우리는 귀중한 조언, 토론 및 기술 지원 알랭 테시어에 감사하고 있습니다. 우리는 뛰어난 서비스 콩코디아 대학에서 질량 분석법의 생물 학적 응용 프로그램을위한 센터를 인정합니다. 이 작품은 CIHR과 캐나다의 NSERC에서 보조금에 의해 지원되었다. VIT는 CIHR 새로운 인베스티게이터와 게놈의 콩코디아 대학 연​​구 위원장, 세포 생물학 및 노화입니다.

재료 및 방법 <ol><li> 효모 변종과 성장 조건 야생 형 변형 BY4742는 (MATα his3Δ1 leu2Δ0 lys2Δ0 ura3Δ0) (1 % 효모 추출물, 펩톤 2 %, 2 % 포도당) 풍부한 YEPD 매체에서 재배되었다. 전지는 30 ° C 회전이 5시 1분의 &quot;플라스크 볼륨 / 볼륨 매체&quot;비율 Erlenmeyer flasks의 200 rpm으로 잡고 교양되었습니다. </li><li> 지질 추출을위한 효모 세포의 스토리지 <ol><li> 세포의 50 ML 문화 5 분 동안 3,000 XG에서 원심 분리에 의해 수확했다. </li><li> 찬물로 두 번 씻어. <ol style=" list-style-type:lower-alpha;"><li> 25 ML 얼음 냉수에 Resuspend 펠릿 </li><li> 5 분 3,000 XG에 원심 분리기의 펠릿 세포 </li></ol></li><li> eppendorf 튜브에 펠렛 및 전송을 Resuspend </li><li> 원심 분리에 의해 펠렛, 2 분 16,000 XG, 사용할 때까지 -80 ° C에서 뜨는 및 동결을 제거하십시오. (우리는 이소 프로필 알코올의 비이커를 사용, 액체 질소도 사용할 수있는 -80 냉동실에 보관) </li></ol></li><li> 시약 생명 공학 등급 클로로포름과 메탄올은 시그마 - 알드리치에서 있었다. 자유 지방산과 triacylglycerols는 Larodan (말뫼, 스웨덴)에서 구입했다. phospholipids의 다양한 종류 - phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidic 산성 및 cardiolipins 포함하여 - 아반티 북극 지질 (엘라 베스터, AL, 미국)에서 얻은되었습니다. 테플론 늘어선 모자와 고속 유리 원심 분리기 튜브는 피셔에서 있었다. </li></ol> 지질 추출 이것은 블라과 다이어 8 시까지 설명한 프로토콜의 수정입니다. 추출 lipids로 모든 조작은 유리 pipettes이나 주사기를 사용하여 완료해야합니다, 그들은 클로로포름과 접촉하면 플라스틱이 큰 배경 신호를 생성합니다. MeOH - - 클로로포름에 대한 H 2 단계 3 O 및 2:2:1.8 - MeOH - H 2 O 7 단계에서 보존 아르 클로로포름에 대한 1:2:0.8의 비율이로 정확한 볼륨은 한 중요하지 않습니다. <ol><li> 얼음처럼 차가운 소주 H 2 O.의 1.6 ML에 냉동 세포를 Resuspend </li><li> 고속 유리 원심 튜브에 세포 현탁액의 1.6 ML을 전송합니다. </li><li> 클로로포름과 MeOH (1시 2분) 믹스와 세포 현탁액을 유리 구슬의 0.8 ML 6 ML을 추가합니다. </li><li> 유리 구슬 1 분 두 배와 함께 소용돌이 세포 현탁액을. </li><li> 클로로포름 2 ML을 추가하고 부드럽게 섞는다. </li><li> 가끔 혼합과 함께 실온에서 5 분 알을 품다. </li><li> 소주 H 2 O 2 ML을 추가하고 부드럽게 섞는다. </li><li> 가끔 혼합과 함께 실온에서 5 분 알을 품다. </li><li> 상온에서 3,000 XG에서 5 분 원심 분리기. </li><li> 새로운 고속 유리 원심 튜브에 전체 액상를 수집합니다. </li><li> 9 단계에서 세포 펠렛을 클로로포름 3.2 ML를 추가합니다. </li><li> 1 분 와동을 차례로 두 번. </li><li> 상온에서 3,000 XG에서 5 분 원심 분리기. </li><li> 10 단계에서 액상으로 뜨는을 추가합니다. </li><li> 상온에서 3,000 XG에서 5 분 원심 분리기. </li><li> 상단 (수성) 단계를 폐기하고 새로운 고속 유리 원심 관에 낮은 (유기) 단계를 전송합니다. </li><li> 상온에서 3,000 XG에서 5 분 원심 분리기. </li><li> 유리관에 전체 표면에 뜨는를 전송하고 질소하에 건조. </li><li> -20 ° C. 500 클로로포름의 μl와 저장소에있는 지질 필름을 디졸브 </li></ol> 질량 분석법에 의해 lipids 분석 0.1 %로 클로로포름 (1:1) (V / V) 암모늄 수산화 - 클로로포름의 지질 기준 주식 혼합은 표 1과 같은뿐만 아니라 MeOH의 재고 솔루션마다 미리 준비를해야합니다. <ol><li> 이전 주사로, 표 1에서 제공하는 lipids의 표준 혼합 10 μl와 샘플 10 μl을 결합. 1시 1분 클로로포름의 200μL의 경우 : 0.1 % NH 4 OH와 메탄올. <ul><li> 샘플 비율 표준은 필요에 따라 변경할 수 있습니다. </li></ul></li><li> 1 μl / 분 유량에서 나노 전기 분무 소스 운영 갖춘 Micromass Q - TOF이 질량 분석기를 사용하여 lipids를 해결합니다. <ul><li> 정확한 악기 매개 변수는 악기에서 악기로 달라질 수 있습니다. 나노 전기 분무 소스 갖춘 Micromass Q - ToF 2 (워터스, 밀퍼드, MA, 미국)의 설정 표 2를 참조하십시오. 우리는 질량 분석계의 Q - TOF 유형의 고해상도의 이점을 촬영했지만, 그것은 필수 요구하지 않습니다. </li></ul></li><li> 취득 후 질량 스펙트럼은 smoothed 있으며, 배경 빼는와 중심 후 정상 목록은 Excel로 내보 냈습니다. 각 지질 클래스의 봉우리는 다음의 내부 기준에 정상화됩니다. 응용 프로그램에 따라, 그것은 deisotoping 및 deconvolution 등 추가로 후처리 등을 수행 할 필요가있을 수 있습니다. </li></ol> 표 1. 내부 지질 기준, 그들의 농도에표준 믹스, 그들의 분석을위한 MS 모드. <table border="1" cellspacing="0" cellpadding="0"><tbody><tr><td> 지질 클래스 </td><td> 표준 체인 구성 </td><td> 표준 질량 </td><td> 농도 (μg / ML) </td><td> MS 모드 </td></tr><tr><td> Phosphatidic 수 소산 </td><td> 14시 / 14시 </td><td> 591.40 </td><td> 100 </td><td> 부정 </td></tr><tr><td> Phosphatidylethanolamine </td><td> 14시 / 14시 </td><td> 634.45 </td><td> 200 </td><td> 부정 </td></tr><tr><td> Phosphatidylinositol </td><td> N / A </td><td> N / A </td><td> N / A </td><td> 부정 </td></tr><tr><td> Phosphatidylserine </td><td> 14시 / 14시 </td><td> 622.37 </td><td> 40 </td><td> 부정 </td></tr><tr><td> Cardiolipin </td><td> 4x14 : 0 </td><td> 619.92 </td><td> 100 </td><td> 부정 </td></tr><tr><td> 자유 지방산 </td><td> 19시 </td><td> 297.28 </td><td> 100 </td><td> 부정 </td></tr><tr><td> Phosphatidylcholine </td><td> 14시 / 14시 </td><td> 650.48 </td><td> 100 </td><td> 긍정적인 </td></tr><tr><td> Triacylglycerols </td><td> 13시 / 13시 / 13시 </td><td> 698.63 </td><td> 200 </td><td> 긍정적인 </td></tr></tbody></table> 표 2. Micromass Q - ToF 2 (워터스, 밀퍼드, MA, 미국)의 인스 트루먼트 설정은 나노 전기 분무 소스와 함께 갖추고 있습니다. <table border="1" cellspacing="0" cellpadding="0"><tbody><tr><td></td><td> 유량 </td><td> 콘 전압 </td><td> 모세관 전압 </td><td> 충돌 가스 </td></tr><tr><td> 긍정 모드 </td><td> 1μl/min </td><td> -28 V </td><td> 3.0 KV </td><td> 10 </td></tr><tr><td> 부정 모드 </td><td> 1μl/min </td><td> 30 V </td><td> -3.2 KV </td><td> 10 </td></tr></tbody></table>

