وأيد هذا العمل من قبل الجائزة NSF # 0920274 وجنوب كارولينا تجربة مشروع محطة (SC - 1700340) لKSS. هذه الورقة التقنية رقم 5929 من المساهمة في تجربة جامعة كليمسون محطة.

<ol>
	<li>Bork, P., Sander, C., Valencia, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+ATPase+domain+common+to+prokaryotic+cell+cycle+proteins,+sugar+kinases,+actin,+and+hsp70+heat+shock+proteins.">An ATPase domain common to prokaryotic cell cycle proteins, sugar kinases, actin, and hsp70 heat shock proteins.</a> Proc. Natl. Acad. Sci. U. S. A. 89, 7290-7294 (1992).</li><li>Bork, P., Sander, C., Valencia, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Convergent+evolution+of+similar+enzymatic+function+on+different+protein+folds:+the+hexokinase,+ribokinase,+and+galactokinase+families+of+sugar+kinases.">Convergent evolution of similar enzymatic function on different protein folds: the hexokinase, ribokinase, and galactokinase families of sugar kinases.</a> Protein Sci. 2, 31-40 (1993).</li><li>Buss, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Urkinase:+structure+of+acetate+kinase,+a+member+of+the+ASKHA+superfamily+of+phosphotransferases.">Urkinase: structure of acetate kinase, a member of the ASKHA superfamily of phosphotransferases.</a> J. Bacteriol. 183, 680-686 (2001).</li><li>Hurley, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+sugar+kinase/heat+shock+protein+70/actin+superfamily:+implications+of+conserved+structure+for+mechanism.">The sugar kinase/heat shock protein 70/actin superfamily: implications of conserved structure for mechanism.</a> Annu. Rev. Biophys. Biomol. Struct. 25, 137-162 (1996).</li><li>Holmes, K. C., Sander, C., Valencia, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+ATP-binding+fold+in+actin,+hexokinase+and+Hsc70.">A new ATP-binding fold in actin, hexokinase and Hsc70.</a> Trends. Cell. Biol. 3, 53-59 (1993).</li><li>Ingram-Smith, C., Martin, S. R., Smith, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acetate+kinase:+not+just+a+bacterial+enzyme.">Acetate kinase: not just a bacterial enzyme.</a> Trends. Microbiol. 14, 249-253 (2006).</li><li>Aceti, D. J., Ferry, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification+and+characterization+of+acetate+kinase+from+acetate-grown+Methanosarcina+thermophila.+Evidence+for+regulation+of+synthesis.">Purification and characterization of acetate kinase from acetate-grown Methanosarcina thermophila. Evidence for regulation of synthesis.</a> J. Biol. Chem. 263, 15444-15448 (1988).</li><li>Latimer, M. T., Ferry, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cloning,+sequence+analysis,+and+hyperexpression+of+the+genes+encoding+phosphotransacetylase+and+acetate+kinase+from+Methanosarcina+thermophila.">Cloning, sequence analysis, and hyperexpression of the genes encoding phosphotransacetylase and acetate kinase from Methanosarcina thermophila.</a> J. Bacteriol. 175, 6822-6829 (1993).</li><li>Ingram-Smith, C., Barber, R. D., Ferry, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+histidines+in+the+acetate+kinase+from+Methanosarcina+thermophila.">The role of histidines in the acetate kinase from Methanosarcina thermophila.</a> J. Biol. Chem. 275, 33765-33770 (2000).</li><li>Miles, R. D., Iyer, P. P., Ferry, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Site-directed+mutational+analysis+of+active+site+residues+in+the+acetate+kinase+from+Methanosarcina+thermophila.">Site-directed mutational analysis of active site residues in the acetate kinase from Methanosarcina thermophila.</a> J. Biol. Chem. 276, 45059-45064 (2001).</li><li>Miles, R. D., Gorrell, A., Ferry, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evidence+for+a+transition+state+analog,+MgADP-aluminum+fluoride-acetate,+in+acetate+kinase+from+Methanosarcina+thermophila.">Evidence for a transition state analog, MgADP-aluminum fluoride-acetate, in acetate kinase from Methanosarcina thermophila.