scholarly journals A Click-Flipped Enzyme Substrate Boosts the Performance of the Diagnostic Screening for Hunter Syndrome

2020 ◽  
Author(s):  
Markus Schwarz ◽  
Philipp Skrinjar ◽  
Michael J. Fink ◽  
Stefan Kronister ◽  
Thomas Mechtler ◽  
...  
Keyword(s):  
Metabolic Disorders ◽  
Reaction Times ◽  
Hunter Syndrome ◽  
Dried Blood Spots ◽  
Unexpected Finding ◽  
Diagnostic Screening ◽  
Enzyme Substrate ◽  
Enzyme Substrates ◽  
New Strategy ◽  
Initiation Of Therapy

We report on the unexpected finding that click modification of iduronyl azides results in a conformational flip of the pyranose ring, which led to the development of a new strategy for the design of superior enzyme substrates for the diagnostic assaying of iduronate-2-sulfatase (I2S), a lysosomal enzyme related to Hunter syndrome. Synthetic substrates are essential in testing newborns for metabolic disorders to enable early initiation of therapy. Our click-flipped iduronyl triazole showed a remarkably better performance with I2S than commonly used <i>O</i>-iduronates. We found that both <i>O</i>- and triazole-linked substrates are accepted by the enzyme, irrespective of their different conformations, but only the <i>O</i>-linked product inhibits the activity of I2S. Thus, in the long reaction times required for clinical assays, the triazole substrate substantially outperforms the <i>O</i>-iduronate. Applying our click-flipped substrate to assay I2S in dried blood spots sampled from affected patients and random newborns significantly increased the confidence in discriminating between these groups, clearly indicating the potential of the click-flip strategy to control the biomolecular function of carbohydrates.

scholarly journals A Click-Flipped Enzyme Substrate Boosts the Performance of the Diagnostic Screening for Hunter Syndrome

2020 ◽  
Author(s):  
Markus Schwarz ◽  
Philipp Skrinjar ◽  
Michael J. Fink ◽  
Stefan Kronister ◽  
Thomas Mechtler ◽  
...  
Keyword(s):  
Metabolic Disorders ◽  
Reaction Times ◽  
Hunter Syndrome ◽  
Dried Blood Spots ◽  
Unexpected Finding ◽  
Diagnostic Screening ◽  
Enzyme Substrate ◽  
Enzyme Substrates ◽  
New Strategy ◽  
Initiation Of Therapy

We report on the unexpected finding that click modification of iduronyl azides results in a conformational flip of the pyranose ring, which led to the development of a new strategy for the design of superior enzyme substrates for the diagnostic assaying of iduronate-2-sulfatase (I2S), a lysosomal enzyme related to Hunter syndrome. Synthetic substrates are essential in testing newborns for metabolic disorders to enable early initiation of therapy. Our click-flipped iduronyl triazole showed a remarkably better performance with I2S than commonly used <i>O</i>-iduronates. We found that both <i>O</i>- and triazole-linked substrates are accepted by the enzyme, irrespective of their different conformations, but only the <i>O</i>-linked product inhibits the activity of I2S. Thus, in the long reaction times required for clinical assays, the triazole substrate substantially outperforms the <i>O</i>-iduronate. Applying our click-flipped substrate to assay I2S in dried blood spots sampled from affected patients and random newborns significantly increased the confidence in discriminating between these groups, clearly indicating the potential of the click-flip strategy to control the biomolecular function of carbohydrates.

scholarly journals A click-flipped enzyme substrate boosts the performance of the diagnostic screening for Hunter syndrome

2020 ◽  
Vol 11 (47) ◽  
pp. 12671-12676
Author(s):  
Markus Schwarz ◽  
Philipp Skrinjar ◽  
Michael J. Fink ◽  
Stefan Kronister ◽  
Thomas Mechtler ◽  
...  
Keyword(s):  
Hunter Syndrome ◽  
Diagnostic Screening ◽  
Enzyme Substrate

Click-triggered flip of the conformation of a sulfated iduronyl azide afforded a superior enzyme substrate to screen for Hunter syndrome.

scholarly journals System-wide identification and prioritization of enzyme substrates by thermal analysis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Amir Ata Saei ◽  
Christian M. Beusch ◽  
Pierre Sabatier ◽  
Juan Astorga Wells ◽  
Hassan Gharibi ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Thioredoxin Reductase ◽  
Structural Level ◽  
Post Translational Modification ◽  
Post Translational Modifications ◽  
Enzyme Substrate ◽  
Thioredoxin Reductase 1 ◽  
Enzyme Substrates ◽  
Substrate Proteins

