Sánchez-Piñera P, Micol V, Corbalán-García S, Gómez-Fernández J C
Departamento de Bioqu approximately ímica y Biolog approximately ía Molecular (A), Edificio de Veterinaria, Universidad de Murcia, Apartado Postal 4021, E-30080, Murcia, Spain.
Biochem J. 1999 Feb 1;337 ( Pt 3)(Pt 3):387-95.
The lipid activation of protein kinase C alpha (PKC alpha) has been studied by comparing the activation capacity of different 1, 2-diacylglycerols and 1,3-diacylglycerols incorporated into mixed micelles or vesicles. Unsaturated 1,2-diacylglycerols were, in general, more potent activators than saturated ones when 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine (POPS)/Triton X-100 mixed micelles and pure POPS vesicles were used. In contrast, these differences were not observed when 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/POPS (4:1, molar ratio) vesicles were used. Diacylglycerols bearing short fatty acyl chains showed a very high activation capacity, however, the capacity was less in mixed micelles. Furthermore, 1, 2-diacylglycerols had a considerably higher activating capacity than 1,3-diacylglycerols in POPS/Triton X-100 mixed micelles and in POPC/POPS vesicles. However, the differences between the two types of diacylglycerols were smaller when pure POPS vesicles were used. Differential scanning calorimetry (DSC) showed that POPC/POPS membrane samples containing diacylglycerols had endothermic transitions in the presence of 200 microM Ca2+ and 5 mM Mg2+. Transitions were not detected when using pure POPS vesicles due to the formation of dehydrated phases as demonstrated by FTIR (Fourier-transform infrared) spectroscopy. PKC alpha binding studies, performed by differential centrifugation in the presence of 200 microM Ca2+ and 5 mM Mg2+, showed that 1,2-sn-dioleoylglycerol (1, 2-DOG) was more effective than 1,3-dioleoylglycerol (1,3-DOG) in promoting binding to POPC/POPS vesicles. However, when pure POPS vesicles were used, PKC alpha was able to bind to membranes containing either 1,2-DOG or 1,3-DOG to the same extent.
通过比较掺入混合胶束或囊泡中的不同1,2 - 二酰基甘油和1,3 - 二酰基甘油的激活能力，对蛋白激酶Cα（PKCα）的脂质激活进行了研究。当使用1 - 棕榈酰 - 2 - 油酰 - sn - 甘油 - 3 - 磷酸丝氨酸（POPS）/ Triton X - 100混合胶束和纯POPS囊泡时，不饱和1,2 - 二酰基甘油通常比饱和的更具激活效力。相比之下，当使用1 - 棕榈酰 - 2 - 油酰 - sn - 甘油 - 3 - 磷酸胆碱（POPC）/ POPS（4:1，摩尔比）囊泡时，未观察到这些差异。带有短脂肪酰链的二酰基甘油显示出非常高的激活能力，然而，在混合胶束中的能力较低。此外，在POPS / Triton X - 100混合胶束和POPC / POPS囊泡中，1,2 - 二酰基甘油的激活能力比1,3 - 二酰基甘油高得多。然而，当使用纯POPS囊泡时，两种类型的二酰基甘油之间的差异较小。差示扫描量热法（DSC）表明，含有二酰基甘油的POPC / POPS膜样品在存在200 microM Ca2 +和5 mM Mg2 +时具有吸热转变。如傅里叶变换红外（FTIR）光谱所示，由于脱水相的形成，使用纯POPS囊泡时未检测到转变。在存在200 microM Ca2 +和5 mM Mg2 +的情况下通过差速离心进行的PKCα结合研究表明，1,2 - sn - 二油酰甘油（1,2 - DOG）在促进与POPC / POPS囊泡结合方面比1,3 - 二油酰甘油（1,3 - DOG）更有效。然而，当使用纯POPS囊泡时，PKCα能够以相同程度与含有1,2 - DOG或1,3 - DOG的膜结合。
