This study was supported by the Astellas Foundation for Research on Metabolic Disorders (HT), the Takeda Science Foundation (HT), and by a Japan Society for the Promotion of Science Grants-in-Aid for Young Scientists (B) to HT.

1. 형질 <ol><li> 100 mm 배양 판 (2 × 106 세포 / 접시)에 HEK293 세포 종자. 배양 10 % 소 태아 혈청, 100 μg의 / ㎖ 스트렙토 마이신, 100 유닛 / ㎖의 페니실린으로 보충 된 둘 베코 변형 이글 배지에서 세포. 5 % CO 2 및 37 ℃로 가습 된 배양기에서 세포를 인큐베이션. </li><li> 다음 날, FLAG-태그 ARIP4 플라스미드의 10 μg의 제조업체의 방향 (11)에 따라 형질 전환 시약의 40 μl를 이용하여 세포를 형질. </li></ol> 2. 단백질 추출 <ol><li> 약 트랜 스펙 션 후 36 시간이 빙냉 PBS로 세포를 세척하고 스크레이퍼를 사용하여 세포를 수확. 1.5 mltube에 세포를 전송하고 4 ℃에서 2 분 동안 8,000 XG에 그것을 원심 분리기. 대기음 뜨는 배에서 세포 펠렛을 재현 탁 0.4 M KCl을 버퍼의 펠릿 볼륨 (높은 염 완충액 : 20 mM 트리스 -HCl (pH 8.0), 0.4 M KCl을5 밀리미터의 MgCl 2, 10 % 글리세롤, 0.1 % NP-40, 10 밀리미터 B-mercaptethanol, 1X 프로테아제 억제제 칵테일). 4 ℃에서 20 분 동안 혼합물을 돌립니다. </li><li> 4 ℃에서 10 분 동안 17,700 XG에서 튜브를 원심 분리기. </li><li> (새로운 2 ㎖의 튜브에 상청 (전체 세포 추출물)을 전송하고 0 M KCl을 버퍼의 초기 부피 3 배 추가 희석 완충액 : 20 mM 트리스 -HCl (pH 8.0), 5 밀리미터의 MgCl 2, 10 % 글리세롤, 0.1 % NP-40, 10 밀리미터 β 머 캅토 에탄올, 1X 프로테아제 억제제 칵테일). </li><li> 다른 원심 분리 (4 ℃에서 10 분 동안 17,700 XG)을 수행하고, 새로운 2 ML 튜브에 뜨는 (전체 세포 추출물)를 전송합니다. </li></ol> 3. 면역 침전 <ol><li> 20 mM의 트리스 : 원심 분리 (2.4) 중, (0.1M KCl을 완충액으로 두번 저염 완충액을 세척 한 다음 PBS로 안티 FLAG 비드 50 ㎕의 0.1 M 글리신 - 염산하고 1 M 트리스 - 히드로 클로라이드를 씻어 염산 (PH 8.0), 0.1 M의 KCl, 5 mM의 MgCl2를, 10 % 글리세롤, 0.1 % NP-40, 10mM (B) 머 캅토 에탄올, 1X 프로테아제 억제제 칵테일). 이 세척 공정의 원심 분리는 39 ° C에서 1 분 동안 2,000 × g으로 수행된다. </li><li> 전체 세포 추출물 FLAG 비드의 50 μL를 혼합하고 가볍게 2-4 ℃로한다 (단계 2.4의 전체 세포 추출물의 1 %는 또한 나중에 사용하기 위해 -80 ℃에서 보관한다에서 4 시간 동안 혼합물을 회전 ) 입력으로. </li><li> 마이크로 스핀 열 (중력 드롭)에 샘플을 전송합니다. (입력 및 관류 웨스턴 블롯 분석을 이용하여 양자의 단백질 수준을 확인), 1.5 ㎖의 튜브에 관류 유지 액체 질소를 사용하여 동결하고, -80 ℃에서 보관. </li><li> 국기 비즈 (중력 드롭)을 씻어 0.1 M KCl을 버퍼 (낮은 소금 버퍼)의 1 ML을 추가합니다. </li><li> 3.4 적어도 네 번 이상 (오 세척의 총) 단계를 반복합니다. </li></ol> 4. 용출 <ol><li> 1.5 ML 튜브에 열을 놓고 1 분 동안 2,000 XG에이를 원심 분리; 구슬 건조됩니다. </li><li> 하단 캡열. </li><li> 0.1 M 글리신 - 염산 (PH 2.5)의 (FLAG 구슬의 부피와 동일) 50 μl를 추가합니다. </li><li> 부드럽게 실온에서 10 분 동안 혼합물을 흔들어. </li><li> 새로운 1.5 ML 튜브에 열을 놓고 1 분 동안 2,000 XG에 그것을 원심 분리기. </li><li> 용출액을 1 M Tris-HCl (pH8.0)을 10 ㎕의 중화; 피펫 또는 와류 장치를 이용하여 잘 혼합한다. </li></ol> 5. 알킬화 및 트립신 <ol><li> 100 mM의 NH 4 HCO 3, CH 3 CN 10 μL, 혼합물에 디티 오 트레이 톨의 2 μL (112 μl의 총 부피)의 50 μl를 추가합니다. </li><li> 56 ° C에서 30 분 동안 샘플을 인큐베이션. </li><li> 실온에서 10 분 동안 샘플을 놓는다. </li><li> 요오도 아세트 아미드 시료에 333 mm의 10 μl를 첨가하고 37 ℃에서 30 분 동안 어두운 데에서 부화. </li><li> 혼합물에 트립신의 10 μL (33 NG / μL)을 추가하고 37 ° C에서 하룻밤을 품어. </li></ol><ol><li> 밤새 트립신 처리 후, LC-MS / MS 시설이나 분석 12 타사 질량 분석 실험실로 최종 제품을 수송. </li></ol>

