title: Purification of axonin-1, a protein that is secreted from axons during neurogenesis.
abstract: Using selective metabolic labelling in a compartmental cell culture system two proteins, denoted axonin-1 and axonin-2, were found to be secreted by axons of dorsal root ganglia neurons from chicken embryos. Based on its characteristic coordinates and spot morphology in two-dimensional gel electrophoresis, axonin-1 was detected in the cerebrospinal fluid and the vitreous fluid, axonin-1 was purified 476-fold to homogeneity by a four-step chromatographic procedure. The identity of the purified protein as axonin-1 was confirmed by immunological methods. Axonin-1 is a glycoprotein that subdivides into at least 16 immunologically similar isoelectric variants; their molecular weight range extends from 132 to 140 kd and their pI range from 5.3 to 6.2. In the vitreous fluid of the embryo, axonin-1 could first be detected on the embryonic day 5 and highest concentrations were measured during the second half of embryonic life; in the vitreous fluid of the adult chicken, concentrations were approximately 20 times lower. The early onset of secretion and the time course of expression suggest a role for axonin-1 in the development of the nervous system.
authors.affiliation: Institute of Biochemistry, University of Zürich, Switzerland.
authors.forename: M A
authors.initials: MA
authors.lastname: Ruegg
authors.forename: E T
authors.initials: ET
authors.lastname: Stoeckli
authors.forename: T B
authors.initials: TB
authors.lastname: Kuhn
authors.forename: M
authors.initials: M
authors.lastname: Heller
authors.forename: R
authors.initials: R
authors.lastname: Zuellig
authors.forename: P
authors.initials: P
authors.lastname: Sonderegger
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001369:Axons / Q000378:metabolism*; D002478:Cells, Cultured; D002555:Cerebrospinal Fluid / Q000032:analysis; D002642:Chick Embryo; D005727:Ganglia, Spinal / Q000166:cytology; D006023:Glycoproteins / Q000302:isolation & purification* / Q000378:metabolism; D007525:Isoelectric Focusing; D009024:Morphogenesis; D009419:Nerve Tissue Proteins / Q000302:isolation & purification* / Q000378:metabolism; D014822:Vitreous Body / Q000032:analysis
chemical_list: D000911:Antibodies, Monoclonal; D006023:Glycoproteins; D009419:Nerve Tissue Proteins