diverse isolates of M. pluton. Collectively these data confirm that Australian isolates of M. pluton are genetically homogeneous and that this species may be clonal. Plasmid DNA was not detected in whole cell DNA profiles of any isolate resolved using agarose gel electrophoresis.

Experiment K-6-21. Effect of microgravity on 1) metabolic enzymes of type 1 and type 2 muscle fibers and on 2) metabolic enzymes, neutransmitter amino acids, and neurotransmitter associated enzymes in motor and somatosensory cerebral cortex. Part 1: Metabolic enzymes of individual muscle fibers; part 2: metabolic enzymes of hippocampus and spinal cord

Science.gov (United States)

Lowry, O.; Mcdougal, D., Jr.; Nemeth, Patti M.; Maggie, M.-Y. Chi; Pusateri, M.; Carter, J.; Manchester, J.; Norris, Beverly; Krasnov, I.

1990-01-01

The individual fibers of any individual muscle vary greatly in enzyme composition, a fact which is obscured when enzyme levels of a whole muscle are measured. The purpose of this study was therefore to assess the changes due to weightless on the enzyme patterns composed by the individual fibers within the flight muscles. In spite of the limitation in numbers of muscles examined, it is apparent that: (1) that the size of individual fibers (i.e., their dry weight) was reduced about a third, (2) that this loss in dry mass was accompanied by changes in the eight enzymes studied, and (3) that these changes were different for the two muscles, and different for the two enzyme groups. In the soleus muscle the absolute amounts of the three enzymes of oxidative metabolism decreased about in proportion to the dry weight loss, so that their concentration in the atrophic fibers was almost unchanged. In contrast, there was little loss among the four enzymes of glycogenolysis - glycolysis so that their concentrations were substantially increased in the atrophic fibers. In the TA muscle, these seven enzymes were affected in just the opposite direction. There appeared to be no absolute loss among the oxidative enzymes, whereas the glycogenolytic enzymes were reduced by nearly half, so that the concentrations of the first metabolic group were increased within the atrophic fibers and the concentrations of the second group were only marginally decreased. The behavior of hexokinase was exceptional in that it did not decrease in absolute terms in either type of muscle and probably increased as much as 50 percent in soleus. Thus, their was a large increase in concentration of this enzyme in the atrophied fibers of both muscles. Another clear-cut finding was the large increase in the range of activities of the glycolytic enzymes among individual fibers of TA muscles. This was due to the emergence of TA fibers with activities for enzymes of this group extending down to levels as low as

Abscinazole-F1, a conformationally restricted analogue of the plant growth retardant uniconazole and an inhibitor of ABA 8'-hydroxylase CYP707A with no growth-retardant effect.

Science.gov (United States)

Todoroki, Yasushi; Kobayashi, Kyotaro; Shirakura, Minaho; Aoyama, Hikaru; Takatori, Kokichi; Nimitkeatkai, Hataitip; Jin, Mei-Hong; Hiramatsu, Saori; Ueno, Kotomi; Kondo, Satoru; Mizutani, Masaharu; Hirai, Nobuhiro

2009-09-15

To develop a specific inhibitor of abscisic acid (ABA) 8'-hydroxylase, a key enzyme in the catabolism of ABA, a plant hormone involved in stress tolerance, seed dormancy, and other various physiological events, we designed and synthesized conformationally restricted analogues of uniconazole (UNI), a well-known plant growth retardant, which inhibits a biosynthetic enzyme (ent-kaurene oxidase) of gibberellin as well as ABA 8'-hydroxylase. Although most of these analogues were less effective than UNI in inhibition of ABA 8'-hydroxylase and rice seedling growth, we found that a lactol-bridged analogue with an imidazole is a potent inhibitor of ABA 8'-hydroxylase but not of plant growth. This compound, abscinazole-F1, induced drought tolerance in apple seedlings upon spray treatment with a 10 microM solution.

On the Temperature Dependence of Enzyme-Catalyzed Rates.

Science.gov (United States)

Arcus, Vickery L; Prentice, Erica J; Hobbs, Joanne K; Mulholland, Adrian J; Van der Kamp, Marc W; Pudney, Christopher R; Parker, Emily J; Schipper, Louis A

2016-03-29

One of the critical variables that determine the rate of any reaction is temperature. For biological systems, the effects of temperature are convoluted with myriad (and often opposing) contributions from enzyme catalysis, protein stability, and temperature-dependent regulation, for example. We have coined the phrase "macromolecular rate theory (MMRT)" to describe the temperature dependence of enzyme-catalyzed rates independent of stability or regulatory processes. Central to MMRT is the observation that enzyme-catalyzed reactions occur with significant values of ΔCp(‡) that are in general negative. That is, the heat capacity (Cp) for the enzyme-substrate complex is generally larger than the Cp for the enzyme-transition state complex. Consistent with a classical description of enzyme catalysis, a negative value for ΔCp(‡) is the result of the enzyme binding relatively weakly to the substrate and very tightly to the transition state. This observation of negative ΔCp(‡) has important implications for the temperature dependence of enzyme-catalyzed rates. Here, we lay out the fundamentals of MMRT. We present a number of hypotheses that arise directly from MMRT including a theoretical justification for the large size of enzymes and the basis for their optimum temperatures. We rationalize the behavior of psychrophilic enzymes and describe a "psychrophilic trap" which places limits on the evolution of enzymes in low temperature environments. One of the defining characteristics of biology is catalysis of chemical reactions by enzymes, and enzymes drive much of metabolism. Therefore, we also expect to see characteristics of MMRT at the level of cells, whole organisms, and even ecosystems.

Application of residual polysaccharide-degrading enzymes in dried shiitake mushrooms as an enzyme preparation in food processing.

Science.gov (United States)

Tatsumi, E; Konishi, Y; Tsujiyama, S

2016-11-01

To examine the activities of residual enzymes in dried shiitake mushrooms, which are a traditional foodstuff in Japanese cuisine, for possible applications in food processing. Polysaccharide-degrading enzymes remained intact in dried shiitake mushrooms and the activities of amylase, β-glucosidase and pectinase were high. A potato digestion was tested using dried shiitake powder. The enzymes reacted with potato tuber specimens to solubilize sugars even under a heterogeneous solid-state condition and that their reaction modes were different at 38 and 50 °C. Dried shiitake mushrooms have a potential use in food processing as an enzyme preparation.

PIXE analysis of Zn enzymes

International Nuclear Information System (INIS)

Solis, C.; Oliver, A.; Andrade, E.; Ruvalcaba-Sil, J.L.; Romero, I.; Celis, H.

1999-01-01

Zinc is a necessary component in the action and structural stability of many enzymes. Some of them are well characterized, but in others, Zn stoichiometry and its association is not known. PIXE has been proven to be a suitable technique for analyzing metallic proteins embedded in electrophoresis gels. In this study, PIXE has been used to investigate the Zn content of enzymes that are known to carry Zn atoms. These include the carbonic anhydrase, an enzyme well characterized by other methods and the cytoplasmic pyrophosphatase of Rhodospirillum rubrum that is known to require Zn to be stable but not how many metal ions are involved or how they are bound to the enzyme. Native proteins have been purified by polyacrylamide gel electrophoresis and direct identification and quantification of Zn in the gel bands was performed with an external proton beam of 3.7 MeV energy

Enzymes - important players in green chemistry

Directory of Open Access Journals (Sweden)

Agata Tarczykowska

2017-09-01

Full Text Available Green chemistry has become a worldwide approach that leads to sustainable growth through application and development of its principles. A lot of work has to be put into designing new processes comprising of materials which do not emit pollutants to the atmosphere. Inventing new safer methods and finding less harmful products can be challenging. Enzymes are a great hope of scientists in the field of green chemistry. Enzymes as catalysts require mild conditions therefore it is a great way of saving resources such as energy or water. Processes with the use of enzymes have become more feasible by being more cost effective and eco friendly. Taking into account the benefits of green chemistry, enzyme biocatalysis has quickly replaced traditional chemical processes in several fields, and this substitution is going to reach even more areas because of new emerging technologies in enzyme engineering.

Zymography methods for visualizing hydrolytic enzymes.

Science.gov (United States)

Vandooren, Jennifer; Geurts, Nathalie; Martens, Erik; Van den Steen, Philippe E; Opdenakker, Ghislain

2013-03-01

Zymography is a technique for studying hydrolytic enzymes on the basis of substrate degradation. It is a powerful, but often misinterpreted, tool yielding information on potential hydrolytic activities, enzyme forms and the locations of active enzymes. In this Review, zymography techniques are compared in terms of advantages, limitations and interpretations. With in gel zymography, enzyme forms are visualized according to their molecular weights. Proteolytic activities are localized in tissue sections with in situ zymography. In vivo zymography can pinpoint proteolytic activity to sites in an intact organism. Future development of novel substrate probes and improvement in detection and imaging methods will increase the applicability of zymography for (reverse) degradomics studies.

9 CFR 590.905 - Importation of restricted eggs or eggs containing more restricted eggs than permitted in the...

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Importation of restricted eggs or eggs containing more restricted eggs than permitted in the official standards for U.S. Consumer Grade B. 590.905... EGG PRODUCTS INSPECTION INSPECTION OF EGGS AND EGG PRODUCTS (EGG PRODUCTS INSPECTION ACT) Imports...