<ol>
	<li>Cao, H., Gerhold, K., Mayers, J. R., Wiest, M. M., Watkins, S. M., Hotamisligil, G. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+a+lipokine,+a+lipid+hormone+linking+adipose+tissue+to+systemic+metabolism.">Identification of a lipokine, a lipid hormone linking adipose tissue to systemic metabolism.</a> Cell. 134, 933-944 (2008).</li><li>Claypool, S. M., Oktay, Y., Boontheung, P., Loo, J. A., Koehler, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiolipin+defines+the+interactome+of+the+major+ADP/ATP+carrier+protein+of+the+mitochondrial+inner+membrane.">Cardiolipin defines the interactome of the major ADP/ATP carrier protein of the mitochondrial inner membrane.</a> J. Cell Biol. 182, 937-950 (2008).</li><li>Guo, T., Gregg, C., Boukh-Viner, T., Kyryakov, P., Goldberg, A., Bourque, S., Banu, F., Haile, S., Milijevic, S., San, K. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+signal+from+inside+the+peroxisome+initiates+its+division+by+promoting+the+remodeling+of+the+peroxisomal+membrane.">A signal from inside the peroxisome initiates its division by promoting the remodeling of the peroxisomal membrane.</a> J. Cell Biol. 177, 289-303 (2007).</li><li>Russell, S. J., Kahn, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endocrine+regulation+of+ageing.">Endocrine regulation of ageing.</a> Nat. Rev. Mol. Cell Biol. 8, 681-691 (2007).</li><li>Czabany, T., Athenstaedt, K., Daum, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis,+storage+and+degradation+of+neutral+lipids+in+yeast.">Synthesis, storage and degradation of neutral lipids in yeast.</a> Biochim. Biophys. Acta. 1771, 299-309 (2007).</li><li>Br&amp;uuml, g. g. e. r., Erben, B., Sandhoff, G., Wieland, R., &amp;amp, F. T., Lehmann, W. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+analysis+of+biological+membrane+lipids+at+the+low+picomole+level+by+nano-electrospray+ionization+tandem+mass+spectroscopy.">Quantitative analysis of biological membrane lipids at the low picomole level by nano-electrospray ionization tandem mass spectroscopy.</a> Proc. Natl. Acad. Sci. USA. 94, 2339-2344 (1997).</li><li>Schneiter, R., Br&#252;gger, B., Sandhoff, R., Zellnig, G., Leber, A., Lampl, M., Athenstaedt, K., Hrastnik, C., Eder, S., Daum, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrospray+ionization+tandem+mass+spectrometry+(ESI-MS/MS)+analysis+of+the+lipid+molecular+species+composition+of+yeast+subcellular+membranes+reveals+acyl+chain-based+sorting/remodeling+of+distinct+molecular+species+en+route+to+the+plasma+membrane.">Electrospray ionization tandem mass spectrometry (ESI-MS/MS) analysis of the lipid molecular species composition of yeast subcellular membranes reveals acyl chain-based sorting/remodeling of distinct molecular species en route to the plasma membrane.</a> J. Cell Biol. 146, 741-754 (1999).</li><li>Bligh, E. G., Dyer, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+rapid+method+of+total+lipid+extraction+and+purification.">A rapid method of total lipid extraction and purification.</a> Can. J. Biochem. Physiol. 37, 911-917 (1959).</li></ol>

이 방법은 쉽게 사용할 수, 저렴한 재료를 사용하여 효모 lipidome의 급속한 양적 평가를 수 있습니다. 이러한 lipids가 수산화 리튬과 수산화 암모늄을 대체하여 확인할 수 있지만이 방법은, diacylglycerols, ergosterols 및 ergosteryl 에스테르를 제외한 효모 세포에있는 지질의 종류 대부분의 신분증을 수 있습니다. 설명한 방법은 농도 선형성은 진​​도 2 ~ 3 주문 (지질 종류에 따라 다름) 이상의 확산과 함?...

a quantitative assessment of the yeast lipidome using electrospray ionization mass spectrometry

