这项工作得到了中国国家自然科学基金 (U1503223, 81673407, 21475131) 的资助, 浙江省非营利技术应用研究项目 (2016C37110), 宁波国际科技合作项目 (2014D10019)、宁波市生命科学与健康创新团队 (2015C110026)、宁波市科技 & 科技项目共同财富 (2017C50042)、李家和业杨厝港钦利海洋生物制药发展基金,宁波大学的肯塔基州金麦格纳基金。

1. 解决方案准备
注: 有关试剂来源, 请参阅材料表。
<ol><li>在100毫升的双蒸馏水中加入5克 bsa, 制备5% 牛血清白蛋白 (bsa) 溶液。涡流他们完全混合。将解决方案存储在摄氏4摄氏度, 最多1月。</li>
	<li>在 5% BSA 溶液的10毫升中加入10µL 抗体储存液, 制备抗低聚物抗体 A11 溶液 (1:1, 000)。涡流他们完全混合。将解决方案存储在摄氏4摄氏度, 最多1月。</li>
	<li>在10毫升 5% BSA 溶液中加入10µL 抗体库溶液, 制备抗 Aβ抗体6E10 溶液 (1:1, 000)。完全混合涡流。将解决方案存储在摄氏4摄氏度, 最多1月。</li>
	<li>制备抗纤维寡聚物抗体 OC 溶液 (1:1, 000), 添加10µL 抗体库溶液到10毫升 5% BSA 溶液。完全混合涡流。将解决方案存储在摄氏4摄氏度, 最多1月。</li>
	<li>在1000毫升的双蒸馏水中加入24克的三基和88克氯化钠, 制备三缓冲盐水 (TBS) 溶液。将 pH 值调整为7.4。将解决方案存储在摄氏4摄氏度, 长达3月。</li>
	<li>通过增加1毫升的 Tween-20 到100毫升的 Tween-20 溶液和900毫升的双蒸馏水, 准备一个三缓冲盐水和 TBST 溶液。</li>
	<li>通过添加10µL 辣根过氧化物酶 (HRP) 山羊抗兔 IgG (H + L) 到10毫升的 TBST 溶液, 制备二级抗体溶液。涡流他们完全混合。将解决方案存储在摄氏4摄氏度, 最多1月。</li>
	<li>在1毫升二甲基亚砜 (亚砜) 中溶解3.68 克姜黄素, 形成10毫米姜黄素溶液。</li>
	<li>溶解5毫克合成 Aβ1-42在2毫升 11, 13, 33-氟, 2-丙醇 (HFIP), 形成一个2.5 毫克/毫升 Aβ单体溶液。把它放在室温下 (25 °c) 20 分钟, 使100µL 整除数, 并存储在-20 摄氏度, 长达6月。 注意: 此过程应尽可能快地运行。应切断吸管的提示, 以确保准确的吹打。</li>
	<li>将 ecl 流体 a 和 B 混合, 制备出电化学发光 (ecl) 流体, 体积比为1:1。此解决方案应在使用前准备就绪。</li>
</ol>2. 样品准备
注: 在斑点印迹分析前2天进行样品准备。
<ol><li>将900µL 的双蒸馏水添加到 Aβ1-42单体溶液的管中;Aβ1-42的浓度将为0.25 毫克/毫升。将混合物室温放置20分钟。</li>
	<li>用高纯度的氮气蒸发溶液, 直到其体积约为850µL。Aβ1-42解决方案的浓度将约为0.29 毫克/毫升。 注意: 该解决方案应不时动摇, 以确保 HFIP 完全蒸发。通常, 在蒸发30分钟后, 剩余溶液的体积约为850µL。</li>
	<li>用双蒸馏水稀释姜黄素溶液, 以姜黄素工作溶液 (0.2 和2µM)。将 Aβ1-42解决方案和姜黄素工作解决方案混合在一起, 体积比为1:1。姜黄素的最终浓度将是0.1 和1µM。 注: 如果需要, 潜在的低聚物抑制剂可与 Aβ1-42解决方案混合使用。</li>
	<li>在磁力搅拌器中连续摇动溶液 (请参阅材料表)。<ol>
<li>将塑料分隔盒固定在磁力搅拌器上。在盒子的2个角落放置2个磁力搅拌棒, 将样品管放在盒子的中心。</li>
		<li>在室温下摇动盒子 (25 °c), 48 小时。 注: 磁力搅拌器的速度大约是 60 rpm。</li>
	</ol>
</li>
	<li>离心管15分钟在4°c 和 1.8万 x g. 收集上清。</li>
</ol>3. 斑点印迹分析
注: 所有孵化均在卧式振动筛上执行。
<ol><li>将硝化棉膜切成1厘米宽的长条。 注: 硝化棉膜的宽度可根据实验需要进行调整。</li>
	<li>2-µL 样品均匀地在2条 (条1和 2) 与每个点间隔在 0.5 cm。</li>
	<li>将小条放在室温下5分钟, 直到带上的水滴干燥。</li>
	<li>用 5% BSA 溶液在室温下孵化出30分钟的小条。</li>
	<li>在室温下用 TBST 溶液冲洗带5分钟。</li>
	<li>吸入 TBST 溶液。在室温下1小时, 孵育1的抗寡聚物抗体 A11 溶液和带2的抗 Aβ抗体6E10 溶液。</li>
	<li>用 TBST 溶液冲洗带三次, 每次室温5分钟。</li>
	<li>吸入 TBST 溶液。在室温下用二次抗体溶液孵化带40分钟。</li>
	<li>用 TBST 溶液冲洗带三次, 每次室温5分钟。</li>
	<li>将混合的 ECL 流体均匀地应用于带钢表面。在自动化学发光成像系统中暴露条纹 (请参阅材料表)。 注: 正常情况下, 300 µL 的 ECL 流体足以用于一膜。膜在暴露时必须保持湿润。曝光时间由成像系统自动计算。</li>
	<li>使用 ImageJ (国立卫生研究院) 或其他图像处理软件进行灰度分析, 以获得半定量结果。</li>
</ol>

