We thank the Venters Lab and members of the Molecular Physiology and Biophysics Department for helpful discussions. Special thanks to Frank Pugh for his guidance, mentoring, and many insightful discussions on the nuances of ChIP-exo while I was a post-doctoral fellow in his laboratory.

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The authors have nothing to disclose.

<html> 우리는 염색질 근처 염기쌍 해상도 편견, 게놈 차원의 방식으로 단백질 상호 작용에 대한 정확한 결합 위치를 결정하기 위해 기능 유전체학 프로토콜을 제시한다. 면역 침전이 자성 수지에 남아있는 동안 근처 염기쌍 매핑 해상도를 얻기 위해 가장 중요한 단계는 칩 - 풍부 DNA의 엑소 뉴 클레아 제 처리이다. 표면 상, 단백질 복합체는 잠재적으로 주어진 서브 유닛 (예를 들어, 크로 마?...

크로 마틴 면역 침강 (칩)을 선택적으로 살아있는 세포에서 특정 단백질과 상호 작용하는 DNA 단편을 위해 농축에 의해 유전자 조절 메커니즘을 연구하는 강력한 방법이다. 기술은 높은 처리량 시퀀싱 (칩-SEQ) 1 올리고 뉴클레오티드 마이크로 어레이 (칩 - 칩)에 하이브리드에 하나의 궤적 (표준 칩-qPCR에) 검출에서 향상으로 칩 농축 DNA 단편의 검출 방법은 진화했다. 칩-서열이 광범위한 응용 프로그램, 염색질 이질성과 비특이적 DNA 상호 작용을 볼 수 있지만 오탐 (false positive)과 부정확 한 매핑 최고의 데이터 품질을 방해했다. 이러한 제한을 우회하기 위해, 박사 프랭크 퓨는 칩 - 엑소 방법 (2)를 개발했다. 칩 엑소의 두드러진 특징은 효율적으로 위치를 결합 전사 인자를 footprinting에, 엑소 뉴 클레아 &#39;3&#39;, 5를 포함하고 있다는 것이다. 결과적으로, 칩 - 엑소 방법은 높은 해상도 detectio의 큰 동적 범위를 달성n 및 낮은 소음. 칩 - 엑소 좀 더 기술적으로 어려운 칩-서열보다 마스터하지만 연구는 다양한 생물학적 시스템 3-8를 사용하여 고유의 초 고해상도 통찰력을 확보하는 것을 목표로, 그것은 널리 채택되고있다. 실제로, 칩 엑소 성공적 박테리아, 효모, 마우스, 래트, 인간 세포 시스템에 적용되어왔다. 원리의 증거로, 칩 - 엑소는 원래 효모 전사의 소수는 2 요인에 대한 정확한 바인딩 모티브를 식별하는 데 사용되었다. 이 기술은 또한 전사 개시전 복합체의 구성을 연구하기 위해 다양한 히스톤 9,10 subnucleosomal의 구조를 해독 효모에 사용 하였다. 최근에, 우리는 인간의 발기인에 이벤트를 바인딩 인접 TFIIB와 폴 II를 해결하기 위해 칩 - 엑소을 활용, 별개의 개시 11 복합체에서 널리 발산 전사가 발생하는 것으로 나타났다. 여기에 제시된 워크 플로우 최적화의있다포유 동물 칩 - 엑소 (그림 1)에 대한 treamlined. 첫째, 생활 차 또는 조직 배양 세포를 공유 가교를 통해 생체 내 단백질 DNA 상호 작용에 보존하는 포름 알데히드로 처리됩니다. 세포 용균 및 염색질은 100 ~ 전단된다 - 500 염기쌍 크기 단편. 칩은 선택적으로 관심있는 단백질에 가교 결합 된 DNA 단편에 대한 풍부. 이 시점에서, 칩은 일반적 서열 라이브러리 본질적 수백 염기쌍 단편의 평균 크기를 검출 해상도를 제한하는 제조된다. 그러나, 칩 엑소 왼쪽 및 람다 엑소 뉴 클레아 제와 단백질의 DNA 가교 부위의 바로 5 &#39;DNA 경계를 트리밍함으로써 이러한 제한을 극복한다. 아래에 설명 된대로 시퀀싱 라이브러리는 다음 엑소 뉴 클레아 제 소화 DNA로 구성되어있다. 얻어진 중첩 5 &#39;테두리 단백질 DNA 상호 작용 (도 1, 스텝 14)의 생체 내 공간을 나타내고, 높은 처리량 시퀀싱에 의해 검출된다. Alt 키무릎이 칩 엑소 방법은 칩-서열보다 더 복잡 대부분의 단계 사이의 전환은 샘플 손실과 실험적인 변동성을 최소화 간단한 비드 세척을 필요로한다. 중요한 것은, 칩 - 엑소는 칩-SEQ, 또한 칩 - 엑소에 성공한다 칩-서열에 성공하는 샘플의 세련된 버전 때문이다. 칩 서열에서 근본적으로 구별되는 데이터 구조의 칩 엑소 결과 단백질 DNA의 상호 작용의 생체 배출량 측정. 공통 칩 서열 발신자가 가장 정확한 피크 호출을 수득 칩 엑소 데이터에 적용될 수 있지만, 우리는 특별히 염두 칩 엑소 데이터의 독특한 구조로 설계 정보학 도구를 추천한다. 이들은 Genetrack, GEM, MACE, Peakzilla 및 ExoProfiler 12-15을 포함한다.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr >
			<td >37% formaldehyde, methanol free, 10x10ml ampules</td>
			<td >ThermoFisher Scientific</td>
			<td >28908</td>
			<td >Section 3</td>
		</tr>
		<tr >
			<td >Complete Protease Inhibitor cocktail (CPI)</td>
			<td >Roche Life Science</td>
			<td >11873580001</td>
			<td >Sections 4, 8</td>
		</tr>
		<tr >
			<td >Bioruptor sonicator</td>
			<td >Diagenode</td>
			<td >UCD200</td>
			<td >Section 5</td>
		</tr>
		<tr >
			<td >15 ml polystyrene tubes</td>
			<td >BD Falcon</td>
			<td >352095</td>
			<td >Section 5</td>
		</tr>
		<tr >
			<td >MagSepharose Protein G Xtra beads</td>
			<td >GE Healthcare</td>
			<td >28-9670-66</td>
			<td >Section 6</td>
		</tr>
		<tr >
			<td >DynaMag-1.5ml Side Magnetic Rack</td>
			<td >Invitrogen</td>
			<td >12321D</td>
			<td >Sections 6-17, 22</td>
		</tr>
		<tr >
			<td >Mini-Tube Rotator</td>