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The authors have nothing to disclose.

효율적인 형질 감염 프로토콜이 성공적인 결과를 얻는 것이 필수적이다. 따라서, 우리는 면역 FLAG 태그가 단백질 수준을 결정하는 웨스턴 블롯 분석을 사용하는 것이 좋습니다. 이 단계는 IP가 성공적으로 수행되었는지, 그들의 관심 단백질이 제대로 또한, 과발현되어 있는지 확인하려면 사용자 수 있습니다. FLAG 태그가 단백질 수준은 질량 분광 분석에 앞서 확인하여야한다. 모의 샘플 위양성 결과를 얻는 피하고 진정한 상호 작용 배경을 판별하는 음성 대조군으로 사용한다. 인간 단백질을 연구 할 때 또한, 실험은 오염을 방지하기 위해, 비교적 깨끗한 환경 (예를 들면, 클린 룸)에서 수행되어야한다. 높은 염 농도 (0.3-0.4 M)으로 단백질을 추출 버퍼 때때로 핵 단백질을 추출하기 위해 사용될 수 있지만하는 0.1 ~ 0.15 M 염 농도와 IP 버퍼가 대부분이며열 좋습니다. 이 IP 절차는 단백질 - 단백질 상호 작용을 방해하지 않고 진행 할 수 있습니다. 상기 배경 신호를 최소화하기 위해 자성 비드는 정제 공정에 사용될 수있다. 또한 위양성 결과를 줄이기 위해 세포 용해 조건을 최적화하는 것이 중요하다. 다른 기술에 대한 연구에 기술 된 방법의 중요성 (겔의 예 소화 기반 단일 단백질 식별) 5, 10, 11는 사용자가 높은 처리량 식별을 위해 LC-MS / MS 분석을 수행 할 수 있다는 핵 보조 인자와 그 결합 파트너 간의 단백질 상호 작용의. 전사 유전자 조절 시퀀스 특정 DNA 결합 단백질의 협력에 크게 의존한다. 따라서, 전사 인자들은 표적 유전자의 발현을 변경하는 공동 많은 요소와 상호 작용한다. 일<html> erefore 더 셀룰러 이벤트, 이러한 전사 메카니즘을 관리 대상 단백질 활성이 가장 중요 촉진 전사 파트너를 식별을 이해한다. 우리의 방법은 사용자가 신속하게 관심을 자신의 전사 인자로 추정되는 핵 보조 인자를 식별 할 수 있습니다 추가 전사 조절 메커니즘에 대한 우리의 이해를 향상시킵니다. FLAG 펩티드는 용출 과정에서 0.1 M 글리신 - 염산 용액 (PH 2.5) 대신에 사용될 수있다. 이 변형이 사용되는 경우, 상기 FLAG 펩티드를 희석하는 데 사용되는 버퍼의 pH를 모니터링해야한다. 배의 FLAG 펩티드는 FLAG 비드로부터 용출 된 단백질을 사용한다. 따라서, 상대적으로 높은 pH를 갖는 용액이 변성 조건 FLAG 펩티드를 희석하는 데 사용되어야한다. 이는 적절한 단백질 - 단백질 상호 작용을 유지하기 위해 샘플의 반복되는 동결 융해를 방지하는 것도 중요하다. t &quot;&gt; 계기로 트립신 처리의 최적화는 단백질의 상호 작용을 검사 결과의 정확성을 향상시키기위한 요구 될 수있다. LC-MS / MS 법의 핵 사이의 상호 작용을 식별하기 위해 사용될 수있는 도구이지만 단백질 한계 중 하나는 단백질 복합물의 조립에 관한 정확한 정보를 제공하지 않는다는 것이다. 착물의 안정성을 향상시키기 위해 화학적 처리 가교 14을 사용할 수있다. 다른 방법으로, 모세관 전기 영동-MS / MS는 유용 15 .