Lipids은 biomolecules의 주요 클래스 중 하나이며 중요한 역할 막 역학, 에너지 저장을 재생하고, 신호<sup&gt; 1-4</sup&gt;. 신진 효모<em&gt; Saccharomyces cerevisiae</em&gt; 주석 게놈 매우 간단한 lipidome있는 유전자와 화학적으로 manipulable 단세포 진핵세포 생물은 다세포 eukaryotes 다양한 지질 종류의 생물 학적 기능을 연구를위한 귀중한 모델입니다<sup&gt; 2,3,5</sup&gt;.<em&gt; S. cerevisiae</em&gt; 체인 주로 16 또는 18 탄소 원자와 하나 영 길이 또는 unsaturation 중 하나 학위 lipids 10 주요 클래스를 가지고<sup&gt; 6,7</sup&gt;. 지질 식별 및 부량에 대한 기존 방법 - 같은 고성능 액체 크로마 토그래피, 박막 크로마 토그래피, 형광 현미경, 그리고 MS의 다음 기체 크로마 토그래피로이 - 잘 설립하지만, 낮은 감성, lipids의 충분 별도의 다양한 분자 형태가 이전의 지질 derivitization를 필요로 가지고 있습니다 분석하거나, 꽤 시간이 소요될 수 있습니다. 여기 우리는 효모 세포에서 lipids의 전체 보완의 식별 및 부량에 대한 조사 스캔 ESI / MS를 사용하여 이러한 고유의 한계를 해결하기 위해 실험적인 접근 방법에 대한 자세한 설명을 제시한다. 설명한 방법은 크게함으로써 데이터 수집 과정을 가속, 효모 세포에서 발견한 복잡한 지질 혼합물의 분리 색층을 필요로하지 않습니다. 이 방법은 G / ML로 낮은 농도에서 지질 식별 및 부량을 활성화하고 성공적으로 전체 효모 세포 및 정화 organelles의 lipidomes를 평가에 적용되었습니다. 지질 분석이 방법을 사용하기위한 전체 효모 세포에서 Lipids 추출 두세 시간 정도 소요됩니다. 이것은 나노 전기 분무 소스 갖춘 Q - TOF 질량 분석기를 추출하여 건조 lipids 각각의 예제를 실행하기 위해 다섯 10 분 걸립니다.

Watch this Scientific Journal Video about A Quantitative Assessment of The Yeast Lipidome using Electrospray Ionization Mass Spectrometry at JoVE.com

A Quantitative Assessment of The Yeast Lipidome using Electrospray Ionization Mass Spectrometry

우리는 조사 스캔 전기 분무 이온화 질량 분광법 (ESI / MS)를 사용하여 효모의 수많은 지질 수종을 식별하기위한 새로운 양적 lipidomics 방법을 설명합니다. 이 방법은 현재 lipids, 감도 및 속도의 다양한 분자 형태를 해결하는 능력 지질 식별 및 부량 사용할 방법을 초과했습니다.

전기 분무 이온화 질량 분광법을 사용하여 효모 Lipidome의 양적 평가

Lipids are one of the major classes of biomolecules and play important roles membrane dynamics, energy storage, and signalling1-4. The budding yeast ...

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11.7K 조회수.  Concordia University. 우리는 조사 스캔 전기 분무 이온화 질량 분광법 (ESI / MS)를 사용하여 효모의 수많은 지질 수종을 식별하기위한 새로운 양적 lipidomics 방법을 설명합니다. 이 방법은 현재 lipids, 감도 및 속도의 다양한 분자 형태를 해결하는 능력 지질 식별 및 부량 사용할 방법을 초과했습니다.

비디오: A Quantitative Assessment of The Yeast Lipidome using Electrospray Ionization Mass Spectrometry

MALDI Sample Preparation: the Ultra Thin Layer Method

This video demonstrates the preparation of an ultra-thin matrix/analyte layer for analyzing peptides and proteins by Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS) 1,2. The ultra-thin layer method involves the production of a substrate layer of matrix crystals (alpha-cyano-4-hydroxycinnamic acid) on the sample plate, which serves as a seeding ground for subsequent crystallization of a matrix/analyte mixture. Advantages of the ultra-thin layer method over other sample deposition approaches (e.g. dried droplet) are that it provides (i) greater tolerance to impurities such as salts and detergents, (ii) better resolution, and (iii) higher spatial uniformity. This method is especially useful for the accurate mass determination of proteins. The protocol was initially developed and optimized for the analysis of membrane proteins and used to successfully analyze ion channels, metabolite transporters, and receptors, containing between 2 and 12 transmembrane domains 2. Since the original publication, it has also shown to be equally useful for the analysis of soluble proteins. Indeed, we have used it for a large number of proteins having a wide range of properties, including those with molecular masses as high as 380 kDa 3. It is currently our method of choice for the molecular mass analysis of all proteins. The described procedure consistently produces high-quality spectra, and it is sensitive, robust, and easy to implement.

This video demonstrates the preparation of an ultra-thin matrix/analyte layer for analyzing peptides and proteins by Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS).

든 샘플 준비 : 울트라 씬 레이어 방법

This video demonstrates the preparation of an ultra-thin matrix/analyte layer for analyzing peptides and proteins by Matrix-Assisted Laser Desorption ...