			<td >Fisher Scientific</td>
			<td >05-450-127</td>
			<td >Sections 7, 22</td>
		</tr>
		<tr >
			<td >T4 DNA Polymerase</td>
			<td >New England BioLabs</td>
			<td >M0203</td>
			<td >Section 9</td>
		</tr>
		<tr >
			<td >DNA Polymerase I, Klenow</td>
			<td >New England BioLabs</td>
			<td >M0210</td>
			<td >Section 9</td>
		</tr>
		<tr >
			<td >10x NEBuffer 2 (10x Reaction Buffer 2)</td>
			<td >New England BioLabs</td>
			<td >B7002</td>
			<td >Sections 9-11, 13, 15, 20</td>
		</tr>
		<tr >
			<td >Thermomixer C</td>
			<td >Eppendorf</td>
			<td >5382</td>
			<td >Sections 9-16</td>
		</tr>
		<tr >
			<td >ATP</td>
			<td >Roche Life Science</td>
			<td >010419979001</td>
			<td >Sections 9, 11, 13</td>
		</tr>
		<tr >
			<td >dNTPs</td>
			<td >New England BioLabs</td>
			<td >N0447</td>
			<td >Sections 9, 12, 19, 23</td>
		</tr>
		<tr >
			<td >T4 Polynucleotide Kinase</td>
			<td >New England BioLabs</td>
			<td >M0201</td>
			<td >Sections 9, 13</td>
		</tr>
		<tr >
			<td >dATP</td>
			<td >New England BioLabs</td>
			<td >N0440</td>
			<td >Sections 10, 20</td>
		</tr>
		<tr >
			<td >Klenow 3&#39;-5&#39; Exo Minus</td>
			<td >New England BioLabs</td>
			<td >M0212</td>
			<td >Sections 10, 20</td>
		</tr>
		<tr >
			<td >T4 DNA ligase&#160;</td>
			<td >New England BioLabs</td>
			<td >M0202</td>
			<td >Sections 11, 21</td>
		</tr>
		<tr >
			<td >&#934;-29 DNA Polymerase</td>
			<td >New England BioLabs</td>
			<td >M0269</td>
			<td >Sections 12, 19</td>
		</tr>
		<tr >
			<td >10x &#934;-29 Buffer</td>
			<td >New England BioLabs</td>
			<td >B0269</td>
			<td >Sections 12, 19</td>
		</tr>
		<tr >
			<td >Lambda Exonuclease</td>
			<td >New England BioLabs</td>
			<td >M0262</td>
			<td >Section 14</td>
		</tr>
		<tr >
			<td >10x Lambda Buffer</td>
			<td >New England BioLabs</td>
			<td >B0262</td>
			<td >Section 14</td>
		</tr>
		<tr >
			<td >RecJf Exonuclease</td>
			<td >New England BioLabs</td>
			<td >M0264</td>
			<td >Section 15</td>
		</tr>
		<tr >
			<td >Proteinase K</td>
			<td >Roche Life Science</td>
			<td >03115828001</td>
			<td >Section 16</td>
		</tr>
		<tr >
			<td >Glycogen</td>
			<td >Roche Life Science</td>
			<td >010901393001</td>
			<td >Section 18</td>
		</tr>
		<tr >
			<td >10x T4 Ligase Buffer</td>
			<td >New England BioLabs</td>
			<td >B0202</td>
			<td >Section 21</td>
		</tr>
		<tr >
			<td >AMPure XP (clean up) beads&#160;</td>
			<td >Beckman Coulter</td>
			<td >A63881</td>
			<td >Section 22</td>
		</tr>
		<tr >
			<td >Q5 Hot Start DNA Polymerase&#160;</td>
			<td >New England BioLabs</td>
			<td >M0493</td>
			<td >Section 23</td>
		</tr>
		<tr >
			<td >5x Q5 Buffer (5x PCR Buffer)</td>
			<td >New England BioLabs</td>
			<td >B9027</td>
			<td >Section 23</td>
		</tr>
		<tr >
			<td >Qubit Fluorometer</td>
			<td >Invitrogen</td>
			<td >Q33216</td>
			<td >Section 25</td>
		</tr>
		<tr >
			<td >QIAquick Gel Extraction Kit</td>
			<td >Qiagen</td>
			<td >28704</td>
			<td >Section 25</td>
		</tr>
		<tr >
			<td >Optical Clear Qubit tubes&#160;</td>
			<td >Invitrogen</td>
			<td >Q32856</td>
			<td >Section 26</td>
		</tr>
		<tr >
			<td >Qubit dsDNA High Sensitivity Assay kit</td>
			<td >Invitrogen</td>
			<td >Q32851</td>
			<td >Section 26</td>
		</tr>
	</tbody>
</table>

