scholarly journals Characterization of two family AA9 LPMOs from Aspergillus tamarii with distinct activities on xyloglucan reveals structural differences linked to cleavage specificity

PLoS ONE ◽  
2020 ◽  
Vol 15 (7) ◽  
pp. e0235642 ◽  
Author(s):  
Antonielle V. Monclaro ◽  
Dejan M. Petrović ◽  
Gabriel S. C. Alves ◽  
Marcos M. C. Costa ◽  
Glaucia E. O. Midorikawa ◽  
...  
Keyword(s):  
Aspergillus Tamarii ◽  
Cleavage Specificity ◽  
Structural Differences

scholarly journals Conjuring up a ghost: structural and functional characterization of FhuF, a ferric siderophore reductase from E. coli

2021 ◽  
Author(s):  
I. B. Trindade ◽  
G. Hernandez ◽  
E. Lebègue ◽  
F. Barrière ◽  
T. Cordeiro ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Paramagnetic Nmr ◽  
E Coli ◽  
The Past ◽  
Internal Cavities ◽  
Structural Differences ◽  
Bond Strengths ◽  
Redox Bohr Effect ◽  
Micromolar Range

AbstractIron is a fundamental element for virtually all forms of life. Despite its abundance, its bioavailability is limited, and thus, microbes developed siderophores, small molecules, which are synthesized inside the cell and then released outside for iron scavenging. Once inside the cell, iron removal does not occur spontaneously, instead this process is mediated by siderophore-interacting proteins (SIP) and/or by ferric-siderophore reductases (FSR). In the past two decades, representatives of the SIP subfamily have been structurally and biochemically characterized; however, the same was not achieved for the FSR subfamily. Here, we initiate the structural and functional characterization of FhuF, the first and only FSR ever isolated. FhuF is a globular monomeric protein mainly composed by α-helices sheltering internal cavities in a fold resembling the “palm” domain found in siderophore biosynthetic enzymes. Paramagnetic NMR spectroscopy revealed that the core of the cluster has electronic properties in line with those of previously characterized 2Fe–2S ferredoxins and differences appear to be confined to the coordination of Fe(III) in the reduced protein. In particular, the two cysteines coordinating this iron appear to have substantially different bond strengths. In similarity with the proteins from the SIP subfamily, FhuF binds both the iron-loaded and the apo forms of ferrichrome in the micromolar range and cyclic voltammetry reveals the presence of redox-Bohr effect, which broadens the range of ferric-siderophore substrates that can be thermodynamically accessible for reduction. This study suggests that despite the structural differences between FSR and SIP proteins, mechanistic similarities exist between the two classes of proteins. Graphic abstract

scholarly journals Structural differences and the presence of unsubstituted amino groups in heparan sulphates from different tissues and species

1997 ◽  
Vol 322 (2) ◽  
pp. 499-506 ◽  
Author(s):  
Toshihiko TOIDA ◽  
Hisao YOSHIDA ◽  
Hidenao TOYODA ◽  
Ichiro KOSHIISHI ◽  
Toshio IMANARI ◽  
...  
Keyword(s):  
Acid Content ◽  
Heparan Sulphate ◽  
Kidney Medulla ◽  
Isolation And Characterization ◽  
Iduronic Acid ◽  
Structural Differences ◽  
Liver And Kidney ◽  
High Degree ◽  
Different Tissues

