Interaction of the C2 Domain from Protein Kinase C with Model Membranes
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- 作者：Sonia Sá ; nchez-Bautista ; Ana de Godos ; José ; A. Rodrí ; guez-Alfaro ; Alejandro Torrecillas ; Senena Corbalá ; n-Garcí ; a ; Juan C. Gó ; mez-Ferná ; ndez
- 刊名：Biochemistry
- 出版年：2007
- 出版时间：March 20, 2007
- 年：2007
- 卷：46
- 期：11
- 页码：3183 - 3192
- 全文大小：164K
- 年卷期：v.46,no.11(March 20, 2007)
- ISSN：1520-4995
文摘
The C2 domain from protein kinase C
(PKC) binds to membranes but does not requireCa2+ to do so. This work examines the mode in which the conformation and organization of thephospholipids present in model membranes are altered by the presence of the C2 domain from PKC(C2-PKC). It is concluded from the results of differential scanning calorimetry that the protein shiftedthe temperature of the gel to the fluid phase transition of pure 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate(POPA), widening the transition and increasing it to a higher temperature. When POPA was mixed with1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), the changes in the transition were smaller andno phase separation was observed. Experiments performed using magic angle spinning NMR showedthat this C2 domain specifically affected POPA when the phospholipid was mixed with POPC, as indicatedby the downfield shift in the isotropic resonance of POPA, the widening of the resonance peak, the decreasein T2, and the decrease in T1 observed at all temperatures. All these effects were quite marked comparedwith the very small effect observed with POPC, indicating the specificity of the effect. The presence ofthe C2-PKC protein changed the conformation of the polar head group of POPA, as shown by infraredspectroscopy. All these results clearly illustrate the electrostatic interaction that takes place between thisC2 domain and membranes which contain POPA in the absence of Ca2+.
(PKC) binds to membranes but does not requireCa2+ to do so. This work examines the mode in which the conformation and organization of thephospholipids present in model membranes are altered by the presence of the C2 domain from PKC(C2-PKC). It is concluded from the results of differential scanning calorimetry that the protein shiftedthe temperature of the gel to the fluid phase transition of pure 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate(POPA), widening the transition and increasing it to a higher temperature. When POPA was mixed with1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), the changes in the transition were smaller andno phase separation was observed. Experiments performed using magic angle spinning NMR showedthat this C2 domain specifically affected POPA when the phospholipid was mixed with POPC, as indicatedby the downfield shift in the isotropic resonance of POPA, the widening of the resonance peak, the decreasein T2, and the decrease in T1 observed at all temperatures. All these effects were quite marked comparedwith the very small effect observed with POPC, indicating the specificity of the effect. The presence ofthe C2-PKC protein changed the conformation of the polar head group of POPA, as shown by infraredspectroscopy. All these results clearly illustrate the electrostatic interaction that takes place between thisC2 domain and membranes which contain POPA in the absence of Ca2+.