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作者没有什么可透露的。

在本协议中, 我们报告了一种方法, 用于准备包含 Aβ1-42低聚物的样本, 并通过斑点印迹分析来分析 A11-positive Aβ1-42寡聚的数量。虽然我们的制备 Aβ1-42富聚物样品的方法非常简单、可靠、重现性好, 但仍有一些值得注意的点。首先, HFIP 用于溶解合成 Aβ1-42肽。聚合 Aβ1-42肽可以在 HFIP 溶液中分解成单体。但是, HFIP 容易挥发, HFIP 的粘度很低。因此, Aβ1-42</s...

阿尔茨海默病 (AD) 是影响全球老年人的最重要的神经退行性疾病之一1。普遍认为β淀粉样蛋白 (Aβ) 的异常聚集可能是 AD 的主要病理因子。Aβ骨料是老年斑块的主要成分, 是 AD 患者大脑中的生物学标志物之一。此外, Aβ聚集物, 特别是寡聚物, 产生强大的神经毒性, 这可能是导致神经元死亡的原因。因此, 抑制 Aβ寡聚物的形成可以防止变性, Aβ寡聚物抑制剂可作为 AD 的病害修饰处理。许多研究使用合成 Aβ肽在体外形成寡聚物, 探讨人工 Aβ寡聚的形貌和结构, 并利用体外模型2,3对 Aβ寡聚物的抑制剂进行研究。,4. 然而, 不同的体外形成协议的 Aβ寡聚物可能导致不同形态特征的聚类, 这可能导致不同研究组之间的不可比拟的结果。因此, 迫切需要一种标准的 Aβ齐聚物生成协议。
到目前为止, 还没有多少方法可以直接检测 Aβ寡聚物。透射电镜 (TEM)、非变性凝胶电泳、酶联免疫吸附试验 (ELISA) 和斑点印迹分析可用于检测 Aβ寡聚物的数量和/或形态学体外5,6. 例如, Aβ齐聚物的形态和结构可以在 TEM 中观察到。用非变性凝胶电泳法测定 Aβ聚合的相对含量和分子量。ELISA 可用于测定血清、血浆和脑组织提取物中的 Aβ寡聚体。最后, 斑点印迹分析, 一种用于检测、分析和识别蛋白质的技术, 可用于评价不同样品中 Aβ齐聚物的相对浓度, 并借助于寡聚特异性和 Aβ特异抗体。此外, 斑点印迹检测提供了大量的时间节省, 因为凝胶电泳和印迹程序的凝胶是不需要的。因此, 这种检测通常用于筛查潜在的 Aβ寡聚物抑制剂。本协议的总体目标是描述一种相对简单、可靠且可重现的方法, 用于准备 Aβ1-42富聚物的样本, 通过斑点印迹分析来分析 Aβ1-42低聚物的数量, 并筛选 Aβ寡聚使用半定量实验结果的抑制剂。

