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Journal of Neurology, Neurosurgery, and... Jul 1996
Topics: Adult; Ataxia; Cerebellum; Humans; Intellectual Disability; Magnetic Resonance Imaging; Male; alpha-Mannosidosis
PubMed: 8676143
DOI: 10.1136/jnnp.61.1.116-a -
The Biochemical Journal Jan 1995Human lysosomal alpha-mannosidase has been purified by a simple and rapid method in sufficient quantities for the analysis of its subunit composition and partial protein...
Human lysosomal alpha-mannosidase has been purified by a simple and rapid method in sufficient quantities for the analysis of its subunit composition and partial protein sequencing. Analysis of the N-terminal residues of the 30 kDa polypeptide has enabled us to confirm the identity of the recently cloned cDNA that was tentatively identified as that of lysosomal alpha-mannosidase [Nebes and Schmidt (1994) Biochem. Biophys. Res. Commun. 200, 239-245] and to locate the position of this polypeptide within the total deduced amino acid sequence. This finding will therefore provide a firm foundation for the characterization of alpha-mannosidosis mutations.
Topics: Amino Acid Sequence; DNA, Complementary; Enzyme Stability; Humans; Leukemia; Lysosomes; Mannosidases; Molecular Sequence Data; Sequence Analysis; Sulfates; Tumor Cells, Cultured; Zinc Compounds; Zinc Sulfate; alpha-Mannosidase
PubMed: 7832746
DOI: 10.1042/bj3050363 -
Proceedings of the National Academy of... Apr 1994Neuronal storage disorders are fatal neurodegenerative diseases of humans and animals that are caused by inherited deficiencies of lysosomal hydrolase activity. Affected...
Neuronal storage disorders are fatal neurodegenerative diseases of humans and animals that are caused by inherited deficiencies of lysosomal hydrolase activity. Affected individuals often appear normal at birth but eventually develop progressive neurologic symptoms including sensory and motor deficits, mental retardation, and seizures. We have examined efficacy of bone marrow transplantation as a means of enzyme replacement, using cats with the lysosomal storage disease alpha-mannosidosis. Treated animals showed little or no progression of neurologic signs 1-2 years after transplant, whereas untreated cats became severely impaired and reached endstage disease by 6 months of age. Increased lysosomal alpha-mannosidase activity was found in brain tissue of the treated animals, and electron microscopy revealed no evidence of lysosomal storage within most neurons. Histochemical localization of acidic alpha-D-mannoside mannohydrolase (EC 3.2. 1.24), using 5-bromo-4-chloro-3-indolyl alpha-D-mannopyranoside, showed that functional enzyme was present in neurons, glial cells, and cells associated with blood vessels. This study provides direct evidence that bone marrow transplantation as treatment for a neuronal storage disease can lead to significant levels of a missing lysosomal hydrolase within neurons of the central nervous system and to compensation for the genetic metabolic defect.
Topics: Animals; Bone Marrow Transplantation; Cat Diseases; Cats; Central Nervous System; Genetic Therapy; Mannosidases; alpha-Mannosidase; alpha-Mannosidosis
PubMed: 8159689
DOI: 10.1073/pnas.91.8.2970 -
Genetics Nov 1993beta-Mannosidosis is a lethal lysosomal storage disease inherited as an autosomal recessive in man, cattle and goats. Laboratory assay data of plasma beta-mannosidase...