단백질 - 단백질 상호 작용은 다양한 생물학적 기능에 중요한 역할을한다. 따라서, 이러한 상호 작용은 신호 전달에 연루되어왔다 세포막 단백질 수송; 세포의 신진 대사; 및 DNA 복제, DNA 손상 복구, 재조합 및 전사 1, 2, 3, 4 등 여러 핵 프로세스. 이러한 상호 작용에 관여하는 단백질을 확인하는 것은이 세포 과정에 대한 우리의 이해를 증진하는 것이 중요하다. 면역 침전 (IP)는 단백질 - 단백질 상호 작용을 분석하는데 사용되는 검증 된 기술이다. 공동 - 면역 침전 된 단백질의 동정을 용이하게하기 위하여, 질량 분석계는 종종 이용 5, 6, 7, 8,9. 항체와 단백질 복합체의 공지 부재 타겟팅함으로써, 단백질 복합체를 분리하고,이어서 질량 분광 분석을 통해 그 미지의 컴포넌트를 식별 할 수있다. ARIP4 (안드로겐 수용체 상호 작용하는 단백질 4), 전사 coregulator은 활성화 또는 상황에 의존적으로 9, 10 년 대상 발기인을 억제하기 위해 핵 수용체 단백질과 상호 작용한다. 더 이러한 핵 인자를 지배하는 전사 조절 메커니즘을 이해하기 위해 정화하고, LC-MS / MS 시스템을 사용하여 ARIP4 상호 작용 단백질을 확인하는 포괄적 인 방법을 설명한다.

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			<td height="81" style="height:81px;width:216px;">Lipofectamine 2000 Transfection Reagent</td>
			<td style="width:71px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">11668019</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:216px;">Protease Inhibitor Cocktail (EDTA free) (100x)</td>
			<td style="width:71px;">nacalai tesque</td>
			<td style="width:119px;">03969-21</td>
			<td></td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:216px;">ANTI-FLAG M2 Affinity Gel</td>
			<td style="width:71px;">Sigma-Aldrich</td>
			<td style="width:119px;">A2220</td>
			<td></td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;">Micro Bio-Spin Columns</td>
			<td style="width:71px;">BIO-RAD</td>
			<td style="width:119px;">732-6204</td>
			<td></td>
		</tr>
	</tbody>
</table>

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.

