TY - JOUR
T1 - Al3+-mediated changes on membrane fluidity affects the activity of PI-PLC but not of PLC
AU - Verstraeten, Sandra V.
AU - Villaverde, Marcela S.
AU - Oteiza, Patricia I.
PY - 2003/1
Y1 - 2003/1
N2 - We investigated whether Al3+-mediated changes in membrane fluidity can affect the activity of prokaryotic enzymes phospholipase C (PLC) and phospholipase C-phosphatidyl inositol specific (PI-PLC) in liposomes of phosphatidyl choline (PC), PC:phosphatidyl inositol (PI), or PC and polyphosphoinositides (PPI). Al3+ (10-100 μM) promoted membrane rigidification, evaluated with the probes 1,6-diphenyl-1,3,5-hexatriene and Laurdan, and followed the order: PC:PPI>PC:PI>PC. Al3+ (25 and 50 μM) did not affect PLC-mediated hydrolysis of PC, PI and PIP2, but stimulated PIP hydrolysis (48.6%). PI-PLC did not affect PC, PI, and PIP concentrations, but caused a 67% decrease in PIP2. Al3+ significantly inhibited PIP2 hydrolysis in a concentration-dependent (25-50 μM) manner. Results suggest that the inhibition of PIP2 hydrolysis by Al3+ could be partially due to a higher lipid packing induced by Al3+ which could affect the interaction between the enzyme and its substrate.
AB - We investigated whether Al3+-mediated changes in membrane fluidity can affect the activity of prokaryotic enzymes phospholipase C (PLC) and phospholipase C-phosphatidyl inositol specific (PI-PLC) in liposomes of phosphatidyl choline (PC), PC:phosphatidyl inositol (PI), or PC and polyphosphoinositides (PPI). Al3+ (10-100 μM) promoted membrane rigidification, evaluated with the probes 1,6-diphenyl-1,3,5-hexatriene and Laurdan, and followed the order: PC:PPI>PC:PI>PC. Al3+ (25 and 50 μM) did not affect PLC-mediated hydrolysis of PC, PI and PIP2, but stimulated PIP hydrolysis (48.6%). PI-PLC did not affect PC, PI, and PIP concentrations, but caused a 67% decrease in PIP2. Al3+ significantly inhibited PIP2 hydrolysis in a concentration-dependent (25-50 μM) manner. Results suggest that the inhibition of PIP2 hydrolysis by Al3+ could be partially due to a higher lipid packing induced by Al3+ which could affect the interaction between the enzyme and its substrate.
KW - Aluminum
KW - Fluidity
KW - Membranes
KW - Phosphoinositides
KW - Phospholipase
KW - PI-PLC
KW - PLC
UR - http://www.scopus.com/inward/record.url?scp=0037277581&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037277581&partnerID=8YFLogxK
U2 - 10.1016/S0009-3084(02)00192-5
DO - 10.1016/S0009-3084(02)00192-5
M3 - Article
C2 - 12598047
AN - SCOPUS:0037277581
VL - 122
SP - 159
EP - 163
JO - Chemistry and Physics of Lipids
JF - Chemistry and Physics of Lipids
SN - 0009-3084
IS - 1-2
ER -