该项目由内布拉斯加州大学医学中心 (开办基金, MC) 资助;NIH-COBRE, 5P20GM103480 (t Bronich) 和美国化学学会, PRF 57434 号-DNI7 (MC S)。

1. PPAs 合成通用议定书
<ol><li>计算合成的尺度 (通常为毫摩尔)。此刻度基于目标 PPA 金额的质量。请记住, 随着氨基酸序列的增加, 许可证的反应效率逐渐降低。因此, 准确的反应效率是难以计算的。</li>
	<li>根据树脂的载荷计算出所用树脂的重量。装载在树脂的容器或分析协议被发现并且表达在毫摩尔/g。以下公式可用于计算树脂的重量:</li>
	<li>仔细权衡 2-chlorotrityl 氯树脂 (在我们的情况下, 负载是 ~ 0.85 毫摩尔)</li>
	<li>将树脂置于烧结合成容器中, 其规格如下: 容量-50 毫升, 烧结盘-25 毫米, 孔隙度-介质。</li>
	<li>向树脂中添加15毫升二氯甲烷 (DCM)。</li>
	<li>将合成容器粘贴到变速机械振动筛 (烧瓶式振动筛/搅拌器) 上, 并将容器转到45°角 (或水平) 以最大程度地搅拌。</li>
	<li>允许树脂珠膨胀15分钟, 提高反应的屈服率, 因为它有利于分子扩散和可进入活性部位, 提高耦合效率。</li>
	<li>将所需多胺 (胺、胺、Diethyelenetriamine、13丙烷等) 的8当量 (2 毫摩尔) 添加到树脂上, 并允许其对 5 h 进行反应。 注意: 一个较小的反应期会降低产量。</li>
	<li>做一个凯撒测试 (见材料表), 以确认多胺与树脂的成功耦合。主要胺的成功的联结产生紫罗兰色或蓝色, 对应于自由胺。</li>
	<li>用4当量 1-(44-二甲基-26-dioxocyclohex-1-ylidene) 乙酯 (Dde), 用无水甲醇 (15 毫升) 溶解, 通过摇动反应混合物过夜11, 保护原胺组。 注意: 较小的反应时间可以降低产量。</li>
	<li>执行凯撒测试。树脂珠没有蓝色, 证实了成功的保护。在未成功保护主胺的情况下, 重复上一步骤。</li>
	<li>用 dcm 和 DMF (2:1, 15 毫升) 的混合物将 dcm 排出并清洗两次树脂。</li>
	<li>在 DCM (20 毫升) 中溶解20当量 (5 毫摩尔) 二叔丁基二碳酸酯 (中行), 并允许反应进行 3 h。</li>
	<li>做一个四氯苯醌测试 (见材料表), 以确认对二胺的完全保护。阳性测试 (保护) 产生无色或浅黄色。游离二胺给出深绿色/蓝色, 而初级胺给出红色的颜色。</li>
	<li>将溶剂混合物排出, 用 DCM 和 DMF (2:1, 15 毫升) 的混合物清洗两次。</li>
	<li>加入2% 溶液的肼在 DMF (10 毫升) 和动摇1小时。</li>
	<li>做一个凯撒测试, 以确认成功脱的主胺。</li>
	<li>
在你写/画它们的相反顺序中加入所需的氨基酸。多肽是从 N 总站到 c 终点, 但在相反的方向合成, c 到 N。例如, 对于需要以下肽芯 GLFD 的苯丙醇, 添加天门冬氨酸 (D), 其次是苯丙胺 (F)、亮氨酸 (L), 最后是甘酸 (G)。 注: 对于大多数氨基酸, 以下偶联鸡尾酒适合于附着于多胺负载树脂。<ol>
<li>混合4当量 (1 毫摩尔) 的芴甲氧羰基保护氨基酸, 3.95 当量 2-(1 h-benzotriazol 1 基)-11, 33-tetramethyluronium hexaﬂuorophosphate (HBTU), 15 当量 diisopropylethyl 胺 (DIPEA)。</li>
		<li>将它们溶解在 DCM 和 DMF (1:1, 15 毫升) 的混合物中, 并将鸡尾酒油脂实验2分钟 (直到完全溶解)。</li>
		<li>等待额外的3–5分钟, 以确保羧酸在氨基酸上活化。</li>
		<li>将反应混合物添加到容器中。在室温下进行2-4 小时的反应。 注: 我们发现以下作为有效的替代 HBTU (通常需要较低数量的氨基酸和偶联剂): COMU, PyBOP, 哈图, DIC/Oxima。</li>
		<li>做一个凯撒测试, 以确认成功的耦合。</li>
		<li>在 DMF 中加入 4-甲基哌啶 (10 毫升) 的20% 溶液, 从氨基酸中脱去保护 n-芴甲氧羰基基团。做两次, 每次摇动反应混合物15分钟。 注: 一种高效的替代 n-芴甲氧羰基哌嗪/DBU12。<ol>
<li>在添加之间执行 DCM (15 毫升) 清洗。</li>
		</ol>
</li>
		<li>做一个凯撒测试, 以确认成功的脱保护氨基酸。</li>
		<li>彻底清洗树脂, 除去所有4甲基的痕迹。用 DMF (10 毫升) 清洗树脂两次, 每次洗涤持续5分钟, 最后用 DCM (10 毫升) 进行10分钟。</li>
		<li>通过连续重复耦合和脱保护步骤, 添加所有剩余的氨基酸。</li>
	</ol>
</li>
	<li>
最后, 将所有必需氨基酸耦合后, 将疏水尾与多胺-肽结构的最后一个氨基酸共轭:
	<ol>
<li>在 DCM 和 DMF 混合物 (1:1, 20 毫升) 中添加10个等价的所需羧酸功能到 9.5 HBTU 和12当量 DIPEA。 注意: 记住比一些尾巴可能需要不同比例的溶剂 (通常是 larger% 的 DCM) 或添加或其他溶剂, 如 n-methylpyrrolidone (NMP)。</li>
		<li>油脂实验鸡尾酒为5–10分钟直到溶解 (我们已经看到它需要更长的尾巴完全溶解), 并添加到容器。 注: 对于包含多个反应性站点的尾部, 在将它们耦合之前, 需要对其进行保护。</li>
		<li>执行这个反应 (耦合疏水尾巴) 至少5小时, 虽然它是可取的为最高的产量隔夜执行它。</li>
	</ol>
</li>
</ol>2. 固体支护中的苯丙醇裂解
这一步骤的目的是从树脂裂解苯丙醇, 并从氨基酸和多胺残渣中去除中银保护基团。
<ol><li>用 DMF (8 毫升2分钟) 和两次与 DCM (8 毫升, 每次5分钟) 洗涤树脂。在每次添加之前, 将溶剂从容器中排出。当最后一次清洗完成后, 在真空下干燥树脂15分钟。</li>
	<li>用以下混合物配比制备解乳液: 28:1: 1 三氟乙酸酸 (TFA): H2O: 三异丙硅烷 (小贴士)。使 15 毫升的鸡尾酒添加 14 毫升的 TFA , 0 . 5 毫升的 H2O 和 0 . 5 毫升的提示。</li>
	<li>在树脂中加入这个解裂液, 在室温下 2–4 h。</li>
	<li>在25或50毫升的圆底烧瓶中收集溶液。</li>
	<li>将 TFA 集中在真空中, 使用旋转蒸发器在减压的同时加热混合物在40°c (不超过55°c, 以避免分解的苯丙胺醇)。</li>
	<li>蒸发后, 将获得的 TFA 溶液 (滴状) 添加到含有无水冷醚 (15 毫升) 的圆底烧瓶中。这将立即沉淀苯丙醇。</li>
	<li>另外, 将无水冷醚 (5 毫升) 添加到 TFA 集中的原烧瓶中。</li>
	<li>油脂实验这个烧瓶, 以恢复额外的固体, 并结合以太解决方案从步骤2.6。 注: 转移吸管可以用小体积的 DCM 洗涤。避免在过程中引入 DMF, 因为它倾向于形成一种凝胶状物质。</li>
	<li>把烧瓶放在冰箱内, 让它过夜, 以最大限度地沉淀。</li>
	<li>采用烧结圆盘过滤漏斗, 通过真空过滤收集沉淀材料。理想的孔径是精细的或中等的。</li>
	<li>用冷乙醚 (5–10毫升) 冲洗两次沉淀, 以除去任何残留的有机物。</li>
</ol>3. 使用 MALDI 干滴法鉴别原油产品
<ol><li>
正态分析的矩阵准备:
	<ol>
<li>用基质辅助激光解吸/电离 (MALDI) 质谱法开始分子量分析, 在离心管中加入10到20毫克的α氰基 4-肉桂酸。</li>
		<li>添加一个溶液的水/乙腈 (1:1, 1.0 毫升) 与0.1% 三氟乙酸酸 (TFA)。彻底混合涡流。 注: 该基质应用于正电荷肽。MALDI 负模式相似, 但需要一个含有0.1% 氨的 9-氨基吖啶的基质作为溶剂添加剂。</li>
		<li>将样品的µL 添加到不锈钢靶板上 MALDI, 并在空气中干燥样品。添加µL 的矩阵, 并再次干燥。 注意: 板块有圆形标记网格化沿目标板, 以帮助找到特定的地点。</li>
	</ol>
</li>