우리는 강한 신호 ARIP4 약 160 KDa의뿐 모의 샘플 제어 및 몇몇 다른 미지의 단백질의 것과 (도 1)을 확인 하였다. LC-MS / MS 분석은 펩티드 복합체 ARIP4 FLAG 비드 (표 1)의 분획 내의 잠재적 인 펩티드 공동 인자를 모두 식별. P62 (Sequestosome1)는 공지 ARIP4 공동 인자 (11)는이 시스템 (11)의 유효성을 확인하는 분석 (표 1)에서 확인되었다. 우리는 또한 ARIP4와 상호 작용하는 많은 다른 이전에보고 된 단백질을 확인했다. 이러한 방식으로, Sumo2 10 DryK (13)는 LC-MS / MS 분석을 통해 검출 하였다. ARIP4 펩티드는 또한 IP 고품질의 것을 제안하는 LC-MS / MS 분석을 이용하여 확인 하였다. 전반적으로, LC-MS / MS 기술은 알려지지 핵 이벤트의 링크를 식별 할 수있는 강력한 도구이며단백질 - 단백질 상호 작용 에디션. 전체 질량 분석 결과는 요청에 따라 사용할 수 있습니다. <img alt="그림 1" src="/files/ftp_upload/55077/55077fig1.jpg" /> 그림 1 : ARIP4 단지의 정화. FLAG 에피토프 태그가 ARIP4의 실버 염색 (ARIP4-F)는 FLAG 특정 항체 HEK293 세포와 면역 표현. 정제 된 단백질을 전기 영동을 이용하여 해결하고 실버 염색으로 가시화 하였다. 대조군으로서, 모의 정제하여 외래 단백질을 발현하지 않았다 HEK293 세포에서 수행 하였다. 분자량 표준은 왼쪽에 표시됩니다. <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55077/55077fig1large.jpg" target="_blank">이 그림의 더 큰 버전을 보려면 여기를 클릭하십시오.</a> <img alt="1 번 테이블" src="/files/ftp_upload/55077/55077table1.jpg" /> 표 1 : Identificatio소설 ARIP4 결합 단백질의 N. 정제 된 단백질 복합체에 결합 FLAG 비드 트립신 기반 절단에 의해 분해 하였다. 이러한 단백질은이어서 LC-MS / MS 분석을 이용하여 확인 하였다. 한편, LC-MS / MS 데이터는 스위스 보호 해주는 MASCOT 데이터베이스와 소프트웨어를 사용하여 분석 하였다. 펩티드의 수와 이들 단백질의 신원이 도시된다. 중요한 마스코트 점수 (P &lt;0.05) 만 단백질이 선정되었다.

Watch this Scientific Journal Video about A Protein Preparation Method for the High-throughput Identification of Proteins Interacting with a Nuclear Cofactor Using LC-MS/MS Analysis at JoVE.com

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

우리는 LC-MS / MS 시스템을 사용 coregulatory 상호 작용 단백질의 정제 방법을 확립 하였다.

LC-MS / MS 분석을 이용하여 핵 공동 인자와 상호 작용 단백질의 높은 처리량 식별 단백질 제조 방법

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

a-protein-preparation-method-for-high-throughput-identification

Nanyang Technological University

Research

JoVE Journal

Biochemistry

8.2K 조회수.  Osaka University.  우리는 LC-MS / MS 시스템을 사용 coregulatory 상호 작용 단백질의 정제 방법을 확립 하였다. 