<table border="0" cellpadding="0" cellspacing="0" style="width:1159px;" width="1158">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">A11 (ab126892 Rb pAb to Amyloid Oligomers)</td>
			<td style="width:219px;">Abcam</td>
			<td style="width:211px;">GR91739-58</td>
			<td style="width:359px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">6E10 (beta-Amyloid Rabbit Ab)</td>
			<td>Cell&#160;Signalling Technology</td>
			<td>2454S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">OC (Anti-Amyloid Fibrils OC Antibody)</td>
			<td>Millipore</td>
			<td>AB2286</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Horseradish Peroxidase (HRP) Marker Goat anti rabbit IgG (H+L)&#160;</td>
			<td>Beyotime</td>
			<td>A0208</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">A&#946;1-42</td>
			<td>GL Biochem</td>
			<td>52487</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1,1,1,3,3,3-Hexafiuoro-2-propanol</td>
			<td>Aladdin</td>
			<td>I1523078</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Curcumin</td>
			<td>Sigma</td>
			<td>C1386</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Albumin Bovine V</td>
			<td>Solarbio</td>
			<td>A8020</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium chloride</td>
			<td>Sangon Biotech</td>
			<td>D920BA0003</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium dodecyl sulfate</td>
			<td>SCR</td>
			<td>30166428</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TRIS</td>
			<td>Solarbio</td>
			<td>T8060</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glycine</td>
			<td>Solarbio</td>
			<td>G8200</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">&#160;Dimethyl sulfoxide</td>
			<td>Solarbio</td>
			<td>D8370</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">5&#215;nondenaturing gel PAGE Protein Marker</td>
			<td>Beyotime</td>
			<td>P0016</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Genshare CFAS anyKD PAGE</td>
			<td>Genshare</td>
			<td>JC-PE022</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pure Nitrocellulose Blotting Membrane</td>
			<td>Pall Corporation</td>
			<td>T50189</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Methanol</td>
			<td>SCR</td>
			<td>10014118</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ethanol</td>
			<td>SCR</td>
			<td>10009218</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Super low range&#160;protein Marker</td>
			<td>Solarbio</td>
			<td>PR1300</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Transfer Membranes</td>
			<td>Immobilon-PSQ</td>
			<td>ISEQ00010</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BeyoECL Star</td>
			<td>Beyotime</td>
			<td>P0018A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Commassie Blue Fast staining solution</td>
			<td>Beyotime</td>
			<td>P0017</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">All - automatic chemiluminescence imaging system</td>
			<td>Tanon</td>
			<td>Tanon 5200</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Image J</td>
			<td>National Institutes of Health</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Image processing software</td>
			<td>Adobe</td>
			<td>Photoshop CS6</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Magnetic agitator</td>
			<td>Shanghai Huxi</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

a11-positive &#946;-amyloid oligomer preparation and assessment using dot blotting analysis

β淀粉样蛋白 (Aβ) 是一种疏水性肽, 具有自组装成骨料的内在倾向。在各种团聚体中, Aβ寡聚物作为阿尔茨海默病 (ad) 进展的主要神经毒素被广泛接受, 被认为是 ad 发病的关键事件。因此, Aβ寡聚物抑制剂可以防止变性, 并有潜力发展为疾病修改治疗的 AD。然而, Aβ寡聚物的不同形成方案可能会导致不同特征的寡聚。此外, 有效筛选 Aβ1-42寡聚物抑制剂的方法也不多。A11 抗体可以与含有反平行β片结构的毒性 Aβ1-42齐聚物的子集发生反应。在本协议中, 我们描述了如何从 Aβ的合成 Aβ1-42肽的体外准备一个 A11-positive 的1-42富齐聚的样本, 并通过斑点印迹来评估样本中 A11-positive Aβ1-42齐聚物的相对数量使用 A11 和 Aβ1-42特定6E10 抗体进行分析。使用该协议, A11-positive Aβ1-42齐聚物的抑制剂也可以从半定量实验结果中筛选出来。

