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Hanamatsu H, Nishikaze T, Furukawa JI. Comprehensive Glycan Analysis of Sphingolipids in Human Serum/Plasma. Methods Mol Biol 2023; 2613:289-299. [PMID: 36587086 DOI: 10.1007/978-1-0716-2910-9_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Glycosphingolipids (GSLs) are glycolipids with ceramide and carbohydrate head groups that play an important role in numerous biological processes. Previously, we performed GSL-glycan analysis of various cell lines and virus-infected cells using a glycoblotting approach. Recently, we developed several methods for sialic acid linkage-specific chemical modification to distinguish sialylated glycan isomers by mass spectrometry. In this chapter, we describe a method for analyzing GSL-glycans in human serum/plasma using glycoblotting combined with aminolysis-SALSA (sialic acid linkage-specific alkylamidation) and lactone-driven ester-to-amide derivatization (LEAD)-SALSA for comprehensive and detailed structural glycomics.
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Affiliation(s)
- Hisatoshi Hanamatsu
- Department of Advanced Clinical Glycobiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
| | | | - Jun-Ichi Furukawa
- Institute for Glyco-core Research (iGCORE), Nagoya University, Nagoya, Aichi, Japan
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
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2
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Aberrant Ganglioside Functions to Underpin Dysregulated Myelination, Insulin Signalling, and Cytokine Expression: Is There a Link and a Room for Therapy? Biomolecules 2022; 12:biom12101434. [PMID: 36291644 PMCID: PMC9599472 DOI: 10.3390/biom12101434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 11/17/2022] Open
Abstract
Gangliosides are molecules widely present in the plasma membranes of mammalian cells, participating in a variety of processes, including protein organization, transmembrane signalling and cell adhesion. Gangliosides are abundant in the grey matter of the brain, where they are critically involved in postnatal neural development and function. The common precursor of the majority of brain gangliosides, GM3, is formed by the sialylation of lactosylceramide, and four derivatives of its a- and b-series, GM1, GD1a, GD1b and GT1b, constitute 95% of all the brain gangliosides. Impairments in ganglioside metabolism due to genetic abnormalities of GM-synthases are associated with severe neurological disorders. Apart from that, the latest genome-wide association and translational studies suggest a role of genes involved in brain ganglioside synthesis in less pervasive psychiatric disorders. Remarkably, the most recent animal studies showed that abnormal ganglioside functions result in dysregulated neuroinflammation, aberrant myelination and altered insulin receptor signalling. At the same time, these molecular features are well established as accompanying developmental psychiatric disorders such as attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD). This led us to hypothesize a role of deficient ganglioside function in developmental neuropsychiatric disorders and warrants further gene association clinical studies addressing this question. Here, we critically review the literature to discuss this hypothesis and focus on the recent studies on ST3GAL5-deficient mice. In addition, we elaborate on the therapeutic potential of various anti-inflammatory remedies for treatment of developmental neuropsychiatric conditions related to aberrant ganglioside functions.
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3
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The GM2 gangliosidoses: Unlocking the mysteries of pathogenesis and treatment. Neurosci Lett 2021; 764:136195. [PMID: 34450229 PMCID: PMC8572160 DOI: 10.1016/j.neulet.2021.136195] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/13/2021] [Accepted: 08/20/2021] [Indexed: 12/28/2022]
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Sandhoff K. Secondary ganglioside GM2 accumulation in mucopolysaccharidoses. Mol Genet Metab Rep 2021; 28:100789. [PMID: 34485082 PMCID: PMC8403895 DOI: 10.1016/j.ymgmr.2021.100789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 06/01/2021] [Accepted: 08/03/2021] [Indexed: 11/15/2022] Open
Affiliation(s)
- Konrad Sandhoff
- LIMES, c/o Kekule-Institut f. Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universitaet Bonn, Bonn, Germany
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Breiden B, Sandhoff K. Mechanism of Secondary Ganglioside and Lipid Accumulation in Lysosomal Disease. Int J Mol Sci 2020; 21:ijms21072566. [PMID: 32272755 PMCID: PMC7178057 DOI: 10.3390/ijms21072566] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/26/2020] [Accepted: 04/04/2020] [Indexed: 02/06/2023] Open
Abstract
Gangliosidoses are caused by monogenic defects of a specific hydrolase or an ancillary sphingolipid activator protein essential for a specific step in the catabolism of gangliosides. Such defects in lysosomal function cause a primary accumulation of multiple undegradable gangliosides and glycosphingolipids. In reality, however, predominantly small gangliosides also accumulate in many lysosomal diseases as secondary storage material without any known defect in their catabolic pathway. In recent reconstitution experiments, we identified primary storage materials like sphingomyelin, cholesterol, lysosphingolipids, and chondroitin sulfate as strong inhibitors of sphingolipid activator proteins (like GM2 activator protein, saposin A and B), essential for the catabolism of many gangliosides and glycosphingolipids, as well as inhibitors of specific catabolic steps in lysosomal ganglioside catabolism and cholesterol turnover. In particular, they trigger a secondary accumulation of ganglioside GM2, glucosylceramide and cholesterol in Niemann–Pick disease type A and B, and of GM2 and glucosylceramide in Niemann–Pick disease type C. Chondroitin sulfate effectively inhibits GM2 catabolism in mucopolysaccharidoses like Hurler, Hunter, Sanfilippo, and Sly syndrome and causes a secondary neuronal ganglioside GM2 accumulation, triggering neurodegeneration. Secondary ganglioside and lipid accumulation is furthermore known in many more lysosomal storage diseases, so far without known molecular basis.
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6
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Adams JW, Cugola FR, Muotri AR. Brain Organoids as Tools for Modeling Human Neurodevelopmental Disorders. Physiology (Bethesda) 2019; 34:365-375. [PMID: 31389776 PMCID: PMC6863377 DOI: 10.1152/physiol.00005.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/12/2019] [Accepted: 04/12/2019] [Indexed: 12/15/2022] Open
Abstract
Brain organoids recapitulate in vitro the specific stages of in vivo human brain development, thus offering an innovative tool by which to model human neurodevelopmental disease. We review here how brain organoids have been used to study neurodevelopmental disease and consider their potential for both technological advancement and therapeutic development.