	<li>分析 MALDI 仪器中的样品以验证其身份。电喷雾电离 (ESI) 是确认 PPAs 身份的有效方法。</li>
</ol>4. 用制备反相高效液相色谱 (HPLC) 纯化 PPAs
<ol><li>
在最小的乙腈和水中溶解苯丙醇沉淀。
	<ol>
<li>作为经验法则, 在不到5毫升的乙腈和水中溶解100毫克的干粗苯丙醇。由于 PPAs 的净电荷 (表 1), 更多的疏水性 PPAs 可能需要更大比例的乙腈溶解, 而且可能还需要更大的溶剂量。</li>
		<li>如果完全溶解不发生, 增加 1% TFA (ACN 或 H2O)。还可以添加微量的其他相容溶剂, 包括 dimethylsulfoxide, 甲醇, 或异丙醇 (限制其内容为 5%)。</li>
	</ol>
</li>
</ol><table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody>
<tr>
<td>溶剂</td>
			<td colspan="2">正电荷 PPAs</td>
			<td colspan="2">负电荷 PPAs</td>
		</tr>
<tr>
<td></td>
			<td colspan="2">0.1% TFA 在水中</td>
			<td colspan="2">0.1% NH3在水中</td>
		</tr>
<tr>
<td></td>
			<td colspan="2">0.1% TFA 在 ACN</td>
			<td colspan="2">0.1% NH3在 ACN</td>
		</tr>
</tbody></table>表 1: 溶剂系统.提出了带正电和负电荷 PPAs 的溶剂体系。
<ol start="2"><li>油脂实验使用一个喇叭 sonicator 20 分钟在十年代脉冲与 Amp1 48% 或2-3 小时的超声浴。</li>
	<li>
然后, 过滤器使用0.45 微米注射器过滤器, 然后过滤使用0.20 微米聚四氟乙烯 (PTFE) 注射器过滤器。苯丙醇溶液应清楚, 不含所有微粒材料。
	<ol>
<li>如果过滤太难, 油脂实验长一段时间。强烈建议, 在注射器过滤后立即纯化苯丙胺醇溶液, 因为长时间贮存可能导致其聚合或 gelate, 这将需要重新超声波, 或许还要重新过滤。</li>
	</ol>
</li>
	<li>在纯化过程中和之后, 使用 HPLC 级溶剂或通过0.25 微米注射器过滤器/膜过滤的一种。 注: 净化 PPAs 最常见的溶剂条件为 H2O 和 ACN 的梯度。</li>
	<li>使用标准的反相色谱仪对该协议。它应该包括一个洗脱梯度程序员, 二进制溶剂交付系统, 一个紫外线探测器能够检测到220和 254 nm, 和可编程分数收集器。最大流量应为50毫升/分。</li>
	<li>使用 C-18 反相柱进行分离。以下尺寸的列可以根据固体被提纯的质量和 PPA 的净电荷 (表 2) 来使用。</li>
</ol><table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody>
<tr>
<td>苯丙醇充电</td>
			<td>粒度</td>
			<td>列大小</td>
			<td>粗苯丙醇质量</td>
		</tr>
<tr>
<td>+ ve 收费</td>
			<td>5微米</td>
			<td>150 x 30 毫米</td>
			<td>170毫克</td>
		</tr>
<tr>
<td>ve 收费</td>
			<td>5微米</td>
			<td>150 x 30 毫米</td>
			<td>170毫克</td>
		</tr>
<tr>
<td>+ ve 收费</td>
			<td>5微米</td>
			<td>150 x 21.2 毫米</td>
			<td>90毫克</td>
		</tr>
<tr>
<td>ve 收费</td>
			<td>5微米</td>
			<td>150 x 21.2 毫米</td>
			<td>90毫克</td>
		</tr>
</tbody></table>表 2: 建议的列:C18 反相色谱柱的柱尺寸、粒径和每注入最大承载能力
<ol start="7"><li>将该列的容量和 hplc 的注入回路体积确定的容积注入 PPA。根据表 3中所见的设置 (40 分钟的洗脱时间) 运行 HPLC 梯度法。</li>
</ol><table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody>
<tr>
<td>时间</td>
			<td>溶剂 A (乙腈)</td>
			<td>溶剂 B (水)</td>
			<td>流量 (毫升/分钟)</td>
		</tr>
<tr>
<td>0</td>
			<td>5%</td>
			<td>95%</td>
			<td rowspan="5">流速取决于柱填料及其尺寸。</td>
		</tr>
<tr>
<td>2</td>
			<td>5%</td>
			<td>95%</td>
		</tr>
<tr>
<td>35</td>
			<td>95%</td>
			<td>5%</td>
		</tr>
<tr>
<td>38</td>
			<td>100%</td>
			<td>0%</td>
		</tr>
<tr>
<td>40</td>
			<td>5%</td>
			<td>95%</td>
		</tr>
</tbody></table>表 3: 建议的渐变:建议的反相梯度显示了一段时间内水与乙腈的相对组成。流量将取决于列规格。
<ol start="8"><li>
分析使用 MALDI 在各种试管中收集的分数, 并确定哪些管 (或管) 含有苯丙醇。这是通过研究每管中发现的分子量来评估的。
	<ol>
<li>在分析 HPLC 上检查分数的纯度。采用高效液相色谱-梯度系统, 配以 220 nm 的紫外线探测器。</li>
		<li>如果有杂质, 做一个额外的循环纯化的 hplc。上述梯度用于制备高效液相色谱法, 可以用柱形变换器在线软件对其进行降阶分析。每一个分数都是≥95% 纯的物理表征或生物评价。</li>
	</ol>
</li>
	<li>收集在一个大的圆底瓶或蒸发瓶的分数, 并删除所有的乙腈和大部分的水。最终的 PPA 溶液不应超过10毫升。</li>
	<li>把这个浓缩物转移到50毫升离心管上。请注意, PPAs 是洗涤剂类物质;因此, 在溶剂蒸发过程中会产生气泡。我们发现添加乙醇会减少气泡的形成。</li>
	<li>真空浓缩精矿。在真空蒸发过程中, 大量的苯丙醇可能附着在容器的壁上。通过用高效液相色谱水反复冲洗烧瓶壁来恢复。浓缩的苯丙醇和 rinsate 的复合体积不应超过30毫升。</li>
	<li>将水溶液放入50毫升管内。</li>
	<li>
在液氮中, 这种苯丙醇溶液的闪光冻结: 注: 闪光冷冻会导致更小的冰晶, 在冻干机中会更快地升华。此外, 较慢的冰冻可能允许形成自组装的超分子结构。另一种选择 (但不太可取) 是逐步冻结在-80 °c 冷冻机或冻结使用干冰 + 丙酮混合物<ol>
<li>在将离心管放置在冻干机中之前, 穿孔或松开管帽以允许湿气逸出样品并收集在制冷装置中。将冻干装置设置为-54 °c 和0.016 毫巴。 注: 另一种选择是卸下瓶盖, 并将擦拭 (带橡皮筋) 放在开口顶部。此外, 我们发现, 冻结样品的角度或打破冰成小的部分, 可以更快, 更好地冻干, 由于增加的表面积。</li>
		<li>如果固体开始融化, 这可能表明有机溶剂的痕迹 (通常是乙腈) 存在。重复冷冻步骤, 评估冻干的条件。</li>
		<li>如果熔化仍然存在, 有两个潜在的解决方案:<ol>
<li>将样品分成两部分 (放在管子里), 稀释水, 再冷冻。不要经常使用这个溶液, 因为大量的有机溶剂会损坏设备。</li>
			<li>或者, 将样品放在烧瓶中, 在真空下进一步蒸发有机溶剂。冻干液体形式的样品通常会导致苯丙醇化合物的碰撞和损失。</li>
		</ol>
</li>
	</ol>
</li>
</ol>5. PPAs 的储存
<ol><li>将 PPAs 放在-20 摄氏度, 将瓶盖拧紧, 用适当的标签将 Parafilm 密封在管子上。</li>
	<li>使用前, 将苯丙醇恢复到真空室的室温, 以避免 PPAs 上的水蒸气凝结。</li>
</ol>