为研究 Aβ1-42单体在制备后是否能形成 Aβ1-42齐聚物, 采用 TEM 分析。在 HFIP 溶解 Aβ1-42单体样本中未观察到可见骨料 (图 1A)。此外, 在48小时的震动后, 在 Aβ1-42样本中观察到了直径约 10-80 nm 的球状骨料, 这表明 Aβ1-42在准备后形成寡聚 (图 1B)。
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Watch this Scientific Journal Video about A11-positive ÃŽÂ²-amyloid Oligomer Preparation and Assessment Using Dot Blotting Analysis at JoVE.com

A11-positive &#946;-amyloid Oligomer Preparation and Assessment Using Dot Blotting Analysis

本协议描述如何从合成肽体外制备 Aβ寡聚物, 并通过斑点印迹分析来评价 Aβ的相对含量。

用斑点印迹分析 A11-positive β淀粉样寡聚物的制备与评价

&#946;-amyloid (A&#946;) is a hydrophobic peptide with an intrinsic tendency to self-assemble into aggregates. Among various aggregates, A&#946; oligomer ...

a11-positive-amyloid-oligomer-preparation-assessment-using-dot

Universidad de Cartagena UDEC

Research

JoVE Journal

Biochemistry

11.7K 次观看.  Ningbo University. 本协议描述如何从合成肽体外制备 Aβ寡聚物, 并通过斑点印迹分析来评价 Aβ的相对含量。

视频: A11-positive β-amyloid Oligomer Preparation and Assessment Using Dot Blotting Analysis

SorLA and CLC:CLF-1-dependent Downregulation of CNTFR&#945; as Demonstrated by Western Blotting, Inhibition of Lysosomal Enzymes, and Immunocytochemistry

The heterodimeric cytokine Cardiotrophin-like Cytokine:Cytokine-like Factor-1 (CLC:CLF-1) targets the glycosylphosphatidylinositol (GPI)-anchored CNTFR&#945; to form a trimeric complex that subsequently recruits glycoprotein 130/Leukemia Inhibitory Factor Receptor-&#946; (gp130/LIFR&#946;) for signaling. Both CLC and CNTFR&#945; are necessary for signaling but so far CLF-1 has only been known as a putative facilitator of CLC secretion. However, it has recently been shown that CLF-1 contains three binding sites: one for CLC; one for CNTFR&#945; (that may promote assembly of the trimeric complex); and one for the endocytic receptor sorLA. The latter site provides high affinity binding of CLF-1, CLC:CLF-1, as well as the trimeric (CLC:CLF-1:CNTFR&#945;) complex to sorLA, and in sorLA-expressing cells the soluble ligands CLF-1 and CLC:CLF-1 are rapidly taken up and internalized. In cells co-expressing CNTFR&#945; and sorLA, CNTFR&#945; first binds CLC:CLF-1 to form a membrane-associated trimeric complex, but it also connects to sorLA via the free sorLA-binding site in CLF-1. As a result, CNTFR&#945;, which has no capacity for endocytosis on its own, is tugged along and internalized by the sorLA-mediated endocytosis of CLC:CLF-1.
The present protocol describes the experimental procedures used to demonstrate i) the sorLA-mediated and CLC:CLF-1-dependent downregulation of surface-membrane CNTFR&#945; expression; ii) sorLA-mediated endocytosis and lysosomal targeting of CNTFR&#945;; and iii) the lowered cellular response to CLC:CLF-1-stimulation upon sorLA-mediated downregulation of CNTFR&#945;.

The present protocol describes how Western blotting and immunocytochemistry combined with inhibition of lysosomal enzymes can be used to demonstrate the downregulation of Ciliary Neurotrophic Factor Receptor-&#945; (CNTFR&#945;), which is conveyed by the interaction between Cytokine-like Factor-1 (CLF-1) and the endocytic receptor sorLA.

SorLA和CLC:这表现在免疫印迹，溶酶体酶的抑制，和免疫组化CNTFRα的CLF-1依赖性下调

The heterodimeric cytokine Cardiotrophin-like Cytokine:Cytokine-like Factor-1 (CLC:CLF-1) targets the glycosylphosphatidylinositol (GPI)-anchored ...

