Name: identification of fatty acids in bacillus cereus
Uploaded: 2016-12-05T15:00:00
Description: Watch this Scientific Journal Video about Identification of Fatty Acids in Bacillus cereus at JoVE.com

Yazarlar kendi teknik destek için Thomas Mison minnettarız ve yazının gözden geçirilmesi için Rachel Kopec için.

1. Bakteri kültürleri <ol><li> LB agar ortamı bir plaka yüzeyi üzerine, LB (Luria-Bertani ortamında) içinde 30 ° C&#39;de inkübe soyun bir gecelik kültüründen 100 ul yayarak bakteriler (Bacillus cereus ATCC 14579) &#39;in bir çim hazırlayın. 30 ° C&#39;de gece boyunca inkübasyona bırakılır. </li></ol> 2. ECL: Eşdeğer Zincir uzunluğu <ol><li> şöyle ECL hesaplayın: <img alt="denklem" src="/files/ftp_upload/54960/54960eq1.jpg" /> ile: Ben ilgi çözünen...

<ol>
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Y., Yu, Q. T., Liu, B. N., Huang, Z. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+modification+in+mass+spectrometry+IV-2-alkenyl-4,4-dimethyloxazolines+as+derivatives+for+the+double+bond+location+of+long-chain+olefinic+acids.">Chemical modification in mass spectrometry IV-2-alkenyl-4,4-dimethyloxazolines as derivatives for the double bond location of long-chain olefinic acids.</a> Biol Mass Spect. 15 (1), 33-44 (1988).</li><li>de Sarrau, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unsaturated+fatty+acids+from+food+and+in+the+growth+medium+improve+growth+of+Bacillus+cereus+under+cold+and+anaerobic+conditions.">Unsaturated fatty acids from food and in the growth medium improve growth of Bacillus cereus under cold and anaerobic conditions.</a> Food Microbiol. 36 (2), 113-122 (2013).</li><li>Miwa, T. K., Mikolajczak, K. L., Earle, F. R., Wolff, I. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gas+chromatographic+characterization+of+fatty+acids.Identification+constants+for+mono-+and+dicarboxylic+methyl+esters.">Gas chromatographic characterization of fatty acids.Identification constants for mono- and dicarboxylic methyl esters.</a> Anal Chem. 32 (13), 1739-1742 (1960).</li><li>van Den Dool, H., Kratz, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+generalization+of+the+retention+index+system+including+linear+temperature+programmed+gas-liquid+partition+chromatography.">A generalization of the retention index system including linear temperature programmed gas-liquid partition chromatography.</a> J Chromatogr A. 11, 463-471 (1963).</li><li>Stransky, K., Jursik, T., Vitek, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Standard+equivalent+chain+length+values+of+monoenic+and+polyenic+(methylene+interrupted)+fatty+acids.">Standard equivalent chain length values of monoenic and polyenic (methylene interrupted) fatty acids.</a> J High Res Chromatogr. 20 (3), 143-158 (1997).</li></ol>

Tablo 1 &#39;de gösterilen FAs kromatogram profilleri bir agar plakası yüzeyi üzerinde büyütülmüş, B. cereus ATCC 14579 karşılık gelmektedir. Bakteri, aynı sıcaklıkta 8 de gaz sıvı ortam içinde büyütülmüştür da benzer profilleri elde edilmiştir. Sıvı ortamda yetişen bakteri durumunda, bakteriyel biyokütlenin büyüme ortamının santrifüj ile toplanır ve büyüme koşulları 8,19 bağlı olarak daha önce tarif edilen protokollere göre yıka...