<ol><li>Cui, H., Pashuck, E. T., Velichko, Y. S., Weigand, S. J., Cheetham, A. G., Newcomb, C. J., Stupp, S. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Spontaneous+and+x-ray-triggered+crystallization+at+long+range+in+self-assembling+filament+networks%5BTitle%5D)+AND+%22Science%22%5BJournal%5D)">Spontaneous and x-ray-triggered crystallization at long range in self-assembling filament networks.</a> Science. 327, 555-559 (2010).</li>
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<li>Stupp, S. I., Zha, R. H., Palmer, L. C., Cui, H., Bitton, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Self-assembly+of+biomolecular+soft+matter%5BTitle%5D)+AND+%22Faraday+Discussions%22%5BJournal%5D)">Self-assembly of biomolecular soft matter.</a> Faraday Discussions. 166, 9-30 (2013).</li>
<li>Conda-Sheridan, M., Lee, S. S., Preslar, A. T., Stupp, S. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Esterase-activated+release+of+naproxen+from+supramolecular+nanofibres%5BTitle%5D)+AND+%22Chemical+Communications%22%5BJournal%5D)">Esterase-activated release of naproxen from supramolecular nanofibres.</a> Chemical Communications. 50, 13757-13760 (2014).</li>
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<li>Nel, A. E., Mädler, L., Velegol, D., Xia, T., Hoek, E. M., Somasundaran, P., Klaessig, F., Castranova, V., Thompson, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Understanding+biophysicochemical+interactions+at+the+nano-bio+interface%5BTitle%5D)+AND+%22Nature+Materials%22%5BJournal%5D)">Understanding biophysicochemical interactions at the nano-bio interface.</a> Nature Materials. 8, 543(2009).</li>
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<li>Planas-Portell, J., Gallart, M., Tiburcio, A. F., Altabella, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Copper-containing+amine+oxidases+contribute+to+terminal+polyamine+oxidation+in+peroxisomes+and+apoplast+of+Arabidopsis+thaliana%5BTitle%5D)+AND+%22BMC+Plant+Biology%22%5BJournal%5D)">Copper-containing amine oxidases contribute to terminal polyamine oxidation in peroxisomes and apoplast of Arabidopsis thaliana.</a> BMC Plant Biology. 13, 109(2013).</li>
<li>Nash, I. A., Bycroft, B. W., Chan, W. C. <a target="_blank" href="https://www.sciencedirect.com/science/article/pii/0040403996003449">Dde - A selective primary amine protecting group: A facile solid phase synthetic approach to polyamine conjugates.</a> Tetrahedron Letters. 37, 2625-2628 (1996).</li>
<li>Ralhan, K., KrishnaKumar, V. G., Gupta, S. <a target="_blank" href="http://pubs.rsc.org/en/content/articlelanding/2015/ra/c5ra23441g">Piperazine and DBU: a safer alternative for rapid and efficient Fmoc deprotection in solid phase peptide synthesis.</a> RSC Advances. 5, 104417-104425 (2015).</li>
<li>Casero, R. A. Jr, Marton, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Targeting+polyamine+metabolism+and+function+in+cancer+and+other+hyperproliferative+diseases%5BTitle%5D)+AND+%22Nature+Reviews+Drug+Discovery%22%5BJournal%5D)">Targeting polyamine metabolism and function in cancer and other hyperproliferative diseases.</a> Nature Reviews Drug Discovery. 6, 373(2007).</li>
<li>Wuts, P. G. M., Greene, T. W. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aWuts%2C+PGM+%22Protection+for+the+Amino+Group.+In+Greene%27s+Protective+Groups+in+Organic+Synthesis%22">Protection for the Amino Group. In Greene's Protective Groups in Organic Synthesis</a>. , John Wiley &, Sons, Inc. 696-926 (2006).</li>
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作者没有利益冲突申报

