Name: caffeine extraction, enzymatic activity and gene expression of caffeine synthase from plant cell suspensions
Uploaded: 2018-10-02T13:00:00
Description: Watch this Scientific Journal Video about Caffeine Extraction, Enzymatic Activity and Gene Expression of Caffeine Synthase from Plant Cell Suspensions at JoVE.com

The work of our laboratory was funded by a grant from the Consejo Nacional de Ciencia y Tecnolog&#237;a (CONACyT 219893) to SMTHS. This research was also supported by a fellowship granted to RJPK (No. 37938) by CONACyT and the Sistema Nacional de Investigadores (4422). The authors thank CIATEJ for the use of its installations during the writing of this manuscript. Special thanks are extended to Dr. V&#237;ctor Manuel Gonz&#225;lez Mendoza for all recommendations in the molecular biology section&#160;and Valent&#237;n Mendoza Rodr&#237;guez, IFC, UNAM for the facilities during the filming of this article.

1. Caffeine Extraction in Cell Suspensions of C. arabica L.
<ol>
	<li>Use C. arabica cell suspensions9. Maintain the suspensions by biweekly subcultures in Murashige and Skoog medium at pH 4.3 with constant 100 rpm shaking at 25 &#176;C under continuous light (8.3 W/m2).</li>
	<li>Harvest the cells under vacuum filtration using 11 &#181;m pore filter paper and a Buchner funnel.</li>
	<li>Register the fresh weight of the collected cells using a scale, wrap them in alu...