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Affiliation(s)
- Jason W Adams
- Department of Pediatrics/Rady Children's Hospital San Diego, School of Medicine, University of California San Diego, San Diego, California
- Department of Cellular & Molecular Medicine, Stem Cell Program, Center for Academic Research and Training in Anthropogeny (CARTA), Kavli Institute for Brain and Mind, La Jolla, California
- Department of Neurosciences, School of Medicine, University of California San Diego, San Diego, California
| | - Fernanda R Cugola
- Department of Pediatrics/Rady Children's Hospital San Diego, School of Medicine, University of California San Diego, San Diego, California
- Department of Cellular & Molecular Medicine, Stem Cell Program, Center for Academic Research and Training in Anthropogeny (CARTA), Kavli Institute for Brain and Mind, La Jolla, California
| | - Alysson R Muotri
- Department of Pediatrics/Rady Children's Hospital San Diego, School of Medicine, University of California San Diego, San Diego, California
- Department of Cellular & Molecular Medicine, Stem Cell Program, Center for Academic Research and Training in Anthropogeny (CARTA), Kavli Institute for Brain and Mind, La Jolla, California
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7
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Electrospray ionization ion mobility mass spectrometry provides novel insights into the pattern and activity of fetal hippocampus gangliosides. Biochimie 2017; 139:81-94. [DOI: 10.1016/j.biochi.2017.05.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 05/24/2017] [Indexed: 12/19/2022]
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8
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Catabolism of N-glycoproteins in mammalian cells: Molecular mechanisms and genetic disorders related to the processes. Mol Aspects Med 2016; 51:89-103. [DOI: 10.1016/j.mam.2016.05.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 05/11/2016] [Accepted: 05/24/2016] [Indexed: 11/17/2022]
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9
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Lew RM, Burnett L, Proos AL, Delatycki MB. Tay-Sachs disease: current perspectives from Australia. APPLICATION OF CLINICAL GENETICS 2015; 8:19-25. [PMID: 25653550 PMCID: PMC4309774 DOI: 10.2147/tacg.s49628] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Tay-Sachs disease (TSD) is a fatal, recessively inherited neurodegenerative condition of infancy and early childhood. Although rare in most other populations, the carrier frequency is one in 25 in Ashkenazi Jews. Australian high-school-based TSD preconception genetic screening programs aim to screen, educate, and optimize reproductive choice for participants. These programs have demonstrated high uptake, low psychological morbidity, and have been shown to result in fewer than expected Jewish TSD-affected births over 18 years of operation. The majority of Jewish individuals of reproductive age outside of the high school screening program setting in Australia have not accessed screening. Recent recommendations advocate supplementing the community high school screening programs with general practitioner- and obstetrician-led genetic screening of Ashkenazi Jewish individuals for TSD and other severe recessive diseases for which this group is at risk. Massively parallel DNA sequencing is expected to become the testing modality of choice over the coming years.
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Affiliation(s)
- Raelia M Lew
- Department of Obstetrics and Gynecology, QEII Research Institute for Mothers and Infants, The University of Sydney, Australia ; Department of Obstetrics and Gynaecology, Dentistry and Health Sciences, Faculty of Medicine, The University of Melbourne, Melbourne, Australia
| | - Leslie Burnett
- NSW Health Pathology North, Royal North Shore Hospital, St Leonards, Australia ; SEALS, Prince of Wales Hospital, Randwick, Australia ; Sydney Medical School-Northern, Royal North Shore Hospital E25, University of Sydney, Sydney, Australia
| | - Anné L Proos
- NSW Health Pathology North, Royal North Shore Hospital, St Leonards, Australia
| | - Martin B Delatycki
- Department of Clinical Genetics, Austin Health, Heidelberg, Australia ; Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Parkville, Australia
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Cachón-González MB, Wang SZ, Ziegler R, Cheng SH, Cox TM. Reversibility of neuropathology in Tay-Sachs-related diseases. Hum Mol Genet 2014; 23:730-48. [PMID: 24057669 PMCID: PMC3888261 DOI: 10.1093/hmg/ddt459] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 09/16/2013] [Indexed: 01/22/2023] Open
Abstract
The GM2 gangliosidoses are progressive neurodegenerative disorders due to defects in the lysosomal β-N-acetylhexosaminidase system. Accumulation of β-hexosaminidases A and B substrates is presumed to cause this fatal condition. An authentic mouse model of Sandhoff disease (SD) with pathological characteristics resembling those noted in infantile GM2 gangliosidosis has been described. We have shown that expression of β-hexosaminidase by intracranial delivery of recombinant adeno-associated viral vectors to young adult SD mice can prevent many features of the disease and extends lifespan. To investigate the nature of the neurological injury in GM2 gangliosidosis and the extent of its reversibility, we have examined the evolution of disease in the SD mouse; we have moreover explored the effects of gene transfer delivered at key times during the course of the illness. Here we report greatly increased survival only when the therapeutic genes are expressed either before the disease is apparent or during its early manifestations. However, irrespective of when treatment was administered, widespread and abundant expression of β-hexosaminidase with consequent clearance of glycoconjugates, α-synuclein and ubiquitinated proteins, and abrogation of inflammatory responses and neuronal loss was observed. We also show that defects in myelination occur in early life and cannot be easily resolved when treatment is given to the adult brain. These results indicate that there is a limited temporal opportunity in which function and survival can be improved-but regardless of resolution of the cardinal pathological features of GM2 gangliosidosis, a point is reached when functional deterioration and death cannot be prevented.
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Affiliation(s)
| | - Susan Z. Wang
- Department of Medicine, University of Cambridge, Cambridge, UK and
| | | | | | - Timothy M. Cox
- Department of Medicine, University of Cambridge, Cambridge, UK and
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11
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Molino D, Galli T. Biogenesis and transport of membrane domains-potential implications in brain pathologies. Biochimie 2013; 96:75-84. [PMID: 24075975 DOI: 10.1016/j.biochi.2013.09.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 09/12/2013] [Indexed: 11/28/2022]
Abstract
Lipids in biological membranes show astonishing chemical diversity, but they also show some key conserved structures in different organisms. In addition, some of their biophysical properties have been related to specific functions. In this review, we aim to discuss the role of sphingolipids- and cholesterol-rich micro- and nano-membrane domains (MD) and highlight their pivotal role in lipid-protein clustering processes, vesicle biogenesis and membrane fusion. We further review potential connections between human pathologies and defects in MD biosynthesis, recycling and homeostasis. Brain, which is second only to the adipose tissues in term of lipid abundance, is particularly affected by MD defects which are linked to neurodegenerative disorders. Finally we propose a potential connection between MD and several nutrient-related processes and envision how diet and autophagy could bring insights towards understanding the impact of global lipid homeostasis on human health and disease.