연구

생물학

Quantification of Proteins Using Peptide Immunoaffinity Enrichment Coupled with Mass Spectrometry

There is a great need for quantitative assays in measuring proteins. Traditional sandwich immunoassays, largely considered the gold standard in quantitation, are associated with a high cost, long lead time, and are fraught with drawbacks (e.g. heterophilic antibodies, autoantibody interference, 'hook-effect').1 An alternative technique is affinity enrichment of peptides coupled with quantitative mass spectrometry, commonly referred to as SISCAPA (Stable Isotope Standards and Capture by Anti-Peptide Antibodies).2 In this technique, affinity enrichment of peptides with stable isotope dilution and detection by selected/multiple reaction monitoring mass spectrometry (SRM/MRM-MS) provides quantitative measurement of peptides as surrogates for their respective proteins. SRM/MRM-MS is well established for accurate quantitation of small molecules 3, 4 and more recently has been adapted to measure the concentrations of proteins in plasma and cell lysates.5-7 To achieve quantitation of proteins, these larger molecules are digested to component peptides using an enzyme such as trypsin. One or more selected peptides whose sequence is unique to the target protein in that species (i.e. "proteotypic" peptides) are then enriched from the sample using anti-peptide antibodies and measured as quantitative stoichiometric surrogates for protein concentration in the sample. Hence, coupled to stable isotope dilution (SID) methods (i.e. a spiked-in stable isotope labeled peptide standard), SRM/MRM can be used to measure concentrations of proteotypic peptides as surrogates for quantification of proteins in complex biological matrices. The assays have several advantages compared to traditional immunoassays. The reagents are relatively less expensive to generate, the specificity for the analyte is excellent, the assays can be highly multiplexed, enrichment can be performed from neat plasma (no depletion required), and the technique is amenable to a wide array of proteins or modifications of interest.8-13 In this video we demonstrate the basic protocol as adapted to a magnetic bead platform.

Stable Isotope Standards and Capture by Anti-Peptide Antibodies (SISCAPA) couples affinity enrichment of peptides with stable isotope dilution mass spectrometry (MRM-MS) to provide quantitative measurement of peptides as surrogates for their respective proteins. Here we describe the protocol using magnetic particles in a partially automated format.

펩타이드 면역 친 화성 농축을 사용하여 단백질의 양을 정함은 질량 분광법과 함께

There is a great need for quantitative assays in measuring proteins. Traditional sandwich immunoassays, largely considered the gold standard in ...

Amide Hydrogen/Deuterium Exchange &amp; MALDI-TOF Mass Spectrometry Analysis of Pak2 Activation

Amide hydrogen/deuterium exchange (H/D exchange) coupled with mass spectrometry has been widely used to analyze the interface of protein-protein interactions, protein conformational changes, protein dynamics and protein-ligand interactions. H/D exchange on the backbone amide positions has been utilized to measure the deuteration rates of the micro-regions in a protein by mass spectrometry1,2,3. The resolution of this method depends on pepsin digestion of the deuterated protein of interest into peptides that normally range from 3-20 residues. Although the resolution of H/D exchange measured by mass spectrometry is lower than the single residue resolution measured by the Heteronuclear Single Quantum Coherence (HSQC) method of NMR, the mass spectrometry measurement in H/D exchange is not restricted by the size of the protein4. H/D exchange is carried out in an aqueous solution which maintains protein conformation. We provide a method that utilizes the MALDI-TOF for detection2, instead of a HPLC/ESI (electrospray ionization)-MS system5,6. The MALDI-TOF provides accurate mass intensity data for the peptides of the digested protein, in this case protein kinase Pak2 (also called &gamma;-Pak). Proteolysis of Pak 2 is carried out in an offline pepsin digestion. This alternative method, when the user does not have access to a HPLC and pepsin column connected to mass spectrometry, or when the pepsin column on HPLC does not result in an optimal digestion map, for example, the heavily disulfide-bonded secreted Phospholipase A2 (sPLA2). Utilizing this method, we successfully monitored changes in the deuteration level during activation of Pak2 by caspase 3 cleavage and autophosphorylation7,8,9.

Amide Hydrogen/Deuterium Exchange & MALDI-TOF Mass Spectrometry Analysis of Pak2 Activation

MALDI-TOF mass spectrometry was successfully utilized to monitor the amide hydrogen/deuterium exchange in protein kinase Pak2 activation.

Pak2 활성화의 아미드 수소 / 중수소 교환 및 든 - TOF 질량 분광법 분석

Amide hydrogen/deuterium exchange (H/D exchange) coupled with mass spectrometry has been widely used to analyze the interface of protein-protein ...