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

Method for Identifying Small Molecule Inhibitors of the Protein-protein Interaction Between HCN1 and TRIP8b

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed ubiquitously throughout the brain, where they function to regulate the excitability of neurons. The subcellular distribution of these channels in pyramidal neurons of hippocampal area CA1 is regulated by tetratricopeptide repeat-containing Rab8b interacting protein (TRIP8b), an auxiliary subunit. Genetic knockout of HCN pore forming subunits or TRIP8b, both lead to an increase in antidepressant-like behavior, suggesting that limiting the function of HCN channels may be useful as a treatment for Major Depressive Disorder (MDD). Despite significant therapeutic interest, HCN channels are also expressed in the heart, where they regulate rhythmicity. To circumvent off-target issues associated with blocking cardiac HCN channels, our lab has recently proposed targeting the protein-protein interaction between HCN and TRIP8b in order to specifically disrupt HCN channel function in the brain. TRIP8b binds to HCN pore forming subunits at two distinct interaction sites, although here the focus is on the interaction between the tetratricopeptide repeat (TPR) domains of TRIP8b and the C terminal tail of HCN1. In this protocol, an expanded description of a method for purifying TRIP8b and executing a high throughput screen to identify small molecule inhibitors of the interaction between HCN and TRIP8b, is described. The method for high throughput screening utilizes a Fluorescence Polarization (FP) -based assay to monitor the binding of a large TRIP8b fragment to a fluorophore-tagged eleven amino acid peptide corresponding to the HCN1 C terminal tail. This method allows &#39;hit&#39; compounds to be identified based on the change in the polarization of emitted light. Validation assays are then performed to ensure that &#39;hit&#39; compounds are not artifactual.

The interaction between HCN channels and their auxiliary subunit has been identified as a therapeutic target in Major Depressive Disorder. Here, a fluorescence polarization-based method for identifying small molecule inhibitors of this protein-protein interaction, is presented.

방법 및 HCN1 TRIP8b 간의 단백질 - 단백질 상호 작용의 작은 분자 억제제 식별

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed ubiquitously throughout the brain, where they function to regulate the ...

연구

생화학

Using Scaffold Liposomes to Reconstitute Lipid-proximal Protein-protein Interactions In Vitro

Studies of integral membrane proteins in vitro are frequently complicated by the presence of a hydrophobic transmembrane domain. Further complicating these studies, reincorporation of detergent-solubilized membrane proteins into liposomes is a stochastic process where protein topology is impossible to enforce. This paper offers an alternative method to these challenging techniques that utilizes a liposome-based scaffold. Protein solubility is enhanced by deletion of the transmembrane domain, and these amino acids are replaced with a tethering moiety, such as a His-tag. This tether interacts with an anchoring group (Ni2+ coordinated by nitrilotriacetic acid (NTA(Ni2+)) for His-tagged proteins), which enforces a uniform protein topology at the surface of the liposome. An example is presented wherein the interaction between Dynamin-related protein 1 (Drp1) with an integral membrane protein, Mitochondrial Fission Factor (Mff), was investigated using this scaffold liposome method. In this work, we have demonstrated the ability of Mff to efficiently recruit soluble Drp1 to the surface of liposomes, which stimulated its GTPase activity. Moreover, Drp1 was able to tubulate the Mff-decorated lipid template in the presence of specific lipids. This example demonstrates the effectiveness of scaffold liposomes using structural and functional assays and highlights the role of Mff in regulating Drp1 activity.

Using Scaffold Liposomes to Reconstitute Lipid-proximal Protein-protein Interactions In Vitro

This paper describes a method for assessing the interactions and assemblies of integral membrane proteins in vitro with various partner factors in a lipid-proximal environment.

비계 리포좀을 사용하여 근위 지질 단백질 - 단백질 상호 작용을 재구성<em&gt; 체외</em

Studies of integral membrane proteins in vitro are frequently complicated by the presence of a hydrophobic transmembrane domain. Further complicating ...

