Glycosphingolipid Activator Proteins

  • W. Fürst
  • A. Vogel
  • M. Lee-Vaupel
  • E. Conzelmann
  • K. Sandhoff
Part of the NATO ASI Series book series (NSSA, volume 116)


The catabolism of sphingolipids is accomplished in the intracellular digestive vacuoles known as lysosomes by the sequential action of acid exohydrolases, starting at the hydrophilic end of the molecule. For nearly every degradation step an inherited enzyme deficiency is known leading to a severe sphingolipid storage disease. In the last 20 years intensive studies were performed in many laboratories to understand the molecular basis and the increasing heterogeneity of these disorders (1–6). The lysosomal hydrolases involved in glycolipid degradation have been purified and characterized. Some of these enzymes are membrane-bound whereas others are water-soluble. When the degradation of the presumtive glycosphingolipid substrates by purified soluble enzymes was studied in vitro, only low, often negligible degradation rates were observed. Since sphingolipids are amphiphilic molecules, they form micelles (higher glycosylated glycolipids) or liposomes (sphingomyelin) when dispersed in water. In this tightly packed form, they are hardly accessible to the purified hydrolases.An enormous stimulation of the enzymic hydrolysis can be achieved by the addition of suitable detergents, such as bile salts (3, 7). At appropriate concentrations, detergents and glycolipids form small mixed micelles from which the oligosaccharide chains protrude far enough to be attacked by the hydrolases. However, these detergent-based assay mixtures do not reflect the in vivo situation, since lysosomes do not contain detergents. The interaction between lysosomal, water-soluble hydrolases and their membrane-bound glycolipid substrates must be brought about in some other way. Since 1964 several non-enzymic protein factors, called activators, have been described, which perform this function and thus accelerate the enzymic degradation of glycosphingolipids.


Sialic Acid Activator Protein Lipid Substrate Metachromatic Leukodystrophy Sandhoff Disease 
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  1. 1.
    J. B. Stanbury, J. B. Wyngaarden, D. S. Fredrickson, J. L. Goldstein and M. S. Brown, “The Metabolic Basis of Inherited Disease,”5th edition, McGraw-Hill, New York (1983).Google Scholar
  2. 2.
    K. Sandhoff, The biochemistry of sphingolipid storage diseases, Angew. Chem., Int. Ed. 16:273 (1977).CrossRefGoogle Scholar
  3. 3.
    K. Sandhoff and H. Christomanou, Biochemistry and genetics of gangliosidoses, Hum. Genet. 50:107 (1979).PubMedCrossRefGoogle Scholar
  4. 4.
    R. O. Brady, Inherited metabolic storage disorders, in: “Annual Reviews of Neuroscience,” W. M. Cowan, Z. W. Hall and E. R. Kandel, eds., Annual Review Inc., Palo Alto (1982).Google Scholar
  5. 5.
    E. F. Neufeld, T. W. Lim and L. J. Shapiro, Inherited disorders of lysosomal metabolism, Annu. Rev. Biochem. 44: 357 (1975).PubMedCrossRefGoogle Scholar
  6. 6.
    H. G. Hers, The concept of inborn lysosomal disease, in: “Lysosomes and Storage Diseases,” H. G. Hers, ed., Academic Press, New York (1973).Google Scholar
  7. 7.
    A. W. Schram, M. N. Hamers, M. R. Samson, S. Cordus, A. de Jonge, I. Brown, D. Robinson and J. M. Tager, Factors affecting the hydrolysis of ceramide-3 by a-galactosidase A from human liver, Biochim. Biophys. Acta 568:59 (1979).PubMedCrossRefGoogle Scholar
  8. 8.
    E. Mehl and H. Jatzkewitz, Eine Cerebrosidsulfatase aus Schweineniere, Hoppe-Seyler’s Z. Physiol. Chem. 339:260 (1964).CrossRefGoogle Scholar
  9. 9.
    H. Jatzkewitz and K. Stinshoff, An activator of cerebroside sulfatase in human normal liver and in cases of congenital metachromatic leukodystrophy, FEBS Lett. 32: 129 (1973).PubMedCrossRefGoogle Scholar
  10. 10.