<ol>
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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+influence+of+beverage+composition+on+delivery+of+phenolic+compounds+from+coffee+and+tea.">The influence of beverage composition on delivery of phenolic compounds from coffee and tea.</a> Physiolgy &amp; Behavior. 100 (1), 33-41 (2010).</li><li>Majheni&#269;, L., &#352;kerget, M., Knez, &. #. 3. 8. 1. ;. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antioxidant+and+antimicrobial+activity+of+guarana+seed+extracts.">Antioxidant and antimicrobial activity of guarana seed extracts.</a> Food Chemistry. 104 (3), 1258-1268 (2007).</li><li>Sledz, W., Los, E., Paczek, A., Rischka, J., Motyka, A., Zoledowska, S., Lojkowska, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antibacterial+activity+of+caffeine+against+plant+pathogenic+bacteria.">Antibacterial activity of caffeine against plant pathogenic bacteria.</a> Acta Biochimica Polonica. 62 (3), 605-612 (2015).</li><li>Lipton, R. B., Diener, H. C., Robbins, M. S., Garas, S. Y., Patel, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Caffeine+in+the+management+of+patients+with+headache.">Caffeine in the management of patients with headache.</a> Journal of Headache and Pain. 18 (1), 1-11 (2017).</li><li>De Mejia, E. G., Ramirez-Mares, M. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+caffeine+and+coffee+on+our+health.">Impact of caffeine and coffee on our health.</a> Trends in Endocrinology &amp; Metabolism. 25 (10), 489-492 (2014).</li><li>Uefuji, H., Tatsumi, Y., Morimoto, M., Kaothien-Nakayama, P., Ogita, S., Sano, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Caffeine+production+in+tobacco+plants+by+simultaneous+expression+of+three+coffee+N-methyltrasferases+and+its+potential+as+a+pest+repellant.">Caffeine production in tobacco plants by simultaneous expression of three coffee N-methyltrasferases and its potential as a pest repellant.</a> Plant Molecular Biology. 59 (2), 221-227 (2005).</li><li>Denoeud, F., Carretero-Paulet, L., Dereeper, A., Droc, G., Guyot, R., Pietrella, M., Aury, J. 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+coffee+genome+provides+insight+into+the+convergent+evolution+of+caffeine+biosynthesis.">The coffee genome provides insight into the convergent evolution of caffeine biosynthesis.</a> Science. 345 (6201), 1181-1184 (2014).</li><li>Kurata, H., Matsumura, S., Furusaki, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light+irradiation+causes+physiological+and+metabolic+changes+for+purine+alkaloid+production+by+a+Coffea+arabica+cell+suspension+culture.">Light irradiation causes physiological and metabolic changes for purine alkaloid production by a Coffea arabica cell suspension culture.</a> Plant Science. 123 (1-2), 197-203 (1997).</li><li>Pech-K&#250;, R., Mu&#241;oz-S&#225;nchez, J. A., Monforte-Gonz&#225;lez, M., V&#225;zquez-Flota, F., Rodas-Junco, B. A., Gonz&#225;lez-Mendoza, V. M., Hern&#225;ndez-Sotomayor, S. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relationship+between+aluminum+stress+and+caffeine+biosynthesis+in+suspension+cells+of+Coffea+arabica+L.">Relationship between aluminum stress and caffeine biosynthesis in suspension cells of Coffea arabica L.</a> Journal of Inorganic Biochemistry. 181, 177-182 (2018).</li><li>Huang, R., O'Donnell, A. J., Barboline, J. J., Barkman, T. J. <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+caffeine+in+plants+by+co-option+of+exapted+ancestral+enzymes.">Convergent evolution of caffeine in plants by co-option of exapted ancestral enzymes.</a> Proceedings of the National Academy of Sciences. 113 (38), 10613-10618 (2016).</li><li>Mizuno, K., Okuda, A., Kato, M., Yoneyama, N., Tanaka, H., Ashihara, H., Fujimura, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+a+new+dual-functional+caffeine+synthase+gene+encoding+an+enzyme+for+the+conversion+of+7-methylxanthine+to+caffeine+from+coffee+(Coffea+arabica+L.).">Isolation of a new dual-functional caffeine synthase gene encoding an enzyme for the conversion of 7-methylxanthine to caffeine from coffee (Coffea arabica L.).</a> FEBS letters. 534 (1-3), 75-81 (2003).</li><li>Kato, M., Mizuno, K., Fujimura, T., Iwama, M., Irie, M., Crozier, A., Ashihara, H. <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+caffeine+synthase+from+tea+leaves.">Purification and characterization of caffeine synthase from tea leaves.</a> Plant Physiology. 120 (2), 579-586 (1999).</li><li>Livak, K. J., Schmittgen, T. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+relative+gene+expression+data+using+real-time+quantitative+PCR+and+the+2(-Delta+Delta+C(T))+Method.">Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method.</a> Method. 25 (4), 402-408 (2001).</li><li>Kurata, H., Achioku, T., Furusaki, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+light/dark+cycle+operation+with+an+hour-scale+period+enhances+caffeine+production+by+Coffea+arabica+cells.">The light/dark cycle operation with an hour-scale period enhances caffeine production by Coffea arabica cells.</a> Enzyme and Microbial Technology. 23 (7-8), 518-523 (1998).</li><li>Sartor, R. M., Mazzafera, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Caffeine+formation+by+suspension+cultures+of+Coffea+dewevrei.">Caffeine formation by suspension cultures of Coffea dewevrei.</a> Brazilian Archives of Biology Technology. 43 (1), 1-9 (2000).</li><li>Koshiro, Y., Zheng, X. Q., Wang, M. L., Nagai, C., Ashihara, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+in+content+and+biosynthetic+activity+of+caffeine+and+trigonelline+during+growth+and+ripening+of+Coffea+arabica+and+Coffea+canephora+fruits.">Changes in content and biosynthetic activity of caffeine and trigonelline during growth and ripening of Coffea arabica and Coffea canephora fruits.</a> Plant Science. 171 (2), 242-250 (2006).</li><li>Schimpl, F. C., Kiyota, E., Mayer, J. L. S., de Carvalho Gon&#231;alves, J. F., da Silva, J. F., Mazzafera, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+and+biochemical+characterization+of+caffeine+synthase+and+purine+alkaloid+concentration+in+guarana+fruit.">Molecular and biochemical characterization of caffeine synthase and purine alkaloid concentration in guarana fruit.</a> Phytochemistry. 105, 25-36 (2014).</li><li>Perrois, C., Strickler, S. R., Mathieu, G., Lepelley, M., Bedon, L., Michaux, S., Privat, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+regulation+of+caffeine+metabolism+in+Coffea+arabica+(Arabica)+and+Coffea+canephora+(Robusta).">Differential regulation of caffeine metabolism in Coffea arabica (Arabica) and Coffea canephora (Robusta).</a> Planta. 241 (1), 179-191 (2015).</li></ol>