the chip-exo method: identifying protein-dna interactions with near base pair precision

크로 마틴 면역 침강 (칩)은 후성 유전학 및 특정 단백질 DNA 상호 작용을 분리 유전자 조절의 분야에서 필수적인 도구입니다. 높은 처리량 시퀀싱 (칩 서열)에 결합 된 칩은 일반적으로 염색질 상호 작용 단백질의 게놈 위치를 결정하기 위해 사용된다. 그러나, 칩 서열은 수백 염기쌍 비교적 낮은 매핑 해상도 및 높은 백그라운드 신호에 의해 방해된다. 칩 엑소 방법은 실질적으로 해상도 및 노이즈 모두 개선 한 칩 서열의 정제 된 버전이다. 칩 엑소 방법론의 키 차이는 효과적으로 왼쪽 풋 프린트 라이브러리 준비 워크 플로의 람다 엑소 뉴 클레아 제 소화의 설립 및 단백질 DNA의 가교 사이트의 오른쪽 5 &#39;DNA 테두리입니다. 칩 엑소 라이브러리는 다음 높은 처리량 시퀀싱을 실시한다. 얻어진 데이터는 기능적 조직 O에 고유 초 고해상도 통찰력을 제공하기 위해 활용 될 수있다게놈 바. 여기, 우리는 우리가 최적화 및 포유류 시스템과 차세대 시퀀싱 합성에 의한 플랫폼 간소화 한 칩 - 엑소 방법을 설명합니다.