科研

生物化学

A Protein Preparation Method for the High-throughput Identification of Proteins Interacting with a Nuclear Cofactor Using LC-MS/MS Analysis

Transcriptional coregulators are vital to the efficient transcriptional regulation of nuclear chromatin structure. Coregulators play a variety of roles in regulating transcription. These include the direct interaction with transcription factors, the covalent modification of histones and other proteins, and the occasional chromatin conformation alteration. Accordingly, establishing relatively quick methods for identifying proteins that interact within this network is crucial to enhancing our understanding of the underlying regulatory mechanisms. LC-MS/MS-mediated protein binding partner identification is a validated technique used to analyze protein-protein interactions. By immunoprecipitating a previously-identified member of a protein complex with an antibody (occasionally with an antibody for a tagged protein), it is possible to identify its unknown protein interactions via mass spectrometry analysis. Here, we present a method of protein preparation for the LC-MS/MS-mediated high-throughput identification of protein interactions involving nuclear cofactors and their binding partners. This method allows for a better understanding of the transcriptional regulatory mechanisms of the targeted nuclear factors.

We have established a method for the purification of coregulatory interaction proteins using the LC-MS/MS system.

A蛋白制备方法在蛋白质与核余子交互使用LC-MS / MS分析的高通量鉴定

Transcriptional coregulators are vital to the efficient transcriptional regulation of nuclear chromatin structure. Coregulators play a variety of roles in ...

A Tailored HPLC Purification Protocol That Yields High-purity Amyloid Beta 42 and Amyloid Beta 40 Peptides, Capable of Oligomer Formation

Amyloidogenic peptides such as the Alzheimer's disease-implicated Amyloid beta (A&#946;), can present a significant challenge when trying to obtain high purity material. Here we present a tailored HPLC purification protocol to produce high-purity amyloid beta 42 (A&#946;42) and amyloid beta 40 (A&#946;40) peptides. We have found that the combination of commercially available hydrophobic poly(styrene/divinylbenzene) stationary phase, polymer laboratory reverse phase - styrenedivinylbenzene (PLRP-S) under high pH conditions, enables the attainment of high purity (&gt;95%) A&#946;42 in a single chromatographic run. The purification is highly reproducible and can be amended to both semi-preparative and analytical conditions depending upon the amount of material wished to be purified. The protocol can also be applied to the A&#946;40 peptide with identical success and without the need to alter the method.

Herein we report a tailored HPLC purification protocol that yields high-purity amyloid beta 42 (A&#946;42) and amyloid beta 40 (A&#946;40) peptides, capable of oligomer formation. Amyloid beta is a highly aggregation prone, hydrophobic peptide implicated in Alzheimer&#39;s disease. The amyloidogenic nature of the peptide makes its purification a challenge.

一个定制HPLC纯化协议，产量高纯度淀粉样蛋白β42和贝塔淀粉样蛋白肽40，有能力寡聚物形成的

Amyloidogenic peptides such as the Alzheimer's disease-implicated Amyloid beta (A&#946;), can present a significant challenge when trying to obtain high ...

A Western Blotting Protocol for Small Numbers of Hematopoietic Stem Cells

Hematopoietic stem cells (HSCs) are rare cells, with the mouse bone marrow containing only ~25,000 phenotypic long term repopulating HSCs. A Western blotting protocol was optimized and suitable for the analysis of small numbers of HSCs (500 - 15,000 cells). Phenotypic HSCs were purified, accurately counted, and directly lysed in Laemmli sample buffer. Lysates containing equal numbers of cells were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the blot was prepared and processed following standard Western blotting protocols. Using this protocol, 2,000 - 5,000 HSCs can be routinely analyzed, and in some cases data can be obtained from as few as 500 cells, compared to the 20,000 to 40,000 cells reported in most publications. This protocol should be generally applicable to other hematopoietic cells, and enables the routine analysis of small numbers of cells using standard laboratory procedures.

A standard Western blotting protocol was optimized for analyzing as few as 500 hematopoietic stem or progenitor cells. Optimization involves careful handling of the cell sample, limiting transfers between tubes, and directly lysing the cells in Laemmli sample buffer.

一种用于小数目造血干细胞的西方印迹协议

Hematopoietic stem cells (HSCs) are rare cells, with the mouse bone marrow containing only ~25,000 phenotypic long term repopulating HSCs. A Western ...

