TY - JOUR
T1 - Membrane asymmetry in isolated canine cardiac sarcoplasmic reticulum
T2 - Comparison with skeletal muscle sarcoplasmic reticulum
AU - Bick, R. J.
AU - Buja, L. M.
AU - Van Winkle, W. B.
AU - Taffet, G. E.
PY - 1998/7/15
Y1 - 1998/7/15
N2 - Cardiac sarcoplasmic reticulum (CSR), isolated from dog hearts, was shown to be asymmetric in the distribution of phospholipids across the CSR bilayer. Phosphatidylethanolamine was mostly resident in the outer leaflet, phosphatidylcholine was equally distributed across both monolayers and phosphatidylserine was found primarily in the inner monolayer. This distribution of headgroups is similar to that found in fast skeletal muscle sarcoplasmic reticulum (SSR); however, the asymmetry in CSR is not as striking as that in SSR. Phospholipids retained by the CSR calcium pump protein (CaATPase) after detergent 'stripping' were similar to those intimate to the SSR CaATPase, although the percentages of unsaturated phospholipids and plasmalogenic phospholipids are not as great as in the skeletal system. Lipids associated with the CSR CaATPase Following DFDNB cross-linking showed a preference for retention of the aminophospholipids, again similar to the SSR CaATPase. Because the nonrandom distribution of membrane lipids modifies SSR function, it is likely these membrane lipids impact in situ the function of the CSR.
AB - Cardiac sarcoplasmic reticulum (CSR), isolated from dog hearts, was shown to be asymmetric in the distribution of phospholipids across the CSR bilayer. Phosphatidylethanolamine was mostly resident in the outer leaflet, phosphatidylcholine was equally distributed across both monolayers and phosphatidylserine was found primarily in the inner monolayer. This distribution of headgroups is similar to that found in fast skeletal muscle sarcoplasmic reticulum (SSR); however, the asymmetry in CSR is not as striking as that in SSR. Phospholipids retained by the CSR calcium pump protein (CaATPase) after detergent 'stripping' were similar to those intimate to the SSR CaATPase, although the percentages of unsaturated phospholipids and plasmalogenic phospholipids are not as great as in the skeletal system. Lipids associated with the CSR CaATPase Following DFDNB cross-linking showed a preference for retention of the aminophospholipids, again similar to the SSR CaATPase. Because the nonrandom distribution of membrane lipids modifies SSR function, it is likely these membrane lipids impact in situ the function of the CSR.
KW - Asymmetry
KW - Membranes
KW - Phospholipids
KW - Sarcoplasmic reticulum
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U2 - 10.1007/s002329900402
DO - 10.1007/s002329900402
M3 - Article
C2 - 9662560
AN - SCOPUS:0032527931
SN - 0022-2631
VL - 164
SP - 169
EP - 175
JO - Journal of Membrane Biology
JF - Journal of Membrane Biology
IS - 2
ER -