scholarly journals Recent Advances in Camel Immunology

2021 ◽  
Vol 11 ◽  
Author(s):  
Jamal Hussen ◽  
Hans-Joachim Schuberth
Keyword(s):  
Cytotoxic T Cells ◽  
Functional Characterization ◽  
Desert Ecosystem ◽  
Physiological Age ◽  
Cellular Immunology ◽  
Wide Range ◽  
Innate Recognition ◽  
Antigen Presenting ◽  
The Impact

Camels are domesticated animals that are highly adapted to the extreme desert ecosystem with relatively higher resistance to a wide range of pathogens compared to many other species from the same geographical region. Recently, there has been increased interest in the field of camel immunology. As the progress in the analysis of camel immunoglobulins has previously been covered in many recent reviews, this review intends to summarize published findings related to camel cellular immunology with a focus on the phenotype and functionality of camel leukocyte subpopulations. The review also describes the impact of different physiological (age and pregnancy) and pathological (e.g. infection) conditions on camel immune cells. Despite the progress achieved in the field of camel immunology, there are gaps in our complete understanding of the camel immune system. Questions remain regarding innate recognition mechanisms, the functional characterization of antigen-presenting cells, and the characterization of camel NK and cytotoxic T cells.

Micro-Scale Flow Simulations and Permeability Estimation of Cleat Networks in Coal

2016 ◽  
Vol 846 ◽  
pp. 42-47
Author(s):  
J. Busse ◽  
S. Galindo Torres ◽  
Alexander Scheuermann ◽  
L. Li ◽  
D. Bringemeier
Keyword(s):  
Gas Flow ◽  
Structural Information ◽  
Porous Matrix ◽  
Groundwater Levels ◽  
Micro Scale ◽  
Wide Range ◽  
Boltzmann Method ◽  
The Impact ◽  
Flow Experiments

Coal mining raises a number of environmental and operational challenges, including the impact of changing groundwater levels and flow patterns on adjacent aquifer and surface water systems. Therefore it is of paramount importance to fully understand the flow of water and gases in the geological system on all scales. Flow in coal seams takes place on a wide range of scales from large faults and fractures to the micro-structure of a porous matrix intersected by a characteristic cleat network. On the micro-scale these cleats provide the principal source of permeability for fluid and gas flow. Description of the behaviour of the flow within the network is challenging due to the variations in number, sizing, orientation, aperture and connectivity at a given site. This paper presents a methodology to simulate flow and investigate the permeability of fractured media. A profound characterization of the geometry of the cleat network in micrometer resolution can be derived by CT-scans. The structural information is fed into a Lattice Boltzmann Method (LBM) based model that allows the implementation of virtual flow experiments. With the application of suitable hydraulic boundary conditions the full permeability tensor can be calculated in 3D.

scholarly journals Human xylosyltransferase I and N-terminal truncated forms: functional characterization of the core enzyme

2006 ◽  
Vol 394 (1) ◽  
pp. 163-171 ◽  
Author(s):  
Sandra Müller ◽  
Jennifer Disse ◽  
Manuela Schöttler ◽  
Sylvia Schön ◽  
Christian Prante ◽  
...  
Keyword(s):  
Amino Acids ◽  
Catalytic Activity ◽  
Binding Capacity ◽  
Functional Characterization ◽  
Terminal Region ◽  
Binding Motif ◽  
Heparin Binding ◽  
Loss Of Function ◽  
The Impact