这里描述的协议可以用来合成 PPAs 作为 PAs 和相关的肽基分子 (如混合 peptoids)。虽然使用许可证合成肽是一个简单的过程, 但合成含有生物自导分子的肽尤其具有挑战性。多胺如胺、胺、diethyelenetriamine等, 可作为靶向分子定位于肿瘤细胞13。PPAs 可以自组装成具有不同形貌的纳米结构6。他们的正电荷还可以帮助更长的循环时间 (由于细胞膜逃逸) 和不同的代谢剖面 (与传统 PA 相比)。然而, 合成 PPAs 及其类似物可能是一个特殊的挑战, 因为存在的主要和次要胺。通过对正交保护群的合理使用, 提出了综合策略, 克服了这一挑战。Dde 分子有选择地仅发生反应与主要胺11。另一方面, 中行不加区别地与主要和次要胺反应, 因此, 只能添加后, 主胺被保护。我们想指出的是, 其他保护团体可以代替中银使用。例如, 与醋酸酐的反应将永久 acetylate 二胺 (这个组不会被去除在分裂期间)。同样, 使用 trifluoacetic 酸酐将提供一个基敏感的保护, 而 benzylcarbamate 将给一个组, 可以被删除2/镍14。一旦多胺得到了必要的保护, 苯丙醇的合成可以使用标准许可证进行。疏水尾与多胺肽结构其余部分的耦合不仅需要较长的时间, 而且还需要两次氨基酸的摩尔量。有些疏水性的尾巴可能不会在室温下溶解在一些传统的溶剂中, 或者即使在最初溶解后也可能沉淀。这种反应最好是在轻度加热 (40 摄氏度) 的情况下, 将所有的反应物转移到圆底烧瓶中。另外, 套包合成器容器可能被用来保持反应物的温暖。如果可用, 微波合成器可以帮助与耦合15。
虽然许多形式的质谱可以用来确定 PPAs 的质量, 但我们使用 MALDI 光谱学来鉴定。我们发现 MALDI 能更有效地产生分子离子峰, 最大限度地减少碎片和加成物的形成。MALDI 应该被编程生成一个与苯丙醇最可能的电离状态相对应的离子。除了编程的仪器, 以产生特定电荷的离子, 我们还需要结合的适当矩阵, 适合我们将使用的模式。
PAs 通常倾向于在 MALDI 板上形成盐加合物。这个问题经常被带负电荷的分子所看到。最常见的盐是那些钠 (Na+ = 23 da) 和钾 (钾+ = 39 da)。这些加合物可以通过加入µL 乙酸来抑制。PPAs 通常提供 H+加成。建议只使用纳米水或高效液相色谱水在整个合成和纯化过程中, 避免引入额外的离子。硼硅酸盐玻璃容器和反应容器可能含有相当数量的钠离子, 将浸入最终产品。用 nanopurewater 冲洗玻璃器皿, 最后清洗。
如果基质溶液不能完全饱和于固体基质, 则识别分子离子峰也变得困难。为了确保饱和, 应该总是有少量的固体矩阵, 没有可溶性。
作为最后的说明, 请考虑一些 PPAs 或 PAs 可能不会形成任何沉淀后添加醚。这主要是观察到更亲水性的 PPAs。在这种情况下, 我们将首先蒸发所有醚, 中和过剩的 TFA 与 NH4oh, 并添加水和乙腈 (与 0.1% TFA 或 NH4OH), 以充分溶解, 然后进行净化照常。
本文所描述的协议可用于合成自组装多胺基多肽 amphiphiles (PPAs) 的高度纯变异体和 PAs。正交保护/脱步骤可用于其他情况下, 需要选择性掩蔽的主要和二胺组。