Nuclear Magnetic Resonance Spectroscopy for the Identification of Multiple Phosphorylations of Intrinsically Disordered Proteins

Aggregates of the neuronal Tau protein are found inside neurons of Alzheimer's disease patients. Development of the disease is accompanied by increased, abnormal phosphorylation of Tau. In the course of the molecular investigation of Tau functions and dysfunctions in the disease, nuclear magnetic resonance (NMR) spectroscopy is used to identify the multiple phosphorylations of Tau. We present here detailed protocols of recombinant production of Tau in bacteria, with isotopic enrichment for NMR studies. Purification steps that take advantage of Tau's heat stability and high isoelectric point are described. The protocol for in vitro phosphorylation of Tau by recombinant activated ERK2 allows for generating multiple phosphorylations. The protein sample is ready for data acquisition at the issue of these steps. The parameter setup to start recording on the spectrometer is considered next. Finally, the strategy to identify phosphorylation sites of modified Tau, based on NMR data, is explained. The benefit of this methodology compared to other techniques used to identify phosphorylation sites, such as immuno-detection or mass spectrometry (MS), is discussed.

We describe here a method to identify multiple phosphorylations of an intrinsically disordered protein by Nuclear Magnetic Resonance Spectroscopy (NMR), using Tau protein as a case study. Recombinant Tau is isotopically enriched and modified in vitro by a kinase prior to data acquisition and analysis.

본질적으로 무질서 단백질의 여러 인산화의 식별을위한 핵 자기 공명 분광학

Aggregates of the neuronal Tau protein are found inside neurons of Alzheimer's disease patients. Development of the disease is accompanied by increased, ...

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.

높은 처리량, 양적 도트를 사용 하 여 조직 수준에서 선택 된 단백질의 내용의 절대 결정 오 점 분석 (QDB)

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

A Simple Method for High Throughput Chemical Screening in Caenorhabditis Elegans

Caenorhabditis elegans is a useful organism for testing chemical effects on physiology. Whole organism small molecule screens offer significant advantages for identifying biologically active chemical structures that can modify complex phenotypes such as lifespan. Described here is a simple protocol for producing hundreds of 96-well culture plates with fairly consistent numbers of C. elegans in each well. Next, we specified how to use these cultures to screen thousands of chemicals for effects on the lifespan of the nematode C. elegans. This protocol makes use of temperature sensitive sterile strains, agar plate conditions, and simple animal handling to facilitate the rapid and high throughput production of synchronized animal cultures for screening.

A Simple Method for High Throughput Chemical Screening in Caenorhabditis Elegans

Here we describe a simple protocol for rapidly producing hundreds of nematode growth media agar, 96-well culture plates with consistent numbers of Caenorhhabditis elegans per well. These cultures are useful for the phenotypic screening of whole organisms. We focus here on using these cultures to screen chemicals for pro-longevity effects.

꼬마 선 충 에서 높은 처리량 화학 심사 하는 간단한 방법

Caenorhabditis elegans is a useful organism for testing chemical effects on physiology. Whole organism small molecule screens offer significant advantages ...

Efficient Purification and LC-MS/MS-based Assay Development for Ten-Eleven Translocation-2 5-Methylcytosine Dioxygenase

The epigenetic transcription regulation mediated by 5-methylcytosine (5mC) has played a critical role in eukaryotic development. Demethylation of these epigenetic marks is accomplished by sequential oxidation by ten-eleven translocation dioxygenases (TET1-3), followed by the thymine-DNA glycosylase-dependent base excision repair. Inactivation of the TET2 gene due to genetic mutations or by other epigenetic mechanisms is associated with a poor prognosis in patients with diverse cancers, especially hematopoietic malignancies. Here, we describe an efficient single step purification of enzymatically active untagged human TET2 dioxygenase using cation exchange chromatography. We further provide a liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach that can separate and quantify the four normal DNA bases (A, T, G, and C), as well as the four modified cytosine bases (5-methyl, 5-hydroxymethyl, 5-formyl, and 5-carboxyl). This assay can be used to evaluate the activity of wild type and mutant TET2 dioxygenases.

Here, we present a protocol for an efficient single step purification of the active untagged human ten-eleven translocation-2 (TET2) 5-methylcytosine dioxygenase using ion-exchange chromatography and its assay using a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based approach.