Yağlı asit metil ester (FAME), gaz kromatografisi (GC), lipid karakterizasyonu için gerekli bir yöntemdir. Bu hızlı bir şekilde ayırır ve kısa bir ekstraksiyon aşamasından sonra bir numune, çeşitli yağlı asitleri (FAS) ifade etmektedir. metil ester türevleri, kromatografik kolona doğru yüksek, uçucu istikrarlı ve inert böylece atık doruklarına kaçınarak. kromatografik profiller yayımlanmış veya standartlarla karşılaştırıldığında, çünkü örnek tanınmış finansman kurumu oluşuyorsa kendi kimlik oldukça basittir. Buna ek olarak, çeşitli Fas&#39;ın ölçümü için bir kalibrasyon standartları tekrar enjeksiyon alev iyonizasyon saptamasıyla (FID) 1 kendi hemen hemen sabit tepki verilir, gerekli değildir. FID ek olarak, kütle spektrometrisi (MS) tespit FAMEler teyit etmek için bir bilgi tamamlayıcı bir dizi sağlar. Kareleri elektron iyonizasyonu (El) ile şarj edilir, ancak elde edilen spektrumlar her th için izin vermeFA ince yapısının e tanımlanması. Teşhis iyonları 1 tespit edilmesi zor olan ve hedef iyon bolca karakteristik bir değişiklik kütle spektrumu kütüphaneleri 2 kullanımını engelleyen, makineye bağlı olduğu için, örneğin, konum dallanma (yani, metil dallı grup) tahmin etmek zordur. Başka bir sorun EI çift bağ göçünü neden olduğundan çift bağ pozisyonunu belirleme yatıyor. Böylece, çift bağ pozisyonlarını değişen FA izomerleri kendi kütle spektrumları ayırt edilemez. Neyse ki, başka araçlar FA tanımlanması için geliştirilmiştir. Örneğin, durum ve fasıl&#39;da çift bağların ya da dallanma konumu eş zincir uzunluğuna sahip (ECL) 3 hesaplanarak conjectured edilebilir. Diğer türetme yöntemleri bir çift bağ ya da kollara ayrılmış bir metil grubunun konumuna bağlı olarak, farklı kütle spektrumları ile sonuçlanır. 4,4-Dimetil oksazolin türevleri (DMOX) 4 EAS izintekli doymamış yağ asidi çift bağların pozisyon y tanımlanması. Ester (pikolinil ester) türevleridir metil yerini kesin tanımlanması için izin veren 3-pyridylcarbinyl FAs 5 dallanmış. Nükleer manyetik rezonans (NMR) spektrumu, yapısal karakterizasyon 1 tartışılmaz bir yöntem için gerekli olan, saflaştırma karmaşık yöntemler kullanmaya gerek kalmadan kromatografik (ECL) ile kütle spektrumları (DMOX ve pikolinil) bilgi çoğu Fas&#39;ın saptanmasına olanak birleştirme . Bazı insan ve hayvan patojenleri içeren Bacillus, bakteriler, çok çeşitli bir niş kolonize edebiliyoruz ve bu nedenle yaygın olarak çevre 6 dağıtılır. Bacillus cinsi içinde, FA bileşimi (çevresel değişiklikler geniş bir uyum FA desen modülasyonlar türlerin ekolojik niş etkilenir, örneğin, büyüme ortamı, sıcaklık,pH, vs.) 7-9. Çünkü standart koşullarda büyüme sırasında Bacillus türleri arasında FA model göreli homojenlik FA bileşimin belirlenmesi Bacillus türleri tanımlamak için kullanılan temel kriterlerden biridir. Bacillus cinsinin eşsiz bir nitelik 12-17 karbon iso ve çevre koşullarına uyum önemli bir belirleyicisi olan anteiso- izomerler arasındaki oran ile 10-12 ihtiva eden dallı zincirli finansman kurumu bolluğu olduğunu. Bacillus türleri de doymamış yağ asitlerinin oranının değiştirilmesiyle çevresel değişimlerin uyum. Bacillus cereus gibi bazı türler, iki yağ asidi desatürazlar uyum 9 farklı rollere sahip alkil zincirinin 13 farklı pozisyonlarda çift bağ oluşturur. Bacillus cinsinin örnek tam çift bağ pozisyonunu belirleme ve FA dallanma önemini göstermektedir. Toplamakively, Bacillus FA desen kimlik birçok yararlı uygulamalar vardır. Bu yazıda, klasik bir GC-MS analizi doğasında kısıtlamaların üstesinden Bacillus FA desen tanımlanması için yeni bir GC-MS yaklaşımı öneriyoruz. Bu yenilikçi yaklaşım, ham biyolojik bir malzeme üzerinde doğrudan kullanılan ve mevcut tekniklerin bir kombinasyonundan oluşur edilebilir: tutma süreleri (ECL) ve farklı FAs türevleri (FAME, DMOX ve pikolinil-ester) kütle spektrumları modülleri. Biz şu FA isimlendirme kullanın. a ve n, iso gösterir I, anteiso- metil sırasıyla dallanmış ve düz zincirli yağlı asit. Doymamış FAs C olarak seçilmiştir: Cı karbonlu yağlı asit atomuna ve D sayısı D ikili bağların sayısı. Δ X bir çift bağ karboksilik asit uç sayarak, X. karbon-karbon bağı bulunmaktadır çift bağ pozisyonunu gösterir.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>GC/MS</td>
			<td>Shimadzu</td>
			<td>QP2010</td>
			<td></td>
		</tr>
		<tr>
			<td>capillary column ZB WAX</td>
			<td>Phenomenex</td>
			<td>7HG-G007-11</td>
			<td>30m x 0.25mm x 0.25&#181;m</td>
		</tr>
		<tr>
			<td>Methanol Lichrosolv</td>
			<td>VWR</td>
			<td>1.06018.2500</td>
			<td></td>
		</tr>
		<tr>
			<td>potassium hydroxide</td>
			<td>Aldrich</td>
			<td>P1767</td>
			<td></td>
		</tr>
		<tr>
			<td>THF</td>
			<td>Hipersolv Chromanorm</td>
			<td>28559.320</td>
			<td></td>
		</tr>
		<tr>
			<td>Dichloromethane</td>
			<td>Hipersolv Chromanorm</td>
			<td>23373.320</td>
			<td></td>
		</tr>
		<tr>
			<td>Hexane</td>
			<td>Hipersolv Chromanorm</td>
			<td>24575.320</td>
			<td></td>
		</tr>
		<tr>
			<td>3-pyridinemethanol</td>
			<td>Aldrich</td>
			<td>P6-680-7</td>
			<td></td>
		</tr>
		<tr>
			<td>potassium tertiobutoxide</td>
			<td>Aldrich</td>
			<td>156671</td>
			<td></td>
		</tr>
		<tr>
			<td>2-amino-2-methyl-1-propanol</td>
			<td></td>
			<td>A-9879</td>
			<td></td>
		</tr>
		<tr>
			<td>MilliQ Academic</td>
			<td>Millipore</td>
			<td>ZMQS50001</td>
			<td></td>
		</tr>
		<tr>
			<td>Bacterial Acid Methyl Ester (BAME) Mix</td>
			<td>Sigma-Aldrich</td>
			<td>47080-U Supelco</td>
			<td></td>
		</tr>
	</tbody>
</table>