다음 그림은 여기에 제시된 칩 - 엑소 프로토콜 대표 결과를 보여줍니다. 몇 효소 단계를 기존의 칩-SEQ 방법과는 달리, 칩 - 엑소는 열한 순차적으로 의존 효소 반응 (그림 1)가 필요합니다. 따라서, 치료는 각 반응 성분이 각각의 반응 마스터 믹스에 추가되도록 각 단계에서 수행되어야한다. 우리는 생성 된 표를 인쇄하는 자동 반응 마스터 믹스 계산을 수행하?...

Watch this Scientific Journal Video about The ChIP-exo Method: Identifying Protein-DNA Interactions with Near Base Pair Precision at JoVE.com

The ChIP-exo Method: Identifying Protein-DNA Interactions with Near Base Pair Precision

Here, we present a protocol to achieve near base pair resolution of protein-DNA interactions. This is obtained by exonuclease treatment of DNA fragments selectively enriched by chromatin immunoprecipitation (ChIP-exo) followed by high throughput sequencing.

칩 엑소 방법 : 가까운 자료 쌍의 정밀과 단백질 DNA 상호 작용을 확인

Chromatin immunoprecipitation (ChIP) is an indispensable tool in the fields of epigenetics and gene regulation that isolates specific protein-DNA ...

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16.5K 조회수.  Vanderbilt University. Here, we present a protocol to achieve near base pair resolution of protein-DNA interactions. This is obtained by exonuclease treatment of DNA fragments selectively enriched by chromatin immunoprecipitation (ChIP-exo) followed by high throughput sequencing.

비디오: The ChIP-exo Method: Identifying Protein-DNA Interactions with Near Base Pair Precision

Exploring Cognitive Functions in Babies, Children &amp; Adults with Near Infrared Spectroscopy

An explosion of functional Near Infrared Spectroscopy (fNIRS) studies investigating cortical activation in relation to higher cognitive processes, such as language1,2,3,4,5,6,7,8,9,10, memory11, and attention12 is underway worldwide involving adults, children and infants 3,4,13,14,15,16,17,18,19 with typical and atypical cognition20,21,22. The contemporary challenge of using fNIRS for cognitive neuroscience is to achieve systematic analyses of data such that they are universally interpretable23,24,25,26, and thus may advance important scientific questions about the functional organization and neural systems underlying human higher cognition.
Existing neuroimaging technologies have either less robust temporal or spatial resolution. Event Related Potentials and Magneto Encephalography (ERP and MEG) have excellent temporal resolution, whereas Positron Emission Tomography and functional Magnetic Resonance Imaging (PET and fMRI) have better spatial resolution. Using non-ionizing wavelengths of light in the near-infrared range (700-1000 nm), where oxy-hemoglobin is preferentially absorbed by 680 nm and deoxy-hemoglobin is preferentially absorbed by 830 nm (e.g., indeed, the very wavelengths hardwired into the fNIRS Hitachi ETG-400 system illustrated here), fNIRS is well suited for studies of higher cognition because it has both good temporal resolution (~5s) without the use of radiation and good spatial resolution (~4 cm depth), and does not require participants to be in an enclosed structure27,28. Participants cortical activity can be assessed while comfortably seated in an ordinary chair (adults, children) or even seated in mom s lap (infants). Notably, NIRS is uniquely portable (the size of a desktop computer), virtually silent, and can tolerate a participants subtle movement. This is particularly outstanding for the neural study of human language, which necessarily has as one of its key components the movement of the mouth in speech production or the hands in sign language. 
The way in which the hemodynamic response is localized is by an array of laser emitters and detectors. Emitters emit a known intensity of non-ionizing light while detectors detect the amount reflected back from the cortical surface. The closer together the optodes, the greater the spatial resolution, whereas the further apart the optodes, the greater depth of penetration. For the fNIRS Hitachi ETG-4000 system optimal penetration / resolution the optode array is set to 2cm. 
Our goal is to demonstrate our method of acquiring and analyzing fNIRS data to help standardize the field and enable different fNIRS labs worldwide to have a common background.

Exploring Cognitive Functions in Babies, Children & Adults with Near Infrared Spectroscopy

Here we describe a data collection and data analysis method for functional Near Infrared Spectroscopy (fNIRS), a novel non-invasive brain imaging system used in cognitive neuroscience, particularly in studying child brain development. This method provides a universal standard of data acquisition and analysis vital to data interpretation and scientific discovery.

가까운 적외선 분광학과 함께 아기, 어린이 및 성인의인지 기능을 탐색

An explosion of functional Near Infrared Spectroscopy (fNIRS) studies investigating cortical activation in relation to higher cognitive processes, such as ...