효율적인 정화와 10-11 전-2 5-Methylcytosine Dioxygenase에 대 한 LC-MS/MS 기반 분석 결과 개발

The epigenetic transcription regulation mediated by 5-methylcytosine (5mC) has played a critical role in eukaryotic development. Demethylation of these ...

A Semi-High-Throughput Adaptation of the NADH-Coupled ATPase Assay for Screening Small Molecule Inhibitors

ATPase enzymes utilize the free energy stored in adenosine triphosphate to catalyze a wide variety of endergonic biochemical processes in vivo that would not occur spontaneously. These proteins are crucial for essentially all aspects of cellular life, including metabolism, cell division, responses to environmental changes and movement. The protocol presented here describes a nicotinamide adenine dinucleotide (NADH)-coupled ATPase assay that has been adapted to semi-high throughput screening of small molecule ATPase inhibitors. The assay has been applied to cardiac and skeletal muscle myosin II's, two actin-based molecular motor ATPases, as a proof of principle. The hydrolysis of ATP is coupled to the oxidation of NADH by enzymatic reactions in the assay. First, the ADP generated by the ATPase is regenerated to ATP by pyruvate kinase (PK). PK catalyzes the transition of phosphoenolpyruvate (PEP) to pyruvate in parallel. Subsequently, pyruvate is reduced to lactate by lactate dehydrogenase (LDH), which catalyzes the oxidation of NADH in parallel. Thus, the decrease in ATP concentration is directly correlated to the decrease in NADH concentration, which is followed by change to the intrinsic fluorescence of NADH. As long as PEP is available in the reaction system, the ADP concentration remains very low, avoiding inhibition of the ATPase enzyme by its own product. Moreover, the ATP concentration remains nearly constant, yielding linear time courses. The fluorescence is monitored continuously, which allows for easy estimation of the quality of data and helps to filter out potential artifacts (e.g., arising from compound precipitation or thermal changes).

A nicotinamide adenine dinucleotide (NADH)-coupled ATPase assay has been adapted to semihigh throughput screening of small molecule myosin inhibitors. This kinetic assay is run in a 384-well microplate format with total reaction volumes of only 20 &#181;L per well. The platform should be applicable to virtually any ADP producing enzyme.

소분자 억제제 스크리닝을 위한 NADH 결합 ATPase 분석의 반 높은 처리량 적응

ATPase enzymes utilize the free energy stored in adenosine triphosphate to catalyze a wide variety of endergonic biochemical processes in vivo that would ...

Transverse Sectioning of Mature Rice (Oryza sativa L.) Kernels for Scanning Electron Microscopy Imaging Using Pipette Tips as Immobilization Support

Starch granules (SGs) exhibit different morphologies depending on the plant species, especially in the endosperm of the Poaceae family. Endosperm phenotyping can be used to classify genotypes based on SG morphotype using scanning electron microscopic (SEM) analysis. SGs can be visualized using SEM by slicing through the kernel (pericarp, aleurone layers, and endosperm) and exposing the organellar contents. Current methods require the rice kernel to be embedded in plastic resin and sectioned using a microtome or embedded in a truncated pipette tip and sectioned by hand using a razor blade. The former method requires specialized equipment and is time-consuming, while the latter introduces a new host of problems depending on rice genotype. Chalky rice varieties, particularly, pose a problem for this type of sectioning due to the friable nature of their endosperm tissue. Presented here is a technique for preparing translucent and chalky rice kernel sections for microscopy, requiring only pipette tips and a scalpel blade. Preparing the sections within the confines of a pipette tip prevents rice kernel endosperm from shattering (for translucent or &#8216;vitreous&#8217; phenotypes) and crumbling (for chalky phenotypes). Using this technique, endosperm cell patterning and the structure of intact SGs can be observed.

