scholarly journals Characterization of Each St and Y Genome Chromosome of Roegneria grandis Based on Newly Developed FISH Markers

2021 ◽  
pp. 213-222
Author(s):  
Dandan Wu ◽  
Xiaoxia Zhu ◽  
Lu Tan ◽  
Haiqin Zhang ◽  
Lina Sha ◽  
...  
Keyword(s):  
Structural Changes ◽  
Distribution Patterns ◽  
Proximal Region ◽  
Genome Chromosome ◽  
High Affinity ◽  
Complete Set ◽  
Genome Analyses ◽  
First Time ◽  
Homoeologous Chromosomes

The genera of the tribe Triticeae (family Poaceae), constituting many economically important plants with abundant genetic resources, carry genomes such as St, H, P, and Y. The genome symbol of <i>Roegneria</i> C. Koch (Triticeae) is StY. The St and Y genomes are crucial in Triticeae, and tetraploid StY species participate extensively in polyploid speciation. Characterization of St and Y nonhomologous chromosomes in StY-genome species could help understand variation in the chromosome structure and differentiation of StY-containing species. However, the high genetic affinity between St and Y genome and the deficiency of a complete set of StY nonhomologous probes limit the identification of St and Y genomes and variation of chromosome structures among <i>Roegneria</i> species. We aimed to identify St- and Y-enhanced repeat clusters and to study whether homoeologous chromosomes between St and Y genomes could be accurately identified due to high affinity. We employed comparative genome analyses to identify St- and Y-enhanced repeat clusters and generated a FISH-based karyotype of <i>R. grandis</i> (Keng), one of the taxonomically controversial StY species, for the first time. We explored 4 novel repeat clusters (StY_34, StY_107, StY_90, and StY_93), which could specifically identify individual St and Y nonhomologous chromosomes. The clusters StY_107 and StY_90 could identify St and Y addition/substitution chromosomes against common wheat genetic backgrounds. The chromosomes V_St, VII_St, I_Y, V_Y, and VII_Y displayed similar probe distribution patterns in the proximal region, indicating that the high affinity between St and Y genome might result from chromosome rearrangements or transposable element insertion among V_St/Y, VII_St/Y, and I_Y chromosomes during allopolyploidization. Our results can be used to employ FISH further to uncover the precise karyotype based on colinearity of Triticeae species by using the wheat karyotype as reference, to analyze diverse populations of the same species to understand the intraspecific structural changes, and to generate the karyotype of different StY-containing species to understand the interspecific chromosome variation.

scholarly journals Influence of Cation Exchange on the 27Al-NMR Spectra of Zeolites

2003 ◽  
Vol 217 (12) ◽  
pp. 1613-1626 ◽  
Author(s):  
W. Masierak ◽  
T. Emmler ◽  
Gerd Buntkowsky ◽  
A. Gutsze
Keyword(s):  
Cation Exchange ◽  
Nmr Spectra ◽  
Structural Changes ◽  
Divalent Cations ◽  
Second Order ◽  
Quadrupolar Coupling ◽  
Frame Work ◽  
Ion Radius ◽  
First Time

AbstractThe influence of cation exchange on the 27Al-NMR spectra of NaA-zeolites has been studied by 27Al-MAS- and MQ-MAS-Solid State-NMR. From the 27Al-spectra a characterization of the different Al sites in the A zeolites according to their chemical environment and the structural changes on the aluminosilicate network caused by the cation exchange are obtained. It is found that the exchange with cations with smaller ion-radius cause stronger distortions of the 27Al-NMR-spectra than exchange with larger cations like Ba2+. Employing MQ-MAS spectroscopy these distortions are revealed as second order quadrupolar effects for the smaller cations and as a combination of chemical shift and second order quadrupolar interaction for the Ba cation. These changes of the quadrupolar coupling are interpreted numerically via calculations of the lowering of the symmetry of the EFG tensor. Finally it is found that the exchange with divalent cations leads to distortions of the zeolitic framework and the formation of an extra-framework aluminum. To the best of our knowledge this is for the first time that evidence for the production of extra frame work aluminum by pure cation exchange without any thermal treatment has been found in type A zeolites.

