The enzymatic function of the honorary enzyme: S-nitrosylation of hemoglobin in physiology and medicine

2021 ◽  
pp. 101056
Author(s):  
Richard T. Premont ◽  
David J. Singel ◽  
Jonathan S. Stamler
Keyword(s):  
Enzymatic Function

scholarly journals Nitrocellulose-bound achromopeptidase for point-of-care nucleic acid tests

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Georgios Chondrogiannis ◽  
Shirin Khaliliazar ◽  
Anna Toldrà ◽  
Pedro Réu ◽  
Mahiar M. Hamedi
Keyword(s):  
Nucleic Acid ◽  
Sample Preparation ◽  
Point Of Care ◽  
Dna Amplification ◽  
Recombinase Polymerase Amplification ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Enzymatic Function ◽  
Modern Biotechnology ◽  
Nucleic Acid Tests

AbstractEnzymes are the cornerstone of modern biotechnology. Achromopeptidase (ACP) is a well-known enzyme that hydrolyzes a number of proteins, notably proteins on the surface of Gram-positive bacteria. It is therefore used for sample preparation in nucleic acid tests. However, ACP inhibits DNA amplification which makes its integration difficult. Heat is commonly used to inactivate ACP, but it can be challenging to integrate heating into point-of-care devices. Here, we use recombinase polymerase amplification (RPA) together with ACP, and show that when ACP is immobilized on nitrocellulose paper, it retains its enzymatic function and can easily and rapidly be activated using agitation. The nitrocellulose-bound ACP does, however, not leak into the solution, preventing the need for deactivation through heat or by other means. Nitrocellulose-bound ACP thus opens new possibilities for paper-based Point-of-Care (POC) devices.

Self-Assembled Nano-Bioreactor from Block Ionomers with Elevated and Stabilized Enzymatic Function

2007 ◽  
Vol 18 (5) ◽  
pp. 1555-1559 ◽  
Author(s):  
Akifumi Kawamura ◽  
Atsushi Harada ◽  
Kenji Kono ◽  
Kazunori Kataoka
Keyword(s):  
Block Ionomers ◽  
Enzymatic Function ◽  
Self Assembled

scholarly journals PLCε1 regulates SDF-1α–induced lymphocyte adhesion and migration to sites of inflammation

2017 ◽  
Vol 114 (10) ◽  
pp. 2693-2698 ◽  
Author(s):  
Marianne Strazza ◽  
Inbar Azoulay-Alfaguter ◽  
Michael Peled ◽  
Alan V. Smrcka ◽  
Edward Y. Skolnik ◽  
...  
Keyword(s):  
T Cell ◽  
Small Gtpase ◽  
The Body ◽  
Delayed Type Hypersensitivity ◽  
Intercellular Adhesion Molecule ◽  
Intercellular Adhesion Molecule 1 ◽  
Regional Lymph Nodes ◽  
Lymphocyte Adhesion ◽  
Enzymatic Function ◽  
And Migration

Regulation of integrins is critical for lymphocyte adhesion to endothelium and migration throughout the body. Inside-out signaling to integrins is mediated by the small GTPase Ras-proximate-1 (Rap1). Using an RNA-mediated interference screen, we identified phospholipase Cε 1 (PLCε1) as a crucial regulator of stromal cell-derived factor 1 alpha (SDF-1α)-induced Rap1 activation. We have shown that SDF-1α-induced activation of Rap1 is transient in comparison with the sustained level following cross-linking of the antigen receptor. We identified that PLCε1 was necessary for SDF-1α-induced adhesion using shear stress, cell morphology alterations, and crawling on intercellular adhesion molecule 1 (ICAM-1)–expressing cells. Structure–function experiments to separate the dual-enzymatic function of PLCε1 uncover necessary contributions of the CDC25, Pleckstrin homology, and Ras-associating domains, but not phospholipase activity, to this pathway. In the mouse model of delayed type hypersensitivity, we have shown an essential role for PLCε1 in T-cell migration to inflamed skin, but not for cytokine secretion and proliferation in regional lymph nodes. Our results reveal a signaling pathway where SDF-1α induces T-cell adhesion through activation of PLCε1, suggesting that PLCε1 is a specific potential target in treating conditions involving migration of T cells to inflamed organs.

scholarly journals Identification of a 2-propanol analogue modulating the non-enzymatic function of indoleamine 2,3-dioxygenase 1