Transverse Sectioning of Mature Rice Oryza sativa L. Kernels for Scanning Electron Microscopy Imaging Using Pipette Tips as Immobilization Support

This protocol allows for the preparation of transverse sections of cereal seeds (e.g., rice) for the analysis of endosperm and starch granule morphology using scanning electron microscopy.

성숙한 쌀의 횡단 단면(오리자 사티 라 L.) 파이펫 팁을 사용하여 전자 현미경 이미징을 스캐닝하기 위한 커널

Starch granules (SGs) exhibit different morphologies depending on the plant species, especially in the endosperm of the Poaceae family. Endosperm ...

Removal and Replacement of Endogenous Ligands from Lipid-Bound Proteins and Allergens

Many major allergens bind to hydrophobic lipid-like molecules, including Mus m 1, Bet v 1, Der p 2, and Fel d 1. These ligands are strongly retained and have the potential to influence the sensitization process either through directly stimulating the immune system or altering the biophysical properties of the allergenic protein. In order to control for these variables, techniques are required for the removal of endogenously bound ligands and, if necessary, replacement with lipids of known composition. The cockroach allergen Bla g 1 encloses a large hydrophobic cavity which binds a heterogeneous mixture of endogenous lipids when purified using traditional techniques. Here, we describe a method through which these lipids are removed using reverse-phase HPLC followed by thermal annealing to yield Bla g 1 in either its Apo-form or reloaded with a user-defined mixture of fatty acid or phospholipid cargoes. Coupling this protocol with biochemical assays reveal that fatty acid cargoes significantly alter the thermostability and proteolytic resistance of Bla g 1, with downstream implications for the rate of T-cell epitope generation and allergenicity. These results highlight the importance of lipid removal/reloading protocols such as the one described herein when studying allergens from both recombinant and natural sources. The protocol is generalizable to other allergen families including lipocalins (Mus m 1), PR-10 (Bet v 1), MD-2 (Der p 2) and Uteroglobin (Fel d 1), providing a valuable tool to study the role of lipids in the allergic response.

This protocol describes the removal of endogenous lipids from allergens, and their replacement with user-specified ligands through reverse-phase HPLC coupled with thermal annealing. 31P-NMR and circular dichroism allow for the rapid confirmation of ligand removal/loading, and the recovery of native allergen structure.

지질 결합 단백질및 알레르겐에서 내인성 리간드의 제거 및 교체

Many major allergens bind to hydrophobic lipid-like molecules, including Mus m 1, Bet v 1, Der p 2, and Fel d 1. These ligands are strongly retained and ...

An Economical and Versatile High-Throughput Protein Purification System Using a Multi-Column Plate Adapter

Protein purification is imperative to the study of protein structure and function and is usually used in combination with biophysical techniques. It is also a key component in the development of new therapeutics. The evolving era of functional proteomics is fueling the demand for high-throughput protein purification and improved techniques to facilitate this. It was hypothesized that a multi column plate adaptor (MCPA) can interface multiple chromatography columns of different resins with multi-well plates for parallel purification. This method offers an economical and versatile method of protein purification that can be used under gravity or vacuum, rivaling the speed of an automated system. The MCPA can be used to recover milligram yields of protein by an affordable and time efficient method for subsequent characterization and analysis. The MCPA has been used for high-throughput affinity purification of SH3 domains. Ion exchange has also been demonstrated via the MCPA to purify protein post Ni-NTA affinity chromatography, indicating how this system can be adapted to other purification types. Due to its setup with multiple columns, individual customization of parameters can be made in the same purification, unachievable by the current plate-based methods.

A multi-column plate adapter allows chromatography columns to be interfaced with multi-well collection plates for parallel affinity or ion exchange purification providing an economical high throughput protein purification method. It can be used under gravity or vacuum yielding milligram quantities of protein via affordable instrumentation.

다중 컬럼 플레이트 어댑터를 사용하는 경제적이고 다재다능한 고처리량 단백질 정화 시스템

Protein purification is imperative to the study of protein structure and function and is usually used in combination with biophysical techniques. It is ...