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Affiliation(s)
- Diana Molino
- Institut Jacques Monod, UMR 7592, CNRS, Université Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France; INSERM ERL U950, Membrane Traffic in Neuronal and Epithelial Morphogenesis, F-75013 Paris, France.
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12
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Kolter T. Ganglioside biochemistry. ISRN BIOCHEMISTRY 2012; 2012:506160. [PMID: 25969757 PMCID: PMC4393008 DOI: 10.5402/2012/506160] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 10/09/2012] [Indexed: 01/21/2023]
Abstract
Gangliosides are sialic acid-containing glycosphingolipids. They occur especially on the cellular surfaces of neuronal cells, where they form a complex pattern, but are also found in many other cell types. The paper provides a general overview on their structures, occurrence, and metabolism. Key functional, biochemical, and pathobiochemical aspects are summarized.
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Affiliation(s)
- Thomas Kolter
- Program Unit Membrane Biology & Lipid Biochemistry, LiMES, University of Bonn, Gerhard-Domagk Straße 1, 53121 Bonn, Germany
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13
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Gene transfer corrects acute GM2 gangliosidosis--potential therapeutic contribution of perivascular enzyme flow. Mol Ther 2012; 20:1489-500. [PMID: 22453766 DOI: 10.1038/mt.2012.44] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The GM2 gangliosidoses are fatal lysosomal storage diseases principally affecting the brain. Absence of β-hexosaminidase A and B activities in the Sandhoff mouse causes neurological dysfunction and recapitulates the acute Tay-Sachs (TSD) and Sandhoff diseases (SD) in infants. Intracranial coinjection of recombinant adeno-associated viral vectors (rAAV), serotype 2/1, expressing human β-hexosaminidase α (HEXA) and β (HEXB) subunits into 1-month-old Sandhoff mice gave unprecedented survival to 2 years and prevented disease throughout the brain and spinal cord. Classical manifestations of disease, including spasticity-as opposed to tremor-ataxia-were resolved by localized gene transfer to the striatum or cerebellum, respectively. Abundant biosynthesis of β-hexosaminidase isozymes and their global distribution via axonal, perivascular, and cerebrospinal fluid (CSF) spaces, as well as diffusion, account for the sustained phenotypic rescue-long-term protein expression by transduced brain parenchyma, choroid plexus epithelium, and dorsal root ganglia neurons supplies the corrective enzyme. Prolonged survival permitted expression of cryptic disease in organs not accessed by intracranial vector delivery. We contend that infusion of rAAV into CSF space and intraparenchymal administration by convection-enhanced delivery at a few strategic sites will optimally treat neurodegeneration in many diseases affecting the nervous system.
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14
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Identification of two HEXA mutations causing infantile-onset Tay-Sachs disease in the Persian population. J Hum Genet 2011; 56:682-4. [PMID: 21796138 DOI: 10.1038/jhg.2011.78] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The β-hexosaminidase A (HEXA) mutations in the first reported cases of infantile Tay-Sachs disease in the Persian population were identified in two unrelated consanguineous families. The clinical diagnoses of the affected infants were confirmed by their markedly deficient levels of HEXA activity in plasma or peripheral leukocytes. The specific causative mutation in each family was determined by sequencing the HEXA alleles in both sets of related parents. Two mutations were identified: c.1A>G (p.MIV), which obliterated the initiating methionine in codon 1, and c.1177C>T (p.R393X), which predicted a termination codon or nonsense mutation.
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Abstract
Lysosomal lipid storage diseases, or lipidoses, are inherited metabolic disorders in which typically lipids accumulate in cells and tissues. Complex lipids, such as glycosphingolipids, are constitutively degraded within the endolysosomal system by soluble hydrolytic enzymes with the help of lipid binding proteins in a sequential manner. Because of a functionally impaired hydrolase or auxiliary protein, their lipid substrates cannot be degraded, accumulate in the lysosome, and slowly spread to other intracellular membranes. In Niemann-Pick type C disease, cholesterol transport is impaired and unesterified cholesterol accumulates in the late endosome. In most lysosomal lipid storage diseases, the accumulation of one or few lipids leads to the coprecipitation of other hydrophobic substances in the endolysosomal system, such as lipids and proteins, causing a "traffic jam." This can impair lysosomal function, such as delivery of nutrients through the endolysosomal system, leading to a state of cellular starvation. Therapeutic approaches are currently restricted to mild forms of diseases with significant residual catabolic activities and without brain involvement.
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Affiliation(s)
- Heike Schulze
- Life and Medical Sciences Institute, Membrane Biology and Lipid Biochemistry Unit, University of Bonn, Germany
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16
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Wendeler M, Sandhoff K. Hexosaminidase assays. Glycoconj J 2010; 26:945-52. [PMID: 18473163 DOI: 10.1007/s10719-008-9137-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 04/08/2008] [Accepted: 04/09/2008] [Indexed: 10/22/2022]
Abstract
beta-Hexosaminidases (EC 3.2.1.52) are lysosomal enzymes that remove terminal beta-glycosidically bound N-acetylglucosamine and N-acetylgalactosamine residues from a number of glycoconjugates. Reliable assay systems are particularly important for the diagnosis of a family of lysosomal storage disorders, the GM2 gangliosidoses that result from inherited beta-hexosaminidase deficiency. More recently, aberrant hexosaminidase levels have also been found to be associated with a variety of inflammatory diseases. Apart from patient testing and carrier screening, practical in vitro assays are indispensable for the characterization of knock-out mice with potentially altered hexosaminidase activities, for detailed structure-function studies aimed at elucidating the enzymatic mechanism, and to characterize newly described enzyme variants from other organisms. The purpose of this article is to discuss convenient hexosaminidase assay procedures for these and other applications, using fluorogenic or chromogenic artificial substrates as well as the physiological glycolipid substrate GM2. Attempts are also made to provide an overview of less commonly used alternative techniques and to introduce recent developments enabling high-throughput screening for enzyme inhibitors.
