Structural properties of the myelin-associated glycoprotein ectodomain.
Myelin-associated glycoprotein (MAG) has been proposed to mediate adhesive interactions during myelin development. We have used the baculovirus expression system to produce a truncated form of this molecule [soluble extracellular domain of MAG (sMAG)] consisting of the complete extracellular ectodomain. Spectroscopic studies indicate a high beta-sheet content, consistent with the prediction of Ig-like structure. Hydrodynamic studies indicate an asymmetric monomer, with a Stokes radius of 4.1-4.6 nm, a sedimentation coefficient of 3.6S, and a frictional ratio of approximately 1.6. We postulate that the outer two Ig-like domains form a unit that folds back over the rest of the molecule. Fluorescence quenching studies indicate that sMAG interacts with divalent cations and may have a functional lectin domain.
Attia
J
J
Center for Research in Neuroscience, McGill University, Montreal General Hospital Research Institute, Quebec, Canada.
Hicks
L
L
Oikawa
K
K
Kay
C M
CM
Dunn
R J
RJ
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D002413:Cations, Divalent; D002460:Cell Line; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D005110:Extracellular Space / Q000737:chemistry; D009036:Moths; D009185:Myelin Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D018992:Myelin-Associated Glycoprotein; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification; D013050:Spectrometry, Fluorescence
D000596:Amino Acids; D002413:Cations, Divalent; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein; D011994:Recombinant Proteins