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Split-Ubiquitin Based Membrane Yeast Two-Hybrid (MYTH) System: A Powerful Tool For Identifying Protein-Protein Interactions

The fundamental biological and clinical importance of integral membrane proteins prompted the development of a yeast-based system for the high-throughput identification of protein-protein interactions (PPI) for full-length transmembrane proteins. To this end, our lab developed the split-ubiquitin based Membrane Yeast Two-Hybrid (MYTH) system. This technology allows for the sensitive detection of transient and stable protein interactions using Saccharomyces cerevisiae as a host organism. MYTH takes advantage of the observation that ubiquitin can be separated into two stable moieties: the C-terminal half of yeast ubiquitin (Cub) and the N-terminal half of the ubiquitin moiety (Nub). In MYTH, this principle is adapted for use as a 'sensor' of protein-protein interactions. Briefly, the integral membrane bait protein is fused to Cub which is linked to an artificial transcription factor. Prey proteins, either in individual or library format, are fused to the Nub moiety. Protein interaction between the bait and prey leads to reconstitution of the ubiquitin moieties, forming a full-length 'pseudo-ubiquitin' molecule. This molecule is in turn recognized by cytosolic deubiquitinating enzymes, resulting in cleavage of the transcription factor, and subsequent induction of reporter gene expression. The system is highly adaptable, and is particularly well-suited to high-throughput screening. It has been successfully employed to investigate interactions using integral membrane proteins from both yeast and other organisms.

Split-Ubiquitin Based Membrane Yeast Two-Hybrid MYTH System: A Powerful Tool For Identifying Protein-Protein Interactions

MYTH allows the sensitive detection of transient and stable interactions between proteins that are expressed in the model organism Saccharomyces cerevisiae. It has been successfully applied to study exogenous and yeast integral membrane proteins in order to identify their interacting partners in a high throughput manner.

분할 Ubiquitin 기반 막 효모 두 하이브리드 (신화) 시스템 : 단백질 단백질 상호 작용을 확인을위한 강력한 도구

The fundamental biological and clinical importance of integral membrane proteins prompted the development of a yeast-based system for the high-throughput ...

Associated Chromosome Trap for Identifying Long-range DNA Interactions

Genetic information encoded by DNA is organized in a complex and highly regulated chromatin structure. Each chromosome occupies a specific territory, that may change according to stage of development or cell cycle. Gene expression can occur in specialized transcriptional factories where chromatin segments may loop out from various chromosome territories, leading to co-localization of DNA segments which may exist on different chromosomes or far apart on the same chromosome. The Associated Chromosome Trap (ACT) assay provides an effective methodology to identify these long-range DNA associations in an unbiased fashion by extending and modifying the chromosome conformation capture technique. The ACT assay makes it possible for us to investigate mechanisms of transcriptional regulation in trans, and can help explain the relationship of nuclear architecture to gene expression in normal physiology and during disease states.

The associated chromosome trap (ACT) assay is a novel unbiased method for identifying long-range DNA interactions. The characterization of long range DNA interactions will allow us to determine the relationship of nuclear architecture to gene expression in both normal physiology and in diseased states.

장거리 DNA의 상호 작용을 확인을위한 관련 염색체 트랩

Genetic information encoded by DNA is organized in a complex and highly regulated chromatin structure.  Each chromosome occupies a specific territory, ...

The MultiBac Protein Complex Production Platform at the EMBL

Proteomics research revealed the impressive complexity of eukaryotic proteomes in unprecedented detail. It is now a commonly accepted notion that proteins in cells mostly exist not as isolated entities but exert their biological activity in association with many other proteins, in humans ten or more, forming assembly lines in the cell for most if not all vital functions.1,2 Knowledge of the function and architecture of these multiprotein assemblies requires their provision in superior quality and sufficient quantity for detailed analysis. The paucity of many protein complexes in cells, in particular in eukaryotes, prohibits their extraction from native sources, and necessitates recombinant production. The baculovirus expression vector system (BEVS) has proven to be particularly useful for producing eukaryotic proteins, the activity of which often relies on post-translational processing that other commonly used expression systems often cannot support.3 BEVS use a recombinant baculovirus into which the gene of interest was inserted to infect insect cell cultures which in turn produce the protein of choice. MultiBac is a BEVS that has been particularly tailored for the production of eukaryotic protein complexes that contain many subunits.4 A vital prerequisite for efficient production of proteins and their complexes are robust protocols for all steps involved in an expression experiment that ideally can be implemented as standard operating procedures (SOPs) and followed also by non-specialist users with comparative ease. The MultiBac platform at the European Molecular Biology Laboratory (EMBL) uses SOPs for all steps involved in a multiprotein complex expression experiment, starting from insertion of the genes into an engineered baculoviral genome optimized for heterologous protein production properties to small-scale analysis of the protein specimens produced.5-8 The platform is installed in an open-access mode at EMBL Grenoble and has supported many scientists from academia and industry to accelerate protein complex research projects.