    G. Fischer and H. Jatzkewitz, The activator of cerebroside sulfatase - Purification from human liver and identification as a protein, Hoppe-Seyler’s Z. Physiol. Chem. 356:605 (1975).PubMedCrossRefGoogle Scholar
  11. 11.
    G. Fischer and H. Jatzkewitz, The activator of cerebroside sulfatase - Binding studies with enzyme and substrate demonstrating the detergent function of the activator protein, Biochim. Biophys. Acta 481: 561 (1977).PubMedCrossRefGoogle Scholar
  12. 12.
    G. Fischer and H. Jatzkewitz, The activator of cerebroside sulfatase - A model of the activation, Biochim. Biophys. Acta 528:69 (1978).PubMedCrossRefGoogle Scholar
  13. 13.
    Y.-T. Li, M. Y. Mazzotta, C.-C. Wan, R. Orth and S.-C. Li, Hydrolysis of Tay-Sachs ganglioside by ß-hexosaminidase A of human liver and urine, J. Biol. Chem. 248:7512 (1973).PubMedGoogle Scholar
  14. 14.
    S.-C. Li, C.-C. Wan, M. Y. Mazzotta and Y.-T. Li, Requirement of an activator for the hydrolysis of sphingoglycolipids by glycosidases of human liver, Carbohyd. Res. 34:189 (1974).CrossRefGoogle Scholar
  15. 15.
    S.-C. Li and Y.-T. Li, An activator stimulating the enzymic hydrolysis of sphingoglycolipids, J. Biol. Chem. 251:1159 (1976).PubMedGoogle Scholar
  16. 16.
    E. Conzelmann and K. Sandhoff, AB variant of infantile GM2 gangliosidosis: Deficiency of a factor necessary for stimulation of hexosaminidase A-catalyzed degradation of ganglioside GM2 and glycolipid GA2, Proc. Natl. Acad. Sci. USA.75: 3979 (1978).PubMedCrossRefGoogle Scholar
  17. 17.
    P. Hechtman, B. A. Gordon and N. M. K. Ng Ying Kin, Deficiency of the hexosaminidase A activator protein in a case of GM2 gangliosidosis; variant AB, Pediatr. Res. 16:217 (1982).Google Scholar
  18. 18.
    Y. Hirabayashi, Y.-T. Li and S.-C. Li, The protein activator specific for the enzymic hydrolysis of GM2 ganglioside in normal human brain and brains of three types of GM2 gangliosidosis, J. Neurochem. 40: 168 (1983).PubMedCrossRefGoogle Scholar
  19. 19.
    H.-J. Kytzia, U. Hinrichs, I. Maire, K. Suzuki and K. Sandhoff, Variant of GM2-gangliosidosis with hexosaminidase A having a severely changed substrate specificity, EMBO J. 2: 1201 (1983).PubMedGoogle Scholar
  20. 20.
    P. Hechtman, Characterization of an activating factor required for hydrolysis of G 2 ganglioside catalyzed by hexosaminidase A, Can. J. Biochem. 55:15 (1977).Google Scholar
  21. 21.
    P. Hechtman and D. LeBlanc, Purification and properties of the hexosaminidase A-activating protein from human liver, Biochem. J. 167: 693 (1977).PubMedGoogle Scholar
  22. 22.
    E. Conzelmann and K. Sandhoff, Purification and characterization of an activator protein for the degradation of glycolipids GM2, and GGA2 by hexosaminidase A, Hoppe-Seyler’s Z. Physiol. Chem. 360:1837 (1879).CrossRefGoogle Scholar
  23. 23.
    E. Conzelmann, J. Burg, G. Stephan and K. Sandhoff, Complexing of glycolipids and their transfer between membranes by the activator protein for degradation of lysosomal ganglioside GM2, Eur. J. Biochem. 123: 455 (1982).PubMedCrossRefGoogle Scholar
  24. 24.