Intracerebral metastasis showing restricted diffusion: Correlation with histopathologic findings

Energy Technology Data Exchange (ETDEWEB)

Duygulu, G. [Radiology Department, Ege University Medicine School, Izmir (Turkey); Ovali, G. Yilmaz [Radiology Department, Celal Bayar University Medicine School, Manisa (Turkey)], E-mail: gulgun.yilmaz@bayar.edu.tr; Calli, C.; Kitis, O.; Yuenten, N. [Radiology Department, Ege University Medicine School, Izmir (Turkey); Akalin, T. [Pathology Department, Ege University Medicine School, Izmir (Turkey); Islekel, S. [Neurosurgery Department, Ege University Medicine School, Izmir (Turkey)

2010-04-15

Objective: We aimed to detect the frequency of restricted diffusion in intracerebral metastases and to find whether there is correlation between the primary tumor pathology and diffusion-weighted MR imaging (DWI) findings of these metastases. Material and methods: 87 patients with intracerebral metastases were examined with routine MR imaging and DWI. 11 hemorrhagic metastatic lesions were excluded. The routine MR imaging included three plans before and after contrast enhancement. The DWI was performed with spin-echo EPI sequence with three b values (0, 500 and 1000), and ADC maps were calculated. 76 patients with metastases were grouped according to primary tumor histology and the ratios of restricted diffusion were calculated according to these groups. ADCmin values were measured within the solid components of the tumors and the ratio of metastases with restricted diffusion to that which do not show restricted diffusion were calculated. Fisher's exact and Mann-Whitney U tests were used for the statistical analysis. Results: Restricted diffusion was observed in a total of 15 metastatic lesions (19, 7%). Primary malignancy was lung carcinoma in 10 of these cases (66, 6%) (5 small cell carcinoma, 5 non-small cell carcinoma), and breast carcinoma in three cases (20%). Colon carcinoma and testicular teratocarcinoma were the other two primary tumors in which restricted diffusion in metastasis was detected. There was no statistical significant difference between the primary pathology groups which showed restricted diffusion (p > 0.05). ADCmin values of solid components of the metastasis with restricted diffusion and other metastasis without restricted diffusion also showed no significant statistical difference (0.72 {+-} 0.16 x 10{sup -3} mm{sup 2}/s and 0.78 {+-} 21 x 10{sup -3} mm{sup 2}/s respectively) (p = 0.325). Conclusion: Detection of restricted diffusion on DWI in intracerebral metastasis is not rare, particularly if the primary tumor is lung or breast

Enzymes from Higher Eukaryotes for Industrial Biocatalysis

Directory of Open Access Journals (Sweden)

Zhibin Liu

2004-01-01

Full Text Available The industrial production of fine chemicals, feed and food ingredients, pharmaceuticals, agrochemicals and their respective intermediates relies on an increasing application of biocatalysis, i.e. on enzyme or whole-cell catalyzed conversions of molecules. Simple procedures for discovery, cloning and over-expression as well as fast growth favour fungi, yeasts and especially bacteria as sources of biocatalysts. Higher eukaryotes also harbour an almost unlimited number of potential biocatalysts, although to date the limited supply of enzymes, the high heterogeneity of enzyme preparations and the hazard of infectious contaminants keep some interesting candidates out of reach for industrial bioprocesses. In the past only a few animal and plant enzymes from agricultural waste materials were employed in food processing. The use of bacterial expression strains or non-conventional yeasts for the heterologous production of efficient eukaryotic enzymes can overcome the bottleneck in enzyme supply and provide sufficient amounts of homogenous enzyme preparations for reliable and economically feasible applications at large scale. Ideal enzymatic processes represent an environmentally friendly, »near-to-completion« conversion of (mostly non-natural substrates to pure products. Recent developments demonstrate the commercial feasibility of large-scale biocatalytic processes employing enzymes from higher eukaryotes (e.g. plants, animals and also their usefulness in some small-scale industrial applications.

Origins and Consequences of Religious Restrictions: A Global Overview

Science.gov (United States)

Finke, Roger

2014-01-01

Despite the international controversies surrounding religious restrictions and freedoms, the topic has only recently received substantial research attention. Drawing on this new body of research, and multiple research projects in progress, this address explores both the origins and consequences of religious restrictions in the global arena. To understand the motives for restrictions, I propose hypotheses in three areas: the relationship or lack of relationship between institutional religion and the state, the willingness and capacity of the state to ensure freedoms, and the larger social and cultural pressures restricting freedoms, including social and political movements targeting minority religions. Turning to the consequences of religious restrictions, I explore how and why restrictions alter the religious economy (i.e., formation, supply and operation of religions) and are associated with higher levels of religious persecution, religious violence and intrastate conflict in general. Finally, I review additional areas where research is needed. PMID:25364225

Process for preparing multilayer enzyme coating on a fiber

Science.gov (United States)

Kim, Jungbae [Richland, WA; Kwak, Ja Hun [Richland, WA; Grate, Jay W [West Richland, WA

2009-11-03

A process for preparing high stability, high activity biocatalytic materials is disclosed and processes for using the same. The process involves coating of a material or fiber with enzymes and enzyme aggregate providing a material or fiber with high biocatalytic activity and stability useful in heterogeneous environments. In one illustrative approach, enzyme "seeds" are covalently attached to polymer nanofibers followed by treatment with a reagent that crosslinks additional enzyme molecules to the seed enzymes forming enzyme aggregates thereby improving biocatalytic activity due to increased enzyme loading and enzyme stability. This approach creates a useful new biocatalytic immobilized enzyme system with potential applications in bioconversion, bioremediation, biosensors, and biofuel cells.

10 CFR 1045.33 - Appointment of restricted data management official.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Appointment of restricted data management official. 1045... DECLASSIFICATION Generation and Review of Documents Containing Restricted Data and Formerly Restricted Data § 1045.33 Appointment of restricted data management official. (a) Each agency with access to RD or FRD shall...

Synthesis of conformationally restricted beta-turn mimics

NARCIS (Netherlands)

IJsselstijn, M.

2006-01-01

This thesis aims at developing methods for introducing conformational restriction in Beta-turns, the turn elements present in Beta-sheets. A conformationally restricted peptide might either be formed via incorporation of a bridging diamino acids in a growing peptide chain, or via covalent bond

32 CFR 228.15 - Restriction regarding animals.

Science.gov (United States)

2010-07-01

... 32 National Defense 2 2010-07-01 2010-07-01 false Restriction regarding animals. 228.15 Section 228.15 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS SECURITY PROTECTIVE FORCE § 228.15 Restriction regarding animals. No animals except...

Restrictions on Software for Personal and Professional Use

CERN Multimedia

2004-01-01

A growing number of computer security incidents detected at CERN are due to additional software installed for personal and professional use. As a consequence, the smooth operation of CERN is put at risk and often many hours are lost solving the problems. To reduce this security risk, installation and/or use of software on CERN's computing and network infrastructure needs to be restricted. Therefore: Do NOT install software for personal use Do NOT install 'free' or other software unless you have the expertise to configure and maintain it securely. Please comply to these rules to keep our computer systems safe. Further explanation of these restrictions is at http://cern.ch/security/software-restrictions Restricted software, known to cause security and/or network problems (e.g. KaZaA and other P2P/Peer-to-Peer file sharing applications, Skype P2P telephony software, ICQ, VNC, ...), is listed at: http://cern.ch/security/software-restrictions/list

Can early protein restriction induce the development of binge eating?

Science.gov (United States)

Fechine, Madge Farias; Borba, Tássia Karin; Cabral-Filho, José Eulálio; Bolaños-Jiménez, Francisco; Lopes-de-Souza, Sandra; Manhães-de-Castro, Raul

2016-04-01

We tested the hypothesis that perinatal undernourishment is a factor for binge eating. At 52 days rats born from dams fed on 17% protein (Control) or 8% protein (Undernourished) were distributed into four groups, two of which continued to be fed ad libitum chow and two were submitted to three consecutive Restricted/Refeeding (R/R) cycles. According to the following schedule: Control Naïve (from mothers fed 17% protein/no restriction phase); Control Restricted (from mothers fed 17% protein/restriction phase); Undernourished Naïve (from mothers fed 8% protein/no restriction phase); and Undernourished Restricted (from mothers fed 8% protein/restriction phase). Each cycle consisted of a restriction phase (in the first four days 40% of the mean daily individual chow intake was offered for consumption), followed by a refeeding phase (4 days of chow ad libitum). After the three cycles, all animals were subjected to a feeding test (chow diet and palatable food ad libitum for 24h). During the feeding test, the Undernourished Restricted demonstrated rebound hyperphagia during 2, 4 and 6h. These results suggest the perinatal undernourishment cannot contribute to a binge eating phenotype. Copyright © 2016. Published by Elsevier B.V.

Short-Term Vitamin B-6 Restriction Does Not Affect Plasma Concentrations of Hydrogen Sulfide Biomarkers Lanthionine and Homolanthionine in Healthy Men and Women123

Science.gov (United States)

DeRatt, Barbara N; Ralat, Maria A; Gregory, Jesse F

2016-01-01

Background: Suboptimal vitamin B-6 status is associated with increased cardiovascular disease risk, although the mechanism is unknown. The synthesis of the vasodilator hydrogen sulfide occurs through side reactions of the transsulfuration enzymes cystathionine β-synthase and cystathionine γ-lyase, with pyridoxal 5′-phosphate as a coenzyme. Two proposed hydrogen sulfide biomarkers, lanthionine and homolanthionine, are produced concurrently. Objective: To determine whether hydrogen sulfide production is reduced by vitamin B-6 deficiency, we examined the relations between plasma concentrations of lanthionine and homolanthionine, along with other components of the transsulfuration pathway (homocysteine, cystathionine, and Cys), in a secondary analysis of samples from 2 vitamin B-6 restriction studies in healthy men and women. Methods: Metabolite concentrations were measured in plasma from 23 healthy adults (12 men and 11 women) before and after 28-d controlled dietary vitamin B-6 restriction (0.37 ± 0.04 mg/d). Vitamin B-6 restriction effects on lanthionine and homolanthionine concentrations were assessed. Associations between hydrogen sulfide biomarkers, transsulfuration metabolites, and functional indicators of vitamin B-6 deficiency were analyzed by linear regression. Results: Preprandial plasma lanthionine and homolanthionine concentrations ranged from 89.0 to 372 nmol/L and 5.75 to 32.3 nmol/L, respectively, in healthy adults. Mean lanthionine and homolanthionine concentrations were not affected by vitamin B-6 restriction (P restriction, homolanthionine was positively associated with functional indicators of vitamin B-6 deficiency, which differed from hypothesized negative associations. Plasma lanthionine was positively correlated with the concentration of its precursor, Cys, before (R2 = 0.36; P = 0.002) and after (R2 = 0.37; P = 0.002) restriction. Likewise, homolanthionine concentration was positively correlated with its precursor homocysteine, but only in

7 CFR 57.905 - Importation of restricted eggs or eggs containing more restricted eggs than permitted in the...

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Importation of restricted eggs or eggs containing more restricted eggs than permitted in the official standards for U.S. Consumer Grade B. 57.905 Section 57.905... AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) INSPECTION OF EGGS (EGG...