Profiling Thiol Redox Proteome Using Isotope Tagging Mass Spectrometry

Pseudomonas syringae pv. tomato strain DC3000 not only causes bacterial speck disease in Solanum lycopersicum but also on Brassica species, as well as on Arabidopsis thaliana, a genetically tractable host plant1,2. The accumulation of reactive oxygen species (ROS) in cotyledons inoculated with DC3000 indicates a role of ROS in modulating necrotic cell death during bacterial speck disease of tomato3. Hydrogen peroxide, a component of ROS, is produced after inoculation of tomato plants with Pseudomonas3. Hydrogen peroxide can be detected using a histochemical stain 3'-3' diaminobenzidine (DAB)4. DAB staining reacts with hydrogen peroxide to produce a brown stain on the leaf tissue4. ROS has a regulatory role of the cellular redox environment, which can change the redox status of certain proteins5. Cysteine is an important amino acid sensitive to redox changes. Under mild oxidation, reversible oxidation of cysteine sulfhydryl groups serves as redox sensors and signal transducers that regulate a variety of physiological processes6,7. Tandem mass tag (TMT) reagents enable concurrent identification and multiplexed quantitation of proteins in different samples using tandem mass spectrometry8,9. The cysteine-reactive TMT (cysTMT) reagents enable selective labeling and relative quantitation of cysteine-containing peptides from up to six biological samples. Each isobaric cysTMT tag has the same nominal parent mass and is composed of a sulfhydryl-reactive group, a MS-neutral spacer arm and an MS/MS reporter10. After labeling, the samples were subject to protease digestion. The cysteine-labeled peptides were enriched using a resin containing anti-TMT antibody. During MS/MS analysis, a series of reporter ions (i.e., 126-131 Da) emerge in the low mass region, providing information on relative quantitation. The workflow is effective for reducing sample complexity, improving dynamic range and studying cysteine modifications. Here we present redox proteomic analysis of the Pst DC3000 treated tomato (Rio Grande) leaves using cysTMT technology. This high-throughput method has the potential to be applied to studying other redox-regulated physiological processes.

Reactive oxygen species level is elevated when cells encounter stress conditions. Here we show the example of 3'-3' diaminobenzidine staining as well as cysTMT labeling and mass spectrometry to profile the redox proteome in Pseudomonas syringae treated tomato leaves.

동위 원소 태그 질량 분광법을 사용하여 Thiol 산화 환원 프로테옴 프로 파일링

Pseudomonas syringae pv. tomato strain DC3000 not only causes bacterial speck disease in Solanum lycopersicum but also on Brassica species, as well as on ...

A Protocol for the Identification of Protein-protein Interactions Based on 15N Metabolic Labeling, Immunoprecipitation, Quantitative Mass Spectrometry and Affinity Modulation

Protein-protein interactions are fundamental for many biological processes in the cell. Therefore, their characterization plays an important role in current research and a plethora of methods for their investigation is available1. Protein-protein interactions often are highly dynamic and may depend on subcellular localization, post-translational modifications and the local protein environment2. Therefore, they should be investigated in their natural environment, for which co-immunoprecipitation approaches are the method of choice3. Co-precipitated interaction partners are identified either by immunoblotting in a targeted approach, or by mass spectrometry (LC-MS/MS) in an untargeted way. The latter strategy often is adversely affected by a large number of false positive discoveries, mainly derived from the high sensitivity of modern mass spectrometers that confidently detect traces of unspecifically precipitating proteins. A recent approach to overcome this problem is based on the idea that reduced amounts of specific interaction partners will co-precipitate with a given target protein whose cellular concentration is reduced by RNAi, while the amounts of unspecifically precipitating proteins should be unaffected. This approach, termed QUICK for QUantitative Immunoprecipitation Combined with Knockdown4, employs Stable Isotope Labeling of Amino acids in Cell culture (SILAC)5 and MS to quantify the amounts of proteins immunoprecipitated from wild-type and knock-down strains. Proteins found in a 1:1 ratio can be considered as contaminants, those enriched in precipitates from the wild type as specific interaction partners of the target protein. Although innovative, QUICK bears some limitations: first, SILAC is cost-intensive and limited to organisms that ideally are auxotrophic for arginine and/or lysine. Moreover, when heavy arginine is fed, arginine-to-proline interconversion results in additional mass shifts for each proline in a peptide and slightly dilutes heavy with light arginine, which makes quantification more tedious and less accurate5,6. Second, QUICK requires that antibodies are titrated such that they do not become saturated with target protein in extracts from knock-down mutants.
Here we introduce a modified QUICK protocol which overcomes the abovementioned limitations of QUICK by replacing SILAC for 15N metabolic labeling and by replacing RNAi-mediated knock-down for affinity modulation of protein-protein interactions. We demonstrate the applicability of this protocol using the unicellular green alga Chlamydomonas reinhardtii as model organism and the chloroplast HSP70B chaperone as target protein7 (Figure 1). HSP70s are known to interact with specific co-chaperones and substrates only in the ADP state8. We exploit this property as a means to verify the specific interaction of HSP70B with its nucleotide exchange factor CGE19.

