[Isolation of Ca2+ sensitive proteins linked to the membrane fraction of the brain cortex and the spinal cord in pigs].
Four Ca2+-sensitive proteins of respective subunit molecular weights 67 kDa, 37 kDa, 36 kDa and 32 kDa were purified from pig brain and spinal cord. Associated to the particulate fraction at millimolar concentrations of free Ca2+, they were solubilized using an EGTA-containing buffer and purified by a selective Ca2+-dependent precipitation. The 36 kDa protein is present in the tissues in a tetrameric form of (2 X 36 kDa + 2 X 13 kDa) and in a monomeric form. These proteins with the 37 kDa protein share the functional properties of the two well-known Ca2+-binding proteins, named calpactin I and calpactin II; they were able to interact with F-actin, brain spectrin (fodrin) and phosphatidylserine-liposomes in a Ca2+-dependent manner. The 67 kDa protein depolymerizes the actin filament in presence of Ca2+, it also binds to tubulin and to the neurofilament subunit NF-70, but not to brain spectrin. The 32 kDa protein does not share any association with F-actin and brain spectrin.
Regnouf
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Laboratoire de Biophysique, Institut de Biologie Physico-Chimique, Paris, France.
Pradel
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LA
D000818:Animals; D001923:Brain Chemistry; D002135:Calcium-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D002540:Cerebral Cortex / Q000032:analysis*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D008840:Microfilament Proteins / Q000378:metabolism; D008970:Molecular Weight; D011487:Protein Conformation; D013049:Spectrin / Q000378:metabolism; D013116:Spinal Cord / Q000032:analysis*; D013552:Swine
D002135:Calcium-Binding Proteins; D003598:Cytoskeletal Proteins; D008081:Liposomes; D008840:Microfilament Proteins; D013049:Spectrin
Isolement de protéines sensibles au Ca2+ associées à la fraction membranaire du cortex cérébral et de la moelle épinière de Porc.