Formation of tightly bound forms of annexins V and VI in rabbit skeletal muscle membranes isolated in the presence of barium ions.
After isolation of rabbit skeletal muscle membranes in the presence of Ba2+ or Ca2+, significant portions of annexin V and VI tightly bind to membranes and become inaccessible for chelating agents. Tightly bound annexin VI is virtually completely solubilized only after treatment with a buffer supplemented both with EGTA and detergent. The portion of tightly bound annexin V cannot be removed even by extraction with buffer containing both EGTA and detergent. In some cases, tightly bound annexin V or VI is detected even in the control (not treated with cations) membranes, thus indicating the possible formation of tight annexin--membrane complexes in situ. The addition of exogenous cations seems to promote only the accumulation of tightly bound annexins within the cell. After temperature-induced phase separation, annexin V and VI bound to the membranes isolated in the presence of Ba2+ or Ca2+ remains mainly in the aqueous phase, similarly to annexins isolated from the control membranes. Neither annexin partitions into the detergent-enriched phase. This indicates the absence of hydrophobicity change in comparison with the standard EGTA-soluble annexins.
Krasavchenko
K S
KS
Department of Molecular Biology, School of Biology, Lomonosov Moscow State University, Moscow, 119899, Russia.
Akimova
E I
EI
Melgunov
V I
VI
D000818:Animals; D017304:Annexin A5 / Q000302:isolation & purification / Q000378:metabolism*; D017317:Annexin A6 / Q000302:isolation & purification / Q000378:metabolism*; D001464:Barium / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D066298:In Vitro Techniques; D018482:Muscle, Skeletal / Q000378:metabolism*; D011817:Rabbits
D017304:Annexin A5; D017317:Annexin A6; D001464:Barium; D002118:Calcium