Dissection of the Enzymatic Process for Forming a Central Imidazopiperidine Heterocycle in the Biosynthesis of a Series c Thiopeptide Antibiotic

2021 ◽  
Author(s):  
Botao Cheng ◽  
Heng Guo ◽  
Haoyang Wang ◽  
Qunfei Zhao ◽  
Wen Liu
Keyword(s):  
Enzymatic Process

Efficient Enzymatic Process for Mulberry Paper Production: An Approach for Xylooligosaccharide Production Coupled with Minimizing Bleaching Agent Doses

2021 ◽  
Author(s):  
Thanongsak Chaiyaso ◽  
Pinpanit Boonchuay ◽  
Shinji Takenaka ◽  
Charin Techapun ◽  
Pornchai Rachtanapun ◽  
...  
Keyword(s):  
Bleaching Agent ◽  
Enzymatic Process ◽  
Paper Production ◽  
Mulberry Paper

scholarly journals A new enzymatic process for the treatment of phenolic pollutants

2013 ◽  
Vol 56 (4) ◽  
pp. 653-662 ◽  
Author(s):  
Mauri Sergio Alves Palma ◽  
Harald Horn ◽  
Mario Zilli ◽  
Gisele Pigatto ◽  
Attilio Converti
Keyword(s):  
Enzymatic Process ◽  
Phenolic Pollutants

Understanding cellular glycan surfaces in the central nervous system

2018 ◽  
Vol 47 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Sameera Iqbal ◽  
Mina Ghanimi Fard ◽  
Arun Everest-Dass ◽  
Nicolle H. Packer ◽  
Lindsay M. Parker
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neural Development ◽  
Analytical Techniques ◽  
Detection Methods ◽  
Biological Processes ◽  
Post Translational Modification ◽  
Enzymatic Process ◽  
The Central Nervous System ◽  
Lateral Sclerosis

Abstract Glycosylation, the enzymatic process by which glycans are attached to proteins and lipids, is the most abundant and functionally important type of post-translational modification associated with brain development, neurodegenerative disorders, psychopathologies and brain cancers. Glycan structures are diverse and complex; however, they have been detected and targeted in the central nervous system (CNS) by various immunohistochemical detection methods using glycan-binding proteins such as anti-glycan antibodies or lectins and/or characterized with analytical techniques such as chromatography and mass spectrometry. The glycan structures on glycoproteins and glycolipids expressed in neural stem cells play key roles in neural development, biological processes and CNS maintenance, such as cell adhesion, signal transduction, molecular trafficking and differentiation. This brief review will highlight some of the important findings on differential glycan expression across stages of CNS cell differentiation and in pathological disorders and diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, amyotrophic lateral sclerosis, schizophrenia and brain cancer.

scholarly journals The rhodopsin-retinochrome system for retinal re-isomerization predates the origin of cephalopod eyes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Oliver Vöcking ◽  
Lucas Leclère ◽  
Harald Hausen
Keyword(s):  
In Situ Hybridization ◽  
Photoreceptor Cells ◽  
Visual Cycle ◽  
Phylogenetic Distribution ◽  
Enzymatic Process ◽  
Antibody Staining ◽  
The Individual ◽  
Functional Components ◽  
Visual Rhodopsin

Abstract Background The process of photoreception in most animals depends on the light induced isomerization of the chromophore retinal, bound to rhodopsin. To re-use retinal, the all-trans-retinal form needs to be re-isomerized to 11-cis-retinal, which can be achieved in different ways. In vertebrates, this mostly includes a stepwise enzymatic process called the visual cycle. The best studied re-isomerization system in protostomes is the rhodopsin-retinochrome system of cephalopods, which consists of rhodopsin, the photoisomerase retinochrome and the protein RALBP functioning as shuttle for retinal. In this study we investigate the expression of the rhodopsin-retinochrome system and functional components of the vertebrate visual cycle in a polyplacophoran mollusk, Leptochiton asellus, and examine the phylogenetic distribution of the individual components in other protostome animals. Results Tree-based orthology assignments revealed that orthologs of the cephalopod retinochrome and RALBP are present in mollusks outside of cephalopods. By mining our dataset for vertebrate visual cycle components, we also found orthologs of the retinoid binding protein RLBP1, in polyplacophoran mollusks, cephalopods and a phoronid. In situ hybridization and antibody staining revealed that L. asellus retinochrome is co-expressed in the larval chiton photoreceptor cells (PRCs) with the visual rhodopsin, RALBP and RLBP1. In addition, multiple retinal dehydrogenases are expressed in the PRCs, which might also contribute to the rhodopsin-retinochrome system. Conclusions We conclude that the rhodopsin-retinochrome system is a common feature of mollusk PRCs and predates the origin of cephalopod eyes. Our results show that this system has to be extended by adding further components, which surprisingly, are shared with vertebrates.

scholarly journals Graphical Approach to Compare Concentration Constants of Hill and Michaelis-Menten Equations

2018 ◽  
Vol 1 (3) ◽  
pp. 94-99 ◽  
Author(s):  
Elena V. Emelyanova
Keyword(s):  
Catalytic Activity ◽  
Substrate Concentration ◽  
Hill Equation ◽  
Enzymatic Process ◽  
Michaelis Constant ◽  
Graphical Approach ◽  
Graphical Technique ◽  
Kinetics Of ◽  
Permissible Rate ◽  
Concentration Constants

The aim of present study was to describe the graphical technique how to go from Hill concentration constant to Michaelis constant. To compare enzymatic processes, the kinetics of which is subjected to different regularities, it is possible to use constants that characterize catalytic activity (Vmax) and concentration constants that are the substrate concentration at which the rate of the enzymatic process is equal to a half of maximum permissible rate. Concentration constants are S0.5 for Hill equation and Km for Michaelis-Menton equation. The graphical approach was proposed in order to go from concentration constant of Hill equation to Michaelis concentration of the process that could be characterized by the same catalytic activity (the same values of minimum and maximum rates) similar to that observed in the process described by Hill equation.

scholarly journals Enzymatic evolution driven by entropy production

2018 ◽  
Author(s):  
A. Arango-Restrepo ◽  
J.M. Rubi ◽  
D. Barragán
Keyword(s):  
Enzyme Kinetics ◽  
Entropy Production ◽  
Intermediate State ◽  
State Energy ◽  
Structural Evolution ◽  
Thermodynamic Efficiency ◽  
Total Entropy ◽  
Enzymatic Process ◽  
Intermediate States ◽  
Evolution Proceeds

AbstractWe show that the structural evolution of enzymes is largely influenced by the entropy produced in the enzymatic process. We have computed this quantity for the case in which the process has unstable and metastable intermediate states. By assuming that the kinetics takes place along a potential barrier, we have found that the behavior of the total entropy produced is a non-monotonic function of the intermediate state energy. By diminishing the number of metastable intermediate states, the total entropy produced decreases and consequently the enzyme kinetics and the thermodynamic efficiency are enhanced. Minimizing locally the total entropy produced for an enzymatic process with metastable intermediate states, the kinetics and the thermodynamic efficiency are raised. In contrast, in the absence of metastable intermediate states, a maximum of the entropy produced results in an improvement of the kinetic performance although the thermodynamic efficiency diminishes. Our results show that the enzymatic evolution proceeds not only to enhance the kinetics but also to optimize the total entropy produced.

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