自组装肽 amphiphiles (PAs) 是一类生物材料, 通常由以下部分组成: (a) 亲水性头, (b) 链接器区域, (c) 疏水尾。文献中描述的大多数 PAs 具有亲水性的头, 由带电或极性氨基酸残留物1,2,3,4组成。PAs 已经在生物医学中发现了广泛的应用, 包括药物传递, 疾病诊断, 再生医学等5。在氨基酸序列的基础上, PAs 可以形成各种各样的纳米结构, 包括球形胶束和纳米丝。我们最近报告了一类混合多胺基肽 amphiphiles, 称为 PPAs6。这些生物材料的形貌、自组装动力学和代谢降解都与它们的溶出头组有关。此外, 苯丙醇纳米结构并没有对哺乳动物细胞 (MiaPaCa2 和 HeLa 细胞系) 在经过测试的浓度上表现出毒性。基于苯丙醇的 nanocarriers 是有吸引力的药物运载工具, 因为: (1) 多胺的摄取和新陈代谢已被证明在癌细胞中增加, (2) 阳离子纳米结构可以实现细胞膜逃逸7,8,这导致细胞内的循环和居住更高, (3) 与 PA 相比, 它们应该具有明显的代谢剖面;例如, 它们会更稳定地朝向人体内发现的蛋白酶 (尽管它们可能对其他酶 (如胺氧化酶)9,10敏感。此外, PPAs 已经发现有不同的形态, 物理化学性质, 纳米颗粒的硬度, 和组装动力学取决于不同的长度和电荷的单个 PPA 分子6。在这里, 我们描述了一个详细的协议, 以合成, 鉴定和纯化的 PPAs, 也可以用于制备 PAs 或类似的混合肽分子。
由于多胺在其受保护的形式中通常不具有商业用途, 而且由于保护多胺的主要和次级胺对共轭氨基酸和其他分子具有极其重要的意义, 我们概述了合成步骤, 以实现其保护。该协议的总体目标是提供一种简单的方法, 共轭多胺氨基酸。多胺缺乏羧酸基团;因此, 它们不能耦合到溜冰场酰胺或王树脂。相反, 建议合成协议的树脂, 如 2-chlorotrityl 氯。苯丙醇合成的主要挑战是初级和二胺功能基团的存在。为了我们的目的, 我们保护多胺中的所有次生胺, 同时保持基胺上的主要氨基基团自由地允许偶联反应。在固体相肽合成 (许可证) 原理的基础上, 对其进行了坚实的支持, 以促进每个耦合和脱步骤后的工作。下面的协议用于 PPAs 的手动和自动合成 (尽管在自动化系统中对某些步骤的验证将具有挑战性)。这些分子的合成也可以在自动合成器上进行, 或借助微波反应器 (自动或半自动) 进行。在图 1中总结了反应方案。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57908/57908fig1.jpg"> 图 1:(a) 合成 PPAs 的一般反应方案。(B) 可用于合成 PPAs 的代表性多胺。<a href="/files/ftp_upload/57908/57908fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

<table><tbody><tr><td>2-Chlorotrityl chloride resin&amp;nbsp;</td><td>AappTec</td><td>RTZ001</td><td></td></tr><tr><td>SynthwareTM synthesis vessel&amp;nbsp;</td><td>Aldrich</td><td>SYNP120050M</td><td></td></tr><tr><td>Dichloromethane</td><td>Acros</td><td>AC406920250</td><td>Fisher Sci. Catalogue #</td></tr><tr><td>Wrist Shaker</td><td>Boekel Scientific</td><td>401000-2</td><td></td></tr><tr><td>Kaiser test kit</td><td>Sigma-Aldrich</td><td>60017</td><td></td></tr><tr><td>2-[(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl-amino]-ethanol</td><td>Sigma-Aldrich</td><td>CDS004772</td><td></td></tr><tr><td>Anhydrous Methanol</td><td>Acros</td><td>AC610981000</td><td>Fisher Sci. Catalogue #</td></tr><tr><td>Chloranil test kit</td><td>TCI</td><td>TCC1771-KIT</td><td>VWR Catalogue #</td></tr><tr><td>Di-tert butyl di-carbonate&amp;nbsp;</td><td>Acros</td><td>AC194670250</td><td>Fisher Sci. Catalogue #</td></tr><tr><td>Dimethylformamide</td><td>Fisher Scientific</td><td>BP1160-4</td><td></td></tr><tr><td>Hydrazine</td><td>Acros</td><td>AC296815000</td><td>FIsher Sci. Catalogue #</td></tr><tr><td>(2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate)</td><td>p3biosystems</td><td>31001</td><td></td></tr><tr><td>4-methyl piperidine&amp;nbsp;</td><td>Acros</td><td>AC127515000</td><td>FIsher Sci. Catalogue #</td></tr><tr><td>Trifluoroacetic Acid</td><td>AappTec</td><td>CXZ035</td><td></td></tr><tr><td>Triisopropyl Silane</td><td>Sigma-Aldrich</td><td>233781</td><td></td></tr><tr><td>Ether</td><td>Fisher Scientific</td><td>E138-1</td><td></td></tr><tr><td>&amp;alpha;-Cyano-4-hydroxycinnamic acid</td><td>Sigma-Aldrich</td><td>C8982</td><td></td></tr><tr><td>9-Aminoacridine</td><td>Sigma-Aldrich</td><td>92817</td><td></td></tr><tr><td>Fisherbrand&amp;nbsp;Syringe Filters: PTFE Membrane</td><td>Fisher Scientific</td><td>09-730-21</td><td></td></tr></tbody></table>

facile protocol for the synthesis of self-assembling polyamine-based peptide amphiphiles (ppas) and related biomaterials

多胺基多肽 Amphiphiles (PPAs) 是一种新型的自组装的两亲性生物材料-与肽 Amphiphiles (PAs) 有关。传统的 PAs 有被充电的氨基酸作为溶出的小组 (赖氨酸, 精氨酸), 直接地连接到油脂片断或可能包含由中性氨基酸制成的链接器区域。调谐肽序列的 PAs 可以产生不同的形态。同样, PPAs 具有疏水性段和中性氨基酸, 但也含有多胺分子作为溶水 (亲水性) 基团。与 PAs 的情况一样, PPAs 也可以自组装成不同的形貌, 包括小棒, 扭曲纳米带, 和熔融纳米片, 当溶解在水中。然而, 在单个多胺分子上存在主要和次要胺, 在合成 PPAs 时会带来重大挑战。在本文中, 我们展示了一个简单的协议, 基于文献先例, 以实现一个简便的合成 PPAs 使用固相肽合成 (许可证)。该议定书可扩展到考绩制度和其他类似系统的综合。我们还说明了从树脂, 鉴定和纯化所需的步骤。