Biocatalysis with thermostable enzymes: structure and properties of a thermophilic 'ene'-reductase related to old yellow enzyme.

Science.gov (United States)

Adalbjörnsson, Björn V; Toogood, Helen S; Fryszkowska, Anna; Pudney, Christopher R; Jowitt, Thomas A; Leys, David; Scrutton, Nigel S

2010-01-25

We report the crystal structure of a thermophilic "ene" reductase (TOYE) isolated from Thermoanaerobacter pseudethanolicus E39. The crystal structure reveals a tetrameric enzyme and an active site that is relatively large compared to most other structurally determined and related Old Yellow Enzymes. The enzyme adopts higher order oligomeric states (octamers and dodecamers) in solution, as revealed by sedimentation velocity and multiangle laser light scattering. Bead modelling indicates that the solution structure is consistent with the basic tetrameric structure observed in crystallographic studies and electron microscopy. TOYE is stable at high temperatures (T(m)>70 degrees C) and shows increased resistance to denaturation in water-miscible organic solvents compared to the mesophilic Old Yellow Enzyme family member, pentaerythritol tetranitrate reductase. TOYE has typical ene-reductase properties of the Old Yellow Enzyme family. There is currently major interest in using Old Yellow Enzyme family members in the preparative biocatalysis of a number of activated alkenes. The increased stability of TOYE in organic solvents is advantageous for biotransformations in which water-miscible organic solvents and biphasic reaction conditions are required to both deliver novel substrates and minimize product racemisation.

Consequences in Infants That Were Intrauterine Growth Restricted

Directory of Open Access Journals (Sweden)

Erich Cosmi

2011-01-01

Full Text Available Intrauterine growth restriction is a condition fetus does not reach its growth potential and associated with perinatal mobility and mortality. Intrauterine growth restriction is caused by placental insufficiency, which determines cardiovascular abnormalities in the fetus. This condition, moreover, should prompt intensive antenatal surveillance of the fetus as well as follow-up of infants that had intrauterine growth restriction as short and long-term sequele should be considered.

Fasting or caloric restriction for healthy aging.

Science.gov (United States)

Anton, Stephen; Leeuwenburgh, Christiaan

2013-10-01

Aging is associated with a host of biological changes that contribute to a progressive decline in cognitive and physical function, ultimately leading to a loss of independence, and increased risk of mortality. To date, prolonged caloric restriction (i.e., a reduction in caloric intake without malnutrition) is the only non-genetic intervention that has consistently been found to extend both mean and maximal life span across a variety of species. Most individuals have difficulty sustaining prolonged caloric restriction, which has led to a search for alternative approaches that can produce similar to benefits as caloric restriction. A growing body of evidence indicates that fasting periods and intermittent fasting regimens in particular can trigger similar biological pathways as caloric restriction. For this reason, there is increasing scientific interest in further exploring the biological and metabolic effects of intermittent fasting periods, as well as whether long-term compliance may be improved by this type of dietary approach. This special will highlight the latest scientific findings related to the effects of both caloric restriction and intermittent fasting across various species including yeast, fruit flies, worms, rodents, primates, and humans. A specific emphasis is placed on translational research with findings from basic bench to bedside reviewed and practical clinical implications discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

Type III restriction endonucleases are heterotrimeric: comprising one helicase–nuclease subunit and a dimeric methyltransferase that binds only one specific DNA

Science.gov (United States)

Butterer, Annika; Pernstich, Christian; Smith, Rachel M.; Sobott, Frank; Szczelkun, Mark D.; Tóth, Júlia

2014-01-01

Fundamental aspects of the biochemistry of Type III restriction endonucleases remain unresolved despite being characterized by numerous research groups in the past decades. One such feature is the subunit stoichiometry of these hetero-oligomeric enzyme complexes, which has important implications for the reaction mechanism. In this study, we present a series of results obtained by native mass spectrometry and size exclusion chromatography with multi-angle light scattering consistent with a 1:2 ratio of Res to Mod subunits in the EcoP15I, EcoPI and PstII complexes as the main holoenzyme species and a 1:1 stoichiometry of specific DNA (sDNA) binding by EcoP15I and EcoPI. Our data are also consistent with a model where ATP hydrolysis activated by recognition site binding leads to release of the enzyme from the site, dissociation from the substrate via a free DNA end and cleavage of the DNA. These results are discussed critically in the light of the published literature, aiming to resolve controversies and discuss consequences in terms of the reaction mechanism. PMID:24510100

10 CFR 1016.34 - Accountability for Secret Restricted Data.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Accountability for Secret Restricted Data. 1016.34 Section... Information § 1016.34 Accountability for Secret Restricted Data. Each permittee possessing documents containing Secret Restricted Data shall establish a document accountability procedure and shall maintain...

Cardiovascular adaptation to extrauterine life after intrauterine growth restriction.

Science.gov (United States)

Rodriguez-Guerineau, Luciana; Perez-Cruz, Miriam; Gomez Roig, María D; Cambra, Francisco J; Carretero, Juan; Prada, Fredy; Gómez, Olga; Crispi, Fátima; Bartrons, Joaquim

2018-02-01

Introduction The adaptive changes of the foetal heart in intrauterine growth restriction can persist postnatally. Data regarding its consequences for early circulatory adaptation to extrauterine life are scarce. The aim of this study was to assess cardiac morphometry and function in newborns with late-onset intrauterine growth restriction to test the hypothesis that intrauterine growth restriction causes cardiac shape and functional changes at birth. A comprehensive echocardiographic study was performed in 25 neonates with intrauterine growth restriction and 25 adequate-for-gestational-age neonates. Compared with controls, neonates with intrauterine growth restriction had more globular ventricles, lower longitudinal tricuspid annular motion, and higher left stroke volume without differences in the heart rate. Neonates with intrauterine growth restriction also showed subclinical signs of diastolic dysfunction in the tissue Doppler imaging with lower values of early (e') diastolic annular peak velocities in the septal annulus. Finally, the Tei index in the tricuspid annulus was higher in the intrauterine growth restriction group. Neonates with history of intrauterine growth restriction showed cardiac remodelling and signs of systolic and diastolic dysfunction. Overall, there was a significant tendency to worse cardiac function results in the right heart. The adaptation to extrauterine life occurred with more globular hearts, higher stroke volumes but a similar heart rate compared to adequate-for-gestational-age neonates.

The Enzyme Function Initiative†

Science.gov (United States)

Gerlt, John A.; Allen, Karen N.; Almo, Steven C.; Armstrong, Richard N.; Babbitt, Patricia C.; Cronan, John E.; Dunaway-Mariano, Debra; Imker, Heidi J.; Jacobson, Matthew P.; Minor, Wladek; Poulter, C. Dale; Raushel, Frank M.; Sali, Andrej; Shoichet, Brian K.; Sweedler, Jonathan V.

2011-01-01

The Enzyme Function Initiative (EFI) was recently established to address the challenge of assigning reliable functions to enzymes discovered in bacterial genome projects; in this Current Topic we review the structure and operations of the EFI. The EFI includes the Superfamily/Genome, Protein, Structure, Computation, and Data/Dissemination Cores that provide the infrastructure for reliably predicting the in vitro functions of unknown enzymes. The initial targets for functional assignment are selected from five functionally diverse superfamilies (amidohydrolase, enolase, glutathione transferase, haloalkanoic acid dehalogenase, and isoprenoid synthase), with five superfamily-specific Bridging Projects experimentally testing the predicted in vitro enzymatic activities. The EFI also includes the Microbiology Core that evaluates the in vivo context of in vitro enzymatic functions and confirms the functional predictions of the EFI. The deliverables of the EFI to the scientific community include: 1) development of a large-scale, multidisciplinary sequence/structure-based strategy for functional assignment of unknown enzymes discovered in genome projects (target selection, protein production, structure determination, computation, experimental enzymology, microbiology, and structure-based annotation); 2) dissemination of the strategy to the community via publications, collaborations, workshops, and symposia; 3) computational and bioinformatic tools for using the strategy; 4) provision of experimental protocols and/or reagents for enzyme production and characterization; and 5) dissemination of data via the EFI’s website, enzymefunction.org. The realization of multidisciplinary strategies for functional assignment will begin to define the full metabolic diversity that exists in nature and will impact basic biochemical and evolutionary understanding, as well as a wide range of applications of central importance to industrial, medicinal and pharmaceutical efforts. PMID

The Enzyme Function Initiative.