identification of fatty acids in bacillus cereus

Bacillus türleri metil dalının farklı pozisyonları ile zincirli ve doymamış yağ asitleri (FAS) dallanmış (izo ya anteiso-) ve çift bağın. FA kompozisyonundaki değişikliklerin çevreye bakterilerin adaptasyon önemli bir rol oynamaktadır. Bu değişiklikler anteiso- fas dallı karşı iso oranında bir değişiklik gerektirir ve belirli pozisyonlarda oluşturulan ikili bağlar ile doyurulmuş Fas&#39;a doymamış FAs göreli, oranında. FA profilinin kesin kimlik Bacillus türlerinin adaptasyon mekanizmalarının anlaşılması gereklidir. Bacillus&#39;dan Fas&#39;ı çoğu ticari olarak temin edilebilir değildir. yağlı asit metil esterleri (FAME), 4,4-dimetil oksazolin: Bu tarifnamede önerilen strateji üç FA türevlerinin tiplerine kütle spektrumları ile (eş zincir uzunluğuna sahip (ECL) hesaplanması ile) alıkoyma süresi hakkında bilgi birleştirerek Fas tanımlar türevleri (DMOX) ve3-pyridylcarbinyl ester (pikolinil). Bu yöntem, bilinmeyen fas arındırmak için gerek kalmadan fas belirleyebilir. Standartları ticari bir karışım olan, Bacillus cereus hazırlanabilir FAME kromatografik profillerini karşılaştırmak için diğer Fas&#39;ın kimliğine fas, ECL hesaplama ve hipotez, doymuş, düz zincirli tanımlanmasına izin verir. ve Fames karbona aynı sayıda doğrusal doymuş finansman kurumu göre FAS, iso veya anteiso-, ECL sürekli bir negatif kayma gösterir doymuş dallı. Doymamış Fas&#39;ı kareleri moleküler iyon kütlesi ile tespit ve karşılık gelen doymuş Fas&#39;ına göre ECL olumlu bir artışa neden olabilir. Fas&#39;ı dallanma konumu ve doymamış Fas&#39;ın çift bağ pozisyonu, sırasıyla, pikolinil ve DMOX türevlerinin elektron iyonizasyon kütle spektrumları ile tespit edilebilir. Bu yaklaşım, tüm bilinmeyen doymuş şube tanımlarEd fasının doymamış, düz zincirli Fas ve B. cereus özü doymamış dallı FASB.

Bakteriyel hücrelerden FA kimlik stratejisi Şekil 1 &#39;de sunulmuştur. Her adım tamamlayıcı spektral bilgi veya kromatografik tutma hakkında bilgi sağlar. Aşama 1, standart çözeltisi kullanılarak, ön FA belirlenmesinden oluşur. Adım 2 geçici ürünlerini belirlemek için, FAME EI spektrumları ve ECL yorumlanması için izin verir. Adım 3 dallı zincirli-Fas kesin dallanma konumunu tanımlar. Son olarak, aşama 4, doymamış fasıl&#39;da çift bağlar...

Watch this Scientific Journal Video about Identification of Fatty Acids in Bacillus cereus at JoVE.com

Identification of Fatty Acids in Bacillus cereus

We propose a protocol to identify fatty acids without the need to purify them. It combines information on the retention times with the mass spectra of three types of fatty acid derivatives: fatty acid methyl esters (FAMEs), 4,4-dimethyl oxazoline derivatives (DMOX), and 3-pyridylcarbinyl esters (picolinyl).

