TY - JOUR
T1 - Effect of the Vesicular Stomatitis Virus Matrix Protein on the Lateral Organization of Lipid Bilayers Containing Phosphatidylglycerol
T2 - Use of Fluorescent Phospholipid Analogues†
AU - Wiener, Jon R.
AU - Pal, Ranajit
AU - Barenholz, Yechezkel
AU - Wagner, Robert R.
PY - 1985/12/1
Y1 - 1985/12/1
N2 - In order to investigate the mode of interaction of peripheral membrane proteins with the lipid bilayer, the basic (pI ~ 9.1) matrix (M) protein of vesicular stomatitis virus was reconstituted with small unilamellar vesicles (SUV) containing phospholipids with acidic head groups. The lateral organization of lipids in such reconstituted membranes was probed by fluorescent phospholipid analogues labeled with pyrene fatty acids. The excimer/monomer (E/M) fluorescence intensity ratios of the intrinsic pyrene phospholipid probes were measured at various temperatures in M protein reconstituted SUV composed of 50 mol % each of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG). The M protein showed relatively small effects on the E/M ratio either in the gel or in the liquid-crystalline phase. However, during the gel to liquid-crystalline phase transition, the M protein induced a large increase in the E/M ratio due to phase separation of lipids into a neutral DPPC-rich phase and DPPG domains presumably bound to M protein. Similar phase separation of bilayer lipids was also observed in the M protein reconstituted with mixed lipid vesicles containing one low-melting lipid component (l-palmitoyl-2-oleoylphosphatidylcholine or l-palmitoyl-2-oleoylphosphatidylglycerol) or a low mole percent of cholesterol. The self-quenching of 4-nitro-2,1,3-benzoxadiazole (NBD) fluorescence, as a measure of lipid clustering in the bilayer, was also studied in M protein reconstituted DPPC-DPPG vesicles containing 5 mol % NBD-phosphatidylethanolamine (NBD-PE). The quenching of NBD-PE was enhanced at least 2-fold in M protein reconstituted vesicles at temperatures within or below the phase transition. All these experiments demonstrate that the binding of M protein in lipid bilayers containing acidic phospholipid head groups induces lateral reorganization of lipids in the membrane plane, an effect which is far more pronounced during the transition of membrane lipids from the liquid-crystalline to the gel state.
AB - In order to investigate the mode of interaction of peripheral membrane proteins with the lipid bilayer, the basic (pI ~ 9.1) matrix (M) protein of vesicular stomatitis virus was reconstituted with small unilamellar vesicles (SUV) containing phospholipids with acidic head groups. The lateral organization of lipids in such reconstituted membranes was probed by fluorescent phospholipid analogues labeled with pyrene fatty acids. The excimer/monomer (E/M) fluorescence intensity ratios of the intrinsic pyrene phospholipid probes were measured at various temperatures in M protein reconstituted SUV composed of 50 mol % each of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG). The M protein showed relatively small effects on the E/M ratio either in the gel or in the liquid-crystalline phase. However, during the gel to liquid-crystalline phase transition, the M protein induced a large increase in the E/M ratio due to phase separation of lipids into a neutral DPPC-rich phase and DPPG domains presumably bound to M protein. Similar phase separation of bilayer lipids was also observed in the M protein reconstituted with mixed lipid vesicles containing one low-melting lipid component (l-palmitoyl-2-oleoylphosphatidylcholine or l-palmitoyl-2-oleoylphosphatidylglycerol) or a low mole percent of cholesterol. The self-quenching of 4-nitro-2,1,3-benzoxadiazole (NBD) fluorescence, as a measure of lipid clustering in the bilayer, was also studied in M protein reconstituted DPPC-DPPG vesicles containing 5 mol % NBD-phosphatidylethanolamine (NBD-PE). The quenching of NBD-PE was enhanced at least 2-fold in M protein reconstituted vesicles at temperatures within or below the phase transition. All these experiments demonstrate that the binding of M protein in lipid bilayers containing acidic phospholipid head groups induces lateral reorganization of lipids in the membrane plane, an effect which is far more pronounced during the transition of membrane lipids from the liquid-crystalline to the gel state.
UR - http://www.scopus.com/inward/record.url?scp=0022428147&partnerID=8YFLogxK
U2 - 10.1021/bi00347a023
DO - 10.1021/bi00347a023
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C2 - 3004559
AN - SCOPUS:0022428147
SN - 0006-2960
VL - 24
SP - 7651
EP - 7658
JO - Biochemistry
JF - Biochemistry
IS - 26
ER -