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 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.

The diagnosis of metabolic storage disease in skin biopsies (a light-, electronmicroscopic, and analytical study)

1978 ◽  
Vol 36 (2) ◽  
pp. 648-649
Author(s):  
W. Jurecka ◽  
W. Gebhart ◽  
H. Lassmann
Keyword(s):  
Storage Disease ◽  
Hunter Syndrome ◽  
Histochemical Demonstration ◽  
Sweat Glands ◽  
Type I ◽  
Storage Material ◽  
Scheie Syndrome ◽  
Storage Products ◽  
Skin Biopsies ◽  
Type V

Diagnosis of metabolic storage disease can be established by the determination of enzymes or storage material in blood, urine, or several tissues or by clinical parameters. Identification of the accumulated storage products is possible by biochemical analysis of isolated material, by histochemical demonstration in sections, or by ultrastructural demonstration of typical inclusion bodies. In order to determine the significance of such inclusions in human skin biopsies several types of metabolic storage disease were investigated. The following results were obtained.In MPS type I (Pfaundler-Hurler-Syndrome), type II (Hunter-Syndrome), and type V (Ullrich-Scheie-Syndrome) mainly “empty” vacuoles were found in skin fibroblasts, in Schwann cells, keratinocytes and macrophages (Dorfmann and Matalon 1972). In addition, prominent vacuolisation was found in eccrine sweat glands. The storage material could be preserved in part by fixation with cetylpyridiniumchloride and was also present within fibroblasts grown in tissue culture.

Review of Diagnostic Screening Instruments for Alcohol and Other Drug Use and Other Psychiatric Disorders

2002 ◽  
Author(s):  
Sharon Dawe ◽  
Natalie J. Loxton ◽  
Leanne Hides ◽  
David J. Kavanagh ◽  
Richard P. Mattick
Keyword(s):  
Drug Use ◽  
Psychiatric Disorders ◽  
Screening Instruments ◽  
Diagnostic Screening

Genetics in Ophthalmology

2020 ◽  
pp. 44-45
Author(s):  
А.Ю. Рудник ◽  
М.А. Федяков ◽  
О.С. Глотов
Keyword(s):  
Genetic Basis ◽  
Genetic Diseases ◽  
Mendelian Inheritance ◽  
Diagnostic Screening ◽  
Online Mendelian Inheritance ◽  
Clinical Diagnostic ◽  
Omim Database

На сегодняшний день в базе данных Online Mendelian Inheritance in Man (OMIM) описано более 6613 заболеваний и фенотипов, 4241 имеют доказанную генетическую основу, не менее 45% вкючают офтальмологические проявления. В статье приведен ряд клинический примеров пациентов с офтальмологическими симптомами различных генетических заболеваний (алкаптонурия, болезнь Штаргардта, синдром микроцефалии с или без хориоретинопатии; астроцитарная гамартома) с целью демонстрации эффективного клинико-диагностического скрининга генетической патологии у пациентов. So far, the Online Mendelian Inheritance in Man (OMIM) database describes more than 6613 diseases and phenotypes, 4241 have a proven genetic basis, 45% of which are combined with ophthalmological manifestations. The article provides a number of clinical examples of patients with ophthalmological manifestations of various genetic diseases (alcaptonuria, Stadgart ‘s disease, microcephaly syndrome with or without choriretinopathy; Astrocytic gamartoma) to demonstrate effective clinical-diagnostic screening of genetic pathology in patients.

Cell-Specific Chemical Delivery Using a Selective Nitroreductase–Nitroaryl Pair

2018 ◽  
Author(s):  
Todd D. Gruber ◽  
Chithra Krishnamurthy ◽  
Jonathan B. Grimm ◽  
Michael R. Tadross ◽  
Laura M. Wysocki ◽  
...  
Keyword(s):  
Small Molecules ◽  
Mammalian Cells ◽  
Target Cells ◽  
Specific Chemical ◽  
E Coli ◽  
Enzyme Substrate ◽  
Cell Specificity ◽  
General Chemical ◽  
Increased Activity ◽  
Enzyme Variant

<p>The utility of<b> </b>small molecules to probe or perturb biological systems is limited by the lack of cell-specificity. ‘Masking’ the activity of small molecules using a general chemical modification and ‘unmasking’ it only within target cells could overcome this limitation. To this end, we have developed a selective enzyme–substrate pair consisting of engineered variants of <i>E. coli</i> nitroreductase (NTR) and a 2‑nitro-<i>N</i>-methylimidazolyl (NM) masking group. To discover and optimize this NTR–NM system, we synthesized a series of fluorogenic substrates containing different nitroaromatic masking groups, confirmed their stability in cells, and identified the best substrate for NTR. We then engineered the enzyme for improved activity in mammalian cells, ultimately yielding an enzyme variant (enhanced NTR, or eNTR) that possesses up to 100-fold increased activity over wild-type NTR. These improved NTR enzymes combined with the optimal NM masking group enable rapid, selective unmasking of dyes, indicators, and drugs to genetically defined populations of cells.</p>

The role of secondary alcoholic groups of D-galacturonan in its degradation with exo-D-galacturonanase

1980 ◽  
Vol 45 (2) ◽  
pp. 427-434 ◽  
Author(s):  
Kveta Heinrichová ◽  
Rudolf Kohn
Keyword(s):  
Acetyl Derivative ◽  
Competitive Inhibitor ◽  
Hydroxyl Groups ◽  
Pectic Acid ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
The Individual ◽  
Degradation Degree ◽  
Derivatives Of

The effect of exo-D-galacturonanase from carrot on O-acetyl derivatives of pectic acid of variousacetylation degree was studied. Substitution of hydroxyl groups at C(2) and C(3) of D-galactopyranuronic acid units influences the initial rate of degradation, degree of degradation and its maximum rate, the differences being found also in the time of limit degradations of the individual O-acetyl derivatives. Value of the apparent Michaelis constant increases with increase of substitution and value of Vmax changes. O-Acetyl derivatives act as a competitive inhibitor of degradation of D-galacturonan. The extent of the inhibition effect depends on the degree of substitution. The only product of enzymic reaction is D-galactopyranuronic acid, what indicates that no degradation of the terminal substituted unit of O-acetyl derivative of pectic acid takes place. Substitution of hydroxyl groups influences the affinity of the enzyme towards the modified substrate. The results let us presume that hydroxyl groups at C(2) and C(3) of galacturonic unit of pectic acid are essential for formation of the enzyme-substrate complex.

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