2018 ◽  
Vol 158 ◽  
pp. 286-297 ◽  
Author(s):  
E. Albini ◽  
A. Coletti ◽  
F. Greco ◽  
M.T. Pallotta ◽  
G. Mondanelli ◽  
...  
Keyword(s):  
Indoleamine 2,3 Dioxygenase ◽  
Enzymatic Function

scholarly journals An atomic-resolution view of neofunctionalization in the evolution of apicomplexan lactate dehydrogenases

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Jeffrey I Boucher ◽  
Joseph R Jacobowitz ◽  
Brian C Beckett ◽  
Scott Classen ◽  
Douglas L Theobald
Keyword(s):  
Active Site ◽  
Catalytic Mechanism ◽  
Duplication Event ◽  
Atomic Resolution ◽  
Enzymatic Function ◽  
Evolutionary Trajectories ◽  
Strict Specificity ◽  
Functional Shift ◽  
Lactate Dehydrogenases ◽  
Ancestral Protein

Malate and lactate dehydrogenases (MDH and LDH) are homologous, core metabolic enzymes that share a fold and catalytic mechanism yet possess strict specificity for their substrates. In the Apicomplexa, convergent evolution of an unusual LDH from MDH produced a difference in specificity exceeding 12 orders of magnitude. The mechanisms responsible for this extraordinary functional shift are currently unknown. Using ancestral protein resurrection, we find that specificity evolved in apicomplexan LDHs by classic neofunctionalization characterized by long-range epistasis, a promiscuous intermediate, and few gain-of-function mutations of large effect. In canonical MDHs and LDHs, a single residue in the active-site loop governs substrate specificity: Arg102 in MDHs and Gln102 in LDHs. During the evolution of the apicomplexan LDH, however, specificity switched via an insertion that shifted the position and identity of this ‘specificity residue’ to Trp107f. Residues far from the active site also determine specificity, as shown by the crystal structures of three ancestral proteins bracketing the key duplication event. This work provides an unprecedented atomic-resolution view of evolutionary trajectories creating a nascent enzymatic function.

scholarly journals Identification of an Oligosaccharide Dehydrogenase from Pycnoporus Cinnabarinus Provides Insights into Fungal Breakdown of Lignocellulose

2021 ◽  
Author(s):  
Gabriele Cerutti ◽  
Elena Gugole ◽  
Linda Celeste Montemiglio ◽  
Annick Turbé-Doan ◽  
Dehbia Chena ◽  
...  
Keyword(s):  
Function Analysis ◽  
Sequence Similarity ◽  
Functional Characterization ◽  
Physiological Role ◽  
Free Form ◽  
Lignocellulose Degradation ◽  
Carbohydrate Active Enzymes ◽  
Recognition Mechanism ◽  
Pycnoporus Cinnabarinus ◽  
Enzymatic Function

Abstract Background: Fungal glucose dehydrogenases (GDHs) are FAD-dependent enzymes belonging to the glucose-methanol-choline oxidoreductase superfamily. These enzymes are classified in the “Auxiliary Activity” family 3 (AA3) of the Carbohydrate-Active enZymes database, and more specifically in subfamily AA3_2, that also includes the closely related flavoenzymes aryl-alcohol oxidase and glucose 1-oxidase. Based on sequence similarity to known fungal GDHs, an AA3_2 enzyme active on glucose was identified in the genome of Pycnoporus cinnabarinus, a model Basidiomycete able to completely degrade lignin.Results: In our work, substrate screening and functional characterization showed an unexpected preferential activity of this enzyme toward oligosaccharides containing a b(1à3) glycosidic bond, with the highest efficiency observed for the disaccharide laminaribiose. Despite its sequence similarity to GDHs, we defined a novel enzymatic activity, namely oligosaccharide dehydrogenase (ODH), for this enzyme. The crystallographic structures of ODH in the sugar-free form and in complex with glucose and laminaribiose unveiled a peculiar saccharide recognition mechanism which is not shared with previously characterized AA3 oxidoreductases and accounts for ODH preferential activity toward oligosaccharides. The sugar molecules in the active site of ODH are mainly stabilized through CH-p interactions with aromatic residues rather than through hydrogen bonds with highly conserved residues, as observed instead for the fungal glucose dehydrogenases and oxidases characterized to date. Finally, three sugar-binding sites were identified on ODH external surface, which were not previously observed and might be of importance in the physiological scenario.Conclusions: Structure-function analysis of ODH is consistent with its role as an auxiliary enzyme in lignocellulose degradation and unveils yet another enzymatic function within the AA3 family of the Carbohydrate-Active enZymes database. Our findings allow deciphering the molecular determinants of substrate binding and provide insight into the physiological role of ODH, opening new perspectives to exploit biodiversity for lignocellulose transformation into fuels and chemicals.