</a> J. Biol. Chem. 277, 22547-22552 (2002).</li><li>Ingram-Smith, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+the+acetate+binding+pocket+in+the+Methanosarcina+thermophila+acetate+kinase.">Characterization of the acetate binding pocket in the Methanosarcina thermophila acetate kinase.</a> J. Bacteriol. 187, 2386-2394 (2005).</li><li>Gorrell, A., Lawrence, S. H., Ferry, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+and+kinetic+analyses+of+arginine+residues+in+the+active+site+of+the+acetate+kinase+from+Methanosarcina+thermophila.">Structural and kinetic analyses of arginine residues in the active site of the acetate kinase from Methanosarcina thermophila.</a> J. Biol. Chem. 280, 10731-10742 (2005).</li><li>Gorrell, A., Ferry, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigation+of+the+Methanosarcina+thermophila+acetate+kinase+mechanism+by+fluorescence+quenching.">Investigation of the Methanosarcina thermophila acetate kinase mechanism by fluorescence quenching.</a> Biochemistry. 46, 14170-14176 (2007).</li><li>Reeves, R. E., Guthrie, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acetate+kinase+(pyrophosphate).+A+fourth+pyrophosphate-dependent+kinase+from+Entamoeba+histolytica.">Acetate kinase (pyrophosphate). A fourth pyrophosphate-dependent kinase from Entamoeba histolytica.</a> Biochem. Biophys. Res. Commun. 66, 1389-1395 (1975).</li><li>Fowler, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetic+and+structural+characterization+of+the+novel+PPi-dependent+acetate+kinase+from+the+parasite+Entamoeba+histolytica.">Kinetic and structural characterization of the novel PPi-dependent acetate kinase from the parasite Entamoeba histolytica.</a> , (2011).</li><li>Lipmann, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enzymatic+synthesis+of+acetyl+phosphate.">Enzymatic synthesis of acetyl phosphate.</a> J. Biol. Chem. 155, 55-70 (1944).</li><li>Lipmann, F., Tuttle, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+specific+micromethod+for+determination+of+acyl+phosphates.">A specific micromethod for determination of acyl phosphates.</a> J. Biol. Chem. 159, 21-28 (1945).</li><li>Lipmann, F., Jones, M. E., Black, S., Flynn, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+mechanism+of+the+ATP-CoA-acetate+reaction.">The mechanism of the ATP-CoA-acetate reaction.</a> J. Cell. Physiol. Suppl. 41, 109-112 (1953).</li><li>Rose, I. A., Grunberg-Manago, M., Korey, S. F., Ochoa, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enzymatic+phosphorylation+of+acetate.">Enzymatic phosphorylation of acetate.</a> J. Biol. Chem. 211, 737-756 (1954).</li><li>Allen, S. H., Kellermeyer, R. W., Stjernholm, R. L., Wood, H. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification+and+properties+of+enzymes+involved+in+the+proponic+acid+fermentation.">Purification and properties of enzymes involved in the proponic acid fermentation.</a> Journal of Bacteriology. 87, 171-187 (1964).</li><li>Clarke, P. M., Payton, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+enzymatic+assay+for+acetate+in+spent+bacterial+culture+supernatants.">An enzymatic assay for acetate in spent bacterial culture supernatants.</a> Anal. Biochem. 130, 402-405 (1983).</li><li>Mukhopadhyay, S., Hasson, M. S., Sanders, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+continuous+assay+of+acetate+kinase+activity:+measurement+of+inorganic+phosphate+release+generated+by+hydroxylaminolysis+of+acetyl+phosphate.">A continuous assay of acetate kinase activity: measurement of inorganic phosphate release generated by hydroxylaminolysis of acetyl phosphate.</a> Bioorg. Chem. 36, 65-69 (2008).</li><li>Nakajima, H., Suzuki, K., Imahori, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification+and+properties+of+acetate+kinase+from+Bacillus+stearothermophilus.">Purification and properties of acetate kinase from Bacillus stearothermophilus.</a> J. Biochem. 84, 193-203 (1978).</li></ol>