Science.gov (United States)

Gerlt, John A; Allen, Karen N; Almo, Steven C; Armstrong, Richard N; Babbitt, Patricia C; Cronan, John E; Dunaway-Mariano, Debra; Imker, Heidi J; Jacobson, Matthew P; Minor, Wladek; Poulter, C Dale; Raushel, Frank M; Sali, Andrej; Shoichet, Brian K; Sweedler, Jonathan V

2011-11-22

The Enzyme Function Initiative (EFI) was recently established to address the challenge of assigning reliable functions to enzymes discovered in bacterial genome projects; in this Current Topic, we review the structure and operations of the EFI. The EFI includes the Superfamily/Genome, Protein, Structure, Computation, and Data/Dissemination Cores that provide the infrastructure for reliably predicting the in vitro functions of unknown enzymes. The initial targets for functional assignment are selected from five functionally diverse superfamilies (amidohydrolase, enolase, glutathione transferase, haloalkanoic acid dehalogenase, and isoprenoid synthase), with five superfamily specific Bridging Projects experimentally testing the predicted in vitro enzymatic activities. The EFI also includes the Microbiology Core that evaluates the in vivo context of in vitro enzymatic functions and confirms the functional predictions of the EFI. The deliverables of the EFI to the scientific community include (1) development of a large-scale, multidisciplinary sequence/structure-based strategy for functional assignment of unknown enzymes discovered in genome projects (target selection, protein production, structure determination, computation, experimental enzymology, microbiology, and structure-based annotation), (2) dissemination of the strategy to the community via publications, collaborations, workshops, and symposia, (3) computational and bioinformatic tools for using the strategy, (4) provision of experimental protocols and/or reagents for enzyme production and characterization, and (5) dissemination of data via the EFI's Website, http://enzymefunction.org. The realization of multidisciplinary strategies for functional assignment will begin to define the full metabolic diversity that exists in nature and will impact basic biochemical and evolutionary understanding, as well as a wide range of applications of central importance to industrial, medicinal, and pharmaceutical efforts. �

Supporting several levels of restriction in the UML

DEFF Research Database (Denmark)

Hansen, Klaus Marius; Damm, Christian Heide; Thomsen, Michael

2000-01-01

The emergence of the Unified Modeling Language (UML) has provided software developers with an effective and efficient shared language. However, UML is often too restrictive in initial, informal, and creative modelling, and it is in some cases not restrictive enough, e.g., for code generation. Bas....... This approach potentially increases the usability of the UML, and thus ultimately leads to greater quality and adoption of UML models.......The emergence of the Unified Modeling Language (UML) has provided software developers with an effective and efficient shared language. However, UML is often too restrictive in initial, informal, and creative modelling, and it is in some cases not restrictive enough, e.g., for code generation. Based...

Transmission of the PabI family of restriction DNA glycosylase genes: mobility and long-term inheritance.

Science.gov (United States)

Kojima, Kenji K; Kobayashi, Ichizo

2015-10-19

R.PabI is an exceptional restriction enzyme that functions as a DNA glycosylase. The enzyme excises an unmethylated base from its recognition sequence to generate apurinic/apyrimidinic (AP) sites, and also displays AP lyase activity, cleaving the DNA backbone at the AP site to generate the 3'-phospho alpha, beta-unsaturated aldehyde end in addition to the 5'-phosphate end. The resulting ends are difficult to religate with DNA ligase. The enzyme was originally isolated in Pyrococcus, a hyperthermophilic archaeon, and additional homologs subsequently identified in the epsilon class of the Gram-negative bacterial phylum Proteobacteria, such as Helicobacter pylori. Systematic analysis of R.PabI homologs and their neighboring genes in sequenced genomes revealed co-occurrence of R.PabI with M.PabI homolog methyltransferase genes. R.PabI and M.PabI homolog genes are occasionally found at corresponding (orthologous) loci in different species, such as Helicobacter pylori, Helicobacter acinonychis and Helicobacter cetorum, indicating long-term maintenance of the gene pair. One R.PabI and M.PabI homolog gene pair is observed immediately after the GMP synthase gene in both Campylobacter and Helicobacter, representing orthologs beyond genera. The mobility of the PabI family of restriction-modification (RM) system between genomes is evident upon comparison of genomes of sibling strains/species. Analysis of R.PabI and M.PabI homologs in H. pylori revealed an insertion of integrative and conjugative elements (ICE), and replacement with a gene of unknown function that may specify a membrane-associated toxin (hrgC). In view of the similarity of HrgC with toxins in type I toxin-antitoxin systems, we addressed the biological significance of this substitution. Our data indicate that replacement with hrgC occurred in the common ancestor of hspAmerind and hspEAsia. Subsequently, H. pylori with and without hrgC were intermixed at this locus, leading to complex distribution of hrgC in East

Enzyme-lipid complex. Koso-shishitsu fukugotai

Energy Technology Data Exchange (ETDEWEB)

Okahata, Y; Ijiro, K [Tokyo Inst. of Technology., Tokyo (Japan)

1990-08-01

Enzyme, as unstable against organic solvent, being to be designed not to be quenched, organic solvent was tried to be made soluble by making enzyme-lipid complex. By mixing aqueous solution of enzyme with aqueous dispersion liquid of lipid, white powder was obtaind. Enzyme has monomolecular film through which reaction substance passes. Lipase-lipid complex, of which monomolecular film is qualified by hydrogen and other soft linkages, homogeneously dissolves in organic solvent and has a high activity, not given by the conventional qualification method. That activity being applied, asymmetrical esterificating reaction of alcohol could be done in organic solvent, containing high concentration reactive substance. While substance selectivity, not known in water, was obtained. Through reaction of amine with amino acid dielectrics in isooctane solvent by {alpha}-chymotrypsin-lipid complex, was indicated an exact substance selectivity. Enzyme-lipid complex dissolving in organic solvent, monomolecular film can be formed without being quenched on aqueous surface, which film can be utilized as sensor film. 10 refs., 5 figs. 1 tab.

Intrauterine growth restriction

Directory of Open Access Journals (Sweden)

Bernardita Donoso Bernales

2012-07-01

Full Text Available It is estimated that the true prevalence of intrauterine growth restriction is 3-10% of all pregnancies, making this fetal condition one of the most frequent obstetric problems, together with premature labor and premature rupture of membranes. The article stresses the importance of early diagnosis because of the associated risks.

Biomedical Applications of Enzymes From Marine Actinobacteria.

Science.gov (United States)

Kamala, K; Sivaperumal, P

Marine microbial enzyme technologies have progressed significantly in the last few decades for different applications. Among the various microorganisms, marine actinobacterial enzymes have significant active properties, which could allow them to be biocatalysts with tremendous bioactive metabolites. Moreover, marine actinobacteria have been considered as biofactories, since their enzymes fulfill biomedical and industrial needs. In this chapter, the marine actinobacteria and their enzymes' uses in biological activities and biomedical applications are described. © 2017 Elsevier Inc. All rights reserved.

Structural similarities and functional differences clarify evolutionary relationships between tRNA healing enzymes and the myelin enzyme CNPase.

Science.gov (United States)

Muruganandam, Gopinath; Raasakka, Arne; Myllykoski, Matti; Kursula, Inari; Kursula, Petri

2017-05-16

Eukaryotic tRNA splicing is an essential process in the transformation of a primary tRNA transcript into a mature functional tRNA molecule. 5'-phosphate ligation involves two steps: a healing reaction catalyzed by polynucleotide kinase (PNK) in association with cyclic phosphodiesterase (CPDase), and a sealing reaction catalyzed by an RNA ligase. The enzymes that catalyze tRNA healing in yeast and higher eukaryotes are homologous to the members of the 2H phosphoesterase superfamily, in particular to the vertebrate myelin enzyme 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase). We employed different biophysical and biochemical methods to elucidate the overall structural and functional features of the tRNA healing enzymes yeast Trl1 PNK/CPDase and lancelet PNK/CPDase and compared them with vertebrate CNPase. The yeast and the lancelet enzymes have cyclic phosphodiesterase and polynucleotide kinase activity, while vertebrate CNPase lacks PNK activity. In addition, we also show that the healing enzymes are structurally similar to the vertebrate CNPase by applying synchrotron radiation circular dichroism spectroscopy and small-angle X-ray scattering. We provide a structural analysis of the tRNA healing enzyme PNK and CPDase domains together. Our results support evolution of vertebrate CNPase from tRNA healing enzymes with a loss of function at its N-terminal PNK-like domain.

Enzyme-Powered Pumps: From Fundamentals to Applications

Science.gov (United States)

Ortiz-Rivera, Isamar

Non-mechanical nano and microfluidic devices that function without the aid of an external power source, and can be tailored to meet specific needs, represent the next generation of smart devices. Recently, we have shown that surface-bound enzymes can act as pumps driving large-scale fluid flows in the presence of any substance that triggers the enzymatic reaction (e.g. substrate, co-factor, or biomarker). The fluid velocities attained in such systems depend directly on the enzymatic reaction rate and the concentration of the substance that initiates enzymatic catalysis. The use of biochemical reactions to power a micropump offers the advantages of specificity, sensitivity, and selectively, eliminating at the same time the need of an external power source, while providing biocompatibility. More importantly, these self-powered pumps overcome a significant obstacle in nano- and micro-fluidics: the need to use external pressure-driven pumps to push fluids through devices. Certainly, the development of enzyme-powered devices opens up new venues in biochemical engineering, particularly in the biomedical field. The work highlighted in this dissertation covers all the studies performed with enzyme-powered pumps, from the development of the micropump design, to the efforts invested in understanding the enzyme pump concept as a whole. The data collected to date, aims to expand our knowledge about enzyme-powered micropumps from the inside out: not only by exploring the different applications of these devices at the macroscale, but also by investigating in depth the mechanism of pump activation behind these systems. Specifically, we have focused on: (1) The general features that characterize the pumping behavior observed in enzyme-powered pumps, as well as the optimization of the device, (2) the possible mechanisms behind fluid motion, including the role of enzyme coverage and/or activity on the transduction of chemical energy into mechanical fluid flow in these devices

Evaluation and selection of Bacillus species based on enzyme production, antimicrobial activity and biofilm synthesis as direct-fed microbials candidates for poultry

Directory of Open Access Journals (Sweden)