Human XT-I (xylosyltransferase I; EC 2.4.2.26) initiates the biosynthesis of the glycosaminoglycan linkage region and is a diagnostic marker of an enhanced proteoglycan biosynthesis. In the present study, we have investigated mutant enzymes of human XT-I and assessed the impact of the N-terminal region on the enzymatic activity. Soluble mutant enzymes of human XT-I with deletions at the N-terminal domain were expressed in insect cells and analysed for catalytic activity. As many as 260 amino acids could be truncated at the N-terminal region of the enzyme without affecting its catalytic activity. However, truncation of 266, 272 and 273 amino acids resulted in a 70, 90 and >98% loss in catalytic activity. Interestingly, deletion of the single 12 amino acid motif G261KEAISALSRAK272 leads to a loss-of-function XT-I mutant. This is in agreement with our findings analysing the importance of the Cys residues where we have shown that C276A mutation resulted in a nearly inactive XT-I enzyme. Moreover, we investigated the location of the heparin-binding site of human XT-I using the truncated mutants. Heparin binding was observed to be slightly altered in mutants lacking 289 or 568 amino acids, but deletion of the potential heparin-binding motif P721KKVFKI727 did not lead to a loss of heparin binding capacity. The effect of heparin or UDP on the XT-I activity of all mutants was not significantly different from that of the wild-type. Our study demonstrates that over 80% of the nucleotide sequence of the XT-I-cDNA is necessary for expressing a recombinant enzyme with full catalytic activity.

scholarly journals Plugging Small RNAs into the Network

mSystems ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Lars Barquist
Keyword(s):  
Small Rnas ◽  
Posttranscriptional Regulation ◽  
Network Inference ◽  
Functional Characterization ◽  
The State ◽  
Diverse Range ◽  
Regulatory Interactions ◽  
Link Type ◽  
Wide Range

ABSTRACT Small RNAs (sRNAs) have been discovered in every bacterium examined and have been shown to play important roles in the regulation of a diverse range of behaviors, from metabolism to infection. However, despite a wide range of available techniques for discovering and validating sRNA regulatory interactions, only a minority of these molecules have been well characterized. In part, this is due to the nature of posttranscriptional regulation: the activity of an sRNA depends on the state of the transcriptome as a whole, so characterization is best carried out under the conditions in which it is naturally active. In this issue of mSystems, Arrieta-Ortiz and colleagues (M. L. Arrieta-Ortiz, C. Hafemeister, B. Shuster, N. S. Baliga, et al., mSystems 5:e00057-20, 2020, https://doi.org/10.1128/mSystems.00057-20) present a network inference approach based on estimating sRNA activity across transcriptomic compendia. This shows promise not only for identifying new sRNA regulatory interactions but also for pinpointing the conditions in which these interactions occur, providing a new avenue toward functional characterization of sRNAs.

scholarly journals Review on the Impact of Polyols on the Properties of Bio-Based Polyesters

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2969
Author(s):  
Kening Lang ◽  
Regina J. Sánchez-Leija ◽  
Richard A. Gross ◽  
Robert J. Linhardt
Keyword(s):  
Tissue Engineering ◽  
Biomedical Applications ◽  
Molecular Level ◽  
Potential Utility ◽  
Reaction Conditions ◽  
Wide Range ◽  
Soft Tissue Engineering ◽  
The Impact ◽  
Optimal Reaction

Bio-based polyol polyesters are biodegradable elastomers having potential utility in soft tissue engineering. This class of polymers can serve a wide range of biomedical applications. Materials based on these polymers are inherently susceptible to degradation during the period of implantation. Factors that influence the physicochemical properties of polyol polyesters might be useful in achieving a balance between durability and biodegradability. The characterization of these polyol polyesters, together with recent comparative studies involving creative synthesis, mechanical testing, and degradation, have revealed many of their molecular-level differences. The impact of the polyol component on the properties of these bio-based polyesters and the optimal reaction conditions for their synthesis are only now beginning to be resolved. This review describes our current understanding of polyol polyester structural properties as well as a discussion of the more commonly used polyol monomers.

scholarly journals Proteomics Strategy for Identifying Candidate Bioactive Proteins in Complex Mixtures: Application to the Platelet Releasate

2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Roisin O'Connor ◽  
Lorna M. Cryan ◽  
Kieran Wynne ◽  
Andreas de Stefani ◽  
Desmond Fitzgerald ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Functional Characterization ◽  
Biological Tissues ◽  
Biochemical Properties ◽  
Human Platelets ◽  
Intact Proteins ◽  
Large Numbers ◽  
Wide Range ◽  
Platelet Releasate