الإعلان عن أي تضارب في المصالح.

الكشف عن الفوسفات الاسيتيل في هذا الاختبار يعتمد على تركيز كاف من هيدروكلوريد هيدروكسيل والتركيز والحموضة من محلول كلوريد الحديديك. وتغيير حجم مقايسة تتطلب إعادة النظر في كل من هذه المكونات. ردود الفعل الأنزيمية الموصوفة هنا أجريت في 37 درجة مئوية مع انتهاء تنفيذ هي?...

<table border="1" style=";text-align:right;direction:rtl"><tr><td width="160"> اسم الكاشف </td><td width="108"> شركة </td><td width="134"> فهرس العدد </td><td width="103"> تعليقات </td></tr><tr><td> الاسيتيل الفوسفات </td><td> سيغما الدريتش </td><td> 01409 </td><td> ملح الليثيوم (97 ٪) </td></tr><tr><td> فوسفات الصوديوم أحادي القاعدة (يذوى) </td><td> ThermoFisher </td><td> S381 </td><td></td></tr><tr><td> ثنائي القاعدة فوسفات الصوديوم (اللامائية) </td><td> ThermoFisher </td><td> S374 </td><td></td></tr><tr><td> كلوريد المغنيسيوم (hexahydrate) </td><td> ThermoFisher </td><td> M33 </td><td></td></tr><tr><td> قاعدة تريس </td><td> ThermoFisher </td><td> B152 </td><td></td></tr><tr><td> كلوريد الحديديك (hexahydrate) </td><td> ThermoFisher </td><td> I88 </td><td></td></tr><tr><td> حمض التريكلوروسيتيك حمض </td><td> ThermoFisher </td><td> A324 </td><td></td></tr><tr><td> هيدروكسيل هيدروكلوريد </td><td> ThermoFisher </td><td> H330 </td><td></td></tr><tr><td> ثنائي فسفات الأدينوزين 5&#39; - ملح الصوديوم </td><td> سيغما الدريتش </td><td> A2754 </td><td></td></tr><tr><td> Biomate الثالث الطيف </td><td> ThermoFisher </td><td> 142982082 </td><td> مستوى الأشعة فوق البنفسجية / معمل فيس </td></tr></table>

direct detection of the acetate-forming activity  of the enzyme acetate kinase

كيناز خلات ، عضوا في لخلات والسكر كيناز - Hsp70 - الأكتين فوق الفصيلة انزيم (ASKHA) 1-5 ، هو المسؤول عن الفسفرة عكسها من خلات لاستغلال الفوسفات ATP الاسيتيل باعتبارها الركيزة. كاينيسات خلات موجودة في كل مكان في البكتيريا وجدت في أحد من جنس الأركيا ، وموجودة أيضا في الميكروبات من حقيقيات النوى 6. وتتميز معظم كيناز خلات جيدا هو أن من thermophila المنتجة للغاز الميثان Methanosarcina archaeon 7-14. وقد تم عزل وكيناز خلات التي تستطيع الاستفادة منها فقط PP ط ولكن ليس للاعبي التنس المحترفين في اتجاه تشكيل الاسيتيل الفوسفات من نسج المتحولة ، والعامل المسبب للمرض الزحار الأميبي ، وحتى الآن فقط تم العثور على 15،16 في هذا جنس. في اتجاه تشكيل الفوسفات الاسيتيل ، ويقاس عادة خلات النشاط كيناز باستخدام مقايسة hydroxamate ، وصف لأول مرة من قبل Lipmann17-20 ، ومقايسة يقترن التي يقترن تحويل ATP إلى ADP للأكسدة NADH إلى NAD + من كيناز البيروفات الانزيمات واللاكتات نازعة 21،22 ، أو فحص قياس الافراج عن الفوسفات غير العضوية بعد رد فعل للمنتج الفوسفات الاسيتيل مع هيدروكسيل 23. النشاط في المقابل ، يقاس خلات تشكيل الاتجاه اقتران تشكيل ATP من ADP في الحد من NADP + إلى NADPH من هيكسوكيناز الانزيمات والجلوكوز 6 فوسفات نازعة 24. نحن هنا وصف طريقة للكشف عن النشاط كيناز خلات في اتجاه تشكيل خلات التي لا تتطلب اقتران الانزيمات ، ولكن بدلا من ذلك على ويستند تقرير المباشر للاستهلاك الفوسفات الاسيتيل. بعد رد الفعل الأنزيمية ، يتم تحويل الفوسفات الاسيتيل المتبقية لمجمع الحديد hydroxamate التي يمكن قياسها spectrophotometrically ، أما بالنسبة للمقايسة hydroxamate. وهكذا ، خلافا للشارعandard مقايسة بالإضافة لهذا الاتجاه الذي يعتمد على إنتاج ATP من ADP ، ويمكن استخدام هذا الاختبار المباشر لتحركات خلات التي تنتج ATP أو PP ط.

Watch this Scientific Journal Video about Direct Detection of the Acetate-forming Activity  of the Enzyme Acetate Kinase at JoVE.com

Direct Detection of the Acetate-forming Activity  of the Enzyme Acetate Kinase

يوصف أسلوب لتحديد النشاط كيناز خلات. هذا الاختبار يستخدم لتحديد رد الفعل المباشر لنشاط إنزيم وحركية كيناز خلات في اتجاه تشكيل خلات مع يقبلون فسفوريل مختلفة. وعلاوة على ذلك ، يمكن استخدام هذه الطريقة لمعايرة الفوسفات الاسيتيل أخرى أو أسيتيل التميم استخدام الانزيمات.