scholarly journals The Assembly of Bacteriophage Functional Enzymatic Models in Association with E. coli Proteins' Profiles

2020 ◽  
Vol 1 (7) ◽  
pp. 320-329
Author(s):  
Ayman A Elshayeb ◽  
Amna Elfatih ◽  
Karimeldin MA Salih ◽  
Nada SE Mustafa4
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Lytic Cycle ◽  
Host Bacterium ◽  
Lytic Enzymes ◽  
Isolation And Identification ◽  
Phage Group ◽  
Molecular Weights ◽  
Enzymatic Function ◽  
T7 Phage

Introduction: The invasion of bacteriophage on the associated host bacterium depends on their receptors' orientation that adsorb them to cell surface. During phage replication a valuable number of proteins acts as lytic enzymes for host puncher at the beginning of the infection and other for burst after lytic cycle compilation. Accordingly, the proteomic relationship among phage and bacterium proteins could easily be studied by their protein profiles analysis. Objective: To detect bacteriophages functional enzymes during lytic cycle. Methods: The isolation and identification of Escherichia coli and their parasitic T7 phage group was done using bacterial culture and common plaque assay techniques. The investigations and protein-protein interactions' assays were inveterate by proteins profile of phage and bacterium using Sodium Dodecyl Sulphate Poly Acrylamide Gel Electrophoresis (SDS-PAGE) to find out their molecular weights, where the scaled location of each mobile band was compared to the standards of identified proteins weights in the molecular ladder. Thereafter, Protein model's assembly and bands migration was done by computer analytical software. Results: Mobilization of the phage' proteins inside the Two Dimensions (2D) gel ranged between 60 and 12 kDa where a model of 4 main bands with molecular weights of (46, 35, 24 and 14 kDa) is corresponded to the host ones, where pure 9 bands with molecular weight ranged between 96-24 kDa. The computational model analysis showed common shared molecular masses of 47, 34 and 16 kDa on plot area of the phage and the bacterium. Model interpretation confirmed that proteins ranged from 47.7 to 34.3 kDa resembles 43.3% of whole phage's proteins that assembled the capsid head and the coil, while the molecular weight mass of 22.5 formed the tail's proteins. The lytic enzymes' molecular weight was ranged between 18-14 kDa according to the function of the enzyme. The study revealed that the 34 kDa band has the common shared peak between T7 phage group and associated Escherichia coli host. Conclusion: Functional models of analysed proteins during phage assembly, ensures lytic enzymes are built in the capsid head and the lysozyme in the tail, they facilitate the enzymatic decay for bacterial host. This enzymatic function is related to the lytic cycle of the bacteriophages and their phenomenon in employing the bacterial DNA in proteins manufacturing during their replication inside host.

scholarly journals Genotype-Species Interactions in Neighbourhoods of Forest Tree Communities

2007 ◽  
Vol 56 (1-6) ◽  
pp. 101-110 ◽  
Author(s):  
Chr. Wehenkel ◽  
F. Bergmann ◽  
H.-R. Gregorius
Keyword(s):  
Species Interactions ◽  
Species Coexistence ◽  
Biotic Interactions ◽  
Forest Tree ◽  
Target Species ◽  
Species Identity ◽  
Enzymatic Function ◽  
Genotype Frequencies ◽  
Tree Communities ◽  
Large Survey

Abstract Studies on plant communities of various annual species suggest that there are particular biotic interactions among individuals from different species which could be the basis for long-term species coexistence. In the course of a large survey on species-genetic diversity relationships in several forest tree communities, it was found that statistically significant differences exist among isozyme genotype frequencies of conspecific tree groups, which differ only by species identity of their neighbours. Based on a specific measure, the association of the neighbouring species with the genotypes of the target species or that of the genotypes with the neighbouring species was quantified. Since only AAT and HEK of the five analysed enzyme systems differed in their genotype frequencies among several tree groups of the same target species, a potential involvement of their enzymatic function in the observed differences was discussed. The results of this study demonstrate a fine-scale genetic differentiation within single tree species of forest communities, which may be the result of biotic interactions between the genetic structure of a species and the species composition of its community. This observation also suggests the importance of intraspecific genetic variation for interspecific adaptation.

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