We present here the optimal conditions for evaluating the caffeine content, CS activity and transcript levels in an in vitro plant tissue culture, such as cell suspensions of C. arabica. Previous reports have confirmed that maintaining cells under light irradiation and in the presence of theobromine in the culture medium are suitable parameters for increasing the level of caffeine, making it possible to evaluate the caffeine separation methods using reversed-phase high-performance liquid chromatography ...

Caffeine is a secondary metabolite that is biosynthesized by plants of the genus Coffea1. This alkaloid belongs to the methylxanthine family and is regarded as a chemical plant defense because it can act against the adverse effects of pathogens and herbivores2,3. In addition, this metabolite is responsible for the stimulating properties of the coffee drink, which is commonly consumed worldwide4,5. Due to its properties, several research groups are interested in studying the biosynthetic pathway and catabolism of caffeine6,7. Currently, plant in vitro cell/tissue cultures serve as an alternative for evaluating caffeine accumulation under various biotic and abiotic strategies8,9.
Caffeine biosynthesis involves the hydrolytic release of 7-methylxanthine from the corresponding ribose nucleoside followed by ordered N-methylations at positions 3 and 1. A specific S-adenosyl methionine (SAM)-dependent N-methyltransferase (NMT) catalyzes the methylation at position 7, whereas theobromine synthase (TS) and CS are involved in the 3- and 1-methylations, respectively, producing theobromine and caffeine. The study of genes encoding distinct NMTs has allowed understanding the mechanism that regulates caffeine production10,11. CS, which has N-methyltransferase activity, catalyzes the last two steps of the biosynthetic pathway of caffeine11. In coffee tree seedlings, it has been shown that light radiation can increase CS activity, which results in an increase in caffeine biosynthesis. Recently, we showed that the maintenance of cell suspensions of C. arabica L. under light irradiation is the optimal condition for evaluating the effects that produce abiotic stress factors impacting the biosynthetic pathway of caffeine8. The information obtained in these studies may have applications in metabolic engineering and systems biology for maximizing the study of the caffeine biosynthetic pathway in such in vitro systems.
Given the advantages of obtaining a suitable model for the study of caffeine biosynthesis, we optimized the extraction conditions for caffeine on cell suspensions of C. arabica L. It was also possible to develop a useful protocol for studying the enzymatic activity as well as methodological steps for assessing the level of gene transcripts of Coffea caffeine synthase 1 (CCS1) encoding this enzyme. Herein, we report a protocol to extract and quantify caffeine in C. arabica cell suspensions by thin-layer chromatography and densitometry (TLC-densitometry).