الكشف عن مباشرة النشاط خلات تشكيل لأنزيم كيناز خلات

Acetate kinase, a member of the acetate and sugar kinase-Hsp70-actin (ASKHA) enzyme superfamily1-5, is responsible for the reversible phosphorylation of ...

direct-detection-acetate-forming-activity-enzyme-acetate

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23.0K Views.  Clemson University. يوصف أسلوب لتحديد النشاط كيناز خلات. هذا الاختبار يستخدم لتحديد رد الفعل المباشر لنشاط إنزيم وحركية كيناز خلات في اتجاه تشكيل خلات مع يقبلون فسفوريل مختلفة. وعلاوة على ذلك ، يمكن استخدام هذه الطريقة لمعايرة الفوسفات الاسيتيل أخرى أو أسيتيل التميم استخدام الانز...

Video: Direct Detection of the Acetate-forming Activity  of the Enzyme Acetate Kinase

Detection of Protein Ubiquitination

Ubiquitination, the covalent attachment of the polypeptide ubiquitin to target proteins, is a key posttranslational modification carried out by a set of three enzymes. They include ubiquitin-activating enzyme E1, ubiquitin-conjugating enzyme E2, and ubiquitin ligase E3. Unlike to E1 and E2, E3 ubiquitin ligases display substrate specificity. On the other hand, numerous deubiquitylating enzymes have roles in processing polyubiquitinated proteins. Ubiquitination can result in change of protein stability, cellular localization, and biological activity. Mutations of genes involved in the ubiquitination/deubiquitination pathway or altered ubiquitin system function are associated with many different human diseases such as various types of cancer, neurodegeneration, and metabolic disorders. The detection of altered or normal ubiquitination of target proteins may provide a better understanding on the pathogenesis of these diseases. &nbsp;Here, we describe protocols to detect protein ubiquitination in cultured cells in vivo and test tubes in vitro. These protocols are also useful to detect other ubiquitin-like small molecule modification such as sumolyation and neddylation.

Ubiquitination is a key posttranslational modification carried out by a set of three enzymes. Mutations of genes involved in this modification are associated with many different human diseases. Here, we describe protocols to detect protein ubiquitination in cultured cells in vivo and test tubes in vitro.

اكتشاف بروتين Ubiquitination

Ubiquitination, the covalent attachment of the polypeptide ubiquitin to target proteins, is a key posttranslational modification carried out by a set of ...

Use of the Protease Fluorescent Detection Kit to Determine Protease Activity

The Protease Fluorescent Detection Kit provides ready-to-use reagents for detecting the presence of protease activity. This simple assay to detect protease activity uses casein labeled with fluorescein isothiocyanate (FITC) as the substrate.
Protease activity results in the cleavage of the FITC-labeled casein substrate into smaller fragments, which do not precipitate under acidic conditions. After incubation of the protease sample and substrate, the reaction is acidified with the addition of trichloroacetic acid (TCA). The mixture is then centrifuged with the undigested substrate forming a pellet and the smaller, acid soluble fragments remaining in solution. The supernatant is neutralized and the fluorescence of the FITC-labeled fragments is measured.
The described kit procedure detects the trypsin protease control at a concentration of approximately 0.5 &mu;g/ml (5 ng of trypsin added to the assay). This sensitivity can be increased with a longer incubation time, up to 24 hours. The assay is performed in microcentrifuge tubes and procedures are provided for fluorescence detection using either cuvettes or multiwell plates.

The Protease Fluorescent Detection Kit is designed for the measurement of protease activity using fluorometry. It is also suitable for detection of trace amounts of protease contamination. The method is based on the proteolytic hydroysis of a proprietary formulation of a FITC-labeled casein substrate.

استخدام أدوات الكشف البروتياز نيون تحديد نشاط الأنزيم البروتيني

The Protease Fluorescent Detection Kit provides ready-to-use reagents for detecting the presence of protease activity. This simple assay to detect ...