AbstractDespite the immense importance of enzyme–substrate reactions, there is a lack of general and unbiased tools for identifying and prioritizing substrate proteins that are modified by the enzyme on the structural level. Here we describe a high-throughput unbiased proteomics method called System-wide Identification and prioritization of Enzyme Substrates by Thermal Analysis (SIESTA). The approach assumes that the enzymatic post-translational modification of substrate proteins is likely to change their thermal stability. In our proof-of-concept studies, SIESTA successfully identifies several known and novel substrate candidates for selenoprotein thioredoxin reductase 1, protein kinase B (AKT1) and poly-(ADP-ribose) polymerase-10 systems. Wider application of SIESTA can enhance our understanding of the role of enzymes in homeostasis and disease, opening opportunities to investigate the effect of post-translational modifications on signal transduction and facilitate drug discovery.

scholarly journals Lipid Peroxidation-Mediated Inflammation Promotes Cell Apoptosis through Activation of NF-κB Pathway in Rheumatoid Arthritis Synovial Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Geng Yin ◽  
Ying Wang ◽  
Xiao-min Cen ◽  
Min Yang ◽  
Yan Liang ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Cell Apoptosis ◽  
Inflammatory Responses ◽  
Synovial Fibroblasts ◽  
Systemic Autoimmune Disease ◽  
New Strategy ◽  
Significant Clinical Improvement ◽  
Rheumatoid Arthritis Synoviocytes ◽  
Initiation Of Therapy

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation of multiple joints. The central pathogenesis of RA is the proliferation of synovial fibroblasts in response to inflammatory cytokines. However, some of the targeted therapies for inflammation reactions do not display significant clinical improvement after initiation of therapy. Thus, the relationship between inflammatory responses and RA therapy is still incompletely understood. In the present study, we proposed to determine whether enhanced inflammations may lead to cell apoptosis in rheumatoid arthritis synoviocytes. Our results indicated that products of lipid peroxidations, 4-HNE, may induce synovial intrinsic inflammations by activating NF-κB pathways and it may lead to cell apoptosis. Pharmacological inhibition of NF-κB activation may reduce the 4-HNE mediated inflammation responses and subsequent cell apoptosis. Our results may help to clarify the role of inflammations on RA development and imply that blocking NF-κB activation may be partly beneficial for human RA therapy. These findings might provide a mechanism-based rationale for developing new strategy to RA clinical therapy.

Abstract MP10: Microbiome-based Diagnostic Screening Of Cardiovascular Disease Using A Machine Learning Approach

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Sachin Aryal ◽  
Ahmad Alimadadi ◽  
Ishan Manandhar ◽  
Bina Joe ◽  
Xi Cheng
Keyword(s):  
Machine Learning ◽  
Cardiovascular Disease ◽  
Cardiovascular Health ◽  
Characteristic Curve ◽  
Feature Space ◽  
Supervised Machine Learning ◽  
Support Vector ◽  
Diagnostic Screening ◽  
New Strategy ◽  
Metagenomics Data

In recent years, the microbiome has been recognized as an important factor associated with cardiovascular disease (CVD), which is the leading cause of human mortality worldwide. Disparities in gut microbial compositions between individuals with and without CVD were reported, whereby, we hypothesized that utilizing such microbiome-based data for training with supervised machine learning (ML) models could be exploited as a new strategy for evaluation of cardiovascular health. To test our hypothesis, we analyzed the metagenomics data extracted from the American Gut Project. Specifically, 16S rRNA reads from stool samples of 478 CVD and 473 non-CVD control samples were analyzed using five supervised ML algorithms: random forest (RF), support vector machine with radial kernel (svmRadial), decision tree (DT), elastic net (ENet) and neural networks (NN). Thirty-nine differential bacterial taxa (LEfSe: LDA > 2) were identified between CVD and non-CVD groups. ML classifications, using these taxonomic features, achieved an AUC (area under the receiver operating characteristic curve) of ~0.58 (RF). However, by choosing the top 500 high-variance features of operational taxonomic units (OTUs) for training ML models, an improved AUC of ~0.65 (RF) was achieved. Further, by limiting the selection to only the top 25 highly contributing OTU features to reduce the dimensionality of feature space, the AUC was further significantly enhanced to ~0.70 (RF). In summary, this study is the first to demonstrate the successful development of a ML model using microbiome-based datasets for a systematic diagnostic screening of CVD.