    S.-C. Li, T. Nakamura, A. Ogamo and Y.-T. Li, Evidence for the presence of two separate protein activators for the enzymic hydrolysis of GM1 and GM2 gangliosides, J. Biol. Chem. 254:10592 (1979).PubMedGoogle Scholar
  25. 25.
    S.-C. Li, Y. Hirabayashi and Y.-T. Li, A protein activator for the enzymic hydrolysis of GM2 ganglioside, J. Biol. Chem. 256:6234 (1981).PubMedGoogle Scholar
  26. 26.
    R. L. Stevens, A. L. Fluhary, H. Kihara, M. M. Kaback, L. J. Shapiro, B. Marsh, K. Sandhoff and G. Fischer, Cerebroside sulfatase activator deficiency induced metachromatic leukodystropy, Am. J. Hum. Genet. 33:900 (1981).PubMedGoogle Scholar
  27. 27.
    K. Inui, M. Emmett and D. A. Wenger, Immunological evidence for deficiency in an activator protein for sulfatide sulfatase in a variant form of metachromatic leukodystrophy, Proc. Natl. Acad. Sci. USA 50:3074 (1983).CrossRefGoogle Scholar
  28. 28.
    S. Gärtner, E. Conzelmann and K. Sandhoff, Activator protein for the degradation of globotriaosylceramide by human a-galactosidase, J. Biol. Chem. 258:12378.Google Scholar
  29. 29.
    S.-C. Li, H. Kihara, S. Serizawa, Y.-T. Li, A. L. Fluharty, J. S. Mayes and L. J. Shapiro, Activator protein required for the enzymatic hydrolysis of cerebroside sulfate, J. Biol. Chem. 260:1867 (1985).PubMedGoogle Scholar
  30. 30.
    A. Vogel, W. Fürst, M. Lee-Vaupel, E. Conzelmann and K. Sandhoff, manuscript in preparation.Google Scholar
  31. 31.
    S.-C. Li and Y.-T. Li, Activator proteins for the catabolism of glycosphingolipids, in: Abstracts of NATO Advanced Research Workshop and CNRS-INSERM International Symposium “Enzymes of Lipid Metabolism”, Strasbourg 1985.Google Scholar
  32. 32.
    D. A. Wenger and K. Inui, Studies on the sphingolipid activator protein for enzymatic hydrolysis of GM2, ganglioside and sulfatide, in: “Molecular Basis of Lysosomal Storage Disorders,” A. Barranger and R. O. Brady, ed., Academic Press, Orlando (1984).Google Scholar
  33. 33.
    M. W. Ho and J. S. O’Brien, Gaucher’s disease: Deficiency of ‘acid’ B-glucosidase and reconstitution of enzyme activity in vitro, Proc. Natl. Acad. Sci. USA 68:2810 (1971).PubMedCrossRefGoogle Scholar
  34. 34.
    M. W. Ho, J. S. O’Brien, N. S. Radin and J. S. Erickson, Glucocerebrosidase: Reconstitution of activity from macromolecular components, Biochem. J. 131:173 (1973).PubMedGoogle Scholar
  35. 35.
    M. W. Ho, Specificity of low molecular weight glycoprotein effector of lipid glycosidase, FEES Lett. 53: 243 (1975).CrossRefGoogle Scholar
  36. 36.
    M. W. Ho and N. D. Light, Glucocerebrosidase: Reconstitution from macro-molecular components depends on acidic phospholipids, Biochem. J. 136: 821 (1973).PubMedGoogle Scholar
  37. 37.
    A. Basu, R. H. Glew, L. B. Daniels and L. S. Clark, Activators of spleen glucocerebrosidase from controls and patients with various forms of Gaucher’s disease, J. Biol. Chem. 259:1714 (1984).PubMedGoogle Scholar
  38. 38.
    S. L. Berent and N. S. Radin, Mechanism of activation of glucocerebrosidase by co-B-glucosidase (glucosidase activator protein), Biochim. Biophys. Acta 664:572 (1981).PubMedCrossRefGoogle Scholar
  39. 39.
