Locations of local anesthetic dibucaine in model membranes and the interaction between dibucaine and a Na+ channel inactivation gate peptide as studied by 2H- and 1H-NMR spectroscopies.
Locations of local anesthetic dibucaine in model membranes and the interaction between dibucaine and a Na+ channel inactivation gate peptide as studied by 2H- and 1H-NMR spectroscopies.
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通过 2H- 和 1H-NMR 光谱研究了模型膜中局麻药丁布卡因的位置以及丁布卡因与 Na 通道失活门肽之间的相互作用。
DOI：
10.1016/s0006-3495(96)79327-x
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发表时间：
1996
影响因子：
3.4
通讯作者：
Terumichi Nakagawa
中科院分区：
文献类型：
--
作者：
Yoshihiro Kuroda;Masahiro Ogawa;Hirosato Nasu;Maiko Terashima;Mikio Kasahara;Yasunori Kiyama;Misako Wakita;Yasuhiro Fujiwara;N. Fujii;Terumichi Nakagawa
为了研究局部麻醉的分子机制，用2H-和1H-核磁共振波谱研究了局麻药地布卡因在模型膜中的定位以及地布卡因与Na+通道失活门肽的相互作用。在磷脂酰胆碱、磷脂酰丝氨酸和磷脂酰乙醇胺组成的脂类混合物的多层分散体系中，观察到丁氧基和喹啉环3位上的双氢卡因D9和双布卡因-D1的2H-核磁共振波谱。还观察到了以氚棕榈酸为探针掺入含胆固醇的脂类混合物的~2H-核磁共振谱。根据观察到的四极分裂计算了每个碳段的有序参数SCD。综合这些结果，我们得出结论：第一，地布卡因的丁氧基穿透在模型膜的脂酰链之间；第二，地布卡因的喹啉环位于脂类的极区，而不是疏水的酰基链部分。这些结果意味着地布卡因处于有利的位置，使其能够与Na+通道蛋白结构域III和IV之间的细胞内连接物中的一簇疏水氨基酸(Ile-Phe-Met)相互作用，后者起失活门的作用。为了证实脂类表面区的地布卡因分子是否真的能与疏水氨基酸相互作用，我们合成了一个含有疏水氨基酸(Ac-GGQDIFMTEEQK-OH，MP-1)的模型肽，其氨基酸序列对应于大鼠脑型IIA型Na+通道的连接子部分，其中Phe被Gln(MP-2)取代，并在磷酸盐缓冲液和磷脂酰丝氨酸脂质体中测量了1H-核磁共振谱。研究发现，地布卡因的喹啉环与苯丙氨酸的芳香环可以通过堆积的方式相互作用，而且脂类的存在可以增强这种相互作用。综上所述，我们认为局部麻醉起源于麻醉剂分子的芳环之间的pi堆积作用，该芳环位于所谓的边界脂的极性头基区，与Na+通道蛋白结构域III和IV之间的细胞内连接子中的Phe相互作用，延长了失活状态，从而使其不可能进入静息状态。
To study the molecular mechanisms of local anesthesia, locations of local anesthetic dibucaine in model membranes and the interactions of dibucaine with a Na+ channel inactivation gate peptide have been studied by 2H- and 1H-NMR spectroscopies. The 2H-NMR spectra of dibucaine-d9 and dibucaine-d1, which are deuterated at the butoxy group and at the 3 position in its quinoline ring, respectively, have been observed in multilamellar dispersions of the lipid mixture composed of phosphatidylcholine, phosphatidylserine, and phosphatidylethanolamine. 2H-NMR spectra of deuterated palmitic acids incorporated, as a probe, into the lipid mixture containing cholesterol have also been observed. An order parameter, SCD, for each carbon segment was calculated from the observed quadrupole splittings. Combining these results, we concluded that first, the butoxy group of dibucaine is penetrating between the acyl chains of lipids in the model membranes, and second, the quinoline ring of dibucaine is located at the polar region of lipids but not at the hydrophobic acyl chain moiety. These results mean that dibucaine is situated in a favorable position that permits it to interact with a cluster of hydrophobic amino acids (Ile-Phe-Met) within the intracellular linker between domains III and IV of Na+ channel protein, which functions as an inactivation gate. To confirm whether the dibucaine molecule at the surface region of lipids can really interact with the hydrophobic amino acids, we synthesized a model peptide that includes the hydrophobic amino acids (Ac-GGQDIFMTEEQK-OH, MP-1), the amino acid sequence of which corresponds to the linker part of rat brain type IIA Na+ channel, and the one in which Phe has been substituted by Gln (MP-2), and measured 1H-NMR spectra in both phosphate buffer and phosphatidylserine liposomes. It was found that the quinoline ring of dibucaine can interact with the aromatic ring of Phe by stacking of the rings; moreover, the interaction can be reinforced by the presence of lipids. In conclusion, we wish to propose that local anesthesia originates from the pi-stacking interaction between aromatic rings of an anesthetic molecule located at the polar headgroup region of the so-called boundary lipids and of the Phe in the intracellular linker between domains III and IV of the Na+ channel protein, prolonging the inactivated state and consequently making it impossible to proceed to the resting state.
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DOI：
10.1073/pnas.89.22.10910
发表时间：
1992-11-15
影响因子：
11.1
作者：
WEST, JW;PATTON, DE;CATTERALL, WA
通讯作者：
CATTERALL, WA
通过平衡 Ca2 结合检测共存的流体磷脂相：缺乏肽的 L α 和富含肽的 HII 相共存于短杆菌肽 A/磷脂分散体中。
影响因子：
2.9
作者：
Dibble,AR;Feigenson,GW
通讯作者：
Feigenson,GW
影响因子：
56.9
作者：
RAGSDALE, DS;MCPHEE, JC;CATTERALL, WA
通讯作者：
CATTERALL, WA
局部麻醉剂抑制[3H]箭毒毒素A 20-α-苯甲酸盐与钠通道的结合。
影响因子：
3.6
作者：
Postma,SW;Catterall,WA
通讯作者：
Catterall,WA