Yağ Asitlerinin Tanımlanması içinde<em&gt; Bacillus cereus</em

The Bacillus species contain branched chain and unsaturated fatty acids (FAs) with diverse positions of the methyl branch (iso or anteiso) and of the ...

The overall goal of this protocol is to identify fatty acids from bacteria and to identify the position of methyl branching and double bonds. This method can help answer key questions in the bacteriology field such as the role of fatty acids in the way bacteria adapt to their environment. The main advantage of this technique is that prolification of fatty acids is not required.The implications of this technique extend toward bacterial identification because of the importance of fatty acid composition in bacterial taxonomy. Though this method was developed on the bacteria Bacillus cereus, it is also very relevant to study other species containing branch chain fatty acids. Generally, in development to this method, we struggled.Because current identification method for fatty acids do not identify methyl branching in double bond position. To begin this procedure, prepare a lawn of the bacteria by spreading 100 microliters of an overnight culture of the strain, incubated at 30 degrees Celsius in LB over the surface of the plate of LB agar medium. Incubate the plate overnight at 30 degrees Celsius.In order to obtain lipid fatty acids, harvest bacterial cells by scraping colonies from the agar plate. And transferring approximately 40 milligrams into a ten milliliter glass tube with a screw cap and PTFE seal. To perform transesterification, add five milliliters of 0.2 molar potassium hydroxide in methanol to the fresh bacterial cells.Vortex, and incubate at 37 degrees Celsius for one hour. Following this, add one milliliter of one molar ascetic acid to lower the pH to seven. Now, add three milliliters of hexane and vortex one minute to extract the fatty acid methyl esters or FAMEs.Transfer the upper phase into clean tubes and concentrate by evaporation at room temperature under a continuous flow of nitrogen to obtain approximately 200 microliters of FAME extract. Then, transfer the extracts into GC vials with inserts. Inject the extracts into a gas chromatography mass spectrometry, or GC-MS system equipped with a capillary column.Set the injection port temperature to 250 degrees Celsius. Hold the oven temperature at 50 degrees Celsius for one minute. Increase to 190 degrees Celsius at a rate of 20 degrees Celsius per minute and increase to a final temperature of 230 degrees Celsius at a rate of two degrees Celsius per minute.For the MS, record the mass spectra by electron ionization, or EI, at 70 electron volts, and set the acquisition of the total ion current between 50 and 400 atomic mass units, or AMU. Dissolve a sample of the dried FAME extract in one milliliter of dry dichloromethane. Then, add the extract solution and 0.2 milliliters of 3-pyridinemethanol to 0.1 milliliters of one molar potassium tert-butoxide in tetrahydrofuran.Heat the solution at 40 degrees Celsius for 30 minutes in a closed vial. After cooling the solution to room temperature, add two milliliters of purified deionized water and four milliliters of hexane. Mix the solution for one minute with a vortex mixer.After allowing the phases to separate, collect the upper organic phase. Next, add anhydrous sodium sulfate until the organic phase is clear. Transfer the organic phase into a clean tube, then evaporate the organic phase under a stream of nitrogen until reaching a volume of approximately 200 microliters.Add 250 milligrams of 2-amino-2-methyl-1-propanol to sample of dried FAME extract. Flush the tube with nitrogen and close it with a stopper. Then, heat the solution at 190 degrees Celsius overnight.After cooling the solution to room temperature, add three milliliters of dichloromethane and five milliliters of purified deionized water. Vortex the mixture and allow the phases to separate. Then, remove the aqueous phase.Following this, wash the organic phase with five milliliters of water. Add anhydrous sodium sulfate until the organic phase is clear. After transferring the organic phase to a new test tube, evaporate it under a stream of nitrogen until reaching a volume of approximately 200 microliters.The I16 picolinal derivative mass spectrum confirms methyl branching. The gap of 28 AMU between ions at 304 and 332 corresponds to fragments created before and after the branched carbon. The diagnostic ions, 113 and 126, characteristic of DMOX derivatives, are shown here.The molecular ion 307 is characteristic of the 16:1 isomer, and a gap of 12 AMU between 196 and 208 indicates a double bond at carbon. The gap of 12 AMU is no longer observed when the double bond is before carbon 7. The intense 153 ion, characteristic of a double bond at carbon 5, and the 307 molecular ion in the DMOX derivative mass spectrum identified this compound as n16 one delta five.The 307 ion of the DMOX derivative and the 345 ion of the picolinal derivative indicate a 16:1 fatty acid isomer. A gap of 28 AMU indicates the branching position, and a gap of 12 AMU for DMOX and 26 AMU for picolinal ester identifies the double bond. Fatty acids and corresponding diagnostic ions identified in Bacillus cereus are listed here.The diagnostic ions identify the methyl branching and double bond positions on the carbon chain for the DMOX and picolinal ester derivatives. Once mastered, this technique can be done in two days, if it is performed properly. Following this procedure, fatty acid can be quantified by GC-MS and the release of the FAME derivatives.After it's development, this technique paved the way for researchers in the field of bacteriology to explore bacterial diversity and mechanisms of bacterial adaptations. After watching this video, you should have a good understanding of how to study fatty acids in bacteria including methyl branched and unsaturated fatty acids. Don't forget that working with reagents can be extremely hazardous, and precautions such as working with a laboratory fume hood and wearing gloves should always be taken while performing this procedure.