Protein complexes catalyze key cellular functions. Detailed functional and structural characterization of many essential complexes requires recombinant production. MultiBac is a baculovirus/insect cell system particularly tailored for expressing eukaryotic proteins and their complexes. MultiBac was implemented as an open-access platform, and standard operating procedures developed to maximize its utility.

EMBL에서 MultiBac 단백질 복잡한 생산 플랫폼

Proteomics  research revealed the impressive complexity of eukaryotic proteomes in  unprecedented detail. It is now a commonly accepted notion that ...

Combining Single-molecule Manipulation and Imaging for the Study of Protein-DNA Interactions

The paper describes the combination of optical tweezers and single molecule fluorescence detection for the study of protein-DNA interaction. The method offers the opportunity of investigating interactions occurring in solution (thus avoiding problems due to closeby surfaces as in other single molecule methods), controlling the DNA extension and tracking interaction dynamics as a function of both mechanical parameters and DNA sequence. The methods for establishing successful optical trapping and nanometer localization of single molecules are illustrated. We illustrate the experimental conditions allowing the study of interaction of lactose repressor (lacI), labeled with Atto532, with a DNA molecule containing specific target sequences (operators) for LacI binding. The method allows the observation of specific interactions at the operators, as well as one-dimensional diffusion of the protein during the process of target search. The method is broadly applicable to the study of protein-DNA interactions but also to molecular motors, where control of the tension applied to the partner track polymer (for example actin or microtubules) is desirable.

Here we describe the instrumentation and methods for detecting single fluorescently-labeled protein molecules interacting with a single DNA molecule suspended between two optically trapped microspheres.

단백질-DNA 상호 작용의 연구에 대한 단일 분자 조작 및 이미지를 결합

The paper describes the combination of optical tweezers and single molecule fluorescence detection for the study of protein-DNA interaction. The method ...

Identifying Protein-protein Interaction Sites Using Peptide Arrays

Protein-protein interactions mediate most of the processes in the living cell and control homeostasis of the organism. Impaired protein interactions may result in disease, making protein interactions important drug targets. It is thus highly important to understand these interactions at the molecular level. Protein interactions are studied using a variety of techniques ranging from cellular and biochemical assays to quantitative biophysical assays, and these may be performed either with full-length proteins, with protein domains or with peptides. Peptides serve as excellent tools to study protein interactions since peptides can be easily synthesized and allow the focusing on specific interaction sites. Peptide arrays enable the identification of the interaction sites between two proteins as well as screening for peptides that bind the target protein for therapeutic purposes. They also allow high throughput SAR studies. For identification of binding sites, a typical peptide array usually contains partly overlapping 10-20 residues peptides derived from the full sequences of one or more partner proteins of the desired target protein. Screening the array for binding the target protein reveals the binding peptides, corresponding to the binding sites in the partner proteins, in an easy and fast method using only small amount of protein.
In this article we describe a protocol for screening peptide arrays for mapping the interaction sites between a target protein and its partners. The peptide array is designed based on the sequences of the partner proteins taking into account their secondary structures. The arrays used in this protocol were Celluspots arrays prepared by INTAVIS Bioanalytical Instruments. The array is blocked to prevent unspecific binding and then incubated with the studied protein. Detection using an antibody reveals the binding peptides corresponding to the specific interaction sites between the proteins.

Peptide array screening is a high throughput assay for identifying protein-protein interaction sites. This allows mapping multiple interactions of a target protein and can serve as a method for identifying sites for inhibitors that target a protein. Here we describe a protocol for screening and analyzing peptide arrays.

펩타이드 배열을 사용하여 단백질 - 단백질 상호 작용 사이트를 확인

Protein-protein interactions mediate most of the processes in the living cell and control homeostasis of the organism. Impaired protein interactions may ...