scholarly journals NAD metabolism in aging and cancer

2020 ◽  
Vol 245 (17) ◽  
pp. 1594-1614 ◽  
Author(s):  
John WR Kincaid ◽  
Nathan A Berger
Keyword(s):  
Redox Reactions ◽  
Metabolic Disorders ◽  
Therapeutic Interventions ◽  
Transport Pathways ◽  
Nad Metabolism ◽  
Regulatory Enzymes ◽  
Enzyme Substrate ◽  
Cyclic Adp Ribose ◽  
And Function ◽  
Pathologic Processes

NAD+ and its derivatives NADH, NADP+, and NADPH are essential cofactors in redox reactions and electron transport pathways. NAD serves also as substrate for an extensive series of regulatory enzymes including cyclic ADP-ribose hydrolases, mono(ADP-ribosyl)transferases, poly(ADP-ribose) polymerases, and sirtuin deacetylases which are O-acetyl-ADP-ribosyltransferases. As a result of the numerous and diverse enzymes that utilize NAD as well as depend on its synthesis and concentration, significant interest has developed in its role in a variety of physiologic and pathologic processes, and therapeutic initiatives have focused both on augmenting its levels as well as inhibiting some of its pathways. In this article, we examine the biosynthesis of NAD, metabolic processes in which it is involved, and its role in aging, cancer, and other age-associated comorbidities including neurodegenerative, cardiovascular, and metabolic disorders. Therapeutic interventions to augment and/or inhibit these processes are also discussed. Impact statement NAD is a central metabolite connecting energy balance and organismal growth with genomic integrity and function. It is involved in the development of malignancy and has a regulatory role in the aging process. These processes are mediated by a diverse series of enzymes whose common focus is either NAD’s biosynthesis or its utilization as a redox cofactor or enzyme substrate. These enzymes include dehydrogenases, cyclic ADP-ribose hydrolases, mono(ADP-ribosyl)transferases, poly(ADP-ribose) polymerases, and sirtuin deacetylases. This article describes the manifold pathways that comprise NAD metabolism and promotes an increased awareness of how perturbations in these systems may be important in disease prevention and/or progression.

A novel fluorometric enzyme analysis method for Hunter syndrome using dried blood spots

2012 ◽  
Vol 105 (3) ◽  
pp. 519-521 ◽  
Author(s):  
Adviye A. Tolun ◽  
Carrie Graham ◽  
Qun Shi ◽  
Ramakrishna S. Sista ◽  
Tong Wang ◽  
...  
Keyword(s):  
Hunter Syndrome ◽  
Dried Blood Spots ◽  
Enzyme Analysis ◽  
Analysis Method ◽  
Blood Spots

scholarly journals System-wide identification and prioritization of enzyme substrates by thermal analysis (SIESTA)

2018 ◽  
Author(s):  
Amir Ata Saei ◽  
Christian M. Beusch ◽  
Pierre Sabatier ◽  
Juan Astorga Wells ◽  
Alexey Chernobrovkin ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Protein Kinase B ◽  
Thioredoxin Reductase ◽  
Post Translational Modification ◽  
Enzyme Substrate ◽  
Thioredoxin Reductase 1 ◽  
Enzyme Substrates ◽  
Substrate Proteins

AbstractDespite the immense importance of enzyme-substrate reactions, there is a lack of generic and unbiased tools for identifying and prioritizing substrate proteins which are modulated in the structural and functional levels through modification. Here we describe a high-throughput unbiased proteomic method called System-wide Identification and prioritization of Enzyme Substrates by Thermal Analysis (SIESTA). The approach assumes that enzymatic post-translational modification of substrate proteins might change their thermal stability. SIESTA successfully identifies several known and novel substrate candidates for selenoprotein thioredoxin reductase 1, protein kinase B (AKT1) and poly-(ADP-ribose) polymerase-10 systems in up to a depth of 7179 proteins. Wider application of SIESTA can enhance our understanding of the role of enzymes in homeostasis and disease, open new opportunities in investigating the effect of PTMs on signal transduction, and facilitate drug discovery.

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