Abstract
Bovine testicular β-galactosidase (β-D-galactoside galactohydrolase, EC 3.2.1.23) is rapidly and selectively assimilated by human skin fibroblasts. The assimilation of the enzyme is strongly inhibited by mannose 6-phosphate and by a glycoprotein fraction isolated from bovine testes (glycoprotein inhibitors). These results suggest that β-galactosidase and the glycoprotein inhibitors have a common recognition marker that contains mannose 6-phosphate. The presence of mannose phosphate in the glycoprotein inhibitors was demonstrated by acid hydrolysis of the glycoproteins to liberate mannose phosphate followed by reduction with NaB3H4 to give [3H]mannitol phosphate. The 3H-labeled compound was identified by paper electrophoresis and by the release of [3H]mannitol on treatment with phosphatase. The [3H]mannitol phosphate was oxidized with periodate and the resulting phosphorylated fragment, on reduction with NaB3H4, yielded [3H]ethylene glycol phosphate, indicating substitution of phosphate on carbon 6 of mannitol. Mannose 6-phosphate was also found in a major carbohydrate-containing fraction of peptides produced from the glycoprotein inhibitors by tryspin digestion. It was estimated that about 2% of the mannose residues were present as mannose 6-phosphate. Phosphorylated oligosaccharides were also identified in hydrolysates of the glycoprotein inhibitors. One, a disaccharide, was identified as α-(mannosyl-6-phosphate)-(1 → 2)-mannose. These observations suggest that the recognition marker of β-galactosidase contains α1,2-linked mannose 6-phosphate; terminal α1,2-linked mannose residues are known to occur in the high-mannose type oligosaccharides present on β-galactosidase.
Keywords: adsorptive endocytosis, recognition marker, lysosomal enzymes
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- BANDURSKI R. S., AXELROD B. The chromatographic identification of some biologically important phosphate esters. J Biol Chem. 1951 Nov;193(1):405–410. [PubMed] [Google Scholar]
- Ballou C. E., Raschke W. C. Polymorphism of the somatic antigen of yeast. Science. 1974 Apr 12;184(4133):127–134. doi: 10.1126/science.184.4133.127. [DOI] [PubMed] [Google Scholar]
- DISTLER J. J., MERRICK J. M., ROSEMAN S. Glucosamine metabolism. III. Preparation and N-acetylation of crystalline D-glucosamine- and D-galactosamine-6-phosphoric acids. J Biol Chem. 1958 Jan;230(1):497–509. [PubMed] [Google Scholar]
- Distler J. J., Jourdian G. W. beta-Galactosidase from bovine testes. Methods Enzymol. 1978;50:514–520. doi: 10.1016/0076-6879(78)50055-4. [DOI] [PubMed] [Google Scholar]
- HURLBERT R. B., SCHMITZ H., BRUMM A. F., POTTER V. R. Nucleotide metabolism. II. Chromatographic separation of acid-soluble nucleotides. J Biol Chem. 1954 Jul;209(1):23–39. [PubMed] [Google Scholar]
- Hieber V., Distler J., Myerowitz R., Schmickel R. D., Jourdian G. W. The role of glycosidically bound mannose in the assimilation of beta-galactosidase by generalized gangliosidosis fibroblasts. Biochem Biophys Res Commun. 1976 Dec 6;73(3):710–717. doi: 10.1016/0006-291x(76)90868-8. [DOI] [PubMed] [Google Scholar]
- Jackson R. L., Hirs C. H. The primary structure of porcine pancreatic ribonuclease. I. The distribution and sites of carbohydrate attachment. J Biol Chem. 1970 Feb 10;245(3):624–636. [PubMed] [Google Scholar]
- Jourdian G. W., Dean L., Roseman S. The sialic acids. XI. A periodate-resorcinol method for the quantitative estimation of free sialic acids and their glycosides. J Biol Chem. 1971 Jan 25;246(2):430–435. [PubMed] [Google Scholar]
- Kaplan A., Achord D. T., Sly W. S. Phosphohexosyl components of a lysosomal enzyme are recognized by pinocytosis receptors on human fibroblasts. Proc Natl Acad Sci U S A. 1977 May;74(5):2026–2030. doi: 10.1073/pnas.74.5.2026. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kaplan A., Fischer D., Achord D., Sly W. Phosphohexosyl recognition is a general characteristic of pinocytosis of lysosomal glycosidases by human fibroblasts. J Clin Invest. 1977 Nov;60(5):1088–1093. doi: 10.1172/JCI108860. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kaplan A., Fischer D., Sly W. S. Correlation of structural features of phosphomannans with their ability to inhibit pinocytosis of human beta-glucuronidase by human fibroblasts. J Biol Chem. 1978 Feb 10;253(3):647–650. [PubMed] [Google Scholar]
- LLOYD A. G. Fractionation of the products of the direct sulphation of monosaccharides on anion-exchange resin. Biochem J. 1962 Jun;83:455–460. doi: 10.1042/bj0830455. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Neufeld E. F., Sando G. N., Garvin A. J., Rome L. H. The transport of lysosomal enzymes. J Supramol Struct. 1977;6(1):95–101. doi: 10.1002/jss.400060108. [DOI] [PubMed] [Google Scholar]
- Porter W. H. Application of nitrous acid deamination of hexosamines to the simultaneous GLC determination of neutral and amino sugars in glycoproteins. Anal Biochem. 1975 Jan;63(1):27–43. doi: 10.1016/0003-2697(75)90186-4. [DOI] [PubMed] [Google Scholar]
- Robison R. Hexosemonophosphoric esters: mannosemonophosphate. Biochem J. 1932;26(6):2191–2202. doi: 10.1042/bj0262191. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SPIRO R. G. PERIODATE OXIDATION OF THE GLYCOPROTEIN FETUIN. J Biol Chem. 1964 Feb;239:567–573. [PubMed] [Google Scholar]
- Sando G. N., Neufeld E. F. Recognition and receptor-mediated uptake of a lysosomal enzyme, alpha-l-iduronidase, by cultured human fibroblasts. Cell. 1977 Nov;12(3):619–627. doi: 10.1016/0092-8674(77)90262-8. [DOI] [PubMed] [Google Scholar]
- Slodki M. E., Ward R. M., Boundy J. A. Concanavalin A as a probe of phosphomannan molecular structure. Biochim Biophys Acta. 1973 Apr 28;304(2):449–456. doi: 10.1016/0304-4165(73)90264-x. [DOI] [PubMed] [Google Scholar]
- Ullrich K., Mersmann G., Weber E., Von Figura K. Evidence for lysosomal enzyme recognition by human fibroblasts via a phosphorylated carbohydrate moiety. Biochem J. 1978 Mar 15;170(3):643–650. doi: 10.1042/bj1700643. [DOI] [PMC free article] [PubMed] [Google Scholar]