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Affiliation(s)
- Michaela Wendeler
- LIMES, Membrane Biology and Lipid Biochemistry Unit, c/o Kekulé-Institut für Organische Chemie und Biochemie der Universität Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn, Germany
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17
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Conzelmann E, Sandhoff K. Glycolipid and glycoprotein degradation. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 60:89-216. [PMID: 3310533 DOI: 10.1002/9780470123065.ch3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- E Conzelmann
- Institut für Organische Chemie und Biochemie, Universität Bonn, Federal Republic of Germany
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18
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Brandt-Rauf SI, Raveis VH, Drummond NF, Conte JA, Rothman SM. Ashkenazi Jews and breast cancer: the consequences of linking ethnic identity to genetic disease. Am J Public Health 2006; 96:1979-88. [PMID: 17018815 PMCID: PMC1751808 DOI: 10.2105/ajph.2005.083014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
We explored the advantages and disadvantages of using ethnic categories in genetic research. With the discovery that certain breast cancer gene mutations appeared to be more prevalent in Ashkenazi Jews, breast cancer researchers moved their focus from high-risk families to ethnicity. The concept of Ashkenazi Jews as genetically unique, a legacy of Tay-Sachs disease research and a particular reading of history, shaped this new approach even as methodological imprecision and new genetic and historical research challenged it. Our findings cast doubt on the accuracy and desirability of linking ethnic groups to genetic disease. Such linkages exaggerate genetic differences among ethnic groups and lead to unequal access to testing and therapy.
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Affiliation(s)
- Sherry I Brandt-Rauf
- Center for the Study of Society and Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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19
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Strawser LD, Touster O. The cellular processing of lysosomal enzymes and related proteins. Rev Physiol Biochem Pharmacol 2005; 87:169-210. [PMID: 6999583 DOI: 10.1007/bfb0030898] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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20
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Mauri L, Valsecchi M, Casellato R, Li SC, Li YT, Sonnino S. Procedure for separation of GM2 ganglioside species with different ceramide structures by a flash reversed-phase silica gel liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 796:1-10. [PMID: 14552811 DOI: 10.1016/s1570-0232(03)00598-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
GM2 ganglioside, beta-GalNAc-(1-4)-[alpha-Neu5Ac-(2-3)-]beta-Gal-(1-4)-beta-Glc-(1-1)-Cer, is the main ganglioside in the brain of Tay-Sachs patients. In this work, GM2 ganglioside was extracted from a Variant B Tay-Sachs human brain, purified to homogeneity of the oligosaccharide moiety by silica gel chromatography. It was further fractionated for the first time into the molecular species differing in the ceramide structures by reverse-phase flash chromatography. The GM2 ganglioside species were characterized by gas-chromatography, nuclear magnetic resonance spectroscopy, and mass spectrometry. The major GM2 species contained the ceramides with d18:1-18:0 (40.5% of the total GM2 species), d20:1-18:0 (31%) and d18:1-20:0 (12%). We also found minor GM2 species with the ceramides with d18:1-24:1 (4%), d18:1-22:0 (2%) and d18:2-24:1 (1%), which have not been reported previously.
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Affiliation(s)
- Laura Mauri
- Department of Medical Chemistry, Biochemistry and Biotechnology, Center of Excellence on Neurodegenerative Diseases, University of Milan, Via Fratelli Cervi 93, 20090 Segrate, Italy
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Gason AA, Sheffield E, Bankier A, Aitken MA, Metcalfe S, Barlow Stewart K, Delatycki MB. Evaluation of a Tay-Sachs disease screening program. Clin Genet 2003; 63:386-92. [PMID: 12752571 DOI: 10.1034/j.1399-0004.2003.00074.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Tay-Sachs Disease (TSD) is an autosomal recessive neurodegenerative disorder. TSD is prevalent in the Ashkenazi Jewish population, and carrier screening programs have been implemented worldwide in these communities. A screening program initiated in 1997 involving the Melbourne Jewish community (Australia) incorporated education, counselling and carrier testing of high-school students aged 15 to 18 years. This study aimed to assess the participation rates, level of knowledge obtained and predicted feelings and attitudes of the students involved. Seven hundred and ten students participated, there was a 67% uptake for testing with a carrier rate of 1 in 28 determined. The level of knowledge of the students following education was high and of relative importance in regard to decision making, as were their feelings and attitudes about genetic testing for carrier status. A significant impediment to test uptake was the need for blood sampling, resulting in a recommendation for the introduction of DNA analysis on cheek brush samples. The evaluation of this program has given a wider scope for further development as well as providing valuable information for the implementation of community screening programs.
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Affiliation(s)
- A A Gason
- Murdoch Childrens Research Institute and Genetic Health Services Victoria, Royal Children's Hospital, Parkville, Victoria, Australia
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22
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Affiliation(s)
- N Risch
- Department of Genetics, Stanford University School of Medicine, California 94305, USA
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23
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Suzuki K. Recognition and delineation of beta-hexosaminidase alpha-chain variants: a historical and personal perspective. ADVANCES IN GENETICS 2002; 44:173-84. [PMID: 11596982 DOI: 10.1016/s0065-2660(01)44079-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Affiliation(s)
- K Suzuki
- Neuroscience Center, Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, 27599, USA
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24
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Kolodny EH. Molecular genetics of the beta-hexosaminidase isoenzymes: an introduction. ADVANCES IN GENETICS 2002; 44:101-26. [PMID: 11596976 DOI: 10.1016/s0065-2660(01)44074-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Affiliation(s)
- E H Kolodny
- Department of Neurology, New York University School of Medicine, New York, USA
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Sandhoff K. The GM2-gangliosidoses and the elucidation of the beta-hexosaminidase system. ADVANCES IN GENETICS 2002; 44:67-91. [PMID: 11597000 DOI: 10.1016/s0065-2660(01)44072-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- K Sandhoff
- Institut für Organische Chemie und Biochemie der Universität Bonn, Germany
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26
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Kaback MM, Desnick RJ. Tay-Sachs disease: from clinical description to molecular defect. ADVANCES IN GENETICS 2002; 44:1-9. [PMID: 11596975 DOI: 10.1016/s0065-2660(01)44065-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- M M Kaback
- Department of Pediatrics, University of California, San Diego School of Medicine, 92123, USA.