Proteomic approaches have proven powerful at identifying large numbers of proteins, but there are fewer reports of functional characterization of proteins in biological tissues. Here, we describe an experimental approach that fractionates proteins released from human platelets, linking bioassay activity to identity. We used consecutive orthogonal separation platforms to ensure sensitive detection: (a) ion-exchange of intact proteins, (b) SDS-PAGE separation of ion-exchange fractions and (c) HPLC separation of tryptic digests coupled to electrospray tandem mass spectrometry. Migration of THP-1 monocytes in response to complete or fractionated platelet releasate was assessed and located to just one of the forty-nine ion-exchange fractions. Over 300 proteins were identified in the releasate, with a wide range of annotated biophysical and biochemical properties, in particular platelet activation, adhesion, and wound healing. The presence of PEDF and involucrin, two proteins not previously reported in platelet releasate, was confirmed by western blotting. Proteins identified within the fraction with monocyte promigratory activity and not in other inactive fractions included vimentin, PEDF, and TIMP-1. We conclude that this analytical platform is effective for the characterization of complex bioactive samples.

scholarly journals Characterization of PPTNs, a Cyanobacterial Phosphopantetheinyl Transferase from Nodularia spumigena NSOR10

2007 ◽  
Vol 189 (8) ◽  
pp. 3133-3139 ◽  
Author(s):  
J. N. Copp ◽  
A. A. Roberts ◽  
M. A. Marahiel ◽  
B. A. Neilan
Keyword(s):  
Acyl Carrier Protein ◽  
Functional Characterization ◽  
Bioactive Metabolites ◽  
Sequence Motifs ◽  
Phosphopantetheinyl Transferase ◽  
Carrier Proteins ◽  
Nodularia Spumigena ◽  
Conserved Sequence ◽  
Wide Range

ABSTRACT The phosphopantetheinyl transferases (PPTs) are a superfamily of essential enzymes required for the synthesis of a wide range of compounds, including fatty acids, polyketides, and nonribosomal peptide metabolites. These enzymes activate carrier proteins in specific biosynthetic pathways by transfer of a phosphopantetheinyl moiety. The diverse PPT superfamily can be divided into two families based on specificity and conserved sequence motifs. The first family is typified by the Escherichia coli acyl carrier protein synthase (AcpS), which is involved in fatty acid synthesis. The prototype of the second family is the broad-substrate-range PPT Sfp, which is required for surfactin biosynthesis in Bacillus subtilis. Most cyanobacteria do not encode an AcpS-like PPT, and furthermore, some of their Sfp-like PPTs belong to a unique phylogenetic subgroup defined by the PPTs involved in heterocyst differentiation. Here, we describe the first functional characterization of a cyanobacterial PPT based on a structural analysis and subsequent functional analysis of the Nodularia spumigena NSOR10 PPT. Southern hybridizations suggested that this enzyme may be the only PPT encoded in the N. spumigena NSOR10 genome. Expression and enzyme characterization showed that this PPT was capable of modifying carrier proteins resulting from both heterocyst glycoplipid synthesis and nodularin toxin synthesis. Cyanobacteria are a unique and vast source of bioactive metabolites; therefore, an understanding of cyanobacterial PPTs is important in order to harness the biotechnological potential of cyanobacterial natural products.

Microstructural Characterization of Photoluminescent Porous Silicon

1991 ◽  
Vol 256 ◽  
Author(s):  
J. M. Macaulay ◽  
F. M. Ross ◽  
P. C. Searson ◽  
S. K. Sputz ◽  
R. People ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Porous Silicon ◽  
Microstructural Characterization ◽  
Photoluminescence Spectroscopy ◽  
Experimental Results ◽  
Visible Luminescence ◽  
Wide Range ◽  
The Impact

ABSTRACTWe have used electron microscopy to examine the microstructure of porous silicon films over a wide range of doping levels, and photoluminescence spectroscopy to study their optical properties. We discuss the impact of our experimental results on models from the literature which were proposed to explain visible luminescence from porous silicon.

scholarly journals Structural and functional characterization of TesB fromYersinia pestisreveals a unique octameric arrangement of hotdog domains