<table border="0" cellpadding="0" cellspacing="0" style="width:883px;" width="883">
	<tbody>
		<tr>
			<td>Murashige &#38; Skoog Basal salt mixture</td>
			<td>PhytoTechnology Laboratories</td>
			<td>M524</td>
			<td>Packge Size: 50 L 
			Reagent (mg/L) 
			Ammonium Nitrate (1650) 
			Boric acid (6.2) 
			Calcium chloride, anhydrous (322.2) 
			Cobalt Chloride&#8226;H2O (0.025) 
			Cupric Sulfate&#8226;5H2O (0.025) 
			Na2EDTA&#8226;2H2O (37.26) 
			Ferrous Sulfate&#8226;7H2O (27.8) 
			Magnesium Sulfate, Anhydrous (180.7) 
			Manganese Sulfate&#8226;H2O (16.9) 
			Molybdic Acid (Sodium Salt)&#8226; 2H2O (0.25) 
			Potassium Iodide (0.83) 
			Potassium Nitrate (1900) 
			Potassium Phosphate, Monobasic (170) 
			Zinc Sulfate&#8226;7H2O (8.6) 
			Supplemented with 
			myo-inositol (100) 
			thiamine (10) 
			cysteine (25) 
			sucrose (30000) 
			2,4-dichlorophenoxyacetic acid (3) 
			6-benzylamine purine (1)</td>
		</tr>
		<tr>
			<td>Caffeine</td>
			<td>SIGMA</td>
			<td>C0750-5G</td>
			<td>STANDARD-5g</td>
		</tr>
		<tr>
			<td>Theobromine</td>
			<td>SIGMA</td>
			<td>T4500</td>
			<td>20 g</td>
		</tr>
		<tr>
			<td>CAMAG TLC Scanner-4</td>
			<td>CAMAG</td>
			<td>27.62</td>
			<td></td>
		</tr>
		<tr>
			<td>WinCATS Planar Chromatography Manager software</td>
			<td>CAMAG</td>
			<td>1.4.10</td>
			<td>Software</td>
		</tr>
		<tr>
			<td>Isoamyl alcohol (24:1)</td>
			<td>SIGMA</td>
			<td>C-0549</td>
			<td>500 mL</td>
		</tr>
		<tr>
			<td>Cyclohexane</td>
			<td>JALMEX</td>
			<td>C4375-13</td>
			<td>1 L</td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>J.T. BAKER</td>
			<td>900643</td>
			<td>4 L</td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>J.T. BAKER</td>
			<td>9093-03</td>
			<td>4 L</td>
		</tr>
		<tr>
			<td>Chloroform</td>
			<td>JALMEX</td>
			<td>C-4425-15</td>
			<td>3.5 L</td>
		</tr>
		<tr>
			<td>TLC silica gel 60 F254</td>
			<td>Merck</td>
			<td>1.05554.0001</td>
			<td>TLC plate</td>
		</tr>
		<tr>
			<td>&#946;-mercaptoethanol</td>
			<td>M6250</td>
			<td>SIGMA</td>
			<td>100 mL</td>
		</tr>
		<tr>
			<td>(+)-sodium L- ascorbate</td>
			<td>A4034</td>
			<td>SIGMA</td>
			<td>100 g</td>
		</tr>
		<tr>
			<td>Trizma base</td>
			<td>SIGMA</td>
			<td>T6066</td>
			<td>1 Kg</td>
		</tr>
		<tr>
			<td>Hydrochloric acid 36.5-38%</td>
			<td>J.T. Baker</td>
			<td>9535-05</td>
			<td>2.5 L</td>
		</tr>
		<tr>
			<td>Pierce BCA Protein Assay Kit</td>
			<td>Thermo scientific</td>
			<td>232227</td>
			<td>Kit</td>
		</tr>
		<tr>
			<td>Methyl [3H]-S-adenosyl methionine</td>
			<td>Perkin Elmer</td>
			<td>NET155</td>
			<td>Specific activity of 15 Ci/mmol</td>
		</tr>
		<tr>
			<td>Liquid scintillation vials</td>
			<td>SIGMA</td>
			<td>Z253081</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermostatic bath/circulator</td>
			<td>Cole Parmer</td>
			<td>60714</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro centrifugue tube</td>
