Effect of diaminopropionic acid (Dap) on the biophysical properties of a modified synthetic channel-forming peptide.
Effect of diaminopropionic acid (Dap) on the biophysical properties of a modified synthetic channel-forming peptide.
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二氨基丙酸 (Dap) 对修饰的合成通道形成肽生物物理特性的影响。
DOI：
10.1021/mp4002377
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发表时间：
2013
影响因子：
4.9
通讯作者：
Tomich,JohnM
中科院分区：
文献类型：
--
作者：
Bukovnik,Urska;Sala-Rabanal,Monica;Francis,Simonne;Frazier,ShawnaleaJ;Schultz,BruceD;Nichols,ColinG;Tomich,JohnM
通道替代疗法基于合成的通道形成肽(CFPs)，具有取代缺陷内源性离子通道的能力，是一种新的治疗模式，可能会加强对多种疾病的现有干预措施。以前，我们从甘氨酸受体M2GlyR的α亚单位的第二个跨膜片段中提取CFPs，它以其天然的形式形成氯选择通道。最佳候选者NK4-M2GlyR T19R，S22W(p22-T19R，S22W)是水溶性的，结合在细胞膜上，不具免疫原性，但缺乏组装成孔时的高电导和阴离子选择性的结构性质。进一步的研究表明，13、17和20位的苏氨酸残基排列在组装的p22-T19R，S22W的孔道上，在这里，我们使用2，3-二氨基丙酸(DAP)取代来向预测的p22-T19R，S22W通道的孔衬界面引入正电荷。Dap取代的p22-T19R、S22W多肽保留了其亲本多肽的α-螺旋二级结构特征，并在细胞顶膜上产生短路跨上皮电流；含有多个Dap取代残基的序列比含有单一Dap取代或没有Dap取代的多肽产生更大的电流。为了进一步了解Dap残基对孔道性质的影响，我们对暴露于p22-T19R、S22W或其Dap修饰类似物的Xenopus卵母细胞进行了双电极电压钳电生理学。我们观察到，DAP取代的多肽也比母体化合物诱导出明显更大的电压依赖电流，但当外部Na+、Cl-或K+被取代时，翻转电位没有明显变化，表明这些电流仍然是非选择性的。这些结果表明，在预测的孔衬残基中引入带正电的侧链并不能提高阴阳离子的选择性，但会导致较高的电导，这可能是由于较高的齐聚数所致。
Channel replacement therapy, based on synthetic channel-forming peptides (CFPs) with the ability to supersede defective endogenous ion channels, is a novel treatment modality that may augment existing interventions against multiple diseases. Previously, we derived CFPs from the second transmembrane segment of the α-subunit of the glycine receptor, M2GlyR, which forms chloride-selective channels in its native form. The best candidate, NK4-M2GlyR T19R, S22W (p22-T19R, S22W), was water-soluble, incorporated into cell membranes and was nonimmunogenic, but lacked the structural properties for high conductance and anion selectivity when assembled into a pore. Further studies suggested that the threonine residues at positions 13, 17, and 20 line the pore of assembled p22-T19R, S22W, and here we used 2,3-diaminopropionic acid (Dap) substitutions to introduce positive charges to the pore-lining interface of the predicted p22-T19R, S22W channel. Dap-substituted p22-T19R, S22W peptides retained the α-helical secondary structure characteristic of their parent peptide, and induced short-circuit transepithelial currents when exposed to the apical membrane of Madin-Darby canine kidney (MDCK) cells; the sequences containing multiple Dap-substituted residues induced larger currents than the peptides with single or no Dap substitutions. To gain further insights into the effects of Dap residues on the properties of the putative pore, we performed two-electrode voltage clamp electrophysiology onXenopusoocytes exposed to p22-T19R, S22W or its Dap-modified analogues. We observed that Dap-substituted peptides also induced significantly larger voltage-dependent currents than the parent compound, but there was no apparent change in reversal potential upon replacement of external Na+, Cl–or K+, indicating that these currents remained nonselective. These results suggest that the introduction of positively charged side chains in predicted pore-lining residues does not improve anion-to-cation selectivity, but results in higher conductance, perhaps due to higher oligomerization numbers.
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DOI：
--
发表时间：
1993
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Reddy,GL;Iwamoto,T;Tomich,JM;Montal,M
通讯作者：
Montal,M
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G. Gokel
跨膜肽序列的水溶解并保留膜插入和功能。
影响因子：
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作者：
Tomich,JM;Wallace,D;Henderson,K;Mitchell,KE;Radke,G;Brandt,R;Ambler,CA;Scott,AJ;Grantham,J;Sullivan,L;Iwamoto,T
通讯作者：
Iwamoto,T
影响因子：
2.4
作者：
Broughman, JR;Shank, LP;Mitchell, K
通讯作者：
Mitchell, K
不同链长的碱性两亲性 α 螺旋模型肽与磷脂双层的相互作用、离子通道的形成和抗菌活性。
影响因子：
4.8
作者：
Y. Agawa;S. Lee;S. Ono;H. Aoyagi;M. Ohno;T. Taniguchi;K. Anzai;Y. Kirino
通讯作者：
Y. Kirino