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Mahuran DJ. Biochemical consequences of mutations causing the GM2 gangliosidoses. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1455:105-38. [PMID: 10571007 DOI: 10.1016/s0925-4439(99)00074-5] [Citation(s) in RCA: 199] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The hydrolysis of GM2-ganglioside is unusual in its requirements for the correct synthesis, processing, and ultimate combination of three gene products. Whereas two of these proteins are the alpha- (HEXA gene) and beta- (HEXB) subunits of beta-hexosaminidase A, the third is a small glycolipid transport protein, the GM2 activator protein (GM2A), which acts as a substrate specific co-factor for the enzyme. A deficiency of any one of these proteins leads to storage of the ganglioside, primarily in the lysosomes of neuronal cells, and one of the three forms of GM2-gangliosidosis, Tay-Sachs disease, Sandhoff disease or the AB-variant form. Studies of the biochemical impact of naturally occurring mutations associated with the GM2 gangliosidoses on mRNA splicing and stability, and on the intracellular transport and stability of the affected protein have provided some general insights into these complex cellular mechanisms. However, such studies have revealed little in the way of structure-function information on the proteins. It appears that the detrimental effect of most mutations is not specifically on functional elements of the protein, but rather on the proteins' overall folding and/or intracellular transport. The few exceptions to this generalization are missense mutations at two codons in HEXA, causing the unique biochemical phenotype known as the B1-variant, and one codon in both the HEXB and GM2A genes. Biochemical characterization of these mutations has led to the localization of functional residues and/or domains within each of the encoded proteins.
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Affiliation(s)
- D J Mahuran
- Research Institute, The Hospital for Sick Children, Toronto, Ont, Canada.
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Affiliation(s)
- Y T Li
- Department of Biochemistry, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA
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Li YT, Li SC, Hasegawa A, Ishida H, Kiso M, Bernardi A, Brocca P, Raimondi L, Sonnino S. Structural basis for the resistance of Tay-Sachs ganglioside GM2 to enzymatic degradation. J Biol Chem 1999; 274:10014-8. [PMID: 10187778 DOI: 10.1074/jbc.274.15.10014] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To understand the reason why, in the absence of GM2 activator protein, the GalNAc and the NeuAc in GM2 (GalNAcbeta1-->4(NeuAcalpha2-->3)Galbeta1-->4Glcbet a1-1'Cer) are refractory to beta-hexosaminidase A and sialidase, respectively, we have recently synthesized a linkage analogue of GM2 named 6'GM2 (GalNAcbeta1-->6(NeuAcalpha2-->3)Galbeta1-->4Glcbet a1-1'Cer). While GM2 has GalNAcbeta1-->4Gal linkage, 6'-GM2 has GalNAcbeta1-->6Gal linkage (Ishida, H., Ito, Y., Tanahashi, E., Li, Y.-T., Kiso, M., and Hasegawa, A. (1997) Carbohydr. Res. 302, 223-227). We have studied the enzymatic susceptibilities of GM2 and 6'GM2, as well as that of the oligosaccharides derived from GM2, asialo-GM2 (GalNAcbeta1-->4Galbeta1--> 4Glcbeta1-1'Cer) and 6'GM2. In addition, the conformational properties of both GM2 and 6'GM2 were analyzed using NMR spectroscopy and molecular mechanics computation. In sharp contrast to GM2, the GalNAc and the Neu5Ac of 6'GM2 were readily hydrolyzed by beta-hexosaminidase A and sialidase, respectively, without GM2 activator. Among the oligosaccharides derived from GM2, asialo-GM2, and 6'GM2, only the oligosaccharide from GM2 was resistant to beta-hexosaminidase A. Conformational analyses revealed that while GM2 has a compact and rigid oligosaccharide head group, 6'GM2 has an open spatial arrangement of the sugar units, with the GalNAc and the Neu5Ac freely accessible to external interactions. These results strongly indicate that the resistance of GM2 to enzymatic hydrolysis is because of the specific rigid conformation of the GM2 oligosaccharide.
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Affiliation(s)
- Y T Li
- Department of Biochemistry, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
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31
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Butkus A, Coghlan JP. Location of ganglioside GM2 activator protein gene expression in sheep. CLINICAL AND EXPERIMENTAL PHARMACOLOGY & PHYSIOLOGY. SUPPLEMENT 1998; 25:S28-33. [PMID: 9809189 DOI: 10.1111/j.1440-1681.1998.tb02297.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. The present study was aimed at characterizing and establishing the site of production of a 'novel' protein isolated in 1988 during the course of studies on sheep renal morphology. This protein has subsequently been identified as the GM2 activator protein (GM2AP). 2. The 'novel' protein, with an apparent molecular weight of 18-22 kDa and a pI between 4.7 and 4.9, was isolated from enriched granular fractions of sheep kidney cortex using two-dimensional (2-D) polyacrylamide gel electrophoresis. Following electroelution, the N-terminal amino acid sequence was determined and, applying the preferred codon usage formula, an oligodeoxyribonucleotide probe was constructed for examination of sites of expression of this novel protein using northern analyses and hybridization histochemistry. 3. Western blots of the 2-D gels onto nitrocellulose membranes permitted us to select the appropriate spots for injection into rabbits for production of polyclonal antibodies. The antibodies were used to confirm the sites of protein production using immunohistochemistry. 4. Northern analyses revealed that GM2AP mRNA has a widespread distribution in ovine tissues. In the kidney, GM2 was expressed in all major renal arteries and arterioles. In the liver, the expression of the gene was prominent in the hepatic vein and ducts. Antibodies raised against the GM2AP confirmed that the protein was present at the same sites as the mRNA. 5. These are the first studies showing the location of GM2 activator gene expression in normal mammalian tissues. The arterial site of production has implications for local action or an important role in membrane integrity throughout the kidney.
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Affiliation(s)
- A Butkus
- Department of Anatomy and Cell Biology, University of Melbourne, Parkville, Victoria, Australia
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32
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Asfaw B, Schindler D, Ledvinová J, Černý B, Šmíd F, Conzelmann E. Degradation of blood group A glycolipid A-6-2 by normal and mutant human skin fibroblasts. J Lipid Res 1998. [DOI: 10.1016/s0022-2275(20)32164-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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33
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Mahuran DJ. Beta-hexosaminidase: biosynthesis and processing of the normal enzyme, and identification of mutations causing Jewish Tay-Sachs disease. Clin Biochem 1995; 28:101-6. [PMID: 7628066 DOI: 10.1016/0009-9120(95)00003-r] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVES This report presents an overview of the nearly 100-year history of the study of Tay-Sachs disease in the Ashkenazi Jewish population. DESIGN AND METHODS Each major step leading to our present understanding of the disease are highlighted. RESULTS The original interest in the cause of this devastating disease in the late 1800s led to the identification of a novel glycolipid. GM2 ganglioside, stored in the neurons of Tay-Sachs patients in the 1930s, and the elucidation of its structure in the 1960s. The identification of the defective isozyme, beta-hexosaminidase A, followed in 1968-69. Elucidation of the subunit structures of the hexosaminidase A (alpha beta) and B (beta beta) isozymes in 1973 and their purification in 1974-80, led to the characterization of the biosynthesis, assembly, intracellular transport, and posttranslational processing of the two subunits in the 1980s. The ability to purify milligram quantities of the isozymes made possible the isolation of cDNA clones encoding both subunits in 1985, and ultimately the identification of the causes of Jewish Tay-Sachs disease at the genomic DNA level in 1988. CONCLUSIONS Tay-Sachs disease is the major model for lysosomal storage diseases. Similarly, the work done in the 1980s on hexosaminidase has been used as a model for understanding the cell biology of many other lysosomal proteins. Current research encompassing the fields of enzymology, cell biology, and molecular biology is linking genotypes with the clinical phenotypes of patients with Tay-Sachs and related diseases.