High Throughput, Absolute Determination of the Content of a Selected Protein at Tissue Levels Using Quantitative Dot Blot Analysis (QDB)

Lacking a convenient, quantitative, high throughput immunoblot method for absolute determination of the content of a specific protein at cellular and tissue level significantly hampers the progress in proteomic research. Results derived from currently available immunoblot techniques are also relative, preventing any efforts to combine independent studies with a large-scale analysis of protein samples. In this study, we demonstrate the process of quantitative dot blot analysis (QDB) to achieve absolute quantification in a high throughput format. Using a commercially available protein standard, we are able to determine the absolute content of capping actin protein, gelsolin-like (CAPG) in protein samples prepared from three different mouse tissues (kidney, spleen, and prostate) together with a detailed explanation of the experimental details. We propose the QDB analysis as a convenient, quantitative, high throughput immunoblot method of absolute quantification of individual proteins at the cellular and tissue level. This method will substantially aid biomarker validation and pathway verification in various areas of biological and biomedical research.

High Throughput, Absolute Determination of the Content of a Selected Protein at Tissue Levels Using Quantitative Dot Blot Analysis QDB

Here we demonstrate a detailed process of quantitative dot blot analysis (QDB) by determining the absolute content of a targeted protein, capping actin protein, gelsolin-like (CAPG), in three different mouse tissues. We demonstrate a high throughput, convenient, quantitative immunoblot technique for biomarker validation at the cellular and tissue level.

高通量, 用定量斑点杂交分析法绝对测定组织层中选定蛋白质的含量 (QDB)

Lacking a convenient, quantitative, high throughput immunoblot method for absolute determination of the content of a specific protein at cellular and ...

Preparation of Fungal and Plant Materials for Structural Elucidation Using Dynamic Nuclear Polarization Solid-State NMR

This protocol shows how uniformly 13C, 15N-labeled fungal materials can be produced and how these soft materials should be proceeded for solid-state NMR and sensitivity-enhanced DNP experiments. The sample processing procedure of plant biomass is also detailed. This method allows the measurement of a series of 1D and 2D 13C-13C/15N correlations spectra, which enables high-resolution structural elucidation of complex biomaterials in their native state, with minimal perturbation. The isotope-labeling can be examined by quantifying the intensity in 1D spectra and the polarization transfer efficiency in 2D correlation spectra. The success of dynamic nuclear polarization (DNP) sample preparation can be evaluated by the sensitivity enhancement factor. Further experiments examining the structural aspects of the polysaccharides and proteins will lead to a model of the three-dimensional architecture. These methods can be modified and adapted to investigate a wide range of carbohydrate-rich materials, including the natural cell walls of plants, fungi, algae and bacteria, as well as synthesized or designed carbohydrate polymers and their complex with other molecules.

A protocol for preparing 13C,15N-labeled fungal and plant samples for multidimensional solid-state NMR spectroscopy and dynamic nuclear polarization (DNP) investigations is presented.

动态核极化固态核磁共振法制备结构澄清用真菌和植物材料

This protocol shows how uniformly 13C, 15N-labeled fungal materials can be produced and how these soft materials should be proceeded for solid-state NMR ...

Robust Comparison of Protein Levels Across Tissues and Throughout Development Using Standardized Quantitative Western Blotting

Western blotting is a technique that is commonly used to detect and quantify protein expression. Over the years, this technique has led to many advances in both basic and clinical research. However, as with many similar experimental techniques, the outcome of Western blot analyses is easily influenced by choices made in the design and execution of the experiment. Specific housekeeping proteins have traditionally been used to normalize protein levels for quantification, however, these have a number of limitations and have therefore been increasingly criticized over the past few years. Here, we describe a detailed protocol that we have developed to allow us to undertake complex comparisons of protein expression variation across different tissues, mouse models (including disease models), and developmental timepoints. By using a fluorescent total protein stain and introducing the use of an internal loading standard, it is possible to overcome existing limitations in the number of samples that can be compared within experiments and systematically compare protein levels across a range of experimental conditions. This approach expands the use of traditional western blot techniques, thereby allowing researchers to better explore protein expression across different tissues and samples.

This method describes a robust and reproducible approach for the comparison of protein levels in different tissues and at different developmental timepoints using a standardized quantitative western blotting approach.

利用标准化定量西方印迹技术, 对跨组织和整个开发过程中的蛋白质水平进行可靠比较

Western blotting is a technique that is commonly used to detect and quantify protein expression. Over the years, this technique has led to many advances ...