Method for the Assessment of Effects of a Range of Wavelengths and Intensities of Red/near-infrared Light Therapy on Oxidative Stress In Vitro

Red/near-infrared light therapy (R/NIR-LT), delivered by laser or light emitting diode (LED), improves functional and morphological outcomes in a range of central nervous system injuries in vivo, possibly by reducing oxidative stress. However, effects of R/NIR-LT on oxidative stress have been shown to vary depending on wavelength or intensity of irradiation. Studies comparing treatment parameters are lacking, due to absence of commercially available devices that deliver multiple wavelengths or intensities, suitable for high through-put in vitro optimization studies. This protocol describes a technique for delivery of light at a range of wavelengths and intensities to optimize therapeutic doses required for a given injury model. We hypothesized that a method of delivering light, in which wavelength and intensity parameters could easily be altered, could facilitate determination of an optimal dose of R/NIR-LT for reducing reactive oxygen species (ROS) in vitro.
Non-coherent Xenon light was filtered through narrow-band interference filters to deliver varying wavelengths (center wavelengths of 440, 550, 670 and 810nm) and fluences (8.5 x 10-3 to 3.8 x 10-1 J/cm2) of light to cultured cells. Light output from the apparatus was calibrated to emit therapeutically relevant, equal quantal doses of light at each wavelength. Reactive species were detected in glutamate stressed cells treated with the light, using DCFH-DA and H2O2 sensitive fluorescent dyes.&#160;
We successfully delivered light at a range of physiologically and therapeutically relevant wavelengths and intensities, to cultured cells exposed to glutamate as a model of CNS injury. While the fluences of R/NIR-LT used in the current study did not exert an effect on ROS generated by the cultured cells, the method of light delivery is applicable to other systems including isolated mitochondria or more physiologically relevant organotypic slice culture models, and could be used to assess effects on a range of outcome measures of oxidative metabolism.

Method for the Assessment of Effects of a Range of Wavelengths and Intensities of Red/near-infrared Light Therapy on Oxidative Stress In Vitro

Non-coherent Xenon light was passed through narrow-band interference and neutral density filters to deliver light of varying wavelength and intensity to cultured cells. This protocol was used to assess the effects of red/near-infrared light therapy on production of reactive species in vitro: no effects were observed using the tested parameters.

파장과 산화 스트레스에 레드 / 근적외선 치료의 강렬의 범위의 효과의 평가를위한 방법<em&gt; 체외</em

Red/near-infrared light therapy (R/NIR-LT), delivered by laser or light emitting diode (LED), improves functional and morphological outcomes in a range of ...

Enhanced Reduced Representation Bisulfite Sequencing for Assessment of DNA Methylation at Base Pair Resolution

DNA methylation pattern mapping is heavily studied in normal and diseased tissues. A variety of methods have been established to interrogate the cytosine methylation patterns in cells. Reduced representation of whole genome bisulfite sequencing was developed to detect quantitative base pair resolution cytosine methylation patterns at GC-rich genomic loci. This is accomplished by combining the use of a restriction enzyme followed by bisulfite conversion. Enhanced Reduced Representation Bisulfite Sequencing (ERRBS) increases the biologically relevant genomic loci covered and has been used to profile cytosine methylation in DNA from human, mouse and other organisms. ERRBS initiates with restriction enzyme digestion of DNA to generate low molecular weight fragments for use in library preparation. These fragments are subjected to standard library construction for next generation sequencing. Bisulfite conversion of unmethylated cytosines prior to the final amplification step allows for quantitative base resolution of cytosine methylation levels in covered genomic loci. The protocol can be completed within four days. Despite low complexity in the first three bases sequenced, ERRBS libraries yield high quality data when using a designated sequencing control lane. Mapping and bioinformatics analysis is then performed and yields data that can be easily integrated with a variety of genome-wide platforms. ERRBS can utilize small input material quantities making it feasible to process human clinical samples and applicable in a range of research applications. The video produced demonstrates critical steps of the ERRBS protocol.

Enhanced Reduced Representation Bisulfite Sequencing is a method for the preparation of sequencing libraries for DNA methylation analysis based on restriction enzyme digestion combined with cytosine bisulfite conversion. This protocol requires 50 ng of starting material and yields base pair resolution data at GC-rich genomic regions.