scholarly journals Molecular Identification and Characterization of an Essential Pyruvate Transporter from Trypanosoma brucei

2013 ◽  
Vol 288 (20) ◽  
pp. 14428-14437 ◽  
Author(s):  
Marco A. Sanchez
Keyword(s):  
Trypanosoma Brucei ◽  
Drug Target ◽  
Life Cycle Stage ◽  
Bloodstream Form ◽  
Potential Drug Target ◽  
High Affinity ◽  
Physiological Relevance ◽  
First Time ◽  
Identification And Characterization

Pyruvate export is an essential physiological process for the bloodstream form of Trypanosoma brucei as the parasite would otherwise accumulate this end product of glucose metabolism to toxic levels. In the studies reported here, genetic complementation in Saccharomyces cerevisiae has been employed to identify a gene (TbPT0) that encodes this vital pyruvate transporter from T. brucei. Expression of TbPT0 in S. cerevisiae reveals that TbPT0 is a high affinity pyruvate transporter. TbPT0 belongs to a clustered multigene family consisting of five members, whose expression is up-regulated in the bloodstream form. Interestingly, TbPT family permeases are related to polytopic proteins from plants but not to characterized monocarboxylate transporters from mammals. Remarkably, inhibition of the TbPT gene family expression in bloodstream parasites by RNAi is lethal, confirming the physiological relevance of these transporters. The discovery of TbPT0 reveals for the first time the identity of the essential pyruvate transporter and provides a potential drug target against the mammalian life cycle stage of T. brucei.

scholarly journals Production and Characterization of Antibodies against Each of the Three Subunits of the Bacillus cereus Nonhemolytic Enterotoxin Complex

2005 ◽  
Vol 71 (12) ◽  
pp. 8214-8220 ◽  
Author(s):  
Richard Dietrich ◽  
Maximilian Moravek ◽  
Christine Bürk ◽  
Per Einar Granum ◽  
Erwin Märtlbauer
Keyword(s):  
Bacillus Cereus ◽  
Rabbit Antiserum ◽  
Food Poisoning ◽  
Cross Reactivity ◽  
Terminal Part ◽  
Complete Set ◽  
Different Strains ◽  
First Time ◽  
Three Components

ABSTRACT The nonhemolytic enterotoxin (Nhe) is one of the two three-component enterotoxins which are responsible for diarrheal food poisoning syndrome caused by Bacillus cereus. To facilitate the detection of this toxin, consisting of the subunits NheA, NheB, and NheC, a complete set of high-affinity antibodies against each of the three components was established and characterized. A rabbit antiserum specific for the C-terminal part (15 amino acids) of NheC was produced using a respective synthetic peptide coupled to a protein carrier for immunization. Using purified B. cereus exoprotein preparations as immunogens, one monoclonal antibody against NheA and several antibodies against NheB were obtained. No cross-reactivity with other proteins produced by different strains of B. cereus was observed. Antibodies against the NheB component were able to neutralize the cytotoxic activity (up to 98%) of Nhe. Based on indirect enzyme immunoassays, the antibodies developed in this study were successfully used in the characterization of the enterotoxic activity of several B. cereus strains. For the first time, it could be shown that strains carrying the nhe genes usually express the complete set of the three components, including NheC. However, the amount of toxin produced varies considerably between the different strains.

scholarly journals Optimized methods for IL-17A refolding and anti-IL17A Fab production for co-crystallization with small molecules

BioTechniques ◽  
2020 ◽  
Vol 69 (1) ◽  
pp. 70-76
Author(s):  
Xiaoyun Meng ◽  
Lanjun Zhang ◽  
Hong Wei ◽  
Furong Li ◽  
Lihua Hu ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Small Molecules ◽  
Small Molecule ◽  
Yield Enhancement ◽  
High Affinity ◽  
Interleukin 17A ◽  
Affinity Peptide ◽  
First Time ◽  
Essential Prerequisite