A Plasma Sample Preparation for Mass Spectrometry using an Automated Workstation

Sample preparation for mass spectrometry analysis in proteomics requires enzymatic cleavage of proteins into a peptide mixture. This process involves numerous incubation and liquid transfer steps in order to achieve denaturation, reduction, alkylation, and cleavage. Adapting this workflow onto an automated workstation can increase efficiency and reduce coefficients of variance, thereby providing more reliable data for statistical comparisons between sample types. We previously described an automated proteomic sample preparation workflow1. Here, we report the development of a more efficient and better controlled workflow with the following advantages: 1) The number of liquid transfer steps is reduced from nine to six by combining reagents; 2) Pipetting time is reduced by selective tip pipetting using a 96-position pipetting head with multiple channels; 3) Potential throughput is increased by the availability of up to 45 deck positions; 4) Complete enclosure of the system provides improved temperature and environmental control and reduces the potential for contamination of samples or reagents; and 5) The addition of stable isotope labeled peptides, as well as &#946;-galactosidase protein, to each sample makes monitoring and quality control possible throughout the entire process. These hardware and process improvements provide good reproducibility and improve intra-assay and inter-assay precision (CV of less than 20%) for LC-MS based protein and peptide quantification. The entire workflow for digesting 96 samples in a 96-well plate can be completed in approximately 5 hours.

Here, we present an automated plasma protein digestion method for mass spectrometry-based quantitative proteomic analysis. In this protocol, the liquid transferring and incubation steps for protein denaturation, reduction, alkylation, and trypsin digestion reactions are streamlined and automated. It takes approximately five hours to prepare a 96-well plate with desired precision.

使用自动工作站进行质谱测量的等离子体样品制备

Sample preparation for mass spectrometry analysis in proteomics requires enzymatic cleavage of proteins into a peptide mixture. This process involves ...

TMT Sample Preparation for Proteomics Facility Submission and Subsequent Data Analysis

Proteomic technologies are powerful methodologies that can aid our understanding of mechanisms of action in biological systems by providing a global view of the impact of a disease, treatment, or other condition on the proteome as a whole. This report provides a detailed protocol for the extraction, quantification, precipitation, digestion, labeling, and subsequent data analysis of protein samples. Our optimized TMT labeling protocol requires a lower tag-label concentration and achieves consistently reliable data. We have used this protocol to evaluate protein expression profiles in a variety of mouse tissues (i.e., heart, skeletal muscle, and brain) as well as cells cultured in vitro. In addition, we demonstrate how to evaluate thousands of proteins from the resulting dataset.

We present an optimized tandem mass tag (TMT) labeling protocol that includes detailed information for each of the following steps: protein extraction, quantification, precipitation, digestion, labeling, submission to a proteomics facility, and data analyses.

蛋白质组学设施提交和后续数据分析的TMT样品制备

Proteomic technologies are powerful methodologies that can aid our understanding of mechanisms of action in biological systems by providing a global view ...

Sample Preparation and Relative Quantitation using Reductive Methylation of Amines for Peptidomics Studies

Peptidomics can be defined as the qualitative and quantitative analysis of peptides in a biological sample. Its main applications include identifying the peptide biomarkers of disease or environmental stress, identifying neuropeptides, hormones, and bioactive intracellular peptides, discovering antimicrobial and nutraceutical peptides from protein hydrolysates, and can be used in studies to understand the proteolytic processes. The recent advance in sample preparation, separation methods, mass spectrometry techniques, and computational tools related to protein sequencing has contributed to the increase of the identified peptides number and peptidomes characterized. Peptidomic studies frequently analyze peptides that are naturally generated in cells. Here, a sample preparation protocol based on heat-inactivation is described, which eliminates protease activity, and extraction with mild conditions, so there is no peptide bonds cleavage. In addition, the relative quantitation of peptides using stable isotope labeling by reductive methylation of amines is also shown. This labeling method has some advantages as the reagents are commercially available, inexpensive compared to others, chemically stable, and allows the analysis of up to five samples in a single LC-MS run.

This article describes a sample preparation method based on heat-inactivation to preserve endogenous peptides avoiding degradation post-mortem, followed by relative quantitation using isotopic labeling plus LC-MS.

使用胺还原甲基化进行样品制备和相对定量，用于肽学研究

Peptidomics can be defined as the qualitative and quantitative analysis of peptides in a biological sample. Its main applications include identifying the ...