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Affiliation(s)
- D J Mahuran
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
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34
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Dong D, Hart G. Purification and characterization of an O-GlcNAc selective N-acetyl-beta-D-glucosaminidase from rat spleen cytosol. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32170-1] [Citation(s) in RCA: 377] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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35
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Fernandes MJ, Kaplan F, Clow CL, Hechtman P, Scriver CR. Specificity and sensitivity of hexosaminidase assays and DNA analysis for the detection of Tay-Sachs disease gene carriers among Ashkenazic Jews. Genet Epidemiol 1992; 9:169-75. [PMID: 1387862 DOI: 10.1002/gepi.1370090303] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Tay-Sachs disease (TSD), a neurodegenerative disorder resulting from a deficiency of the lysosomal enzyme hexosaminidase A (HexA), clusters in Ashkenazic Jews. Population-based screening programs to detect carriers of TSD genes by means of HexA assays have been active since the 1970s. The recent characterization of 3 mutations in the HEXA gene (in exon 7, exon 11, and intron 12), which account for over 90% of HEXA mutations in Ashkenazim, appeared to offer better options for screening and diagnosis. The relative frequencies of the three mutations in Montreal are similar to those reported in four other North American populations. We compared enzyme and DNA analyses to determine specificity and sensitivity of each test when the other was used as the confirmatory procedure. Neither procedure has a sensitivity of 1.0. Maximum sensitivity and specificity were achieved by using both tests together. The findings here are likely to apply to most cases where the variant screened enzyme phenotype can result from more than one mutation.
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Affiliation(s)
- M J Fernandes
- Department of Biology, McGill University, Montreal, Quebec, Canada
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36
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Ueno R, Yuan CS. Purification and properties of neutral beta-N-acetylglucosaminidase from carp blood. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1074:79-84. [PMID: 2043684 DOI: 10.1016/0304-4165(91)90043-g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A neutral beta-N-acetylglucosaminidase has been purified to homogeneity from carp blood by a seven-step procedure. It was localized in the cytosol of red blood cells. The purified enzyme was specific to beta-N-acetylglucosaminide and inactive to beta-N-acetylgalactosaminide. It was competitively inhibited by free N-acetylglucosamine, but not by free N-acetylgalactosamine. The optimum pH of the enzyme was 6.5, with a stable pH range of 7.0 to 11.0. The enzyme showed greater heat-lability and anodal electrophoretic mobility than acidic beta-N-acetylglucosaminidases. The Mr value, estimated by sucrose density gradient centrifugation, was 122,000, and the enzyme dissociated into two nonidentical subunits with Mr values of 66,000 and 53,000, based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. With respect to the major characteristics, the neutral enzyme in carp blood was supposed to be a counterpart of hexosaminidase C in human and other mammalian tissues.
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Affiliation(s)
- R Ueno
- Department of Bioresources, Mie University, Japan
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37
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Mahuran DJ, Triggs-Raine BL, Feigenbaum AJ, Gravel RA. The molecular basis of Tay-Sachs disease: mutation identification and diagnosis. Clin Biochem 1990; 23:409-15. [PMID: 2147596 DOI: 10.1016/0009-9120(90)90153-l] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Tay-Sachs disease is the prototype of lysosomal storage disease. While it was first described over a century ago, the defective enzyme was not identified until 1969, making possible the development of enzyme-based diagnostic and carrier screening techniques. This led to the establishment of the successful international Tay-Sachs screening program, primarily for the high risk Ashkenazi Jewish population. In the past five years the development of recombinant DNA technology has allowed researchers to characterize 95-99% of the mutations causing Tay-Sachs disease in this high risk ethnic group. Knowledge of the exact mutations responsible for the disease coupled with the powerful polymerase chain reaction technique has now made DNA-based screening and diagnosis possible. While the enzyme-based test has proven to be reliable and economical, it cannot differentiate variant phenotypes and requires the presence of specialized testing centers. Although the DNA-based test is presently less economical, it can provide carrier couples with their exact genotype and thus, predict the general phenotype of an unborn child. Furthermore, as the catalogue of mutations leading to human disease increases, more economical DNA methodologies will be developed. In the future it would be expected that a laboratory using a single DNA-based technology could diagnose and screen for a myriad of human diseases including Tay-Sachs disease.
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Affiliation(s)
- D J Mahuran
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
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Pieretti M, Beccari T, Cosmi EV, Stirling JL, Orlacchio A. Identification of an intermediate form of beta-N-acetylhexosaminidase in chorionic villi. Clin Chim Acta 1990; 188:109-17. [PMID: 2143122 DOI: 10.1016/0009-8981(90)90155-l] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A minor form of beta-N-acetylhexosaminidase has been found in chorionic villi, in addition to the major forms A and B. This form does not hydrolyze the 4-methylumbelliferyl-2-acetamido-2-deoxy-beta-D-glucopyranoside-6-sulpha te substrate, is thermostable, has a higher mol mass (120,000) than A and B (100,000) and on analytical isoelectric focusing, it shows a microheterogeneity with values ranging between 6.3 and 7.0. For these characteristics, it resembles beta-N-Acetylhexosaminidase P from pregnancy serum, from which is chromatographically indistinguishable.
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Affiliation(s)
- M Pieretti
- Istituto Ginecologia ed Ostetricia, University of Perugia, Italy
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Clarke JT, Skomorowski MA, Zuker S. Tay-Sachs disease carrier screening: follow-up of a case-finding approach. AMERICAN JOURNAL OF MEDICAL GENETICS 1989; 34:601-5. [PMID: 2624277 DOI: 10.1002/ajmg.1320340430] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In order to determine the status of Tay-Sachs disease carrier identification in Toronto, Canada, since a change was made in 1978 from testing in the context of large-scale community clinics (up to 1,200 individuals tested in 1 day) to a case-finding approach to screening, a sample of area Jews was surveyed by questionnaire. The results indicated that a trend has developed for individuals at risk to delay testing until pregnancy when carrier detection is technically more difficult and the time available for retesting and organizing prenatal diagnosis is limited. If the trend continues, the full potential of chorionic villus sampling (CVS) for the prenatal diagnosis of the disease will be difficult to realize.