Juan D Latorre

2016-10-01

Full Text Available Social concern about misuse of antibiotics as growth promoters (AGP and generation of multidrug-resistant bacteria have restricted the dietary inclusion of antibiotics in livestock feed in several countries. Direct-fed microbials (DFM are one of the multiple alternatives commonly evaluated as substitutes of AGP. Sporeformer bacteria from the genus Bacillus have been extensively investigated because of their extraordinary properties to form highly-resistant endospores, production of antimicrobial compounds and synthesize different exogenous enzymes. The purpose of the present study was to evaluate and select Bacillus spp. from environmental and poultry sources as DFM candidates, considering their enzyme production profile, biofilm synthesis capacity and pathogen-inhibition activity. Thirty one Bacillus isolates were screened for in vitro relative enzyme activity of amylase, protease, lipase and phytase using a selective media for each enzyme, with 3/31 strains selected as superior enzyme producers. These three isolates were identified as B. subtilis (1/3, and B. amyloliquefaciens (2/3 based on biochemical tests and 16S rRNA sequence analysis. For evaluation of biofilm synthesis, the generation of an adherent crystal violet-stained ring was determined in polypropylene tubes, resulting in 11/31 strains showing a strong biofilm formation. Moreover, all Bacillus strains were evaluated for growth inhibition activity against Salmonella enterica serovar Enteritidis (26/31, Escherichia coli (28/31 and Clostridioides difficile (29/31. Additionally, in previous in vitro and in vivo studies, these selected Bacillus strains have shown to be resistant to different biochemical conditions of the gastrointestinal tract of poultry. Results of the present study suggest that the selection and consumption of Bacillus-DFM, producing a variable set of enzymes and antimicrobial compounds may contribute to enhanced performance through improving nutrient digestibility

Digestive enzymes of some earthworms.

Science.gov (United States)

Mishra, P C; Dash, M C

1980-10-15

4 species of tropical earthworms differed with regard to enzyme activity. The maximum activity of protease and of cellulase occurred in the posterior region of the gut of the earthworms. On the average Octochaetona surensis shows maximum activity and Drawida calebi shows minimum activity for all the enzymes studied.

Activity assessment of microbial fibrinolytic enzymes.

Science.gov (United States)

Kotb, Essam

2013-08-01

Conversion of fibrinogen to fibrin inside blood vessels results in thrombosis, leading to myocardial infarction and other cardiovascular diseases. In general, there are four therapy options: surgical operation, intake of antiplatelets, anticoagulants, or fibrinolytic enzymes. Microbial fibrinolytic enzymes have attracted much more attention than typical thrombolytic agents because of the expensive prices and the side effects of the latter. The fibrinolytic enzymes were successively discovered from different microorganisms, the most important among which is the genus Bacillus. Microbial fibrinolytic enzymes, especially those from food-grade microorganisms, have the potential to be developed as functional food additives and drugs to prevent or cure thrombosis and other related diseases. There are several assay methods for these enzymes; this may due to the insolubility of substrate, fibrin. Existing assay methods can be divided into three major groups. The first group consists of assay of fibrinolytic activity with natural proteins as substrates, e.g., fibrin plate methods. The second and third groups of assays are suitable for kinetic studies and are based on the determination of hydrolysis of synthetic peptide esters. This review will deal primarily with the microorganisms that have been reported in literature to produce fibrinolytic enzymes and the first review discussing the methods used to assay the fibrinolytic activity.

Caloric restriction and intermittent fasting: Two potential diets for successful brain aging

Science.gov (United States)

Martin, Bronwen; Mattson, Mark P.; Maudsley, Stuart

2008-01-01

The vulnerability of the nervous system to advancing age is all too often manifest in neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. In this review article we describe evidence suggesting that two dietary interventions, caloric restriction (CR) and intermittent fasting (IF), can prolong the health-span of the nervous system by impinging upon fundamental metabolic and cellular signaling pathways that regulate life-span. CR and IF affect energy and oxygen radical metabolism, and cellular stress response systems, in ways that protect neurons against genetic and environmental factors to which they would otherwise succumb during aging. There are multiple interactive pathways and molecular mechanisms by which CR and IF benefit neurons including those involving insulin-like signaling, FoxO transcription factors, sirtuins and peroxisome proliferator-activated receptors. These pathways stimulate the production of protein chaperones, neurotrophic factors and antioxidant enzymes, all of which help cells cope with stress and resist disease. A better understanding of the impact of CR and IF on the aging nervous system will likely lead to novel approaches for preventing and treating neurodegenerative disorders. PMID:16899414

Purification and characterization of extracellular amylolytic enzyme ...

African Journals Online (AJOL)

In the present study, the amylase enzyme producing potential of four different Aspergillus species was analyzed. The extracted amylase enzyme was purified by diethyl amino ethyl (DEAE) cellulose and Sephadex G-50 column chromatography and the enzyme activity was measured by using synthetic substrate starch.

Restricted mass energy absorption coefficients for use in dosimetry

International Nuclear Information System (INIS)

Brahme, A.

1977-02-01

When matter is irradiated by a photon beam the fraction of energy absorbed locally in some region Rsub(Δ) (where the size of the region Rsub(Δ) is related to the range of secondary electrons of some restriction energy Δ) is expressed by the restricted mass energy absorption coefficient. In this paper an example is given of how restricted mass energy absorption coefficients can be calculated from existing differential photon interaction cross sections. Some applications of restricted mass absorption coefficients in dosimetry are also given. (B.D.)

Universal Cycles of Restricted Classes of Words

OpenAIRE

Leitner, Arielle; Godbole, Anant

2008-01-01

It is well known that Universal Cycles of $k$-letter words on an $n$-letter alphabet exist for all $k$ and $n$. In this paper, we prove that Universal Cycles exist for restricted classes of words, including: non-bijections, equitable words (under suitable restrictions), ranked permutations, and "passwords".

32 CFR 234.12 - Restriction on animals.

Science.gov (United States)

2010-07-01

... 32 National Defense 2 2010-07-01 2010-07-01 false Restriction on animals. 234.12 Section 234.12 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS CONDUCT ON THE PENTAGON RESERVATION § 234.12 Restriction on animals. Animals, except guide dogs...

[Automated analyzer of enzyme immunoassay].

Science.gov (United States)

Osawa, S

1995-09-01

Automated analyzers for enzyme immunoassay can be classified by several points of view: the kind of labeled antibodies or enzymes, detection methods, the number of tests per unit time, analytical time and speed per run. In practice, it is important for us consider the several points such as detection limits, the number of tests per unit time, analytical range, and precision. Most of the automated analyzers on the market can randomly access and measure samples. I will describe the recent advance of automated analyzers reviewing their labeling antibodies and enzymes, the detection methods, the number of test per unit time and analytical time and speed per test.

Comparison of Enzymes / Non-Enzymes Proteins Classification Models Based on 3D, Composition, Sequences and Topological Indices

OpenAIRE

Munteanu, Cristian Robert

2014-01-01

Comparison of Enzymes / Non-Enzymes Proteins Classification Models Based on 3D, Composition, Sequences and Topological Indices, German Conference on Bioinformatics (GCB), Potsdam, Germany (September, 2007)

Early evolution of efficient enzymes and genome organization

Directory of Open Access Journals (Sweden)

Szilágyi András

2012-10-01

Full Text Available Abstract Background Cellular life with complex metabolism probably evolved during the reign of RNA, when it served as both information carrier and enzyme. Jensen proposed that enzymes of primordial cells possessed broad specificities: they were generalist. When and under what conditions could primordial metabolism run by generalist enzymes evolve to contemporary-type metabolism run by specific enzymes? Results Here we show by numerical simulation of an enzyme-catalyzed reaction chain that specialist enzymes spread after the invention of the chromosome because protocells harbouring unlinked genes maintain largely non-specific enzymes to reduce their assortment load. When genes are linked on chromosomes, high enzyme specificity evolves because it increases biomass production, also by reducing taxation by side reactions. Conclusion The constitution of the genetic system has a profound influence on the limits of metabolic efficiency. The major evolutionary transition to chromosomes is thus proven to be a prerequisite for a complex metabolism. Furthermore, the appearance of specific enzymes opens the door for the evolution of their regulation. Reviewers This article was reviewed by Sándor Pongor, Gáspár Jékely, and Rob Knight.

Contemporary enzyme based technologies for bioremediation: A review.

Science.gov (United States)

Sharma, Babita; Dangi, Arun Kumar; Shukla, Pratyoosh

2018-03-15

The persistent disposal of xenobiotic compounds like insecticides, pesticides, fertilizers, plastics and other hydrocarbon containing substances is the major source of environmental pollution which needs to be eliminated. Many contemporary remediation methods such as physical, chemical and biological are currently being used, but they are not sufficient to clean the environment. The enzyme based bioremediation is an easy, quick, eco-friendly and socially acceptable approach used for the bioremediation of these recalcitrant xenobiotic compounds from the natural environment. Several microbial enzymes with bioremediation capability have been isolated and characterized from different natural sources, but less production of such enzymes is a limiting their further exploitation. The genetic engineering approach has the potential to get large amount of recombinant enzymes. Along with this, enzyme immobilization techniques can boost the half-life, stability and activity of enzymes at a significant level. Recently, nanozymes may offer the potential bioremediation ability towards a broad range of pollutants. In the present review, we have described a brief overview of the microbial enzymes, different enzymes techniques (genetic engineering and immobilization of enzymes) and nanozymes involved in bioremediation of toxic, carcinogenic and hazardous environmental pollutants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characterization of European Yersinia enterocolitica 1A strains using restriction fragment length polymorphism and multilocus sequence analysis.