    S. L. Berent and N. S. Radin, B-Glucosidase activator protein from bovine spleen (“coglucosidase”), Arch. Biochem. Biophys. 208:248 (1981).PubMedCrossRefGoogle Scholar
  40. 40.
    S. P. Peters, C. J. Coffee, R. H. Glew, R. E. Lee, D. A. Wenger, S.-C. Li and Y.-T. Li, Isolation of heat-stable glucocerebrosidase activator from the spleens of three variants of Gaucher’s disease, Arch. Biochem. Biophys. 183:290 (1977).PubMedCrossRefGoogle Scholar
  41. 41.
    S. P. Peters, P. Coyle, C. J. Coffee, R. H. Glew, M. S. Kuhlenschmidt, L. Rosenfeld and Y. C. Lee, Purification and properties of a heat-stable glucocerebrosidase activating factor from control and Gaucher spleen, J. Biol. Chem. 252:563 (1977).Google Scholar
  42. 42.
    D. A. Wenger, M. Sattler and S. Roth, A protein activator of galactosylceramide B-galactosidase activity, Trans. Am. Soc. Neurochem. 12: 210 (1981).Google Scholar
  43. 43.
    H. Christomanou, Niemann-Pick disease type C: Evidence for the deficiency of an activating factor stimulating sphingomyelin and glucocerebroside degradation, Hoppe-Seyler’s Z. Physiol. Chem. 361:1489 (1980)PubMedCrossRefGoogle Scholar
  44. 44.
    H. Christomanou and T. Kleinschmidt, Isolation of two forms of an activator protein for the enzymic sphingomyelin degradation from human spleen, Biol. Chem. Hoppe-Seyler 366:245 (1985).PubMedCrossRefGoogle Scholar
  45. 45.
    A. M. Vaccaro, M. Muscillo, E. Gallozzi, R. Salvioli, M. Tatti and K. Suzuki, An endogenous activator protein in human placenta for enzymic degradation of glucosylceramide, Biochim. Biophys. Acta 836:157 (1985).Google Scholar
  46. 46.
    M. W. Ho and M. Rigby, Glucocerebrosidase: Stoichiometry of association between effector and catalytic proteins, Biochim. Biophys. Acta 397:267 (1975).PubMedCrossRefGoogle Scholar
  47. 47.
    J. Burg, A. Banerjee and K. Sandhoff, Molecular forms of GM2-activator protein, Biol. Chem. Hoppe-Seyler 366:887 (1985).PubMedCrossRefGoogle Scholar
  48. 48.
    A. Banerjee, J. Burg, E. Conzelmann, M. Carroll and K. Sandhoff, Enzyme-linked immunosorbent assay for the ganglioside GM2-activator protein - Screening of normal human tissues and body fluids, of tissues of GM2 gangliosidosis, and for its subcellular localization, HoppeSeyler’s Z. Physiol. Chem. 365:347 (1984).CrossRefGoogle Scholar
  49. 49.
    J. Burg, E. Conzelmann, K. Sandhoff, E. Solomon and D. M. Swallow, Mapping of the gene coding for the human GM2 activator protein to chromosome 5, Ann. Hum. Genet. 49:41 (1985).PubMedCrossRefGoogle Scholar
  50. 50.
    J. Burg, A. Banerjee, E. Conzelmann and K. Sandhoff, Activating proteins for ganglioside GM2 degradation by B-hexosaminidase isoenzymes in tissue extracts from different species, Hoppe-Seyler’s Z. Physiol. Chem. 364:821 (1983).PubMedCrossRefGoogle Scholar
  51. 51.
    S.-C. Li, S. Serizawa and Y.-T. Li, Effect of modification of sialic acid on enzymic hydrolysis of gangliosides GM1 and GM2, J. Biol. Chem. 259:5409 (1984).PubMedGoogle Scholar
  52. 52.
    S. Neuenhofer and K. Sandhoff, Affinity labelling of the GM2-activator protein, FEBS Lett. 185: 112 (1985).CrossRefGoogle Scholar
  53. 53.