Refolding of human interleukin 17A (IL-17A) has been reported; however, the key refolding protocol was not robust enough to deliver consistent results and to be easily scaled up for crystallization. Here we report an optimized refolding method for IL-17A. Although co-crystal structures of IL-17A with ligands have been obtained with a high-affinity peptide and an anti-IL-17A Fab as stabilizers, neither the production yield nor the characterization of the IL-17A/Fab complex was reported. To facilitate co-crystallization of IL-17A with small-molecule compounds derived from our DNA encoded library, we also describe the method for yield enhancement of anti-IL-17A Fab production and characterize the IL-17A/Fab complex for the first time, providing an essential prerequisite for structure-based drug discovery targeting IL-17A.

scholarly journals Acetylacetone-cleaving enzyme Dke1: a novel C-C-bond-cleaving enzyme from Acinetobacter johnsonii

2003 ◽  
Vol 369 (3) ◽  
pp. 573-581 ◽  
Author(s):  
Grit D. STRAGANZ ◽  
Anton GLIEDER ◽  
Lothar BRECKER ◽  
Douglas W. RIBBONS ◽  
Walter STEINER
Keyword(s):  
Metabolic Pathway ◽  
Metabolic Pathways ◽  
Active Protein ◽  
Acinetobacter Johnsonii ◽  
High Affinity ◽  
Gene Coding ◽  
High Yields ◽  
Relationship Of ◽  
First Time

The toxicity of acetylacetone has been demonstrated in various studies. Little is known, however, about metabolic pathways for its detoxification or mineralization. Data presented here describe for the first time the microbial degradation of acetylacetone and the characterization of a novel enzyme that initiates the metabolic pathway. From an Acinetobacter johnsonii strain that grew with acetylacetone as the sole carbon source, an inducible acetylacetone-cleaving enzyme was purified to homogeneity. The corresponding gene, coding for a 153 amino acid sequence that does not show any significant relationship to other known protein sequences, was cloned and overexpressed in Escherichia coli and gave high yields of active enzyme. The enzyme cleaves acetylacetone to equimolar amounts of methylglyoxal and acetate, consuming one equivalent of molecular oxygen. No exogenous cofactor is required, but Fe2+ is bound to the active protein and essential for its catalytic activity. The enzyme has a high affinity for acetylacetone with a Km of 9.1μM and a kcat of 8.5s-1. A metabolic pathway for acetylacetone degradation and the putative relationship of this novel enzyme to previously described dioxygenases are discussed.

scholarly journals Intraoperative Cerebral Glioma Characterization with Contrast Enhanced Ultrasound

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Francesco Prada ◽  
Luca Mattei ◽  
Massimiliano Del Bene ◽  
Luca Aiani ◽  
Marco Saini ◽  
...  
Keyword(s):  
Real Time ◽  
Flow Distribution ◽  
Distribution Patterns ◽  
Cerebral Glioma ◽  
Contrast Enhanced Ultrasound ◽  
Contrast Enhanced ◽  
Venous Phase ◽  
First Time ◽  
Fast Perfusion

Background. Contrast enhanced ultrasound (CEUS) is a dynamic and continuous modality providing real-time view of vascularization and flow distribution patterns of different organs and tumors. Nevertheless its intraoperative use for brain tumors visualization has been performed few times, and a thorough characterization of cerebral glioma had never been performed before.Aim. To perform the first characterization of cerebral glioma using CEUS and to possibly achieve an intraoperative differentiation of different gliomas.Methods. We performed CEUS in an off-label setting in 69 patients undergoing surgery for cerebral glioma. An intraoperative qualitative analysis was performed comparing iCEUS with B-mode imaging. A postprocedural semiquantitative analysis was then performed for each case, according to EFSUMB criteria. Results were related to histopathology.Results. We observed different CE patterns: LGG show a mild, dotted CE with diffuse appearance and slower, delayed arterial and venous phase. HGG have a high CE with a more nodular, nonhomogeneous appearance and fast perfusion patterns.Conclusion. Our study characterizes for the first time human brain glioma with CEUS, providing further insight regarding these tumors’ biology. CEUS is a fast, safe, dynamic, real-time, and economic tool that might be helpful during surgery in differentiating malignant and benign gliomas and refining surgical strategy.

scholarly journals On the optimal use of isotherm models for the characterization of biosorption of lead onto algae