beta-Mannosidosis is a lethal lysosomal storage disease inherited as an autosomal recessive in man, cattle and goats. Laboratory assay data of plasma beta-mannosidase activity represent a mixture of homozygous normal and carrier genotype distributions in a proportion determined by genotype frequency. A maximum likelihood approach employing data transformations for each genotype distribution and assuming a diallelic model of inheritance is described. Estimates of the transformation and genotype distribution parameters, gene frequency, genotype fitness and carrier probability were obtained simultaneously from a sample of 2,812 observations on U.S. purebred Salers cattle with enzyme activity, age, gender, month of pregnancy, month of testing, and parents identified. Transformations to normality were not required, estimated gene and carrier genotype frequencies of 0.074 and 0.148 were high, and the estimated relative fitness of heterozygotes was 1.36. The apparent overdominance in fitness may be due to a nonrandom sampling of progeny genotypes within families. The mean of plasma enzyme activity was higher for males than females, higher in winter months, lower in summer months and decreased with increased age. Estimates of carrier probabilities indicate that the test is most effective when animals are sampled as calves, although effectiveness of the plasma assay was less for males than females. Test effectiveness was enhanced through averaging repeated assays of enzyme activity on each animal. Our approach contributes to medical diagnostics in several ways. Rather than assume underlying normality for the distributions comprising the mixture, we estimate transformations to normality for each genotype distribution simultaneously with all other model parameters. This process also excludes potential biases due to data preadjustment for systematic effects. We also provide a method for partitioning phenotypic variation within each genotypic distribution which allows an assessment of the value of repeat measurements of the predictive variable for genotype assignment.
Topics: Animals; Cattle; Cattle Diseases; Female; Gene Frequency; Genotype; Humans; Male; Mannosidases; Models, Genetic; Models, Statistical; Probability; Seasons; United States; alpha-Mannosidosis; beta-Mannosidase
PubMed: 8293984
DOI: 10.1093/genetics/135.3.855 -
The American Journal of Pathology Mar 1993
Comparative Study
Topics: Adolescent; Adult; Animals; Cattle; Cattle Diseases; Child; Child, Preschool; Disease Models, Animal; Female; Humans; Infant; Male; alpha-Mannosidosis
PubMed: 8456950
DOI: No ID Found -
The Biochemical Journal Jan 1993Lysosomal beta-mannosidase was purified 160,000-fold in 24% yield from bovine kidney by a four-step purification procedure, which included concanavalin A-Sepharose,... (Comparative Study)
Comparative Study
Lysosomal beta-mannosidase was purified 160,000-fold in 24% yield from bovine kidney by a four-step purification procedure, which included concanavalin A-Sepharose, immunoaffinity, TSK-butyl and h.p.l.c. cation-exchange chromatography. When analysed by SDS/PAGE and detected by Coomassie Blue or silver staining, the purified enzyme preparation consists of two prominent peptides (100 and 110 kDa) and a third minor peptide (84 kDa). These three peptides are immunologically related and are consistently associated with beta-mannosidase activity in all chromatographic steps. Removal of N-linked carbohydrate from the 84, 100 and 110 kDa peptides decreases their molecular sizes to 75, 86 and 91 kDa respectively. Bovine kidneys lacking beta-mannosidase, activity, acquired from calves affected with beta-mannosidosis, do not contain detectable quantities of the three beta-mannosidase peptides, as judged by monoclonal- and polyclonal-antibody reactivity.