Science.gov (United States)

Murros, A; Säde, E; Johansson, P; Korkeala, H; Fredriksson-Ahomaa, M; Björkroth, J

2016-10-01

Yersinia enterocolitica is currently divided into two subspecies: subsp. enterocolitica including highly pathogenic strains of biotype 1B and subsp. palearctica including nonpathogenic strains of biotype 1A and moderately pathogenic strains of biotypes 2-5. In this work, we characterized 162 Y. enterocolitica strains of biotype 1A and 50 strains of biotypes 2-4 isolated from human, animal and food samples by restriction fragment length polymorphism using the HindIII restriction enzyme. Phylogenetic relatedness of 20 representative Y. enterocolitica strains including 15 biotype 1A strains was further studied by the multilocus sequence analysis of four housekeeping genes (glnA, gyrB, recA and HSP60). In all the analyses, biotype 1A strains formed a separate genomic group, which differed from Y. enterocolitica subsp. enterocolitica and from the strains of biotypes 2-4 of Y. enterocolitica subsp. palearctica. Based on these results, biotype 1A strains considered nonpathogenic should not be included in subspecies palearctica containing pathogenic strains of biotypes 2-5. Yersinia enterocolitica strains are currently divided into six biotypes and two subspecies. Strains of biotype 1A, which are phenotypically and genotypically very heterogeneous, are classified as subspecies palearctica. In this study, European Y. enterocolitica 1A strains isolated from both human and nonhuman sources were characterized using restriction fragment length polymorphism and multilocus sequence analysis. The European biotype 1A strains formed a separate group, which differed from strains belonging to subspecies enterocolitica and palearctica. This may indicate that the current division between the two subspecies is not sufficient considering the strain diversity within Y. enterocolitica. © 2016 The Society for Applied Microbiology.

A thermodynamic and theoretical view for enzyme regulation.

Science.gov (United States)

Zhao, Qinyi

2015-01-01

Precise regulation is fundamental to the proper functioning of enzymes in a cell. Current opinions about this, such as allosteric regulation and dynamic contribution to enzyme regulation, are experimental models and substantially empirical. Here we proposed a theoretical and thermodynamic model of enzyme regulation. The main idea is that enzyme regulation is processed via the regulation of abundance of active conformation in the reaction buffer. The theoretical foundation, experimental evidence, and experimental criteria to test our model are discussed and reviewed. We conclude that basic principles of enzyme regulation are laws of protein thermodynamics and it can be analyzed using the concept of distribution curve of active conformations of enzymes.

Activation of interfacial enzymes at membrane surfaces

DEFF Research Database (Denmark)

Mouritsen, Ole G.; Andresen, Thomas Lars; Halperin, Avi

2006-01-01

A host of water-soluble enzymes are active at membrane surfaces and in association with membranes. Some of these enzymes are involved in signalling and in modification and remodelling of the membranes. A special class of enzymes, the phospholipases, and in particular secretory phospholipase A2 (s...

32 CFR 1903.16 - Restriction on animals.

Science.gov (United States)

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Restriction on animals. 1903.16 Section 1903.16... AGENCY INSTALLATIONS § 1903.16 Restriction on animals. Animals, except for those animals used for the assistance of persons with disabilities, or animals under the charge and control of the Central Intelligence...

37 CFR 1.142 - Requirement for restriction.

Science.gov (United States)

2010-07-01

... at any time before final action. (b) Claims to the invention or inventions not elected, if not... Inventions in One Application; Restriction § 1.142 Requirement for restriction. (a) If two or more independent and distinct inventions are claimed in a single application, the examiner in an Office action will...

Rethinking fundamentals of enzyme action.

Science.gov (United States)

Northrop, D B

1999-01-01

Despite certain limitations, investigators continue to gainfully employ concepts rooted in steady-state kinetics in efforts to draw mechanistically relevant inferences about enzyme catalysis. By reconsidering steady-state enzyme kinetic behavior, this review develops ideas that allow one to arrive at the following new definitions: (a) V/K, the ratio of the maximal initial velocity divided by the Michaelis-Menten constant, is the apparent rate constant for the capture of substrate into enzyme complexes that are destined to yield product(s) at some later point in time; (b) the maximal velocity V is the apparent rate constant for the release of substrate from captured complexes in the form of free product(s); and (c) the Michaelis-Menten constant K is the ratio of the apparent rate constants for release and capture. The physiologic significance of V/K is also explored to illuminate aspects of antibiotic resistance, the concept of "perfection" in enzyme catalysis, and catalytic proficiency. The conceptual basis of congruent thermodynamic cycles is also considered in an attempt to achieve an unambiguous way for comparing an enzyme-catalyzed reaction with its uncatalyzed reference reaction. Such efforts promise a deeper understanding of the origins of catalytic power, as it relates to stabilization of the reactant ground state, stabilization of the transition state, and reciprocal stabilizations of ground and transition states.

[Restricted motion after total knee arthroplasty].

Science.gov (United States)

Kucera, T; Urban, K; Karpas, K; Sponer, P

2007-10-01

The aim of the study was to ascertain what proportion of patients undergoing total knee arthroplasty (TKA) complain of restricted knee joint motion, and to investigate options for improvement of this situation. Our evaluation included a group of 796 patients treated with TKA at our department in the period from January 1, 1990, to December 31, 2004. In all cases, a condylar implant with preservation of the posterior cruciate ligaments was used. In addition to medical history, the range of motion, knee joint malalignment and radiological findings were assessed before surgery. After THA, the type of implant and complications, if any, were recorded, and improvement in joint motion was followed up. Based on the results of Kim et al., flexion contracture equal to or higher than 15 degrees and/or flexion less than 75 degrees were made the criteria of stiffness after THA. Patients with restricted THA motion who had aseptic or septic implant loosening were not included. Of the 796 evaluated patients, 32 (4.14 %) showed restricted motion after total knee arthroplasty, as assessed by the established criteria. In 16 patients, stiffness defined by these criteria had existed before surgery, and three patients showed an excessive production of adhesions and heterotopic ossifications. In three patients, the implantation procedure resulted in an elevated level of the original joint line and subsequent development of patella infera and increased tension of the posterior cruciate ligament. Four patients declined physical therapy and, in six, the main cause of stiffness could not be found. Seventeen patients did not require surgical therapy for restricted motion; TKA provided significant pain relief and they considered the range of motion achieved to be sufficient. One patient underwent redress 3 months after surgery, but with no success. Repeated releases of adhesions, replacement of a polyethylene liner and revision surgery of the extensor knee structures were performed in 15

Binding affinity and adhesion force of organophosphate hydrolase enzyme with soil particles related to the isoelectric point of the enzyme.

Science.gov (United States)

Islam, Shah Md Asraful; Yeasmin, Shabina; Islam, Md Saiful; Islam, Md Shariful

2017-07-01

The binding affinity of organophosphate hydrolase enzyme (OphB) with soil particles in relation to the isoelectric point (pI) was studied. Immobilization of OphB with soil particles was observed by confocal microscopy, Fourier transform infrared spectroscopy (FT-IR), and Atomic force microscopy (AFM). The calculated pI of OphB enzyme was increased from 8.69 to 8.89, 9.04 and 9.16 by the single, double and triple mutant of OphB enzyme, respectively through the replacement of negatively charged aspartate with positively charged histidine. Practically, the binding affinity was increased to 5.30%, 11.50%, and 16.80% for single, double and triple mutants, respectively. In contrast, enzyme activity of OphB did not change by the mutation of the enzyme. On the other hand, adhesion forces were gradually increased for wild type OphB enzyme (90 pN) to 96, 100 and 104 pN for single, double and triple mutants of OphB enzyme, respectively. There was an increasing trend of binding affinity and adhesion force by the increase of isoelectric point (pI) of OphB enzyme. Copyright © 2017 Elsevier Inc. All rights reserved.

Ultra-performance liquid chromatography-tandem mass spectrometry-based multiplex enzyme assay for six enzymes associated with hereditary hemolytic anemia.

Science.gov (United States)

Park, Chul Min; Lee, Kyunghoon; Jun, Sun-Hee; Song, Sang Hoon; Song, Junghan

2017-08-15

Deficiencies in erythrocyte metabolic enzymes are associated with hereditary hemolytic anemia. Here, we report the development of a novel multiplex enzyme assay for six major enzymes, namely glucose-6-phosphate dehydrogenase, pyruvate kinase, pyrimidine 5'-nucleotidase, hexokinase, triosephosphate isomerase, and adenosine deaminase, deficiencies in which are implicated in erythrocyte enzymopathies. To overcome the drawbacks of traditional spectrophotometric enzyme assays, the present assay was based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The products of the six enzymes were directly measured by using ion pairing UPLC-MS/MS, and the precision, linearity, ion suppression, optimal sample amounts, and incubation times were evaluated. Eighty-three normal individuals and 13 patients with suspected enzymopathy were analyzed. The UPLC running time was within 5min. No ion suppression was observed at the retention time for the products or internal standards. We selected an optimal dilution factor and incubation time for each enzyme system. The intra- and inter-assay imprecision values (CVs) were 2.5-12.1% and 2.9-14.3%, respectively. The linearity of each system was good, with R 2 values >0.97. Patient samples showed consistently lower enzyme activities than those from normal individuals. The present ion paring UPLC-MS/MS assay enables facile and reproducible multiplex evaluation of the activity of enzymes implicated in enzymopathy-associated hemolytic anemia. Copyright © 2017 Elsevier B.V. All rights reserved.