2016 ◽  
Author(s):  
F. Brouers ◽  
Tariq Al-Musawi
Keyword(s):  
Removal Rate ◽  
Coefficient Of Determination ◽  
Isotherm Models ◽  
Good Representation ◽  
Nonlinear Fitting ◽  
Linearization Methods ◽  
Complete Set ◽  
The Hill ◽  
First Time

For the first time we apply a new method based on the mathematical derivation of some known isotherm from the Burr function which describes many birth-death (sorption-desorption) phenomena in ecology and economy. Therefore, in this study the experimental isotherm data of biosorption of Pb(II) onto algae was modeled to Langmuir, Hill-Sips, Brouers-Sotolongo, Brouers-Gaspard, and Redlich-Peterson isotherm models. The parameters of each model were determined by nonlinear fitting algorithms using Mathematica program. The maximum Pb(II) removal rate increased with the increase of temperature and reached the maximum value (98%) at the temperature of 40 C. The results showed that the Hill-Sips and the Brouers-Sotolongo isotherms were definitely the most suitable models to satisfactorily describe biosorption of Pb(II) on the algal biomass. In addition, as these two models gave very close results, the use of an intermediate one the Brouers-Gaspard isotherm model could also describe the sorption in most cases. High coefficient of determination values was obtained by using nonlinear methods and these findings are contrary to most works in this field that use linearization methods. Further, this study showed that a complete set of data is necessary to have a good representation of the isotherm and using only coefficient of determination is not always an adequate tool to compare the goodness of the nonlinear fit of an isotherm models.

scholarly journals Histomorphologic characterization of the hepatopancreas of freshwater prawn Macrobrachium rosenbergii (De Man, 1879)

2018 ◽  
Vol 70 (5) ◽  
pp. 1539-1546 ◽  
Author(s):  
M.A.S. Silva ◽  
M.E. Almeida Neto ◽  
B.O. Ramiro ◽  
I.T.F. Santos ◽  
R.R. Guerra
Keyword(s):  
Macrobrachium Rosenbergii ◽  
Distal Region ◽  
Proximal Region ◽  
Freshwater Prawn ◽  
Cell Type ◽  
Nutrient Storage ◽  
Macrobrachium Amazonicum ◽  
De Man ◽  
First Time

ABSTRACT This study aimed to describe the Macrobrachium rosenbergii hepatopancreas histomorphology. The hepatopancreas is constituted by a set of blind end tubules, divided into proximal, middle, and distal regions, with the epithelium formed by E, F, B, R, and M cells differently of other species. Measurements of the length and width of the tubules were 419.64+69.09µm and 117.42+16.99µm, respectively. The percentage of each cell type per region was: proximal region (40%B, 20%F, 6.7%M, 33.3%R), middle region (45.4%B, 18.2%F, 9.1%M, and 27.3%R) and distal region (36.4%E, 27.2%B, 18.2%F, 9.1%M, 9.1%R). Cell B that stores glycogen and lipids, is the most commonly found cell in proximal and middle regions. In the distal region, the E, responsible for the mitosis, is the most prominent. M, responsible by nutrient storage, is numerically constant among the portions differently in the Macrobrachium amazonicum. The study for the first time also suggests that in addition to digestive enzymes, the F cell produces protective mucus. The present study generated for the first time a morphometric profile of M. rosenbergii hepatopancreas, demonstrating differences from other species, and can be an important tool for new studies in nutrition, reproduction, and production with the species.

scholarly journals Characterization of the Modulatory Effect of Hydroxychloroquine on ACE2 Activity: New Insights in relation to COVID-19

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Juan E. Tichauer ◽  
Dagoberto Soto ◽  
Max Andresen
Keyword(s):  
Structural Changes ◽  
Three Dimensional ◽  
Specific Inhibitor ◽  
In Vitro System ◽  
Trial Outcomes ◽  
A Cell ◽  
The One ◽  
First Time