在合成纯化后, 在理化或生物评价之前, 建议 PPAs 的质量进行重新检查, 用解析 HPLC 法确定纯度。对于材料表征或生物评价, PPAs 需要纯度 > 95%。图 2显示了 HPLC 示踪 (顶端) 和 MALDI 光谱 (底部) 确认产品的存在。高效液相色谱分析系统将整合曲线下的区域 (联合自卫队), 联合自卫 > 95% 可与产品纯度相关。在紫外基高效液相色谱系统中, 期望看到一个单一的, 尖峰。MALDI 谱应与±1中苯丙醇的计算分子量相对应 (取决于 MALDI 的分析模式)。
PPAs 的自组装可以通过多种技术进行可视化和分析, 包括透射电镜 (图 3A、B)、原子力显微镜 (AFM) (图 3C、D)、小角度 x 射线散射 (SAXS), 扫描电子显微镜 (SEM) 和动态光散射 (dl)。成功的自组装将在 AFM 和 TEM 中产生良好定义的纳米结构。如果不进行自组装, 就会形成数以百纳米的不规则骨料。
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/57908/57908fig2.jpg"> 图 2: 苯丙醇 C16V22胺的代表性分析高效液相色谱 (顶部) 和 MALDI 谱 (下).这一数字已从 Samad等20176修改;在约翰威利 & 儿子的允许下重用, 2018。<a href="/files/ftp_upload/57908/57908fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/57908/57908fig3.jpg"> 图 3: 具有代表性的透射电镜 (TEM) 显微图像.(a) 透射电镜图像显示碳纤维和熔融薄片的形成, (B) 放大的嵌入显示捆绑的纳米片的形成, (C) 原子力显微镜 (AFM) 显微照相, (D) 和高度图从显微图像为 C16V2A2KDiethyelenetriamine。(D) 的 X 和 Y 轴分别代表纳米片宽和纳米片高度。这一数字已从 Samad等20176修改;在约翰威利 & 儿子的允许下重用, 2018。<a href="/files/ftp_upload/57908/57908fig3large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

Watch this Scientific Journal Video about Facile Protocol for the Synthesis of Self-assembling Polyamine-based Peptide Amphiphiles PPAs and Related Biomaterials at JoVE.com

Facile Protocol for the Synthesis of Self-assembling Polyamine-based Peptide Amphiphiles PPAs and Related Biomaterials

多胺基肽 amphiphiles (PPAs) 的合成是一个重要的挑战, 由于存在多种胺氮, 这需要明智地使用保护组来掩盖这些反应功能。本文介绍了一种简便的制备这些新型自组装分子的方法。

自组装多胺基多肽 Amphiphiles (PPAs) 及相关生物材料的简易合成协议

Polyamine-based Peptide Amphiphiles (PPAs) are a new class of self-assembling amphiphilic biomaterials-related to the peptide amphiphiles (PAs). ...

facile-protocol-for-synthesis-self-assembling-polyamine-based-peptide

Nanyang Technological University

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JoVE Journal

Chemistry

Facile Protocol for the Synthesis of Self-assembling Polyamine-based Peptide Amphiphiles (PPAs) and Related Biomaterials

8.0K 次观看.  University of Nebraska Medical Center. 多胺基肽 amphiphiles (PPAs) 的合成是一个重要的挑战, 由于存在多种胺氮, 这需要明智地使用保护组来掩盖这些反应功能。本文介绍了一种简便的制备这些新型自组装分子的方法。

视频: Facile Protocol for the Synthesis of Self-assembling Polyamine-based Peptide Amphiphiles PPAs and Related Biomaterials

An Efficient Method for the Synthesis of Peptoids with Mixed Lysine-type/Arginine-type Monomers and Evaluation of Their Anti-leishmanial Activity

This protocol describes the manual solid-phase synthesis of linear peptoids that contain two differently functionalized cationic monomers. In this procedure amino functionalized 'lysine' and guanido functionalized 'arginine' peptoid monomers can be included within the same peptoid sequence. This procedure uses on-resin (N-(1-(4,4-dimethyl-2,6-dioxocyclohexylidene)ethyl) or Dde protection, orthogonal conditions to the Boc protection of lysine monomers. Subsequent deprotection allows an efficient on-resin guanidinylation reaction to form the arginine residues. The procedure is compatible with the commonly used submonomer method of peptoid synthesis, allowing simple peptoids to be made using common laboratory equipment and commercially available reagents. The representative synthesis, purification and characterization of two mixed peptoids is described. The evaluation of these compounds as potential anti-infectives in screening assays against Leishmania mexicana is also described. The protozoan parasite L. mexicana is a causative agent of cutaneous leishmaniasis, a neglected tropical disease that affects up to 12 million people worldwide.

A protocol to synthesize peptoids with mixed cationic functionality in the same sequence is presented (lysine- and arginine-type monomers). Subsequent testing of these compounds against Leishmania mexicana, the protozoan parasites that cause cutaneous leishmaniasis, is also described.

对于拟肽与他们抗利什曼原虫活性混合赖氨酸型/精氨酸型单体及评价合成的有效方法

This protocol describes the manual solid-phase synthesis of linear peptoids that contain two differently functionalized cationic monomers. In this ...

科研

生物化学

Formation of Ordered Biomolecular Structures by the Self-assembly of Short Peptides

In nature, complex functional structures are formed by the self-assembly of biomolecules under mild conditions. Understanding the forces that control self-assembly and mimicking this process in vitro will bring about major advances in the areas of materials science and nanotechnology. Among the available biological building blocks, peptides have several advantages as they present substantial diversity, their synthesis in large scale is straightforward, and they can easily be modified with biological and chemical entities1,2. Several classes of designed peptides such as cyclic peptides, amphiphile peptides and peptide-conjugates self-assemble into ordered structures in solution. Homoaromatic dipeptides, are a class of short self-assembled peptides that contain all the molecular information needed to form ordered structures such as nanotubes, spheres and fibrils3-8. A large variety of these peptides is commercially available.
This paper presents a procedure that leads to the formation of ordered structures by the self-assembly of homoaromatic peptides. The protocol requires only commercial reagents and basic laboratory equipment. In addition, the paper describes some of the methods available for the characterization of peptide-based assemblies. These methods include electron and atomic force microscopy and Fourier-Transform Infrared Spectroscopy (FT-IR). Moreover, the manuscript demonstrates the blending of peptides (coassembly) and the formation of a &#34;beads on a string&#34;-like structure by this process.9 The protocols presented here can be adapted to other classes of peptides or biological building blocks and can potentially lead to the discovery of new peptide-based structures and to better control of their assembly.