ELIME (Enzyme Linked Immuno Magnetic Electrochemical) Method for Mycotoxin Detection

Immunoassays are a valid alternative to the more expensive and time consuming quantitative HPLC or GC1, 2 methods for the screening detection of hazardous mycotoxins in food commodities. In this protocol we show how to fabricate and interrogate an electrochemical competitive Enzyme linked immunomagnetic assay based on the use of magnetic beads as solid support for the immunochemical chain3 and screen printed electrodes as sensing platform.
Our method aims to determine the total amount of HT-2 and T-2 toxins, mycotoxins belonging to the trichothecenes family and of great concern for human health4. The use of an antibody clone with a cross reactivity of 100% towards HT-2 and T-2 allows to simultaneously detect both toxins with similar sensitivity5.
The first step of our assay is the coating step where we immobilize HT2-KLH conjugate toxin on the surface of magnetic beads. After a blocking step, necessary to avoid non-specific absorptions, the addition of a monoclonal antibody allows the competition between immobilized HT-2 and free HT-2 or T-2 present in the sample or dissolved in a standard solution.
At the end of the competition step, the amount of monoclonal antibody linked to the immobilized HT-2 will be inversely proportional to the amount of toxin in the sample solution.
A secondary antibody labeled with alkaline phosphatase (AP) is used to reveal the binding between the specific antibody and the immobilized HT-2. The final measurement step is performed by dropping an aliquot of magnetic bead suspension, corresponding to a specific sample/standard solution, on the surface of a screen-printed working electrode; magnetic beads are immobilized and concentrated by means of a magnet placed precisely under the screen-printed electrode. After two minutes of incubation between magnetic beads and a substrate for AP, the enzymatic product is detected by Differential Pulse Voltammetry (DPV) using a portable instrument (PalmSens) also able to initiate automatically eight measurements within an interval of few seconds.

ELIME Enzyme Linked Immuno Magnetic Electrochemical Method for Mycotoxin Detection

A protocol to detect trichothecenes (mycotoxins of concern for human health) using a newly developed screening method based on a competitive immunochemical method and a final electrochemical detection is demonstrated.

ELIME (انزيم مرتبط المناعي المغناطيسي الكهروكيميائية) طرق الكشف عن السموم الفطرية

Immunoassays are a valid alternative to the more expensive and time consuming quantitative HPLC or GC1, 2 methods for the screening detection of hazardous ...

Production of Transgenic Xenopus laevis by Restriction Enzyme Mediated Integration and Nuclear Transplantation

Stable integration of cloned gene products into the Xenopus genome is necessary to control the time and place of expression, to express genes at later stages of embryonic development, and to define how enhancers and promoters regulate gene expression within the embryo. The protocol demonstrated here can be used to efficiently produce transgenic Xenopus laevis embryos. This transgenesis approach involves three parts: 1. Sperm nuclei are isolated from adult X. laevis testis by treatment with lysolecithin, which permeabilizes the sperm plasma membrane. 2. Egg extract is prepared by low speed centrifugation, addition of calcium to cause the extract to progress to interphase of the cell cycle, and a high-speed centrifugation to isolate interphase cytosol. 3. Nuclear transplantation: the nuclei and extract are combined with the linearized plasmid DNA to be introduced as the transgene and a small amount of restriction enzyme. During a short reaction, egg extract partially decondenses the sperm chromatin and the restriction enzyme generates chromosomal breaks that promote recombination of the transgene into the genome. The treated sperm nuclei are then transplanted into unfertilized eggs. Integration of the transgene usually occurs prior to the first embryonic cleavage such that the resulting embryos are not chimeric. These embryos can be analyzed without any need to breed to the next generation, allowing for efficient and rapid generation of transgenic embryos for analyses of promoter and gene function. Adult X. laevis resulting from this procedure also propagate the transgene through the germline and can be used to generate lines of transgenic animals for multiple purposes.

Production of Transgenic Xenopus laevis by Restriction Enzyme Mediated Integration and Nuclear Transplantation

This video protocol demonstrates a method for generating transgenic Xenopus laevis by introduction of transgenes into sperm nuclei followed by nuclear transplantation into unfertilized eggs.

إنتاج المعدلة وراثيا القيطم المورق عن طريق تقييد أنزيم التكامل وساطة وزرع النووية

Stable integration of cloned gene products into the Xenopus genome is necessary to control the time and place of expression, to express genes at later ...

Detection of Nitric Oxide and Superoxide Radical Anion by Electron Paramagnetic Resonance Spectroscopy from Cells using Spin Traps