Chloroquine (CQ) and hydroxychloroquine (HCQ) have shown the ability to inhibit in vitro viral replications of coronaviridae viruses such as SARS-CoV and SARS-CoV-2. However, clinical trial outcomes have been disparate, suggesting that CQ and HCQ antiviral mechanisms are not fully understood. Based on three-dimensional structural similarities between HCQ and the known ACE2 specific inhibitor MLN-4760, we compared their modulation on ACE2 activity. Here we describe, for the first time, in a cell-free in vitro system that HCQ directly and dose-dependently inhibits the activity of recombinant human ACE2, with a potency similar to the MLN-4760. Further analysis suggests that HCQ binds to a noncompetitive site other than the one occupied by MLN-4760. We also determined that the viral spike glycoprotein segment that comprises the RBD segment has no effect on ACE2 activity but unexpectedly was able to partially reverse the inhibition induced by HCQ but not that by MLN-4760. In summary, here we demonstrate the direct inhibitory action of HCQ over the activity of the enzyme ACE2. Then, by determining the activity of ACE2, we reveal that the interaction with the spike protein of SARS-CoV-2 leads to structural changes that at least partially displace the interaction of the said enzyme with HCQ. These results may help to explain why the effectiveness of HCQ in clinical trials has been so variable. Additionally, this knowledge could be used for to develop techniques for the detection of SARS-CoV-2.

Characterization of a Mode of Specific Binding of Fibrin Monomer through its Amino-Terminal Domain by Macrophages and Macrophage Cell-Lines

1990 ◽  
Vol 63 (02) ◽  
pp. 193-203 ◽  
Author(s):  
John R Shainoff ◽  
Deborah J Stearns ◽  
Patricia M DiBello ◽  
Youko Hishikawa-Itoh
Keyword(s):  
Peritoneal Macrophages ◽  
Affinity Binding ◽  
Macrophage Cell ◽  
High Affinity Binding ◽  
Amino Terminal ◽  
High Affinity ◽  
Terminal Domain ◽  
Weak Binding ◽  
Amino Terminal Domain

SummaryThe studies reported here probe the existence of a receptor-mediated mode of fibrin-binding by macrophages that is associated with the chemical change underlying the fibrinogen-fibrin conversion (the release of fibrinopeptides from the amino-terminal domain) without depending on fibrin-aggregation. The question is pursued by 1) characterization of binding in relation to fibrinopeptide content of both the intact protein and the CNBr-fragment comprising the amino-terminal domain known as the NDSK of the protein, 2) tests of competition for binding sites, and 3) photo-affinity labeling of macrophage surface proteins. The binding of intact monomers of types lacking either fibrinopeptide A alone (α-fibrin) or both fibrinopeptides A and B (αβ-fibrin) by peritoneal macrophages is characterized as proceeding through both a fibrin-specific low density/high affinity (BMAX ≃ 200–800 molecules/cell, KD ≃ 10−12 M) interaction that is not duplicated with fibrinogen, and a non-specific high density/low affinity (BMAX ≥ 105 molecules/cell, KD ≥ 10−6 M) interaction equivalent to the weak binding of fibrinogen. Similar binding characteristics are displayed by monocyte/macrophage cell lines (J774A.1 and U937) as well as peritoneal macrophages towards the NDSK preparations of these proteins, except for a slightly weaker (KD ≃ 10−10 M) high-affinity binding. The high affinity binding of intact monomer is inhibitable by fibrin-NDSK, but not fibrinogen-NDSK. This binding appears principally dependent on release of fibrinopeptide-A, because a species of fibrin (β-fibrin) lacking fibrinopeptide-B alone undergoes only weak binding similar to that of fibrinogen. Synthetic Gly-Pro-Arg and Gly-His-Arg-Pro corresponding to the N-termini of to the α- and the β-chains of fibrin both inhibit the high affinity binding of the fibrin-NDSKs, and the cell-adhesion peptide Arg-Gly-Asp does not. Photoaffinity-labeling experiments indicate that polypeptides with elec-trophoretically estimated masses of 124 and 187 kDa are the principal membrane components associated with specifically bound fibrin-NDSK. The binding could not be up-regulated with either phorbol myristyl acetate, interferon gamma or ADP, but was abolished by EDTA and by lipopolysaccharide. Because of the low BMAX, it is suggested that the high-affinity mode of binding characterized here would be too limited to function by itself in scavenging much fibrin, but may act cooperatively with other, less limited modes of fibrin binding.

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