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Affiliation(s)
- J T Clarke
- Department of Genetics, Hospital for Sick Children, Toronto, Ontario, Canada
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41
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Ohno K, Suzuki K. Multiple abnormal beta-hexosaminidase alpha chain mRNAs in a compound-heterozygous Ashkenazi Jewish patient with Tay-Sachs disease. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(19)81396-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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42
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Ohno K, Suzuki K. A splicing defect due to an exon-intron junctional mutation results in abnormal beta-hexosaminidase alpha chain mRNAs in Ashkenazi Jewish patients with Tay-Sachs disease. Biochem Biophys Res Commun 1988; 153:463-9. [PMID: 2837213 DOI: 10.1016/s0006-291x(88)81247-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abnormal beta-hexosaminidase alpha chain mRNAs from an Ashkenazi Jewish patient with the classical infantile Tay-Sachs disease contained intact or truncated intron 12 sequences. Sequence analysis showed a single nucleotide transversion at the 5' donor site of intron 12 from the normal G to C. This provides the first evidence that this junctional mutation, also found independently in two other laboratories by analysis of genomic clones, results in functional abnormality. Analysis with normal and mutant oligonucleotides as probes indicated that our patient was a compound heterozygote with only one allele having the transversion. The patient studied in the other two laboratories was also a compound heterozygote. Another Ashkenazi Jewish patient was normal in this region in both alleles. Thus, the splicing defect is the underlying genetic cause in some but not all Ashkenazi Jewish patients with Tay-Sachs disease.
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Affiliation(s)
- K Ohno
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill 27599
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Rosengren B, Månsson JE, Svennerholm L. Composition of gangliosides and neutral glycosphingolipids of brain in classical Tay-Sachs and Sandhoff disease: more lyso-GM2 in Sandhoff disease? J Neurochem 1987; 49:834-40. [PMID: 3612128 DOI: 10.1111/j.1471-4159.1987.tb00969.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The ganglioside composition of the brain from an individual with classical Tay-Sachs disease and from an individual with Sandhoff disease was examined using our new quantitative methods for ganglioside content determination and compared with that of age-matched control brains. The concentration of GM2 was found to be 12.2 and 13.0 mumol/g of fresh tissue in Tay-Sachs disease and in Sandhoff disease cerebral gray matter, respectively. GM2 was 86 and 87% respectively, of total gangliosides. The concentration of GM1 and, in particular, GM3 ganglioside was also found to be increased, whereas the concentration of the major di- and trisialogangliosides (GD1a, GD1b, and GT1b) had diminished markedly. There was no significant increase in level of any other ganglioside than lyso-GM2. Its concentration was 12 and 16 nmol/g in cerebral gray matter of two Tay-Sachs disease brains and 43 nmol/g in Sandhoff disease brain. The Sandhoff disease brain also differed from the classical Tay-Sachs disease brain by having a much higher concentration of gangliotriaosylceramide and globotetraosylceramide. The structures of relevant gangliosides and neutral glycolipids were established by fast atom bombardment-mass spectrometry and permethylation studies.
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44
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Hardy M, Salvayre R, Maret A, Douste-Blazy L. Irreversible inhibition of hexosaminidase C by medium-chain monocarboxylic acids and Triton X-100. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 924:557-61. [PMID: 3593766 DOI: 10.1016/0304-4165(87)90172-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The neutral beta-N-acetylhexosaminidase (hexosaminidase C) from human brain was partially purified (separated from lysosomal beta-N-acetylhexosaminidases by chromatography on a Con A-Sepharose column). Hexosaminidase C was inhibited by medium-chain fatty acids (monocarboxylic acids with chain-length between C6 and C9), whereas shorter-chain monocarboxylic acids showed no inhibitory effect. Studies on the inhibition mechanism showed an irreversible and pH-dependent inhibition which progresses with time and which is not reversed by the removal of fatty acids (by Bio-Beads SM-2). Similar inhibitory effects were also obtained using Triton X-100 (but not with homologous alkylamines). These results suggest that the hexosaminidase C inactivation is related to the hydrophobic properties of the inhibitor which acts as a denaturing agent mainly at acidic pH. The possibility has been discussed that this inactivation effect of monocarboxylic acid on hexosaminidase C could constitute a molecular model of the toxicity of medium-chain-length fatty acids.
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46
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Orlacchio A, Emiliani C, Di Renzo GC, Cosmi EV. beta-N-acetyl-D-glucosaminidase isoenzymes from human amnionic membranes. Clin Chim Acta 1986; 159:279-89. [PMID: 3769215 DOI: 10.1016/0009-8981(86)90061-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Two beta-N-acetylglucosaminidase isoenzymes (A and B) have been identified and purified from amnionic fetal membrane. The final specific activity of A and B isoenzymes increased 225- and 185-fold respectively by a purification scheme, which included a lyophilized extract, chromatofocusing on PBE 94, pH range 5.5 to 4.0, and affinity chromatography on p-aminophenyl-2-acetamido-2-deoxy-1-thio-beta-D-glucopyranoside covalently linked to Sepharose-4B. Different electrophoretic mobility, thermostability and different thiol group modifications of the two isoenzymes were found. Acetate was a more effective competitive inhibitor than were iodoacetamide, N-acetylglucosamine and N-acetylgalactosamine more than glucosamine and galactosamine, confirming a specific 'acetamido receptor site' for both the isoenzymes.