A Protocol for the Identification of Protein-protein Interactions Based on 15N Metabolic Labeling, Immunoprecipitation, Quantitative Mass Spectrometry and Affinity Modulation

We present a variation of the QUICK (QUantitative Immunoprecipitation Combined with Knockdown) approach that was introduced previously to distinguish between true and false protein-protein interactions. Our approach is based on 15N metabolic labeling, the modulation of affinities of protein-protein interactions by the presence/absence of ATP, immunoprecipitation, and quantitative mass spectrometry.

을 바탕으로 단백질 - 단백질 상호 작용의 확인에 프로토콜<sup&gt; 15</sup&gt; N 신진 대사 라벨링, Immunoprecipitation, 수량 질량 분석법 및 선호도 변조

Protein-protein interactions are fundamental for many biological processes in the cell. Therefore, their characterization plays an important role in ...

A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry

The introduced protocol provides a tool for the analysis of multiprotein complexes in the thylakoid membrane, by revealing insights into complex composition under different conditions. In this protocol the approach is demonstrated by comparing the composition of the protein complex responsible for cyclic electron flow (CEF) in Chlamydomonas reinhardtii, isolated from genetically different strains. The procedure comprises the isolation of thylakoid membranes, followed by their separation into multiprotein complexes by sucrose density gradient centrifugation, SDS-PAGE, immunodetection and comparative, quantitative mass spectrometry (MS) based on differential metabolic labeling (14N/15N) of the analyzed strains. Detergent solubilized thylakoid membranes are loaded on sucrose density gradients at equal chlorophyll concentration. After ultracentrifugation, the gradients are separated into fractions, which are analyzed by mass-spectrometry based on equal volume. This approach allows the investigation of the composition within the gradient fractions and moreover to analyze the migration behavior of different proteins, especially focusing on ANR1, CAS, and PGRL1. Furthermore, this method is demonstrated by confirming the results with immunoblotting and additionally by supporting the findings from previous studies (the identification and PSI-dependent migration of proteins that were previously described to be part of the CEF-supercomplex such as PGRL1, FNR, and cyt f). Notably, this approach is applicable to address a broad range of questions for which this protocol can be adopted and e.g. used for comparative analyses of multiprotein complex composition isolated from distinct environmental conditions.

A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry

The described comparative, quantitative proteomic approach aims at obtaining insights into the composition of multiprotein complexes&#160;under different conditions and is demonstrated by comparing genetically different strains. For quantitative analysis equal volumes of different fractions from a sucrose density gradient are mixed and analyzed by mass spectrometry.

multiprotein의 단지의 비교 분석을위한 새로운 접근 방식을 기반으로<sup&gt; 15</sup&gt; N 대사 라벨링 및 정량 질량 분석

The introduced protocol provides a tool for the analysis of multiprotein complexes in the thylakoid membrane, by revealing insights into complex ...

Capture Compound Mass Spectrometry - A Powerful Tool to Identify Novel c-di-GMP Effector Proteins

Considerable progress has been made during the last decade towards the identification and characterization of enzymes involved in the synthesis (diguanylate cyclases) and degradation (phosphodiesterases) of the second messenger c-di-GMP. In contrast, little information is available regarding the molecular mechanisms and cellular components through which this signaling molecule regulates a diverse range of cellular processes. Most of the known effector proteins belong to the PilZ family or are degenerated diguanylate cyclases or phosphodiesterases that have given up on catalysis and have adopted effector function. Thus, to better define the cellular c-di-GMP network in a wide range of bacteria experimental methods are required to identify and validate novel effectors for which reliable in silico predictions fail.
We have recently developed a novel Capture Compound Mass Spectrometry (CCMS) based technology as a powerful tool to biochemically identify and characterize c-di-GMP binding proteins. This technique has previously been reported to be applicable to a wide range of organisms1. Here we give a detailed description of the protocol that we utilize to probe such signaling components. As an example, we use Pseudomonas aeruginosa, an opportunistic pathogen in which c-di-GMP plays a critical role in virulence and biofilm control. CCMS identified 74% (38/51) of the known or predicted components of the c-di-GMP network. This study explains the CCMS procedure in detail, and establishes it as a powerful and versatile tool to identify novel components involved in small molecule signaling.

The ubiquitous second messenger c-di-GMP controls growth and behavior of many bacteria. We have developed a novel Capture Compound Mass Spectrometry based technology to biochemically identify and characterize c-di-GMP binding proteins in virtually any bacterial species.

캡처 복합 질량 분석 - 소설의 C 디 GMP 이펙터 단백질을 식별 할 수있는 강력한 도구

Considerable progress has been made during the last decade towards the identification and characterization of enzymes involved in the synthesis ...