Reactive nitrogen/oxygen species (ROS/RNS) at low concentrations play an important role in regulating cell function, signaling, and immune response but in unregulated concentrations are detrimental to cell viability1, 2. While living systems have evolved with endogenous and dietary antioxidant defense mechanisms to regulate ROS generation, ROS are produced continuously as natural by-products of normal metabolism of oxygen and can cause oxidative damage to biomolecules resulting in loss of protein function, DNA cleavage, or lipid peroxidation3, and ultimately to oxidative stress leading to cell injury or death4. 
Superoxide radical anion (O2&bull;-) is the major precursor of some of the most highly oxidizing species known to exist in biological systems such as peroxynitrite and hydroxyl radical. The generation of O2&bull;- signals the first sign of oxidative burst, and therefore, its detection and/or sequestration in biological systems is important. In this demonstration, O2&bull;- was generated from polymorphonuclear neutrophils (PMNs). Through chemotactic stimulation with phorbol-12-myristate-13-acetate (PMA), PMN generates O2&bull;- via activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase5. 
Nitric oxide (NO) synthase which comes in three isoforms, as inducible-, neuronal- and endothelial-NOS, or iNOS, nNOS or eNOS, respectively, catalyzes the conversion of L- arginine to L-citrulline, using NADPH to produce NO6. Here, we generated NO from endothelial cells. Under oxidative stress conditions, eNOS for example can switch from producing NO to O2&bull;- in a process called uncoupling, which is believed to be caused by oxidation of heme7 or the co-factor, tetrahydrobiopterin (BH4)8.
There are only few reliable methods for the detection of free radicals in biological systems but are limited by specificity and sensitivity. Spin trapping is commonly used for the identification of free radicals and involves the addition reaction of a radical to a spin trap forming a persistent spin adduct which can be detected by electron paramagnetic resonance (EPR) spectroscopy. The various radical adducts exhibit distinctive spectrum which can be used to identify the radicals being generated and can provide a wealth of information about the nature and kinetics of radical production9.
The cyclic nitrones, 5,5-dimethyl-pyrroline-N-oxide, DMPO10, the phosphoryl-substituted DEPMPO11, and the ester-substituted, EMPO12 and BMPO13, have been widely employed as spin traps--the latter spin traps exhibiting longer half-lives for O2&bull;- adduct. Iron (II)-N-methyl-D-glucamine dithiocarbamate, Fe(MGD)2 is commonly used to trap NO due to high rate of adduct formation and the high stability of the spin adduct14.

Electron paramagnetic resonance (EPR) spectroscopy was employed to detect nitric oxide from bovine aortic endothelial cells and superoxide radical anion from human neutrophils using iron (II)-N-methyl-D-glucamine dithiocarbamate, Fe(MGD)2 and 5,5-dimethyl-1-pyroroline-N-oxide, DMPO, respectively.

اكتشاف اكسيد النيتريك وانيون الراديكالي فوق الأكسيد بواسطة الكترون ممغطس التحليل الطيفي بالرنين من الخلايا باستخدام الفخاخ سبين

Reactive nitrogen/oxygen species (ROS/RNS) at low concentrations play an important role in regulating cell function, signaling, and immune response but in ...

Monitoring Kinase and Phosphatase Activities Through the Cell Cycle by Ratiometric FRET

F&ouml;rster resonance energy transfer (FRET)-based reporters1 allow the assessment of endogenous kinase and phosphatase activities in living cells. Such probes typically consist of variants of CFP and YFP, intervened by a phosphorylatable sequence and a phospho-binding domain. Upon phosphorylation, the probe changes conformation, which results in a change of the distance or orientation between CFP and YFP, leading to a change in FRET efficiency (Fig 1). Several probes have been published during the last decade, monitoring the activity balance of multiple kinases and phosphatases, including reporters of PKA2, PKB3, PKC4, PKD5, ERK6, JNK7, Cdk18, Aurora B9 and Plk19. Given the modular design, additional probes are likely to emerge in the near future10. 
Progression through the cell cycle is affected by stress signaling pathways 11. Notably, the cell cycle is regulated differently during unperturbed growth compared to when cells are recovering from stress12.Time-lapse imaging of cells through the cell cycle therefore requires particular caution. This becomes a problem particularly when employing ratiometric imaging, since two images with a high signal to noise ratio are required to correctly interpret the results. Ratiometric FRET imaging of cell cycle dependent changes in kinase and phosphatase activities has predominately been restricted to sub-sections of the cell cycle8,9,13,14.
Here, we discuss a method to monitor FRET-based probes using ratiometric imaging throughout the human cell cycle. The method relies on equipment that is available to many researchers in life sciences and does not require expert knowledge of microscopy or image processing.

FRET-based reporters are increasingly used to monitor kinase and phosphatase activities in live cells. Here we describe a method on how to use FRET-based reporters to assess cell cycle-dependent changes in target phosphorylation.

رصد كيناز والفوسفاتيز الأنشطة من خلال دورة الخلية التي Ratiometric الحنق

F&ouml;rster resonance energy transfer (FRET)-based reporters1 allow the assessment of endogenous kinase and phosphatase activities in living cells. Such ...