Melatonin Therapy Prevents Programmed Hypertension and Nitric Oxide Deficiency in Offspring Exposed to Maternal Caloric Restriction

Directory of Open Access Journals (Sweden)

You-Lin Tain

2014-01-01

Full Text Available Nitric oxide (NO deficiency is involved in the development of hypertension, a condition that can originate early in life. We examined whether NO deficiency contributed to programmed hypertension in offspring from mothers with calorie-restricted diets and whether melatonin therapy prevented this process. We examined 3-month-old male rat offspring from four maternal groups: untreated controls, 50% calorie-restricted (CR rats, controls treated with melatonin (0.01% in drinking water, and CR rats treated with melatonin (CR + M. The effect of melatonin on nephrogenesis was analyzed using next-generation sequencing. The CR group developed hypertension associated with elevated plasma asymmetric dimethylarginine (ADMA, a nitric oxide synthase inhibitor, decreased L-arginine, decreased L-arginine-to-ADMA ratio (AAR, and decreased renal NO production. Maternal melatonin treatment prevented these effects. Melatonin prevented CR-induced renin and prorenin receptor expression. Renal angiotensin-converting enzyme 2 protein levels in the M and CR + M groups were also significantly increased by melatonin therapy. Maternal melatonin therapy had long-term epigenetic effects on global gene expression in the kidneys of offspring. Conclusively, we attributed these protective effects of melatonin on CR-induced programmed hypertension to the reduction of plasma ADMA, restoration of plasma AAR, increase of renal NO level, alteration of renin-angiotensin system, and epigenetic changes in numerous genes.

Seeing & Feeling How Enzymes Work Using Tangible Models

Science.gov (United States)

Lau, Kwok-chi

2013-01-01

This article presents a tangible model used to help students tackle some misconceptions about enzyme actions, particularly the induced-fit model, enzyme-substrate complementarity, and enzyme inhibition. The model can simulate how substrates induce a change in the shape of the active site and the role of attraction force during enzyme-substrate…

Intermittent′ restrictive ventricular septal defect in Tetralogy of Fallot

Directory of Open Access Journals (Sweden)

Sudhir S Shetkar

2015-01-01

Full Text Available Ventricular septal defect (VSD in Tetralogy of Fallot (TOF is usually large and non-restrictive with equalization of right and left ventricular pressures. Restrictive VSD in TOF is rare. We present an unusual case of TOF with restriction to VSD caused by accessory tricuspid valve tissue that varied with respiration.

Mycelial growth interactions and mannan-degrading enzyme ...

African Journals Online (AJOL)

STORAGESEVER

2009-05-18

May 18, 2009 ... enzymes (Frost and Moss, 1987). However, microbial enzymes are more in use due to cheaper substrates and ease of process modification. In microbial enzyme and biomass production, defined mixed culture method in which more than one organism grows simultaneously can result in increased biomass ...

The mechanisms of Excited states in enzymes

DEFF Research Database (Denmark)

Petersen, Frederic Nicolas Rønne; Bohr, Henrik

2010-01-01

Enzyme catalysis is studied on the basis of excited state processes, which are of electronic, vibrational and thermal nature. The ways of achieving the excited state, such as photo-absorption and ligand binding, are discussed and exemplified by various cases of enzymes.......Enzyme catalysis is studied on the basis of excited state processes, which are of electronic, vibrational and thermal nature. The ways of achieving the excited state, such as photo-absorption and ligand binding, are discussed and exemplified by various cases of enzymes....

A High-Throughput (HTS) Assay for Enzyme Reaction Phenotyping in Human Recombinant P450 Enzymes Using LC-MS/MS.

Science.gov (United States)

Li, Xiaofeng; Suhar, Tom; Glass, Lateca; Rajaraman, Ganesh

2014-03-03

Enzyme reaction phenotyping is employed extensively during the early stages of drug discovery to identify the enzymes responsible for the metabolism of new chemical entities (NCEs). Early identification of metabolic pathways facilitates prediction of potential drug-drug interactions associated with enzyme polymorphism, induction, or inhibition, and aids in the design of clinical trials. Incubation of NCEs with human recombinant enzymes is a popular method for such work because of the specificity, simplicity, and high-throughput nature of this approach for phenotyping studies. The availability of a relative abundance factor and calculated intersystem extrapolation factor for the expressed recombinant enzymes facilitates easy scaling of in vitro data, enabling in vitro-in vivo extrapolation. Described in this unit is a high-throughput screen for identifying enzymes involved in the metabolism of NCEs. Emphasis is placed on the analysis of the human recombinant enzymes CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2B6, and CYP3A4, including the calculation of the intrinsic clearance for each. Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.

Spherezymes: A novel structured self-immobilisation enzyme technology

Directory of Open Access Journals (Sweden)

Arumugam Cherise

2008-01-01

Full Text Available Abstract Background Enzymes have found extensive and growing application in the field of chemical organic synthesis and resolution of chiral intermediates. In order to stabilise the enzymes and to facilitate their recovery and recycle, they are frequently immobilised. However, immobilisation onto solid supports greatly reduces the volumetric and specific activity of the biocatalysts. An alternative is to form self-immobilised enzyme particles. Results Through addition of protein cross-linking agents to a water-in-oil emulsion of an aqueous enzyme solution, structured self-immobilised spherical enzyme particles of Pseudomonas fluorescens lipase were formed. The particles could be recovered from the emulsion, and activity in aqueous and organic solvents was successfully demonstrated. Preliminary data indicates that the lipase tended to collect at the interface. Conclusion The immobilised particles provide a number of advantages. The individual spherical particles had a diameter of between 0.5–10 μm, but tended to form aggregates with an average particle volume distribution of 100 μm. The size could be controlled through addition of surfactant and variations in protein concentration. The particles were robust enough to be recovered by centrifugation and filtration, and to be recycled for further reactions. They present lipase enzymes with the active sites selectively orientated towards the exterior of the particle. Co-immobilisation with other enzymes, or other proteins such as albumin, was also demonstrated. Moreover, higher activity for small ester molecules could be achieved by the immobilised enzyme particles than for free enzyme, presumably because the lipase conformation required for catalysis had been locked in place during immobilisation. The immobilised enzymes also demonstrated superior activity in organic solvent compared to the original free enzyme. This type of self-immobilised enzyme particle has been named spherezymes.

Spatial distribution of enzyme activities in the rhizosphere

Science.gov (United States)

Razavi, Bahar S.; Zarebanadkouki, Mohsen; Blagodatskaya, Evgenia; Kuzyakov, Yakov

2015-04-01

The rhizosphere, the tiny zone of soil surrounding roots, certainly represents one of the most dynamic habitat and interfaces on Earth. Activities of enzymes produced by both plant roots and microbes are the primary biological drivers of organic matter decomposition and nutrient cycling. That is why there is an urgent need in spatially explicit methods for the determination of the rhizosphere extension and enzyme distribution. Recently, zymography as a new technique based on diffusion of enzymes through the 1 mm gel plate for analysis has been introduced (Spohn & Kuzyakov, 2013). We developed the zymography technique to visualize the enzyme activities with a higher spatial resolution. For the first time, we aimed at quantitative imaging of enzyme activities as a function of distance from the root tip and the root surface in the soil. We visualized the two dimensional distribution of the activity of three enzymes: β-glucosidase, phosphatase and leucine amino peptidase in the rhizosphere of maize using fluorogenically labelled substrates. Spatial-resolution of fluorescent images was improved by direct application of a substrate saturated membrane to the soil-root system. The newly-developed direct zymography visualized heterogeneity of enzyme activities along the roots. The activity of all enzymes was the highest at the apical parts of individual roots. Across the roots, the enzyme activities were higher at immediate vicinity of the roots (1.5 mm) and gradually decreased towards the bulk soil. Spatial patterns of enzyme activities as a function of distance from the root surface were enzyme specific, with highest extension for phosphatase. We conclude that improved zymography is promising in situ technique to analyze, visualize and quantify spatial distribution of enzyme activities in the rhizosphere hotspots. References Spohn, M., Kuzyakov, Y., 2013. Phosphorus mineralization can be driven by microbial need for carbon. Soil Biology & Biochemistry 61: 69-75

Long-term dietary restriction up-regulates activity and expression of renal arginase II in aging mice.

Science.gov (United States)

Majaw, T; Sharma, R

2017-06-01

Arginase II is a mitochondrial enzyme that catalyses the hydrolysis of L-arginine into urea and ornithine. It is present in other extra-hepatic tissues that lack urea cycle. Therefore, it is plausible that arginase II has a physiological role other than urea cycle which includes polyamine, proline, glutamate synthesis and regulation of nitric oxide production. The high expression of arginase II in kidney, among extrahepatic tissues, might have an important role associated with kidney functions. The present study is aimed to determine the age-associated alteration in the activity and expression of arginase II in the kidney of mice of different ages. The effect of dietary restriction to modulate the agedependent changes of arginase II was also studied. Results showed that renal arginase II activity declines significantly with the progression of age (p less than 0.01 and p less than 0.001 in 6- and 18-month-old mice, respectively as compared to 2-month old mice) and is due to the reduction in its protein as well as the mRNA level (p less than 0.001 in both 6- and 18-month-old mice as compared to 2-month-old mice). Long-term dietary restriction for three months has significantly up-regulated arginase II activity and expression level in both 2- and 18-month-old mice (p less than 0.01 and p less than 0.001, respectively as compared to AL group). These findings clearly indicate that the reducing level of arginase II during aging might have an impact on the declining renal functions. This age-dependent down-regulation of arginase II in the kidney can be attenuated by dietary restriction which may help in the maintenance of such functions.

Review of the biochemical basis of enzyme immunoassays

International Nuclear Information System (INIS)

Klingler, W.