identification-of-fatty-acids-in-bacillus-cereus

Research

JoVE Journal

Biochemistry

Identification of Fatty Acids in Bacillus cereus

A Polyaniline-based Sensor of Nucleic Acids

Detection of nucleic acids is at the center of diagnostic technologies used in research and the clinic. Standard approaches used in these technologies rely on enzymatic modification that can introduce bias and artifacts. A critical element of next generation detection platforms will be direct molecular sensing, thereby avoiding a need for amplification or labels. Advanced nanomaterials may provide the suitable chemical modalities to realize label-free sensors. Conjugated polymers are ideal for biological sensing, possessing properties compatible with biomolecules and exhibit high sensitivity to localized environmental changes. In this article, a method is presented for detecting nucleic acids using the electroconductive polymer polyaniline. Simple DNA "probe" oligonucleotides complementary to target nucleic acids are attached electrostatically to the polymer, creating a sensor system that can differentiate single nucleotide differences in target molecules. Outside the specific and unbiased nature of this technology, it is highly cost effective.

Nucleic acids are common analytes for assessing biological systems; however, bias from enzymatic manipulation can cause concern. Here a method is described for label-free detection of nucleic acids using polyaniline. This sensitive, cost-effective sensor technology can distinguish single nucleotide differences between molecules.

Nükleik Asitlerin bir Polyaniline tabanlı sensör

Detection of nucleic acids is at the center of diagnostic technologies used in research and the clinic. Standard approaches used in these technologies ...

Biyokimya

Recombinant Protein Expression, Crystallization, and Biophysical Studies of a Bacillus-conserved Nucleotide Pyrophosphorylase, BcMazG

To overcome safety restrictions and regulations when studying genes and proteins from true pathogens, their homologues can be studied. Bacillus anthracis is an obligate pathogen that causes fatal inhalational anthrax. Bacillus cereus is considered a useful model for studying B. anthracis due to its close evolutionary relationship. The gene cluster ba1554 - ba1558 of B. anthracis is highly conserved with the bc1531- bc1535 cluster in B. cereus, as well as with the bt1364-bt1368 cluster in Bacillus thuringiensis, indicating the critical role of the associated genes in the Bacillus genus. This manuscript describes methods to prepare and characterize a protein product of the first gene (ba1554) from the gene cluster in B. anthracis using a recombinant protein of its ortholog in B. cereus, bc1531.

Recombinant Protein Expression, Crystallization, and Biophysical Studies of a Bacillus-conserved Nucleotide Pyrophosphorylase, BcMazG

Bacillus anthracis is the obligate pathogen of fatal inhalational anthrax, so studies of its genes and proteins are strictly regulated. An alternative approach is to study orthologous genes. We describe biophysicochemical studies of a B. anthracis ortholog in B. cereus, bc1531, requiring minimal experimental equipment and lacking serious safety concerns.

Birliğin Rekombinant Protein Ekspresyonu, Kristalleştirilmesi ve Biyofiziksel Araştırmaları<em&gt; Bacillus</em&gt; - Konserve Nükleotid Pyrophosphorylase, BcMazG

To overcome safety restrictions and regulations when studying genes and proteins from true pathogens, their homologues can be studied. Bacillus anthracis ...

Voltage-clamp Fluorometry in Xenopus Oocytes Using Fluorescent Unnatural Amino Acids

Voltage-Clamp Fluorometry (VCF) has been the technique of choice to investigate the structure and function of electrogenic membrane proteins where real-time measurements of fluorescence and currents simultaneously report on local rearrangements and global function, respectively1. While high-resolution structural techniques such as cryo-electron microscopy or X-ray crystallography provide static images of the proteins of interest, VCF provides dynamic structural data that allows us to link the structural rearrangements (fluorescence) to dynamic functional data (electrophysiology). Until recently, the thiol-reactive chemistry used for site-directed fluorescent labeling of the proteins restricted the scope of the approach because all accessible cysteines, including endogenous ones, will be labeled. It was thus required to construct proteins free of endogenous cysteines. Labeling was also restricted to sites accessible from the extracellular side. This changed with the use of Fluorescent Unnatural Amino Acids (fUAA) to specifically incorporate a small fluorescent probe in response to stop codon suppression using an orthogonal tRNA and tRNA synthetase pair2. The VCF improvement only requires a two-step injection procedure of DNA injection (tRNA/synthetase pair) followed by RNA/fUAA co-injection. Now, labelling both intracellular and buried sites is possible, and the use of VCF has expanded significantly. The VCF technique thereby becomes attractive for studying a wide range of proteins and &#8211; more importantly &#8211; allows investigating numerous cytosolic regulatory mechanisms.