			<td>Eppendorf</td>
			<td></td>
			<td>Tube of 1.5 mL</td>
		</tr>
		<tr>
			<td>Cryogenic vials</td>
			<td>Heathrow Scientific</td>
			<td>HS23202A</td>
			<td>2 mL</td>
		</tr>
		<tr>
			<td>Centrifuge 5804</td>
			<td>Eppendorf</td>
			<td>5804 000925</td>
			<td></td>
		</tr>
		<tr>
			<td>Vortex</td>
			<td>Thermolyne</td>
			<td>LR 5947</td>
			<td></td>
		</tr>
		<tr>
			<td>Porcelain mortar</td>
			<td>Fisherbrand</td>
			<td>FB961B</td>
			<td></td>
		</tr>
		<tr>
			<td>Filter paper</td>
			<td>Whatman</td>
			<td>Z274844</td>
			<td>Porosity medium</td>
		</tr>
		<tr>
			<td>Picofuge</td>
			<td>Stratagene</td>
			<td>400550</td>
			<td>2000 x g</td>
		</tr>
		<tr>
			<td>Analytical balance</td>
			<td>AND</td>
			<td>HR-120</td>
			<td>Model HR-120</td>
		</tr>
		<tr>
			<td>Scintillation counter</td>
			<td>Beckman Coulter</td>
			<td>6500</td>
			<td></td>
		</tr>
		<tr>
			<td>Gel photodocumentation system</td>
			<td>Bio-Rad</td>
			<td>Chemic XRS</td>
			<td>Model Chemic XRS</td>
		</tr>
		<tr>
			<td>Compact UV lamp</td>
			<td>UVP</td>
			<td>95002112</td>
			<td>UVGL-25</td>
		</tr>
		<tr>
			<td>Scienceware HDPE Buchner funnel</td>
			<td>SIGMA</td>
			<td>2419907</td>
			<td>Type 37600 mixer</td>
		</tr>
		<tr>
			<td>TRIzol reagent</td>
			<td>Thermo scientific</td>
			<td>15596-018</td>
			<td>200 mL</td>
		</tr>
		<tr>
			<td>ReverdAid Reverse transcriptase</td>
			<td>Thermo scientific</td>
			<td>#EP0441</td>
			<td>10000 U</td>
		</tr>
		<tr>
			<td>Oligo (dT)18 primer</td>
			<td>Thermo scientific</td>
			<td>#S0131</td>
			<td>100 &#181;M</td>
		</tr>
		<tr>
			<td>DNase I, RNase-free</td>
			<td>Thermo scientific</td>
			<td>#EN0525</td>
			<td>1000 U</td>
		</tr>
		<tr>
			<td>Magnesium chloride</td>
			<td>Thermo scientific</td>
			<td>EN0525</td>
			<td>1.25 mL</td>
		</tr>
		<tr>
			<td>Ethylenediaminetetraacetic acid</td>
			<td>Thermo scientific</td>
			<td>EN0525</td>
			<td>1 mL</td>
		</tr>
		<tr>
			<td>dNTP mix</td>
			<td>Thermo scientific</td>
			<td>R0191</td>
			<td>R0191</td>
		</tr>
		<tr>
			<td>SYBR Green qPCR Master Mix (2X)</td>
			<td>Thermo scientific</td>
			<td>K0251</td>
			<td>For 200 reactions of 25 &#181;L</td>
		</tr>
		<tr>
			<td>PikoReal</td>
			<td>Thermo scientific</td>
			<td>2.2</td>
			<td>Software</td>
		</tr>
		<tr>
			<td>Phenol, pH 8.0, equilibrated, Molecular Biology Grade, Ultrapure</td>
			<td>USB</td>
			<td>J75829</td>
			<td>100 mL</td>
		</tr>
		<tr>
			<td>Isopropyl alcohol</td>
			<td>Karal</td>
			<td>2040</td>
			<td>1 L</td>
		</tr>
		<tr>
			<td>Ethyl alcohol</td>
			<td>SIGMA</td>
			<td>64175</td>
			<td>1 L</td>
		</tr>
		<tr>
			<td>Diethyl pyrocarbonate</td>
			<td>SIGMA</td>
			<td>D5758</td>
			<td>100 mL</td>
		</tr>
		<tr>
			<td>Lab Rotator</td>
			<td>LW Scientific</td>
			<td>Mod. LW210</td>
			<td></td>
		</tr>
	</tbody>
</table>