Assaying the Kinase Activity of LRRK2 in vitro

Leucine Rich Repeat Kinase 2 (LRRK2) is a 2527 amino acid member of the ROCO family of proteins, possessing a complex, multidomain structure including a GTPase domain (termed ROC, for Ras of Complex proteins) and a kinase domain1. The discovery in 2004 of mutations in LRRK2 that cause Parkinson's disease (PD) resulted in LRRK2 being the focus of a huge volume of research into its normal function and how the protein goes awry in the disease state2,3. Initial investigations into the function of LRRK2 focused on its enzymatic activities4-6. Although a clear picture has yet to emerge of a consistent alteration in these due to mutations, data from a number of groups has highlighted the importance of the kinase activity of LRRK2 in cell death linked to mutations7,8. Recent publications have reported inhibitors targeting the kinase activity of LRRK2, providing a key experimental tool9-11. In light of these data, it is likely that the enzymatic properties of LRRK2 afford us an important window into the biology of this protein, although whether they are potential drug targets for Parkinson's is open to debate.
A number of different approaches have been used to assay the kinase activity of LRRK2. Initially, assays were carried out using epitope tagged protein overexpressed in mammalian cell lines and immunoprecipitated, with the assays carried out using this protein immobilised on agarose beads4,5,7. Subsequently, purified recombinant fragments of LRRK2 in solution have also been used, for example a GST tagged fragment purified from insect cells containing residues 970 to 2527 of LRRK212. Recently, Dani&euml;ls et al. reported the isolation of full length LRRK2 in solution from human embryonic kidney cells, however this protein is not widely available13. In contrast, the GST fusion truncated form of LRRK2 is commercially available (from Invitrogen, see table 1 for details), and provides a convenient tool for demonstrating an assay for LRRK2 kinase activity. Several different outputs for LRRK2 kinase activity have been reported. Autophosphorylation of LRRK2 itself, phosphorylation of Myelin Basic Protein (MBP) as a generic kinase substrate and phosphorylation of an artificial substrate - dubbed LRRKtide, based upon phosphorylation of threonine 558 in Moesin - have all been used, as have a series of putative physiological substrates including &alpha;-synuclein, Moesin and 4-EBP14-17. The status of these proteins as substrates for LRRK2 remains unclear, and as such the protocol described below will focus on using MBP as a generic substrate, noting the utility of this system to assay LRRK2 kinase activity directed against a range of potential substrates.

Assaying the Kinase Activity of LRRK2 in vitro

Leucine Rich Repeat Kinase 2 is a large multidomain kinase, mutations in which are the most common genetic cause of Parkinson's disease. Analysis of the kinase activity of this protein has proven to be a crucial tool in understanding the biology and dysfunction of this protein. In this paper, in vitro assaying of the kinase activity of LRRK2 and a selection of its mutants is described, providing an experimental system to examine phosphorylation of putative substrates and potential dysfunction of LRRK2 in disease.

يعاير النشاط كيناز من LRRK2 في المختبر</em

Leucine Rich Repeat Kinase 2 (LRRK2) is a 2527 amino acid member of the ROCO family of proteins, possessing a complex, multidomain structure including a ...

GC-based Detection of Aldononitrile Acetate Derivatized Glucosamine and Muramic Acid for Microbial Residue Determination in Soil

Quantitative approaches to characterizing microorganisms are crucial for a broader understanding of the microbial status and function within ecosystems. Current strategies for microbial analysis include both traditional laboratory culture-dependent techniques and those based on direct extraction and determination of certain biomarkers1, 2. Few among the diversity of microbial species inhabiting soil can be cultured, so culture-dependent methods introduce significant biases, a limitation absent in biomarker analysis.
The glucosamine, mannosamine, galactosamine and muramic acid have been well served as measures of both the living and dead microbial mass, of these the glucosamine (most abundant) and muramic acid (uniquely from bacterial cell) are most important constituents in the soil systems3, 4. However, the lack of knowledge on the analysis restricts the wide popularization among scientific peers. Among all existing analytical methods, derivatization to aldononitrile acetates followed by GC-based analysis has emerged as a good option with respect to optimally balancing precision, sensitivity, simplicity, good chromatographic separation, and stability upon sample storage5.
Here, we present a detailed protocol for a reliable and relatively simple analysis of glucosamine and muramic acid from soil after their conversion to aldononitrile acetates. The protocol mainly comprises four steps: acid digestion, sample purification, derivatization and GC determination. The step-by-step procedure is modified according to former publications6, 7. In addition, we present a strategy to structurally validate the molecular ion of the derivative and its ion fragments formed upon electron ionization. We applied GC-EI-MS-SIM, LC-ESI-TOF-MS and isotopically labeled reagents to determine the molecular weight of aldononitrile acetate derivatized glucosamine and muramic acid; we used the mass shift of isotope-labeled derivatives in the ion spectrum to investigate ion fragments of each derivatives8. In addition to the theoretical elucidation, the validation of molecular ion of the derivative and its ion fragments will be useful to researchers using &delta;13C or ion fragments of these biomarkers in biogeochemical studies9, 10.