Using Microfluidic Devices to Measure Lifespan and Cellular Phenotypes in Single Budding Yeast Cells

Budding yeast Saccharomyces cerevisiae is an important model organism in aging research. Genetic studies have revealed many genes with conserved effects on the lifespan across species. However, the molecular causes of aging and death remain elusive. To gain a systematic understanding of the molecular mechanisms underlying yeast aging, we need high-throughput methods to measure lifespan and to quantify various cellular and molecular phenotypes in single cells. Previously, we developed microfluidic devices to track budding yeast mother cells throughout their lifespan while flushing away newborn daughter cells. This article presents a method for preparing microfluidic chips and for setting up microfluidic experiments. Multiple channels can be used to simultaneously track cells under different conditions or from different yeast strains. A typical setup can track hundreds of cells per channel and allow for high-resolution microscope imaging throughout the lifespan of the cells. Our method also allows detailed characterization of the lifespan, molecular markers, cell morphology, and the cell cycle dynamics of single cells. In addition, our microfluidic device is able to trap a significant amount of fresh mother cells that can be identified by downstream image analysis, making it possible to measure the lifespan with higher accuracy.

This article presents a protocol optimized for the production of microfluidic chips and the setup of microfluidic experiments to measure the lifespan and cellular phenotypes of single yeast cells.

마이크로 유체 장치를 사용하면 단일 신진 효모 세포의 수명과 세포 표현형을 측정하는

Budding yeast Saccharomyces cerevisiae is an important model organism in aging research. Genetic studies have revealed many genes with conserved effects ...

Sample Preparation for Mass-spectrometry-based Proteomics Analysis of Ocular Microvessels

The use of isolated ocular blood vessels in vitro to decipher the pathophysiological state of the eye using advanced technological approaches has greatly expanded our understanding of certain diseases. Mass spectrometry (MS)-based proteomics has emerged as a powerful tool to unravel alterations in the molecular mechanisms and protein signaling pathways in the vascular beds in health and disease. However, sample preparation steps prior to MS analyses are crucial to obtain reproducible results and in-depth elucidation of the complex proteome. This is particularly important for preparation of ocular microvessels, where the amount of sample available for analyses is often limited and thus, poses a challenge for optimum protein extraction. This article endeavors to provide an efficient, rapid and robust protocol for sample preparation from an exemplary retrobulbar ocular vascular bed employing the porcine short posterior ciliary arteries. The present method focuses on protein extraction procedures from both the supernatant and pellet of the sample following homogenization, sample cleaning with centrifugal filter devices prior to one-dimensional gel electrophoresis and peptide purification steps for label-free quantification in a liquid chromatography-electrospray ionization-linear ion trap-Orbitrap MS system. Although this method has been developed specifically for proteomics analyses of ocular microvessels, we have also provided convincing evidence that it can also be readily employed for other tissue-based samples.

Proteome characterization of ocular microvascular beds is pivotal for in-depth understanding of many ocular pathologies in humans. This study demonstrates an effective, rapid, and robust method for protein extraction and sample preparation from small blood vessels employing the porcine short posterior ciliary arteries as model vessels for mass-spectrometry-based proteomics analyses.

눈 Microvessels의 질량 분석 기반 Proteomics 분석을 위한 시료 준비

The use of isolated ocular blood vessels in vitro to decipher the pathophysiological state of the eye using advanced technological approaches has greatly ...

Genetic Modification of Cyanobacteria by Conjugation Using the CyanoGate Modular Cloning Toolkit

Cyanobacteria are a diverse group of prokaryotic photosynthetic organisms that can be genetically modified for the renewable production of useful industrial commodities. Recent advances in synthetic biology have led to development of several cloning toolkits such as CyanoGate, a standardized modular cloning system for building plasmid vectors for subsequent transformation or conjugal transfer into cyanobacteria. Here we outline a detailed method for assembling a self-replicating vector (e.g., carrying a fluorescent marker expression cassette) and conjugal transfer of the vector into the cyanobacterial strains Synechocystis sp. PCC 6803 or Synechococcus elongatus UTEX 2973. In addition, we outline how to characterize the performance of a genetic part (e.g., a promoter) using a plate reader or flow cytometry.

Here, we present a protocol describing how to i) assemble a self-replicating vector using the CyanoGate modular cloning toolkit, ii) introduce the vector into a cyanobacterial host by conjugation, and iii) characterize transgenic cyanobacteria strains using a plate reader or flow cytometry.

전기 분무 이온화 질량 분광법을 사용하여 효모 Lipidome의 양적 평가

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