caffeine extraction, enzymatic activity and gene expression of caffeine synthase from plant cell suspensions

Caffeine (1,3,7-trimethylxanthine) is a purine alkaloid present in popular drinks such as coffee and tea. This secondary metabolite is regarded as a chemical defense because it has antimicrobial activity and is considered a natural insecticide. Caffeine can also produce negative allelopathic effects that prevent the growth of surrounding plants. In addition, people around the world consume caffeine for its analgesic and stimulatory effects. Due to interest in the technological applications of caffeine, research on the biosynthetic pathway of this compound has grown. These studies have primarily focused on understanding the biochemical and molecular mechanisms that regulate the biosynthesis of caffeine. In vitro tissue culture has become a useful system for studying this biosynthetic pathway. This article will describe a step-by-step protocol for the quantification of caffeine and for measuring the transcript levels of the gene (CCS1) encoding caffeine synthase (CS) in cell suspensions of C. arabica L. as well as its activity.

Caffeine extracts obtained via the process presented here were analyzed by TLC-densitometry by subjecting the samples to plate chromatography according to the scheme shown in Figure 1. To quantify the levels of caffeine in the cell extracts, a curve with various concentrations of commercial standard for this compound was used (Figure 2A). The pattern of absorbance for caffeine was analyzed in the visible light spectrum (UV-VIS) u...

Watch this Scientific Journal Video about Caffeine Extraction, Enzymatic Activity and Gene Expression of Caffeine Synthase from Plant Cell Suspensions at JoVE.com

Caffeine Extraction, Enzymatic Activity and Gene Expression of Caffeine Synthase from Plant Cell Suspensions

This protocol describes an efficient methodology for the extraction and quantification of caffeine in cell suspensions of C. arabica L. and an experimental process for evaluating the enzymatic activity of caffeine synthase with the expression level of the gene that encodes this enzyme.

Caffeine (1,3,7-trimethylxanthine) is a purine alkaloid present in popular drinks such as coffee and tea. This secondary metabolite is regarded as a ...

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Isolation and Respiratory Measurements of Mitochondria from Arabidopsis thaliana

Isolation and Respiratory Measurements of Mitochondria from Arabidopsis thaliana

Mitochondria are essential organelles involved in numerous metabolic pathways in plants, most notably the production of adenosine triphosphate (ATP) from ...

Modifying Baculovirus Expression Vectors to Produce Secreted Plant Proteins in Insect Cells

It has been a challenge for scientists to express recombinant secretory eukaryotic proteins for structural and biochemical studies. The ...

A Colorimetric Assay of Citrate Synthase Activity in Drosophila Melanogaster

A Colorimetric Assay of Citrate Synthase Activity in Drosophila Melanogaster

Mitochondria play the most prominent roles in cellular metabolism by producing ATP through oxidative phosphorylation and regulating a variety of ...

A Customizable Approach for the Enzymatic Production and Purification of Diterpenoid Natural Products

Diterpenoids form a diverse class of small molecule natural products that are widely distributed across the kingdoms of life and have critical biological ...

Obtaining High-Quality Transcriptome Data from Cereal Seeds by a Modified Method for Gene Expression Profiling

The characterization of gene expression is dependent on RNA quality. In germinating, developing and mature cereal seeds, the extraction of high-quality ...

Extraction and Quantification of Soluble, Radiolabeled Inositol Polyphosphates from Different Plant Species using SAX-HPLC

The phosphate esters of myo-inositol, also termed inositol phosphates (InsPs), are a class of cellular regulators playing important roles in plant ...

PCR Mutagenesis, Cloning, Expression, Fast Protein Purification Protocols and Crystallization of the Wild Type and Mutant Forms of Tryptophan Synthase

Structural studies with tryptophan synthase (TS) bienzyme complex (&#945;2&#946;2 TS) from Salmonella typhimurium have been performed to better understand ...