Voltage-clamp Fluorometry in Xenopus Oocytes Using Fluorescent Unnatural Amino Acids

This article describes an enhancement of conventional Voltage-Clamp Fluorometry (VCF) where Fluorescent Unnatural Amino Acids (fUAA) are used instead of maleimide dyes, to probe structural rearrangements in ion channels. The procedure includes Xenopus oocyte DNA injection, RNA/fUAA coinjection, and simultaneous current and fluorescence measurements.

Voltaj kelepçesi florometrisi<em&gt; Xenopus</emFloresan Doğal Olmayan Amino Asitler Kullanan Oositler

Voltage-Clamp Fluorometry (VCF) has been the technique of choice to investigate the structure and function of electrogenic membrane proteins where ...

Sample Preparation for Mass Spectrometry-based Identification of RNA-binding Regions

Noncoding RNAs play important roles in several nuclear processes, including regulating gene expression, chromatin structure, and DNA repair. In most cases, the action of noncoding RNAs is mediated by proteins whose functions are in turn regulated by these interactions with noncoding RNAs. Consistent with this, a growing number of proteins involved in nuclear functions have been reported to bind RNA and in a few cases the RNA-binding regions of these proteins have been mapped, often through laborious, candidate-based methods.
Here, we report a detailed protocol to perform a high-throughput, proteome-wide unbiased identification of RNA-binding proteins and their RNA-binding regions. The methodology relies on the incorporation of a photoreactive uridine analog in the cellular RNA, followed by UV-mediated protein-RNA crosslinking, and mass spectrometry analyses to reveal RNA-crosslinked peptides within the proteome. Although we describe the procedure for mouse embryonic stem cells, the protocol should be easily adapted to a variety of cultured cells.

We describe a protocol to identify RNA-binding proteins and map their RNA-binding regions in live cells using UV-mediated photocrosslinking and mass spectrometry.

Kütle spektrometresi tabanlı kimlik RNA-bağlama bölgelerinin için numune hazırlama

Noncoding RNAs play important roles in several nuclear processes, including regulating gene expression, chromatin structure, and DNA repair. In most ...

Identification of Orexin and Endocannabinoid Receptors in Adult Zebrafish Using Immunoperoxidase and Immunofluorescence Methods

Immunohistochemistry (IHC) is a highly sensitive and specific technique involved in the detection of target antigens in tissue sections with labeled antibodies. It is a multistep process in which the optimization of each step is crucial to obtain the optimum specific signal. Through IHC, the distribution and localization of specific biomarkers can be detected, revealing information on evolutionary conservation. Moreover, IHC allows for the understanding of expression and distribution changes of biomarkers in pathological conditions, such as obesity. IHC, mainly the immunofluorescence technique, can be used in adult zebrafish to detect the organization and distribution of phylogenetically conserved molecules, but a standard IHC protocol is not estasblished. Orexin and endocannabinoid are two highly conserved systems involved in the control of food intake and obesity pathology. Reported here are protocols used to obtain information about orexin peptide (OXA), orexin receptor (OX-2R), and cannabinoid receptor (CB1R) localization and distribution in the gut and brain of normal and diet-induced obese (DIO) adult zebrafish models. Also described are methods for immunoperoxidase and double immunofluorescence, as well as preparation of reagents, fixation, paraffin-embedding, and cryoprotection of zebrafish tissue and preparation for an endogenous activity-blocking step and background counterstaining. The complete set of parameters is obtained from previous IHC experiments, through which we have shown how immunofluorescence can help with the understanding of OXs, OX-2R, and CB1R distribution, localization, and conservation of expression in adult zebrafish tissues. The resulting images with highly specific signal intensity led to the confirmation that zebrafish are suitable animal models for immunohistochemical studies of distribution, localization, and evolutionary conservation of specific biomarkers in physiological and pathological conditions. The protocols presented here are recommended for IHC experiments in adult zebrafish.

Presented here are protocols for immunohistochemical characterization and localization of orexin peptide, orexin receptors, and endocannabinoid receptors in the gut and brains of normal and diet-induced obesity (DIO) adult zebrafish models using immunoperixidase and double immunofluorescence methods.

Immunoperoksidan ve Immünofluoresesan yöntemlerini kullanarak yetişkin Zebrafisinde Orexin ve Endocannabinoid reseptörlerinin tanımlanması

Immunohistochemistry (IHC) is a highly sensitive and specific technique involved in the detection of target antigens in tissue sections with labeled ...