Topics: Animals; Carbohydrates; Cattle; Cattle Diseases; Chromatography, Affinity; Chromatography, High Pressure Liquid; Chromatography, Ion Exchange; Electrophoresis, Polyacrylamide Gel; Kidney; Kinetics; Lysosomes; Mannosidases; Molecular Weight; Reference Values; alpha-Mannosidosis; beta-Mannosidase
PubMed: 8424779
DOI: 10.1042/bj2890343 -
The Journal of Biological Chemistry May 1992A novel lysosomal alpha-mannosidase, with unique substrate specificity, has been partially purified from human spleen by chromatography through concanavalin A-Sepharose,... (Comparative Study)
Comparative Study
A novel lysosomal alpha-mannosidase, with unique substrate specificity, has been partially purified from human spleen by chromatography through concanavalin A-Sepharose, DEAE-Sephadex, and Sephacryl S-300. This enzyme can catalyze the hydrolysis of only 1 mannose residue, that which is alpha(1----6)-linked to the beta-linked mannose in the core of N-linked glycans, as found in the oligosaccharides Man alpha(1----6)[Man alpha(1----3)] Man beta(1----4)GlcNAc and Man alpha(1----6)Man beta(1----4) GlcNAc. The newly described alpha-mannosidase does not catalyze the hydrolysis of mannose residues outside of the core, even if they are alpha(1----6)-linked, and is not active on the other alpha-linked mannose in the core, which is (1----3)-linked. The narrow specificity of the novel mannosidase contrasts sharply with that of the major lysosomal alpha-mannosidase, which is able to catalyze the degradation of oligosaccharides containing diverse linkage and branching patterns of the mannose residues. Importantly, although the major mannosidase readily catalyzes the hydrolysis of the core alpha(1----3)-linked mannose, it is poorly active towards the alpha(1----6)-linked mannose, i.e. the very same mannose residue for which the newly characterized mannosidase is specific. The novel enzyme is further differentiated from the major lysosomal alpha-mannosidase by its inability to catalyze the efficient hydrolysis of the synthetic substrate p-nitrophenyl alpha-mannoside, and by the strong stimulation of its activity by Co2+ and Zn2+. Similarly to the major mannosidase, it is strongly inhibited by swainsonine and 1,4-dideoxy-1,4-imino-D-mannitol, but not by deoxymannojirimycin. The presence of this novel alpha-mannosidase activity in human tissues provides the best explanation, to date, for the structures of the oligosaccharides stored in human alpha-mannosidosis. In this condition the major lysosomal alpha-mannosidase activity is severely deficient, but apparently the alpha(1----6)-mannosidase is unaffected, so that the oligosaccharide structures reflect the unique specificity of this enzyme.
Topics: Animals; Carbohydrate Sequence; Cations, Divalent; Cats; Chromatography, High Pressure Liquid; Humans; Liver; Lysosomes; Mannosidases; Molecular Sequence Data; Oligosaccharides; Pancreas; Sheep; Spleen; Substrate Specificity; Swainsonine
PubMed: 1577805
DOI: No ID Found -
Proceedings of the National Academy of... Dec 1991In a variety of neuronal storage diseases, cortical pyramidal cells elaborate ectopic dendrites at the axon hillock. A feature common to all the diseases characterized...
In a variety of neuronal storage diseases, cortical pyramidal cells elaborate ectopic dendrites at the axon hillock. A feature common to all the diseases characterized by ectopic dendrites is an elevated level of GM2 ganglioside in cerebral cortex. In cats with one such disease, alpha-mannosidosis, the number of pyramidal cells bearing ectopic dendrites is small; the present study shows that GM2 ganglioside is stored only in those pyramidal neurons exhibiting ectopic dendrites. Using a Golgi-electron microscopy method with periodic acid-Schiff (PAS) staining, we first established that pyramidal cells bearing ectopic dendrites contained PAS+ membranous inclusions, consistent with storage of glycolipids. In contrast, those with smooth axon hillocks accumulated PAS- floccular inclusions, consistent with storage of oligosaccharides. Next, application of a monoclonal antibody against GM2 ganglioside revealed that subsets of both pyramidal and intrinsic neurons contained GM2-like immunoreactivity. Every GM2+ cell contained PAS+ membranous inclusions, indicating that pyramidal cells bearing ectopic dendrites stored GM2 ganglioside. In cats with alpha-mannosidosis induced by swainsonine, some pyramidal neurons showed GM2-like immunoreactivity after 4 weeks of treatment, whereas ectopic dendrites only became evident after 7 weeks of treatment. Thus, GM2 ganglioside accumulated in pyramidal neurons before ectopic dendrites emerged from the axon hillock. We propose that the reinitiation of dendrite growth on mature pyramidal cells is brought about by accumulated GM2 ganglioside.