This paper describes the formation of highly ordered peptide-based structures by the spontaneous process of self-assembly. The method utilizes commercially available peptides and common lab equipment. This technique can be applied to a large variety of peptides and may lead to the discovery of new peptide-based assemblies.

生物分子有序结构由短肽的自组装形成

In nature, complex functional structures are formed by the self-assembly of biomolecules under mild conditions. Understanding the forces that control ...

化学

Split-and-pool Synthesis and Characterization of Peptide Tertiary Amide Library

Peptidomimetics are great sources of protein ligands. The oligomeric nature of these compounds enables us to access large synthetic libraries on solid phase by using combinatorial chemistry. One of the most well studied classes of peptidomimetics is peptoids. Peptoids are easy to synthesize and have been shown to be proteolysis-resistant and cell-permeable. Over the past decade, many useful protein ligands have been identified through screening of peptoid libraries. However, most of the ligands identified from peptoid libraries do not display high affinity, with rare exceptions. This may be due, in part, to the lack of chiral centers and conformational constraints in peptoid molecules. Recently, we described a new synthetic route to access peptide tertiary amides (PTAs). PTAs are a superfamily of peptidomimetics that include but are not limited to peptides, peptoids and N-methylated peptides. With side chains on both &#945;-carbon and main chain nitrogen atoms, the conformation of these molecules are greatly constrained by sterical hindrance and allylic 1,3 strain. (Figure 1) Our study suggests that these PTA molecules are highly structured in solution and can be used to identify protein ligands. We believe that these molecules can be a future source of high-affinity protein ligands. Here we describe the synthetic method combining the power of both split-and-pool and sub-monomer strategies to synthesize a sample one-bead one-compound (OBOC) library of PTAs.

Peptide tertiary amides (PTAs) are a superfamily of peptidomimetics that include but are not limited to peptides, peptoids and N-methylated peptides. Here we describe a synthetic method which combines&#160;both split-and-pool and sub-monomer strategies to synthesize a one-bead one-compound library of PTAs.

分裂和池合成及肽叔酰胺图书馆表征

Peptidomimetics are great sources of protein ligands. The oligomeric nature of these compounds enables us to access large synthetic libraries on solid ...

Solid-phase Submonomer Synthesis of Peptoid Polymers and their Self-Assembly into Highly-Ordered Nanosheets

Peptoids are a novel class of biomimetic, non-natural, sequence-specific heteropolymers that resist proteolysis, exhibit potent biological activity, and fold into higher order nanostructures. Structurally similar to peptides, peptoids are poly N-substituted glycines, where the side chains are attached to the nitrogen rather than the alpha-carbon. Their ease of synthesis and structural diversity allows testing of basic design principles to drive de novo design and engineering of new biologically-active and nanostructured materials.
Here, a simple manual peptoid synthesis protocol is presented that allows the synthesis of long chain polypeptoids ( up to 50mers) in excellent yields. Only basic equipment, simple techniques (e.g. liquid transfer, filtration), and commercially available reagents are required, making peptoids an accessible addition to many researchers' toolkits. The peptoid backbone is grown one monomer at a time via the submonomer method which consists of a two-step monomer addition cycle: acylation and displacement. First, bromoacetic acid activated in situ with N,N'-diisopropylcarbodiimide acylates a resin-bound secondary amine. Second, nucleophilic displacement of the bromide by a primary amine follows to introduce the side chain. The two-step cycle is iterated until the desired chain length is reached. The coupling efficiency of this two-step cycle routinely exceeds 98% and enables the synthesis of peptoids as long as 50 residues. Highly tunable, precise and chemically diverse sequences are achievable with the submonomer method as hundreds of readily available primary amines can be directly incorporated.
 
Peptoids are emerging as a versatile biomimetic material for nanobioscience research because of their synthetic flexibility, robustness, and ordering at the atomic level. The folding of a single-chain, amphiphilic, information-rich polypeptoid into a highly-ordered nanosheet was recently demonstrated. This peptoid is a 36-mer that consists of only three different commercially available monomers: hydrophobic, cationic and anionic. The hydrophobic phenylethyl side chains are buried in the nanosheet core whereas the ionic amine and carboxyl side chains align on the hydrophilic faces. The peptoid nanosheets serve as a potential platform for membrane mimetics, protein mimetics, device fabrication, and sensors. Methods for peptoid synthesis, sheet formation, and microscopy imaging are described and provide a simple method to enable future peptoid nanosheet designs.

A simple and general manual peptoid synthesis method involving basic equipment and commercially available reagents is outlined, enabling peptoids to be easily synthesized in most laboratories. The synthesis, purification and characterization of an amphiphilic peptoid 36mer is described, as well as its self-assembly into highly-ordered nanosheets.

固相Submonomer Peptoid聚合物及其自组装成高度有序的纳米片的合成

Peptoids are a novel class of biomimetic, non-natural, sequence-specific heteropolymers that resist proteolysis, exhibit potent biological activity, and ...

生物工程

Synthesis and Characterization of 1,2-Dithiolane Modified Self-Assembling Peptides

This report focuses on the synthesis of an N-terminus 1,2-dithiolane modified self-assembling peptide and the characterization of the resulting self-assembled supramolecular structures. The synthetic route takes advantage of solid-phase peptide synthesis with the on-resin coupling of the dithiolane precursor molecule, 3-(acetylthio)-2-(acetylthiomethyl)propanoic acid, and the microwave-assisted thioacetate deprotection of the peptide N-terminus before final cleavage from the resin to yield the 1,2-dithiolane modified peptide. After the high-performance liquid chromatography (HPLC) purification of the 1,2-dithiolane peptide, derived from the nucleating core of the A&#946; peptide associated with Alzheimer&#39;s disease, the peptide is shown to self-assemble into cross-&#946; amyloid fibers. Protocols to characterize the amyloid fibers by Fourier-transform infrared spectroscopy (FT-IR), circular dichroism spectroscopy (CD) and transmission electron microscopy (TEM) are presented. The methods of N-terminal modification with a 1,2-dithiolane moiety to well-characterized self-assembling peptides can now be explored as model systems to develop post-assembly modification strategies and explore dynamic covalent chemistry on supramolecular peptide nanofiber surfaces.

