title: Human DNase I contains mannose 6-phosphate and binds the cation-independent mannose 6-phosphate receptor.
abstract: DNase I isolated from human urine (hDNase) or expressed in Chinese hamster ovary (CHO) cells contains mannose-phosphorylated oligosaccharides. hDNase binds to a column of immobilized cation-independent mannose 6-phosphate receptor, with the strongest binding exhibited by the protein bearing diphosphorylated oligosaccharides. The binding is inhibited by 5 mM mannose 6-phosphate, and can be prevented by prior treatment of hDNase with alkaline phosphatase. Phosphorylated high-mannose oligosaccharides were observed at both sites of glycosylation in hDNase by high-performance liquid chromatography-mass spectrometry of a tryptic digest. These results indicate that hDNase, though not an acid hydrolase, may enter the lysosomal trafficking pathway, and may have evolved from a lysosomal enzyme.
authors.affiliation: Department of Manufacturing Sciences, Genentech, Inc., South San Francisco, California 94080, USA.
authors.forename: J
authors.initials: J
authors.lastname: Cacia
authors.forename: C P
authors.initials: CP
authors.lastname: Quan
authors.forename: R
authors.initials: R
authors.lastname: Pai
authors.forename: J
authors.initials: J
authors.lastname: Frenz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002240:Carbohydrate Sequence; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006224:Cricetinae; D003850:Deoxyribonuclease I / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000652:urine; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007525:Isoelectric Focusing; D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008360:Mannosephosphates / Q000378:metabolism*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000378:metabolism*
chemical_list: D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008360:Mannosephosphates; D011956:Receptors, Cell Surface; C027693:mannose-6-phosphate; D003850:Deoxyribonuclease I