2015 ◽  
Vol 71 (4) ◽  
pp. 986-995 ◽  
Author(s):  
C. M. D. Swarbrick ◽  
M. A. Perugini ◽  
N. Cowieson ◽  
J. K. Forwood
Keyword(s):  
Analytical Ultracentrifugation ◽  
Quaternary Structure ◽  
Functional Characterization ◽  
Fatty Acyl ◽  
Size Exclusion ◽  
X Ray Scattering ◽  
Wide Range ◽  
Exclusion Chromatography ◽  
Enzyme Families

Acyl-CoA thioesterases catalyse the hydrolysis of the thioester bonds present within a wide range of acyl-CoA substrates, releasing free CoASH and the corresponding fatty-acyl conjugate. The TesB-type thioesterases are members of the TE4 thioesterase family, one of 25 thioesterase enzyme families characterized to date, and contain two fused hotdog domains in both prokaryote and eukaryote homologues. Only two structures have been elucidated within this enzyme family, and much of the current understanding of the TesB thioesterases has been based on theEscherichia colistructure.Yersinia pestis, a highly virulent bacterium, encodes only one TesB-type thioesterase in its genome; here, the structural and functional characterization of this enzyme are reported, revealing unique elements both within the protomer and quaternary arrangements of the hotdog domains which have not been reported previously in any thioesterase family. The quaternary structure, confirmed using a range of structural and biophysical techniques including crystallography, small-angle X-ray scattering, analytical ultracentrifugation and size-exclusion chromatography, exhibits a unique octameric arrangement of hotdog domains. Interestingly, the same biological unit appears to be present in both TesB structures solved to date, and is likely to be a conserved and distinguishing feature of TesB-type thioesterases. Analysis of theY. pestisTesB thioesterase activity revealed a strong preference for octanoyl-CoA and this is supported by structural analysis of the active site. Overall, the results provide novel insights into the structure of TesB thioesterases which are likely to be conserved and distinguishing features of the TE4 thioesterase family.

scholarly journals Efficient randomization of biological networks while preserving functional characterization of individual nodes

2016 ◽  
Author(s):  
Francesco iorio ◽  
Marti Bernardo-Faura ◽  
Andrea Gobbi ◽  
Thomas Cokelae ◽  
Giuseppe Jurman ◽  
...  
Keyword(s):  
Biological Networks ◽  
Functional Characterization ◽  
Directed Network ◽  
Bipartite Networks ◽  
Null Distributions ◽  
Switching Algorithm ◽  
Wide Range ◽  
Unweighted Network ◽  
High Throughput Experiments

AbstractBackgroundNetworks are popular and powerful tools to describe and model biological processes. Many computational methods have been developed to infer biological networks from literature, high-throughput experiments, and combinations of both. Additionally, a wide range of tools has been developed to map experimental data onto reference biological networks, in order to extract meaningful modules. Many of these methods assess results’ significance against null distributions of randomized networks. However, these standard unconstrained randomizations do not preserve the functional characterization of the nodes in the reference networks (i.e. their degrees and connection signs), hence including potential biases in the assessment.ResultsBuilding on our previous work about rewiring bipartite networks, we propose a method for rewiring any type of unweighted networks. In particular we formally demonstrate that the problem of rewiring a signed and directed network preserving its functional connectivity (F-rewiring) reduces to the problem of rewiring two induced bipartite networks. Additionally, we reformulate the lower bound to the iterations’ number of the switching-algorithm to make it suitable for the F-rewiring of networks of any size. Finally, we present BiRewire 3, an open-source Bioconductor software enabling the F-rewiring of any type of unweighted network. We illustrate its application to a case study about the identification of modules from gene expression data mapped on protein interaction networks, and a second one focused on building logic models from more complex signed-directed reference signaling networks and phosphoproteomic data.ConclusionsBiRewire3 it is freely available at https://www.bioconductor.org/packages/BiRewire/, and it should have a broad application as it allows an efficient and analytically derived statistical assessment of results from any network biology tool.

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