A protocol for the synthesis of a 1,2-dithiolane modified peptide and the characterization of the supramolecular structures resulting from the peptide self-assembly.

12-Dithiolane 改性自组装肽的合成与表征

This report focuses on the synthesis of an N-terminus 1,2-dithiolane modified self-assembling peptide and the characterization of the resulting ...

Synthesis of Information-bearing Peptoids and their Sequence-directed Dynamic Covalent Self-assembly

This protocol presents the use of Lewis acidic multi-role reagents to circumvent kinetic trapping observed during the self-assembly of information-encoded oligomeric strands mediated by paired dynamic covalent interactions in a manner mimicking the thermal cycling commonly employed for the self-assembly of complementary nucleic acid sequences. Primary amine monomers bearing aldehyde and amine pendant moieties are functionalized with orthogonal protecting groups for use as dynamic covalent reactant pairs. Using a modified automated peptide synthesizer, the primary amine monomers are encoded into oligo(peptoid) strands through solid-phase submonomer synthesis. Upon purification by high-performance liquid chromatography (HPLC) and characterization by electrospray ionization mass spectrometry (ESI-MS), sequence-specific oligomers are subjected to high-loading of a Lewis acidic rare-earth metal triflate which both deprotects the aldehyde moieties and affects the reactant pair equilibrium such that strands completely dissociate. Subsequently, a fraction of the Lewis acid is extracted, enabling annealing of complementary sequence-specific strands to form information-encoded molecular ladders characterized by matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). The simple procedure outlined in this report circumvents kinetic traps commonly experienced in the field of dynamic covalent assembly and serves as a platform for the future design of robust, complex architectures.

A protocol is presented for the synthesis of information-encoded peptoid oligomers and for the sequence-directed self-assembly of these peptoids into molecular ladders using amines and aldehydes as dynamic covalent reactant pairs and Lewis acidic rare-earth metal triflates as multi-role reagents.

信息承载Peptoids及其序列定向动态共价自组装的合成

This protocol presents the use of Lewis acidic multi-role reagents to circumvent kinetic trapping observed during the self-assembly of information-encoded ...

Constructing Cyclic Peptides Using an On-Tether Sulfonium Center

In recent years, cyclic peptides have attracted increasing attention in the field of drug discovery due to their excellent biological activities, and, as a consequence, they are now used clinically. It is, therefore, critical to seek effective strategies for synthesizing cyclic peptides to promote their application in the field of drug discovery. This paper reports a detailed protocol for the efficient synthesis of cyclic peptides using on-resin or intramolecular (intermolecular) bisalkylation. Using this protocol, linear peptides were synthesized by taking advantage of solid-phase peptide synthesis with cysteine (Cys) and methionine (Met) coupled simultaneously on the resin. Further, cyclic peptides were synthesized via bisalkylation between Met and Cys using a tunable tether and an on-tether sulfonium center. The whole synthetic route can be divided into three major processes: the deprotection of Cys on the resin, the coupling of the linker, and the cyclization between Cys and Met in a trifluoroacetic acid (TFA) cleavage solution. Furthermore, inspired by the reactivity of the sulfonium center, a propargyl group was attached to the Met to trigger thiol-yne addition and form a cyclic peptide. After that, the crude peptides were dried and dissolved in acetonitrile, separated, and then purified by high-performance liquid chromatography (HPLC). The molecular weight of the cyclic peptide was confirmed by liquid chromatography-mass spectrometry (LC-MS), and the stability of the cyclic peptide combination with the reductant was further confirmed using HPLC. In addition, the chemical shift in the cyclic peptide was analyzed by 1H nuclear magnetic resonance (1H NMR) spectra. Overall, this protocol aimed to establish an effective strategy for synthesizing cyclic peptides.

This protocol presents the synthesis of cyclic peptides via bisalkylation between cysteine and methionine and the facile thiol-yne reaction triggered by the propargyl sulfonium center.

使用系绳上的锍中心构建环肽

In recent years, cyclic peptides have attracted increasing attention in the field of drug discovery due to their excellent biological activities, and, as ...

<meta charset="utf8"></head><body> 肽水凝胶:ECF-5 的环境响应性凝胶化方法

Preparation of Mechanically Stable Self-Assembled Peptides Hydrogels

Peptide hydrogels are highly hydrophilic, three-dimensional network gels formed by the self-assembly of nanofibers or polymers, creating water-locking networks. Their morphology closely resembles that of the extracellular matrix, allowing them to exhibit both the biological functions of peptides and responsive gelation properties. These unique characteristics have led to their extensive application in tissue engineering, three-dimensional cell culture, cancer therapy, regenerative medicine, and other biomedical fields. This article describes three methods for preparing ECF-5 peptide hydrogels using self-assembling peptides with environmentally responsive gelation processes: (1) pH-responsive gelation: varying pH levels induce the protonation or deprotonation of amino acid residues, altering electrostatic interactions between peptide molecules and promoting their self-assembly into hydrogels; (2) Metal ion addition: polyvalent metal ions chelate with negatively charged amino acid residues, acting as bridges between peptides to form a network hydrogel; (3) Solvent exchange: hydrophobic peptides are initially dissolved in non-polar organic solvents and subsequently induce self-assembly into hydrogels upon transitioning to a polar aqueous environment. These methods utilize conventional experimental procedures to facilitate peptide self-assembly into hydrogels. By designing peptide sequences to align with specific gelation-inducing conditions, it is possible to achieve finely tuned micro/nanostructures and biological functions, highlighting the significant potential of peptide hydrogels in the biomedical domain.

<meta charset="utf8"></head><body>作者聚焦:改进自组装纤维和肽水凝胶的生产以获得卓越的生物相容性

This protocol presents three fast and simple preparation methods that use environmental conditions to trigger the self-assembly of peptides into hydrogels. Additionally, the characterization of peptide hydrogels is described, demonstrating that mechanically stable peptide hydrogels can be formed under these straightforward conditions.

机械稳定的自组装肽水凝胶的制备

Peptide hydrogels are highly hydrophilic, three-dimensional network gels formed by the self-assembly of nanofibers or polymers, creating water-locking ...

自组装多胺基多肽 Amphiphiles (PPAs) 及相关生物材料的简易合成协议

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信息承载Peptoids及其序列定向动态共价自组装的合成

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