Affinity fractionation and characterization of chick brain synaptosomes.
Chick brain synaptosomes were fractionated by affinity chromatography on concanavalin A-Sepharose. Three subfractions were obtained. One, designated UBF, was not bound to the affinity adsorbent and represented 36% of the total synaptosomal protein treated with the beads. A second fraction, designated BF1, adhered to concanavalin A-Sepharose exclusively through its carbohydrate recognition site. The third fraction, called BF2, bound to the beads through hydrophobic interactions and represented about 20% of the total synaptosomal protein. About 20% of the total synaptosomal protein was found to be retarded on three ligand-less gels, with potential for only hydrophobic interactions. This binding can be reversed, however, by ethylene glycol, a result indicating hydrophobic binding sites on the synaptosomes. Enzyme marker studies and electron microscopy showed differences between UBF, BF1, and BF2, mainly with respect to mitochondrial contamination. Binding studies with [3H]-Con A show the absence of Con A-specific carbohydrates from the surface of UBF or BF2. As expected strong and specific binding between [3H]-Con A and [3H] BF1 was observed. These findings are discussed in relation to a model for the interior working of the synaptosomes.
S K
SK
Sharma
S
S
Bradford
J A
JA
Babitch
E F
EF
Couch
D000042:Absorption; D000818:Animals; D001921:Brain / Q000166:cytology*; D002458:Cell Fractionation / Q000379:methods*; D002645:Chickens; D002846:Chromatography, Affinity / Q000379:methods; D003208:Concanavalin A / Q000378:metabolism; D008297:Male; D008854:Microscopy, Electron; D012685:Sepharose / Q000031:analogs & derivatives; D013347:Subcellular Fractions / Q000201:enzymology / Q000648:ultrastructure; D013574:Synaptosomes / Q000032:analysis* / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure; D014316:Tritium
C028326:concanavalin A-sepharose; D014316:Tritium; D003208:Concanavalin A; D012685:Sepharose