    S. K. Srivastava and E. Beutler, Hex A and B: studies in Tay-Sachs and Sandhoff disease, Nature 241: 463 (1973).PubMedCrossRefGoogle Scholar
  54. 54.
    D. J. Mahuran, F. Tsui, R. A. Gravel and J. A. Lowden, Evidence for two dissimilar polypeptide chains in the ß subunit of hexosaminidase, Proc. Natl. Acad. Sci. USA 79:1602 (1982).PubMedCrossRefGoogle Scholar
  55. 55.
    A. Hasilik and E. F. Neufeld, Biosynthesis of lysosomal enzymes in fibroblasts—Synthesis as precursors of higher molecular weight, J. Biol. Chem. 255:4937 (1980).Google Scholar
  56. 56.
    H.-J. Kytzia, U. Hinrichs and K. Sandhoff, Diagnosis of infantile and juvenile forms of GM2 gangliosidosis variant O. Residual activities towards natural and different synthetic substrates, Hum. Genet. 67: 414 (1984).PubMedCrossRefGoogle Scholar
  57. 57.
    K. Sandhoff, E. Conzelmann and H. Nehrkorn, Specificity of human liver hexosaminidases A and B against glycosphingolipids Gand G Purification of the enzymes by affinity chromatogra y employing specific elution, Hoppe-Seyler’s Z. Physiol. Chem. 358:779 (1977).PubMedCrossRefGoogle Scholar
  58. 58.
    K. Sandhoff, Variant of ß-N-acetylhexosaminidase-pattern in Tay-Sachs disease, FEBS Lett. 4: 351 (1969).Google Scholar
  59. 59.
    S. Okada and J. S. O’Brien, Tay-Sachs disease: Generalized absence of a ß-D-N-acetylhexosaminidase component, Science 165: 698 (1969).Google Scholar
  60. 60.
    K. Sandhoff, K. Harzer, W. Wässle and H. Jatzkewitz, Enzyme alterations and lipid storage in three variants of Tay-Sachs disease, J. Neurochem. 18:2469 (1971).CrossRefGoogle Scholar
  61. 61.
    K. Sandhoff, U. Andreae and H. Jatzkewitz, Deficient hexosaminidase activity in an exceptional case of Tay-Sachs disease with additional storage of kidney globoside in visceral organs, Path. europ. 3: 278 (1968).Google Scholar
  62. 62.
    B. Geiger and R. Arnon, Chemical characterization and subunit structure of human N-acetyl-hexosaminidase A and B, Biochemistry 15: 3484 (1976).Google Scholar
  63. 63.
    H.-J. Kytzia and K. Sandhoff, Evidence for two different active sites on human ß-hexosaminidase A - Interaction of G M2 activator protein with ß-hexosaminidase A, J. Biol. Chem. 260:758 (1985).Google Scholar
  64. 64.
    J. E. Goldman, T. Yamanaka, I. Rapin, M. Adachi, K. Suzuki and K. Suzuki, The AB-variant of GM2 gangliosidosis. Clinical, biochemical and pathological studies of two patients, Acta Neuropathol. (Berl.) 52:189 (1980).CrossRefGoogle Scholar
  65. 65.
    S.-C. Li, Y. Hirabayashi and Y.-T. Li, A new variant of type-AB GM2 - gangliosidosis, Biochem. Biophys. Res. Commun. 101:479 (1981).PubMedCrossRefGoogle Scholar
  66. 66.
    Y.-T. Li, Y. Hirabayashi and S.-C. Li, Differentiation of two variants of type-AB G M2-gangliosidosis using chromogenic substrates, Am. J. Hum. Genet. 5:520 (1983).Google Scholar
  67. 67.
    S. Sonderfeld, E. Conzelmann, G. Schwarzmann, J. Burg, U. Hinrichs and K. Sandhoff, Incorporation and metabolism of ganglioside G in skin fibroblasts from normal and GM2 gangliosidosis subjects, Eur. J. Biochem. 149:247 (1985).PubMedCrossRefGoogle Scholar
  68. 68.