Kinetic Screening of Nuclease Activity using Nucleic Acid Probes

Nucleases are a class of enzymes that break down nucleic acids by catalyzing the hydrolysis of the phosphodiester bonds that link the ribose sugars. Nucleases display a variety of vital physiological roles in prokaryotic and eukaryotic organisms, ranging from maintaining genome stability to providing protection against pathogens. Altered nuclease activity has been associated with several pathological conditions including bacterial infections and cancer. To this end, nuclease activity has shown great potential to be exploited as a specific biomarker. However, a robust and reproducible screening method based on this activity remains highly desirable.
Herein, we introduce a method that enables screening for nuclease activity using nucleic acid probes as substrates, with the scope of differentiating between pathological and healthy conditions. This method offers the possibility of designing new probe libraries, with increasing specificity, in an iterative manner. Thus, multiple rounds of screening are necessary to refine the probes&#39; design with enhanced features, taking advantage of the availability of chemically modified nucleic acids. The considerable potential of the proposed technology lies in its flexibility, high reproducibility, and versatility for the screening of nuclease activity associated with disease conditions. It is expected that this technology will allow the development of promising diagnostic tools with a great potential in the clinic.

Altered nuclease activity has been associated with different human conditions, underlying its potential as a biomarker. The modular and easy to implement screening methodology presented in this paper allows the selection of specific nucleic acid probes for harnessing nuclease activity as a biomarker of disease.

Nükleik Asit Probları Kullanılarak Nükleaz Aktivitesinin Kinetik Taraması

Nucleases are a class of enzymes that break down nucleic acids by catalyzing the hydrolysis of the phosphodiester bonds that link the ribose sugars. ...

SUMO-Binding Entities (SUBEs) as Tools for the Enrichment, Isolation, Identification, and Characterization of the SUMO Proteome in Liver Cancer

Post-translational modification is a key mechanism regulating protein homeostasis and function in eukaryotic cells. Among all ubiquitin-like proteins in liver cancer, the modification by SUMO (Small Ubiquitin MOdifier) has been given the most attention. Isolation of endogenous SUMOylated proteins in vivo is challenging due to the presence of active SUMO-specific proteases. Initial studies of SUMOylation in vivo were based on the molecular detection of specific SUMOylated proteins (e.g., by western blot). However, in many cases, antibodies, generally made with non-modified recombinant protein, did not immunoprecipitate SUMOylated forms of the protein of interest.&#160;Nickel chromatography has been the other approach to study SUMOylation by capturing histidine-tagged versions of SUMO molecules. This approach is mainly used in cells stably expressing or transiently transfected with His-SUMO molecules. To overcome these limitations, SUMO-binding entities (SUBEs) were developed to isolate endogenous SUMOylated proteins. Herein, we describe all the steps required for the enrichment, isolation, and identification of SUMOylated substrates from human hepatoma cells and hepatic tissues from a liver cancer mouse model by using SUBEs. Firstly, we describe methods involved in the preparation and lysis of the human hepatoma cells and liver tumor tissue samples. Then, a thorough explanation of the preparation of SUBEs and controls is detailed along with the protocol for the protein pull-down assays. Finally, some examples are provided regarding the options available for the identification and characterization of the SUMOylated proteome, namely the use of western-blot analysis for the detection of a specific SUMOylated substrate from liver tumors or the use of proteomics by mass spectrometry for high-throughput characterization of the SUMOylated proteome and interactome in hepatoma cells.

SUMO-Binding Entities SUBEs as Tools for the Enrichment, Isolation, Identification, and Characterization of the SUMO Proteome in Liver Cancer

Here, we present a protocol to enrich, isolate, identify, and characterize proteins modified by SUMO in vivo both from human hepatoma cells and liver tumors obtained from mouse models of hepatocellular carcinoma by using SUMO-binding entities (SUBEs).

Karaciğer Kanserinde SUMO Proteomunun Zenginleştirilmesi, İzolasyon, Tanımlama ve Karakterizasyonu Için Araçlar Olarak SUMO Bağlayıcı Varlıklar (SUBEs)

Post-translational modification is a key mechanism regulating protein homeostasis and function in eukaryotic cells. Among all ubiquitin-like proteins in ...