This study presents a comparison of heparan sulphate chains isolated from various porcine and bovine tissues. 1H-NMR spectroscopy (500 MHz) was applied for structural and compositional studies on intact heparan sulphate chains. After enzymic digestion of heparan sulphate using heparin lyase I (EC 4.2.2.7) II and III (EC 4.2.2.8), the compositions of unsaturated disaccharides obtained were determined by analytical capillary electrophoresis. Correlations between the N-sulphated glucosamine residues and O-sulphation and between iduronic acid content and total sulphation were discovered using the data obtained by NMR and disaccharide analysis. Heparan sulphate chains could be classified into two groups based on the sulphation degree and the iduronic acid content. Heparan sulphate chains with a high degree of sulphation possessed also a significant number of iduronic acid residues and were isolated exclusively from porcine brain, liver and kidney medulla. The presence and amount of N-unsubstituted glucosamine residues (GlcNp) was established in all of the heparan sulphates examined. The structural context in which this residue occurs was demonstrated to be: high sulphation domain → 4)-β-d-GlcAp-(1 → 4)-α-d-GlcNp-(1 → 4)-β-d-GlcAp-(1 → low sulphation domain (where GlcNp is 2-amino-2-deoxyglucopyranose, and GlcAp is glucopyranosyluronic acid), based on the isolation and characterization of a novel, heparin lyase III-derived, GlcNp containing tetrasaccharide and hexasaccharide. The results presented suggest that structural differences may play a role in important biological events controlled by heparan sulphate in different tissues.

scholarly journals Structural features of mildly fractionated lignin carbohydrate complexes (LCC) from spruce

RSC Advances ◽  
2016 ◽  
Vol 6 (48) ◽  
pp. 42120-42131 ◽  
Author(s):  
Nicola Giummarella ◽  
Liming Zhang ◽  
Gunnar Henriksson ◽  
Martin Lawoko
Keyword(s):  
Structural Features ◽  
Applied Science ◽  
Structural Differences

Characterization of novel lignin carbohydrate complexes (LCC) unveils structural differences of relevance to fundamental and applied science.

scholarly journals Characterization of fungal and bacterial dysbiosis in young adult Chinese patients with Crohn’s disease

2020 ◽  
Vol 13 ◽  
pp. 175628482097120
Author(s):  
Xinyun Qiu ◽  
Xiaojing Zhao ◽  
Xiufang Cui ◽  
Xiaqiong Mao ◽  
Nana Tang ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Chinese Patients ◽  
Bacterial Composition ◽  
Structural Differences ◽  
Inflammatory Bowel ◽  
Fungal Microbiome ◽  
Chinese Subjects

Intestinal microbiota dysbiosis has been described in inflammatory bowel disease (IBD), but data from China are limited. In this study, we performed molecular analysis of the fecal microbial community from 20 healthy Chinese subjects and 25 patients with Crohn’s disease (CD), and evaluated associations with bacterial and fungal compositions. Decreased richness and diversity of bacterial composition was observed in the CD group compared with healthy (H) subjects. Significant structural differences in bacterial (but not fungal) composition among healthy controls and CD patients were found. A reduction in Firmicutes and Actinobacteria abundance, and overrepresentation of Proteobacteria were observed in the CD patients compared with the H group. The Escherichia-Shigella genus was overrepresented in the CD group, whereas Faecalibacterium, Gemmiger, Bifidobacterium, Romboutsia, Ruminococcus, Roseburia, and Fusicatenibacter abundance were decreased in the CD group compared with H subjects. Differences in fungal microbiota between the H and CD groups were observed at the genus rather than at the phylum level. The Candida genus was overrepresented in the CD (active disease) group compared with the H group, whereas no difference between CD (remission) and H groups was observed. Aspergillus, unclassified_Sordariomycetes, and Penicillium genera had greater representation in the H subjects compared with the CD group. Bacterial and fungal intra- and inter-kingdom correlations were observed between the H and CD groups. Therefore, fecal bacterial and fungal microbiome communities differed considerably between H and CD patients, and between Chinese and Western populations. The role of gut microbiota in homeostasis and in gastrointestinal disorders should be investigated further.

An Approach to Legal Principles Based on Their Justifying Function

2019 ◽  
Vol 32 (02) ◽  
pp. 321-342 ◽  
Author(s):  
Juan B. Etcheverry
Keyword(s):  
Legal Reasoning ◽  
Legal Principles ◽  
Structural Differences ◽  
Different Types ◽  
The Way

AbstractThis paper intends to throw light upon some aspects of the debate on the characterization of legal principles and on their differences when compared to rules. Particularly, this analysis proposes differentiating principles from rules by considering the functions they perform in law instead of their structural differences. To achieve this, we distinguish between the functions of guidance and justification that legal principles fulfill. From that distinction, we observe that the attempt to characterize legal principles based on the way in which they guide conduct does not seem to be the most appropriate either. In contrast, this paper tries to show that all the different types of precepts known as principles perform a justifying function in legal reasoning.