    J. F. Tallman, R. O. Brady, R. Navon and B. Padeh, Ganglioside catabolism in hexosaminidase A deficient adults, Nature 252: 254 (1974).Google Scholar
  69. 69.
    J. Zerfowski and K. Sandhoff, Juvenile GM2-Gangliosidose mit veränder-tterSubstratspezifität der Hexosaminiase A, Acta neuropath. (Berl.)27:225(1974).PubMedCrossRefGoogle Scholar
  70. 70.
    A. Erzbeger, E.Conzelmann and K. Sandhoff, Assay of ganglioside GM2-N-acetyl-ß-D-galactosaminidase activity in human fibroblasts employing the natural activator protein, Clin. Chim. Acta 108:361 (1980).CrossRefGoogle Scholar
  71. 71.
    E. Conzelmann, H.-J. Kytzia, R. Navon and K. Sandhoff, Ganglioside GM2 N-acetyl-ß-D-galactosaminidase activity in cultured fibroblasts of late infantile and adult GM2 gangliosidosis patients and of healthy probands with low hexosaminidase level, Am. J. Hum. Genet. 35:900 (1983).PubMedGoogle Scholar
  72. 72.
    K. Inui and D. A. Wenger, Properties of a protein activator of glycosphingolipid hydrolysis isolated from the liver of a patient with GM1 gangliosidosis, type 1, Biochem. Biophys. Res. Commun. 105:745 (1982).CrossRefGoogle Scholar
  73. 73.
    W. Mraz, G. Fischer and H. Jatzkewitz, The activator of cerebroside sulphatase - Lysosomal localization, Hoppe-Seyler’s Z. Physiol. Chem. 357:1181 (1976).PubMedCrossRefGoogle Scholar
  74. 74.
    K. Inui, F.-T. Kao, S. Fujibayashi, C. Jones, H. G. Morse, M. L. Law and D. A. Wenger, The gene coding for a sphingolipid activator protein, SAP-1, is on human chromosome 10, Hum. Genet. 69:197 (1985).PubMedCrossRefGoogle Scholar
  75. 75.
    G. Fischer, Anreicherung und Charakterisierung des Aktivators der Sulfatase A, Thesis, Universität Stuttgart (1977).Google Scholar
  76. 76.
    K. Inui and D. A. Wenger, Biochemical, immunological, and structural studies on an sphingolipid activator protein (SAP-1), Arch. Biochem. Biophys. 233:556 (1984).PubMedCrossRefGoogle Scholar
  77. 77.
    D. A. Wenger and S. Fujibayashi, Studies of SAP-1 and SAP-2 in cultured skin fibroblasts, in: Abstracts of NATO Advanced Research Workshop and CNRS-INSERM International Symposium “Enzymes of Lipid Metabolism”, Strasbourg 1985.Google Scholar
  78. 78.
    G. Fischer and H. Jatzkewitz, Studies on the function of the activator of sulphatase A, in: “Enzymes of Lipid Metabolism,” S. Gatt, L. Freysz and P. Mandel, eds., Plenum Press, New York (1978).Google Scholar
  79. 79.
    G. Fischer, S. Reiter and H. Jatzkewitz, Enzymic hydrolysis of sulphosphingolipids and sulphoglycerolipids by sulfatase A in the presence and absence of activator protein, Hoppe-Seyler’s Z. Physiol. Chem. 359:863 (1978).PubMedCrossRefGoogle Scholar
  80. 80.
    F. Sarmientos, G. Schwarzmann and K. Sandhoff, Specificity of human glucosylceramide 8-glucosidase against structurally modified glucosylceramides in a detergent-free assay-system, in preparation.Google Scholar

Copyright information

© Plenum Press, New York 1986

Authors and Affiliations

  • W. Fürst
    • 1
  • A. Vogel
    • 1
  • M. Lee-Vaupel
    • 1
  • E. Conzelmann
    • 1
  • K. Sandhoff
    • 1
  1. 1.Institut für Organische Chemie und BiochemieUniversität BonnBonn 1Germany

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