Topics: Animals; Cats; Cerebral Cortex; Dendrites; G(M2) Ganglioside; Microscopy, Electron; Neurons; Pyramidal Tracts; Swainsonine; alpha-Mannosidosis
PubMed: 1763046
DOI: 10.1073/pnas.88.24.11330 -
The Journal of Biological Chemistry Sep 1991Lysosomal alpha-mannosidases were partially purified from bovine and feline liver and employed to digest a large number of oligosaccharides with structures corresponding... (Comparative Study)
Comparative Study
Lysosomal alpha-mannosidases were partially purified from bovine and feline liver and employed to digest a large number of oligosaccharides with structures corresponding to the oligomannosyl parts of complex, hybrid, and high-mannose glycans. The incubation products were identified by high pressure liquid chromatography with reference compounds of defined structure and by acetolysis. For all classes of substrates, the lysosomal alpha-mannosidases displayed a high degree of in vitro specificity with regard to the hydrolysis of mannose residues. Thus, in each case, 1 or at most 2 residues were always preferentially cleaved so that the degradative process proceeded down a well defined pathway. A comparison of the relative efficiency with which lysosomal alpha-mannosidases catalyzed the hydrolysis of particular oligosaccharides and of the structures of the resulting intermediates with those of the compounds accumulated in alpha-mannosidosis allows conclusions to be drawn regarding the nature of the enzymatic defect. In bovine alpha-mannosidosis, the oligosaccharides are those expected for a partial deficiency of normal lysosomal alpha-mannosidase, so that they correspond to intermediates in the normal catabolic pathway. In feline alpha-mannosidosis, in which the alpha-mannosidase deficiency is more severe than in cattle, the accumulated oligosaccharides primarily represent intact oligomannosyl moieties of N-linked glycans rather than the products of residual alpha-mannosidase activity.
Topics: Animals; Carbohydrate Sequence; Cats; Cattle; Chromatography, High Pressure Liquid; Liver; Lysosomes; Mannose; Mannosidases; Molecular Sequence Data; Oligosaccharides; Polysaccharides; Substrate Specificity; alpha-Mannosidase; alpha-Mannosidosis
PubMed: 1885586
DOI: No ID Found -
The Biochemical Journal Aug 1991The specificity of human liver lysosomal alpha-mannosidase (EC 3.2.1.24) towards a series of oligosaccharide substrates derived from high-mannose, complex and hybrid...
The specificity of human liver lysosomal alpha-mannosidase (EC 3.2.1.24) towards a series of oligosaccharide substrates derived from high-mannose, complex and hybrid asparagine-linked glycans and from the storage products in alpha-mannosidosis was investigated. The enzyme hydrolyses all alpha(1-2)-, alpha(1-3)- and alpha(1-6)-mannosidic linkages in these glycans without a requirement for added Zn2+, albeit at different rates. A major finding of this study is that all the substrates are hydrolysed by non-random pathways. These pathways were established by determining the structures of intermediates in the digestion mixtures by a combination of h.p.t.l.c. and h.p.l.c. before and after acetolysis. The catabolic pathway for a particular substrate appears to be determined by its structure, raising the possibility that degradation occurs by an uninterrupted sequence of steps within one active site. The structures of the digestion intermediates are compared with the published structures of the storage products in mannosidosis and of intact asparagine-linked glycans. Most but not all of the digestion intermediates derived from high-mannose glycans have structures found in intact asparagine-linked glycans of human glycoproteins or among the storage products in the urine of patients with mannosidosis. However, the relative abundances of these structures suggests that the catabolic pathway is not the same as the processing pathway. In contrast, the intermediates formed from the digestion of oligosaccharides derived from hybrid and complex N-glycans are completely different from any processing intermediates and also from the oligosaccharides of composition Man2-4GlcNAc that account for 80-90% of the storage products in alpha-mannosidosis. It is postulated that the structures of these major storage products arise from the action of an exo/endo-alpha(1-6)-mannosidase on the partially catabolized oligomannosides that accumulate in the absence of the main lysosomal alpha-mannosidase.
Topics: Chromatography, High Pressure Liquid; Humans; Lysosomes; Mannosidases; Oligosaccharides; Polysaccharides; Structure-Activity Relationship; Substrate Specificity; alpha-Mannosidosis
PubMed: 1872811
DOI: 10.1042/bj2770743