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47
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Orlacchio A, Emiliani C, Tabilio A, Pioda GB. Expression of a particular beta-N-acetylglucosaminidase isoenzyme in human haematopoietic leukemic cell-lines. Cell Biochem Funct 1986; 4:197-203. [PMID: 3488138 DOI: 10.1002/cbf.290040306] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
N-acetyl-beta-D-glucosaminidase (NAG) activity and isoenzyme profiles were studied in myeloid, histiocytic, B-lymphoid, T-lymphoid and lymphoblastoid continuous cell lines in order to determine if N-acetyl-beta-D-glucosaminidase isoenzyme expression may help to distinguish among various types of leukemic proliferation. Total NAG activity in myeloid, histiocytic, erythroleukemic cell lines were higher than Burkitt's lymphoma derived cell lines (B-lymphoid), T- or lymphoblastoid cell lines. On chromatofocusing by PBE 94 coupled with an automated enzyme assay an intermediate (I) beta-N-acetyl-glucosaminidase form, eluting between forms B and A, was found in all leukemic and in Epstein-Barr virus infected lymphoblastoid cell lines analysed. The different profiles recorded, the expression of the I form and the different I/B ratios may be useful as markers of tumour proliferation.
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48
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Kapur DK, Gupta GS. Purification, biochemical properties and active sites of N-acetyl-beta-D-hexosaminidases from human seminal plasma. Biochem J 1986; 236:103-9. [PMID: 2947567 PMCID: PMC1146792 DOI: 10.1042/bj2360103] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Two isoenzymes of N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30) (Hex A and Hex B) from human seminal plasma were purified to homogeneity with specific activities of 26 and 60 units/mg of protein respectively. N-Acetyl-beta-D-glucosaminidase activity was inseparable from N-acetyl-beta-D-galactosaminidase activity in both Hex A and Hex B by various conventional chromatographic procedures. Although Km values of N-acetyl-beta-glucosaminidase activity of Hex A and Hex B were similar (1.33 mM), those of N-acetyl-beta-galactosaminidase activity were 0.14 mM for Hex A and 0.40 mM for Hex B. However, pH optima and temperature optima were identical for N-acetyl-beta-glucosaminidase and N-acetyl-beta-galactosaminidase activities of both isoenzymes; Hex A was far more heat-sensitive than Hex B. Thiol-reactive compounds such as silver salts, mercuric salts, p-chloromercuribenzoate and thimerosal strongly inhibited the N-acetyl-beta-glucosaminidase activities of both isoenzymes. GSH protected the enzyme activities from inactivation caused by these reagents, confirming the presence of thiol groups at the active centres. Inhibitions of N-acetyl-beta-glucosaminidase activities of both isoenzymes by metal salts and organic anions were comparable; acetate and arsenite were effective inhibitors for both isoenzymes. In contrast, inhibitions of N-acetyl-beta-glucosaminidase activities of the two isoenzymes by iodoacetic acid, iodoacetamide and ethylmaleimide were not comparable; Hex B was more susceptible to inhibition by these agents at 20 mM concentration. The N-acetyl-beta-glucosaminidase activities of both isoenzymes are strongly inhibited, in decreasing order, by N-acetyl-galactosamine, mannosamine, disaccharic acid lactone, N-acetylglucosamine and gluconolactone. The Ki values of the N-acetyl-beta-glucosaminidase and N-acetyl-beta-galactosaminidase activities for N-acetylhexosamines and results from mixed-substrate kinetics indicated that the activities for the two substrates are located at different sites in Hex A and at the same site in Hex B. The Mr values of Hex A and Hex B were determined to be 195,000 and 210,000 respectively by gel filtration through Sephadex G-200. SDS/polyacrylamide-gel electrophoresis revealed that Hex A and Hex B are each composed of four subunits corresponding to Mr about 50,000 each. No further polypeptide chain was obtained after reduction and alkylation of Hex A and Hex B with 10 mM-dithiothreitol and 10 mM-iodoacetamide.
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Sonderfeld S, Brendler S, Sandhoff K, Galjaard H, Hoogeveen AT. Genetic complementation in somatic cell hybrids of four variants of infantile GM2 gangliosidosis. Hum Genet 1985; 71:196-200. [PMID: 2933318 DOI: 10.1007/bf00284572] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cell hybridizations between fibroblasts of four variants (B, O, AB, and B1) of infantile GM2 gangliosidosis were performed. Cocultivated as well as hybrid cells were analyzed for their capability to degrade exogenously added [3H]-GM2. Hybridization of variant AB fibroblasts with fibroblasts of variant O, variant B, or variant B1 resulted in an enhanced rate of GM2 hydrolysis, showing intergenic complementation. Similar restoration of GM2 catabolism was observed after hybridization of variant B1 cells with variant O, but not with variant B cells. These results indicate that B1 cells carry a mutation in the gene locus for the alpha-subunit of beta-hexosaminidase. Studies of the processing of immature enzyme in variant B1 cells showed the presence of alpha-precursors and mature alpha-chains, but at a lower level as compared to normal cells.
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Sonderfeld S, Conzelmann E, Schwarzmann G, Burg J, Hinrichs U, Sandhoff K. Incorporation and metabolism of ganglioside GM2 in skin fibroblasts from normal and GM2 gangliosidosis subjects. EUROPEAN JOURNAL OF BIOCHEMISTRY 1985; 149:247-55. [PMID: 3922757 DOI: 10.1111/j.1432-1033.1985.tb08919.x] [Citation(s) in RCA: 139] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Ganglioside GM2, 3H-labeled in the sphingoid base, was added to the culture medium of normal and GM2 gangliosidosis fibroblasts. Ganglioside was found to adsorb rapidly to the cell surface, most of it could however be removed by trypsination. The trypsin-resistant incorporation was about 10 nmol/mg cell protein, after 48 h. The rates of adsorption and incorporation depended strongly on the concentration of fetal calf serum in the medium, higher serum concentrations being inhibitory. After various incubation times, the lipids were extracted, separated by thin-layer chromatography and visualized by fluorography. In normal cells a variety of degradation products as well as sphingomyelin was found whereas in GM2 gangliosidosis cells, only trace amounts of such products (mainly GA2) were found. In contrast, the higher gangliosides GM1 and GD1a were formed in comparable amounts (2.2-3.6% of total radioactivity after 92 h) in normal and pathologic cell lines. Supplementation of cells from GM2 gangliosidosis, variant AB, with purified GM2-activator protein restored ganglioside GM2 degradation to almost normal rates but had no effect on its glycosylation to gangliosides GM1 and GD1a. From these results we conclude that the synthesis of higher gangliosides from incorporated GM2 can occur by direct glycosylation and not only via lysosomal degradation and resynthesis from [3H]sphinganine-containing degradation products. Preliminary studies with subcellular fractionation after various times of [3H]ganglioside incorporation indicated biphasic kinetics for the net transport of membrane-inserted ganglioside to lysosomes, compatible with the notion that a portion of the glycolipids can also escape from secondary lysosomes and migrate to Golgi compartment or cell surface.
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