We describe a method protocol for the GC-based analysis of the aldonitrile acetate derivatives of glucosamine and muramic acid extracted from soil. For elucidation of the chemical mechanism, we also present a strategy to confirm the structure of the derivative and the ion fragments formed upon electron ionization.

GC القائم على الكشف عن حمض Aldononitrile خلات الجلوكوزامين والموراميك Derivatized لتحديد بقايا الميكروبي في التربة

Quantitative approaches to characterizing microorganisms are crucial for a broader understanding of the microbial status and function within ecosystems. ...

Measurement of Larval Activity in the Drosophila Activity Monitor

Drosophila larvae are used in many behavioral studies, yet a simple device for measuring basic parameters of larval activity has not been available. This protocol repurposes an instrument often used to measure adult activity, the TriKinetics Drosophila activity monitor (MB5 Multi-Beam Activity Monitor) to study larval activity. The instrument can monitor the movements of animals in 16 individual 8 cm glass assay tubes, using 17 infrared detection beams per tube. Logging software automatically saves data to a computer, recording parameters such as number of moves, times sensors were triggered, and animals&#8217; positions within the tubes. The data can then be analyzed to represent overall locomotion and/or position preference as well as other measurements. All data are easily accessible and compatible with basic graphing and data manipulation software. This protocol will discuss how to use the apparatus, how to operate the software and how to run a larval activity assay from start to finish.

Measurement of Larval Activity in the Drosophila Activity Monitor

This report describes a method for measuring Drosophila larval activity using the TriKinetics Drosophila Activity Monitor. The device employs infrared beams to detect movements of up to 16 individual animals. Data can be analyzed to represent motion parameters including rates and the positions of the animals within the assay chambers.

قياس اليرقات آخر في<em&gt; ذبابة الفاكهة</em&gt; مراقبة النشاط

Drosophila larvae are used in many behavioral studies, yet a simple device for measuring basic parameters of larval activity has not been available. This ...

Studying the Activity of Neuropeptides and Other Regulators of the Excretory System in the Adult Mosquito

Studies of insect physiology, particularly in those species that are vectors of pathogens causing disease in humans and other vertebrates, provide the foundation to develop novel strategies for pest control. Here, a series of methods are described that are routinely utilized to determine the functional roles of neuropeptides and other neuronal factors (i.e., biogenic amines) on the excretory system of the mosquito, Aedes aegypti. The Malpighian tubules (MTs), responsible for primary urine formation, can continue functioning for hours when removed from the mosquito, allowing for fluid secretion measurements following hormone treatments. As such, the Ramsay assay is a useful technique to measure secretion rates from isolated MTs. Ion-selective microelectrodes (ISME) can sequentially be used to measure ion concentrations (i.e., Na+ and K+) in the secreted fluid. This assay allows for the measurement of several MTs at a given time, determining the effects of various hormones and drugs. The Scanning Ion-selective Electrode Technique uses ISME to measure voltage representative of ionic activity in the unstirred layer adjacent to the surface of ion transporting organs to determine transepithelial transport of ions in near real time. This method can be used to understand the role of hormones and other regulators on ion absorption or secretion across epithelia. Hindgut contraction assays are also a useful tool to characterize myoactive neuropeptides, that may enhance or reduce the ability of this organ to remove excess fluid and waste. Collectively, these methods provide insight into how the excretory system is regulated in adult mosquitoes. This is important because functional coordination of the excretory organs is crucial in overcoming challenges such as desiccation stress after eclosion and before finding a suitable vertebrate host to obtain a bloodmeal.

This protocol outlines methodologies behind the Ramsay assay, ion-selective microelectrodes, Scanning Ion-selective Electrode Technique (SIET) and in vitro contraction assays, applied to study the adult mosquito excretory system, comprised of the Malpighian tubules and hindgut, to collectively measure ion and fluid secretion rates, contractile activity, and transepithelial ion transport.

دراسة نشاط الببتيدات العصبية وغيرها من منظمات نظام الإخراج في البعوض البالغ

Studies of insect physiology, particularly in those species that are vectors of pathogens causing disease in humans and other vertebrates, provide the ...