Acyl chain dynamics of phosphatidylethanolamines containing oleic acid and dihydrosterculic acid: 2H NMR relaxation studies.
Acyl chain dynamics of phosphatidylethanolamines containing oleic acid and dihydrosterculic acid: 2H NMR relaxation studies.
复制标题
含有油酸和二氢梧桐酸的磷脂酰乙醇胺的酰基链动力学：2H NMR 弛豫研究。
作者：
B. Perly;I. Smith;H. Jarrell
采用2H T1和T2弛豫时间研究了1-棕榈酰-2-油基-sn-甘油-3-磷酸胆碱、1-棕榈酰-2-油基-sn-甘油-3-磷酸乙醇胺和1-棕榈酰-2-二氢甾醇-sn-甘油-3-磷酸乙醇胺的酰基链动力学行为。在sn-2酰基链的5-、9-、10-和16位标记脂质。在所有体系中，氘的自旋-晶格弛豫速率（T1(-1)）随链位的变化都表现为碳-碳双键和环丙烷环位置的明显不连续；这些位置上的氘核的弛豫速率比sn-2链上任何其他标记位置上的都要大。对于两种类型的sn-2酰基链，假设单指数相关时间且运动在快速范围内，磷脂酰胆碱脂质系统的流动性低于磷脂酰乙醇胺类似物。含有油基链的体系比含有二氢甾醇链的类似物更具有动力学。磷脂酰乙醇胺在双层结构中的sn-2酰基链的运动速率比倒六边形结构中的脂质慢。在六方相中，二氢甾醇链的运动速率比相应位置的油基链的运动速率慢。
The dynamical behavior of the acyl chains of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine, and 1-palmitoyl-2-dihydrosterculoyl-sn-glycero-3-phosphoethanolamine has been investigated by using 2H T1 and T2 relaxation times. Lipids were labeled at the 5-,9-,10-, and 16-positions of the sn-2 acyl chain. The profile of deuterium spin-lattice relaxation rate (T1(-1) vs. chain position is characterized in all systems by a marked discontinuity at the positions of the carbon-carbon double bond and the cyclopropane ring; the deuterons at these positions have relaxation rates which are greater than at any other labeled position of the sn-2 chain. For both types of sn-2 acyl chain, assuming a single-exponential correlation time and that the motion is within the rapid regime, the phosphatidylcholine lipid systems are less mobile than their phosphatidylethanolamine analogues. Systems containing an oleoyl chain are more dynamic than their analogues containing a dihydrosterculoyl chain. The rates of motion of the sn-2 acyl chains of phosphatidylethanolamine in a bilayer structure are slower than those of the lipid in an inverted hexagonal structure. In the hexagonal phase, the motional rates of a dihydrosterculoyl chain are slower than those of the corresponding positions of an oleoyl chain.