자료 쌍 해상도에서 DNA 메틸화의 평가에 대한 표현 바이 설 파이트 시퀀싱을 감소 향상

DNA methylation pattern mapping is heavily studied in normal and diseased tissues. A variety of methods have been established to interrogate the cytosine ...

A Method for Selecting Structure-switching Aptamers Applied to a Colorimetric Gold Nanoparticle Assay

Small molecules provide rich targets for biosensing applications due to their physiological implications as biomarkers of various aspects of human health and performance. Nucleic acid aptamers have been increasingly applied as recognition elements on biosensor platforms, but selecting aptamers toward small molecule targets requires special design considerations. This work describes modification and critical steps of a method designed to select structure-switching aptamers to small molecule targets. Binding sequences from a DNA library hybridized to complementary DNA capture probes on magnetic beads are separated from nonbinders via a target-induced change in conformation. This method is advantageous because sequences binding the support matrix (beads) will not be further amplified, and it does not require immobilization of the target molecule. However, the melting temperature of the capture probe and library is kept at or slightly above RT, such that sequences that dehybridize based on thermodynamics will also be present in the supernatant solution. This effectively limits the partitioning efficiency (ability to separate target binding sequences from nonbinders), and therefore many selection rounds will be required to remove background sequences. The reported method differs from previous structure-switching aptamer selections due to implementation of negative selection steps, simplified enrichment monitoring, and extension of the length of the capture probe following selection enrichment to provide enhanced stringency. The selected structure-switching aptamers are advantageous in a gold nanoparticle assay platform that reports the presence of a target molecule by the conformational change of the aptamer. The gold nanoparticle assay was applied because it provides a simple, rapid colorimetric readout that is beneficial in a clinical or deployed environment. Design and optimization considerations are presented for the assay as proof-of-principle work in buffer to provide a foundation for further extension of the work toward small molecule biosensing in physiological fluids.

A protocol is provided to select structure-switching aptamers for small molecule targets based on a tunable stringency magnetic bead selection method. Aptamers selected with structure-switching properties are beneficial for assays that require a conformational change to signal the presence of a target, such as the described gold nanoparticle assay.

색채 금 나노 입자 분석에 적용 구조 전환 앱 타머를 선택하는 방법

Small molecules provide rich targets for biosensing applications due to their physiological implications as biomarkers of various aspects of human health ...

Chromatin Immunoprecipitation Assay for the Identification of Arabidopsis Protein-DNA Interactions In Vivo

Intricate gene regulatory networks orchestrate biological processes and developmental transitions in plants. Selective transcriptional activation and silencing of genes mediate the response of plants to environmental signals and developmental cues. Therefore, insights into the mechanisms that control plant gene expression are essential to gain a deep understanding of how biological processes are regulated in plants. The chromatin immunoprecipitation (ChIP) technique described here is a procedure to identify the DNA-binding sites of proteins in genes or genomic regions of the model species Arabidopsis thaliana. The interactions with DNA of proteins of interest such as transcription factors, chromatin proteins or posttranslationally modified versions of histones can be efficiently analyzed with the ChIP protocol. This method is based on the fixation of protein-DNA interactions in vivo, random fragmentation of chromatin, immunoprecipitation of protein-DNA complexes with specific antibodies, and quantification of the DNA associated with the protein of interest by PCR techniques. The use of this methodology in Arabidopsis has contributed significantly to unveil transcriptional regulatory mechanisms that control a variety of plant biological processes. This approach allowed the identification of the binding sites of the Arabidopsis chromatin protein EBS to regulatory regions of the master gene of flowering FT. The impact of this protein in the accumulation of particular histone marks in the genomic region of FT was also revealed through ChIP analysis.

Chromatin Immunoprecipitation Assay for the Identification of Arabidopsis Protein-DNA Interactions In Vivo

Chromatin immunoprecipitation is a powerful technique for the identification of DNA binding sites of Arabidopsis proteins in vivo. This procedure includes chromatin cross-linking and fragmentation, immunoprecipitation with selective antibodies against the protein of interest, and qPCR analysis of bound DNA. We describe a simple ChIP assay optimized for Arabidopsis plants.

애기 장대 단백질 DNA 상호 작용의 식별을위한 염색질 면역 침전 분석<em&gt; 생체</em

Intricate gene regulatory networks orchestrate biological processes and developmental transitions in plants. Selective transcriptional activation and ...