scholarly journals Purification and characterization of three forms of glutathione transferase from Proteus mirabilis

1988 ◽  
Vol 255 (3) ◽  
pp. 971-975 ◽  
Author(s):  
C Di Ilio ◽  
A Aceto ◽  
R Piccolomini ◽  
N Allocati ◽  
A Faraone ◽  
...  
Keyword(s):  
Amino Acid ◽  
Isoelectric Focusing ◽  
Proteus Mirabilis ◽  
Gel Electrophoresis ◽  
Glutathione Transferase ◽  
Total Activity ◽  
Purification And Characterization ◽  
Substrate Specificities ◽  
Structural Differences

Three forms of glutathione transferase (GST) with pI values of 6.0, 6.4 and 7.3 were isolated from Proteus mirabilis AF 2924 by glutathione-affinity chromatography followed by isoelectric focusing, and their structural, kinetic and immunological properties were investigated. Upon SDS/polyacrylamide-slab-gel electrophoresis, all forms proved to be composed of two subunits of identical (22,500) Mr. GST-6.0 and GST-6.4 together account for about 95% of the total activity, whereas GST-7.3 is present only in trace amounts. Extensive similarities have been found between GST-6.0 and GST-6.4. These include subunit molecular mass, amino acid composition, substrate specificities and immunological characteristics. GST-7.3 also cross-reacted (non-identity) with antisera raised against bacterial GST-6.0. None of the antisera raised against a number of human, rat and mouse GSTs cross-reacted with the bacterial enzymes, indicating major structural differences between them and the mammalian GSTs. This conclusion is further supported by c.d. spectra.

Structural Characterization of a Series of New Ternary η-Nitride Compounds

1997 ◽  
Vol 495 ◽  
Author(s):  
K. S. Weil ◽  
P. N. Kumta
Keyword(s):  
Structural Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Route ◽  
Precursor Synthesis ◽  
Structural Differences ◽  
Cubic Structure ◽  
Ternary Nitride

ABSTRACTThe structures of four new tungsten based, ternary nitride compounds, Fe3W3N, Ni6W6N, Ni2W4N, and Fe4W2N, each prepared using a complexed precursor synthesis route, have been determined by Rietveld analyses of the respective powder x-ray diffraction (PXRD) data. Each compound crystallizes in a relatively complex cubic structure which is in general isostructural with the η-carbide structure. However, subtle structural differences which are compositionally dependent do exist between each nitride and these will be examined in detail in this paper.

scholarly journals In silico characterization of human-malarial parasite species based on their DHFR and GST targets leading to a change in binding conformations of anti-malarial drugs

2021 ◽  
Vol 12 (1) ◽  
pp. 793-807
Author(s):  
Shrutika Sakpal ◽  
Alpana Bastikar ◽  
Shanker Lal Kothari ◽  
Virupaksha Bastikar
Keyword(s):  
In Silico ◽  
Plasmodium Species ◽  
Structural Similarity ◽  
Plasmodium Malariae ◽  
Malarial Parasite ◽  
Drug Candidates ◽  
Structural Differences ◽  
Bioinformatics Databases ◽  
In Silico Characterization

In this study, we mainly focused on three anti-malarial drugs which were analyzed against the two malarial targets. Chloroquine, Mefloquine and, Proguanil was chosen as anti-malarial drugs while DHFR and GST targets from human malarial parasites like Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale,  and Plasmodium vivax  were considered for the study. This study was conducted to understand the sequence and structural similarity between protein DHFR and GST among four Plasmodium species  as well as to find out there in silico  interactions with above-stated drug candidates. There were many bioinformatics databases, tools, and software’s were run to bring out research. Our data showed not many structural differences between Plasmodium  sequences but yet other characteristics of them that make them different from each other. Hence that variation has shown a difference in the binding patterns of drugs with target proteins.

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