Quantification of Humic and Fulvic Acids in Humate Ores, DOC, Humified Materials and Humic Substance-Containing Commercial Products

The purpose of this method is to provide an accurate and precise concentration of humic (HA) and/or fulvic acids (FA) in soft coals, humic ores and shales, peats, composts and humic substance-containing commercial products. The method is based on the alkaline extraction of test materials, using 0.1 N NaOH as an extractant, and separation of the alkaline soluble humic substances (HS) from nonsoluble products by centrifugation. The pH of the centrifuged alkaline extract is then adjusted to pH 1 with conc. HCl, which results in precipitation of the HA. The precipitated HA are separated from the fulvic fraction (FF) (the fraction of HS that remains in solution,) by centrifugation. The HA is then oven or freeze dried and the ash content of the dried HA determined. The weight of the pure (i.e., ash-free) HA is then divided by the weight of the sample and the resulting fraction multiplied by 100 to determine the % HA in the sample. To determine the FA content, the FF is loaded onto a hydrophobic DAX-8 resin, which adsorbs the FA fraction also referred to as the hydrophobic fulvic acid (HFA). The remaining non-fulvic acid fraction, also called the hydrophilic fulvic fraction (HyFF) is then removed by washing the resin with deionized H2O until all nonabsorbed material is completely removed. The FA is then desorbed with 0.1 N NaOH. The resulting Na-fulvate is then protonated by passing it over a strong H+-exchange resin. The resulting FA is oven or freeze dried, the ash content determined and the concentration in the sample calculated as described above for HA.

This method provides a gravimetric quantification of humic substances (e.g., humic and fulvic acids) on an ash-free basis, in dry and liquid materials from soft coals (i.e., oxidized and non-oxidized lignite and sub-bituminous coal), humate ores and shales, peats, composts and commercial fertilizers and soil amendments.

Humat Cevselerinde, DOC'ta, Humifik Malzemelerde ve Hümrik Madde İçeren Ticari Ürünlerde Humik ve Fulvik Asitlerin Nicelleştirilmesi

The purpose of this method is to provide an accurate and precise concentration of humic (HA) and/or fulvic acids (FA) in soft coals, humic ores and ...

Optimized Incorporation of Alkynyl Fatty Acid Analogs for the Detection of Fatty Acylated Proteins using Click Chemistry

Fatty acylation, the covalent addition of saturated fatty acids to protein substrates, is important in regulating a myriad of cellular functions in addition to its implications in cancer and neurodegenerative diseases. Recent developments in fatty acylation detection methods have enabled efficient and non-hazardous detection of fatty acylated proteins, particularly through the use of click chemistry with bio-orthogonal labeling. However, click chemistry detection can be limited by the poor solubility and potential toxic effects of adding long chain fatty acids to cell culture. Described here is a labeling approach with optimized delivery using saponified fatty acids in combination with fatty-acid free BSA, as well as delipidated media, which can improve detection of hard to detect fatty acylated proteins. This effect was most pronounced with the alkynyl-stearate analog, 17-ODYA, which has been the most commonly used fatty acid analog in click chemistry detection of acylated proteins. This modification will improve cellular incorporation and increase sensitivity to acylated protein detection. In addition, this approach can be applied in a variety of cell types and combined with other assays such as pulse-chase analysis, stable isotope labeling with amino acids in cell culture, and mass spectrometry for quantitative profiling of fatty acylated proteins.

The study of fatty acylation has important implications in cellular protein interactions and diseases. Presented here is a modified protocol to improve click chemistry detection of fatty acylated proteins, which can be applied in various cell types and combined with other assays, including pulse-chase and mass spectrometry.

Click Kimya Kullanarak Yağ Asillenmiş Proteinlerin Tespiti için Alkinil Yağ Asidi Analoglarının Optimize Edilmiş Birleştirilmesi

Fatty acylation, the covalent addition of saturated fatty acids to protein substrates, is important in regulating a myriad of cellular functions in ...

Making Precise and Accurate Single-Molecule FRET Measurements using the Open-Source smfBox

The smfBox is a recently developed cost-effective, open-source instrument for single-molecule F&#246;rster Resonance Energy Transfer (smFRET), which makes measurements on freely diffusing biomolecules more accessible. This overview includes a step-by-step protocol for using this instrument to make measurements of precise FRET efficiencies in duplex DNA samples, including details of the sample preparation, instrument setup and alignment, data acquisition, and complete analysis routines. The presented approach, which includes how to determine all the correction factors required for accurate FRET-derived distance measurements, builds on a large body of recent collaborative work across the FRET Community, which aims to establish standard protocols and analysis approaches. This protocol, which is easily adaptable to a range of biomolecular systems, adds to the growing efforts in democratising smFRET for the wider scientific community.

This article provides step-by-step instructions for making fully-corrected accurate FRET measurements on individual, freely diffusing biomolecules using the open-source, inexpensive smfBox, from switch on, through alignment and focusing, to data collection and analysis.

Açık Kaynaklı smfBox kullanarak Hassas ve Doğru Tek Moleküllü FRET Ölçümleri Yapma

The smfBox is a recently developed cost-effective, open-source instrument for single-molecule F&#246;rster Resonance Energy Transfer (smFRET), which makes ...