1982-01-01

The ever increasing number of radioimmunological determination poses problems allied with the handling of radioactive substances. In recent years various non-radioactive methods have been developed, among which the enzyme immunoassay is already in routine use. Homogeneous and heterogeneous enzyme immunoassays are described. Criteria for enzymes, substrates and enzyme-substrate reactions are listed. (orig.) [de

Enzymic conversion of starch to glucose

Energy Technology Data Exchange (ETDEWEB)

1964-08-19

Corn is steeped in a SO/sub 2/ solution for 30 to 40 hours, coarsely ground, separated from the germ, and filtered. A 35% suspension of the germ-free corn, still containing fibers, hull, and gluten, is treated with Ca(OH)/sub 2/ to raise the pH to 6.5 to 7.0. A starch-liquifying enzyme is added and after a 2 hours treatment at 85/sup 0/ the liquefied starch is cooled to 60/sup 0/ and the pH is adjusted to 4.5 to 5.0 with H/sub 2/SO/sub 4/. A saccharifying enzyme is now added. After 40 to 81 hours, a raw glucose solution is obtained and is freed from fibers and gluten by filtration. The commercial starch-liquifying enzymes are designated HT-1000 and Neozyme 3 LC (liquid). The saccharifying enzymes are Diazyme or Diazyme L 30 (liquid). The solid enzymes are used at a level up to 0.1% by weight of the starch. Up to 100% conversion of starch into glucose is achieved.

Preliminary characterization of digestive enzymes in freshwater mussels

Science.gov (United States)

Sauey, Blake W.; Amberg, Jon J.; Cooper, Scott T.; Grunwald, Sandra K.; Newton, Teresa J.; Haro, Roger J.

2015-01-01

Resource managers lack an effective chemical tool to control the invasive zebra mussel Dreissena polymorpha. Zebra mussels clog water intakes for hydroelectric companies, harm unionid mussel species, and are believed to be a reservoir of avian botulism. Little is known about the digestive physiology of zebra mussels and unionid mussels. The enzymatic profile of the digestive glands of zebra mussels and native threeridge (Amblema plicata) and plain pocketbook mussels (Lampsilis cardium) are characterized using a commercial enzyme kit, api ZYM, and validated the kit with reagent-grade enzymes. A linear correlation was shown for only one of nineteen enzymes, tested between the api ZYM kit and a specific enzyme kit. Thus, the api ZYM kit should only be used to make general comparisons of enzyme presence and to observe trends in enzyme activities. Enzymatic trends were seen in the unionid mussel species, but not in zebra mussels sampled 32 days apart from the same location. Enzymatic classes, based on substrate, showed different trends, with proteolytic and phospholytic enzymes having the most change in relative enzyme activity.

Bacterial Enzymes and Antibiotic Resistance- Oral Presentation

Energy Technology Data Exchange (ETDEWEB)

Maltz, Lauren [SLAC National Accelerator Lab., Menlo Park, CA (United States)

2015-08-25

By using protein crystallography and X-ray diffraction, structures of bacterial enzymes were solved to gain a better understanding of how enzymatic modification acts as an antibacterial resistance mechanism. Aminoglycoside phosphotransferases (APHs) are one of three aminoglycoside modifying enzymes that confer resistance to the aminoglycoside antibiotics via enzymatic modification, rendering many drugs obsolete. Specifically, the APH(2”) family vary in their substrate specificities and also in their preference for the phosphate donor (ADP versus GDP). By solving the structures of members of the APH(2”) family of enzymes, we can see how domain movements are important to their substrate specificity. Our structure of the ternary complex of APH(2”)-IIIa with GDP and kanamycin, when compared to the known structures of APH(2”)-IVa, reveals that there are real physical differences between these two enzymes, a structural finding that explains why the two enzymes differ in their preferences for certain aminoglycosides. Another important group of bacterial resistance enzymes are the Class D β-lactamases. Oxacillinase carbapenemases (OXAs) are part of this enzyme class and have begun to confer resistance to ‘last resort’ drugs, most notably carbapenems. Our structure of OXA-143 shows that the conformational flexibility of a conserved hydrophobic residue in the active site (Val130) serves to control the entry of a transient water molecule responsible for a key step in the enzyme’s mechanism. Our results provide insight into the structural mechanisms of these two different enzymes.

Extrauterine growth restriction: Universal problem among premature infants

Directory of Open Access Journals (Sweden)

Brunnella Alcantara Chagas de FREITAS

2016-02-01

Full Text Available ABSTRACT Objective: To analyze the growth rate of premature infants in the first weeks of life and factors associated with extrauterine growth restriction. Methods: This is a cross-sectional study of 254 premature infants in a neonatal intensive care unit conducted from January 1, 2008 to December 31, 2010. Infants who died or had malformations incompatible with life were excluded. Median weight curves according to gestational age were constructed for the first four weeks of life. The Fenton growth chart calculations provided the weight Z-scores. Extrauterine growth restriction was defined as corrected weight-for-age Z-score ≤-2. Perinatal, morbidity, and health care variables were analyzed. The Poisson regression model yielded the prevalenceratios . Associations between extrauterine growth restriction and the perinatal, morbidity, and care variables were investigated. Poisson regression controlled possible confounding factors. Results: The frequency of extrauterine growth restriction was 24.0%. Most (85.0% small-for-gestational-age infants developed extrauterine growth restriction; 55.3% of extrauterine growth restriction cases involved small-for-gestational-age infants. Premature infants with gestational age >32 weeks did not recover the median birth weight until the third week of life and had a higher frequency of small-for-gestational-age. The Z-scores of non-small-for-gestational-age infants decreased more after birth than those of small-for-gestational-age infants. extrauterine growth restriction was associated with small-for-gestational-age (PR=6.14; 95%CI=3.33-11.33;p <0.001 and time without enteral diet (PR=1.08; 95%CI=1.04-1.13; p =0.010. Conclusion: Extrauterine growth restriction occurs in premature infants of all gestational age. The participation of small-for-gestational-age and nutritional practices in its genesis is noteworthy. We suggest prospective studies of all premature infants. The implementation of best care practices

Enzyme-Catalyzed Transetherification of Alkoxysilanes

Directory of Open Access Journals (Sweden)

Peter G. Taylor

2013-01-01

Full Text Available We report the first evidence of an enzyme-catalyzed transetherification of model alkoxysilanes. During an extensive enzymatic screening in the search for new biocatalysts for silicon-oxygen bond formation, we found that certain enzymes promoted the transetherification of alkoxysilanes when tert-butanol or 1-octanol were used as the reaction solvents.

Overproduction of ligninolytic enzymes

Science.gov (United States)

Elisashvili, Vladimir; Kachlishvili, Eva; Torok, Tamas

2014-06-17

Methods, compositions, and systems for overproducing ligninolytic enzymes from the basidiomycetous fungus are described herein. As described, the method can include incubating a fungal strain of Cerrena unicolor IBB 303 in a fermentation system having growth medium which includes lignocellulosic material and then cultivating the fungal strain in the fermentation system under conditions wherein the fungus expresses the ligninolytic enzymes. In some cases, the lignocellulosic material is mandarin peel, ethanol production residue, walnut pericarp, wheat bran, wheat straw, or banana peel.

Expression of lignocellulolytic enzymes in Pichia pastoris

Directory of Open Access Journals (Sweden)

Mellitzer Andrea

2012-05-01

Full Text Available Abstract Background Sustainable utilization of plant biomass as renewable source for fuels and chemical building blocks requires a complex mixture of diverse enzymes, including hydrolases which comprise the largest class of lignocellulolytic enzymes. These enzymes need to be available in large amounts at a low price to allow sustainable and economic biotechnological processes. Over the past years Pichia pastoris has become an attractive host for the cost-efficient production and engineering of heterologous (eukaryotic proteins due to several advantages. Results In this paper codon optimized genes and synthetic alcohol oxidase 1 promoter variants were used to generate Pichia pastoris strains which individually expressed cellobiohydrolase 1, cellobiohydrolase 2 and beta-mannanase from Trichoderma reesei and xylanase A from Thermomyces lanuginosus. For three of these enzymes we could develop strains capable of secreting gram quantities of enzyme per liter in fed-batch cultivations. Additionally, we compared our achieved yields of secreted enzymes and the corresponding activities to literature data. Conclusion In our experiments we could clearly show the importance of gene optimization and strain characterization for successfully improving secretion levels. We also present a basic guideline how to correctly interpret the interplay of promoter strength and gene dosage for a successful improvement of the secretory production of lignocellulolytic enzymes in Pichia pastoris.

Epigenetic regulation of caloric restriction in aging

Directory of Open Access Journals (Sweden)

Daniel Michael

2011-08-01

Full Text Available Abstract The molecular mechanisms of aging are the subject of much research and have facilitated potential interventions to delay aging and aging-related degenerative diseases in humans. The aging process is frequently affected by environmental factors, and caloric restriction is by far the most effective and established environmental manipulation for extending lifespan in various animal models. However, the precise mechanisms by which caloric restriction affects lifespan are still not clear. Epigenetic mechanisms have recently been recognized as major contributors to nutrition-related longevity and aging control. Two primary epigenetic codes, DNA methylation and histone modification, are believed to dynamically influence chromatin structure, resulting in expression changes of relevant genes. In this review, we assess the current advances in epigenetic regulation in response to caloric restriction and how this affects cellular senescence, aging and potential extension of a healthy lifespan in humans. Enhanced understanding of the important role of epigenetics in the control of the aging process through caloric restriction may lead to clinical advances in the prevention and therapy of human aging-associated diseases.

Evaluation of thermostable enzymes for bioethanol processing

DEFF Research Database (Denmark)

Skovgaard, Pernille Anastasia

of fermentable sugars (glucose) as cellulose is tightly linked to hemicellulose and lignin. Lignocellulose is disrupted during pretreatment, but to degrade cellulose to single sugars, lignocellulolytic enzymes such as cellulases and hemicellulases are needed. Lignocellulolytic enzymes are costly...... for the ioethanol production, but the expenses can be reduced by using thermostable enzymes, which are known for their increased stability and inhibitor olerance. However, the advantage of using thermostable enzymes has not been studied thoroughly and more knowledge is needed for development of bioethanol processes....... Enzymes are added to the bioethanol process after pretreatment. For an efficient sugar and ethanol yield, the solids content of biomass is normally increased, which results in highly viscous slurries that are difficult to mix. Therefore, the first enzymatic challenge is to ensure rapid reduction...