This project was supported by grants to CJJ from the National Science Foundation and the Society for Biomolecular Sciences.

1. Day 1:
MexB from Pseudomonas aeruginosa is encoded by pFB101. The MexB gene was amplified from P. aeruginosa genomic DNA and inserted in the NdeI and XhoI restriction sites of the pET30b+ vector. The construct contains a C-terminal hexahistidine tag.
<ol>
<li>The plasmid is used to transform E. coli strain C43(DE3) 12, and the transformants are plated on LB agar containing 30 ug/mL kanamycin.</li>
</ol>
2. Day 2: Overnight...

<ol>
	<li>Eda, S., Maseda, H., Nakae, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+elegant+means+of+self-protection+in+gram-negative+bacteria+by+recognizing+and+extruding+xenobiotics+from+the+periplasmic+space.">An elegant means of self-protection in gram-negative bacteria by recognizing and extruding xenobiotics from the periplasmic space.</a> J. Biol. Chem. 278, 2085-2088 (2003).</li><li>Li, X. Z., Ma, D., Livermore, D. M., Nikaido, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+efflux+pump(s)+in+intrinsic+resistance+of+Pseudomonas+aeruginosa:+active+efflux+as+a+contributing+factor+to+beta-lactam+resistance.">Role of efflux pump(s) in intrinsic resistance of Pseudomonas aeruginosa: active efflux as a contributing factor to beta-lactam resistance.</a> Antimicrob. Agents Chemother. 38, 1742-1752 (1994).</li><li>Li, X. Z., Nikaido, H., Poole, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+MexA-MexB-OprM+in+antibiotic+efflux+in+Pseudomonas+aeruginosa.">Role of MexA-MexB-OprM in antibiotic efflux in Pseudomonas aeruginosa.</a> Antimicrob. Agents Chemother. 39, 1948-1953 (1995).</li><li>Masuda, N., Sakagawa, E., Ohya, S., Gotoh, N., Tsujimoto, H., Nishino, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Substrate+specificities+of+MexAB-OprM,+MexCD-OprJ,+and+MexXY-oprM+efflux+pumps+in+Pseudomonas+aeruginosa.">Substrate specificities of MexAB-OprM, MexCD-OprJ, and MexXY-oprM efflux pumps in Pseudomonas aeruginosa.</a> Antimicrob. Agents Chemother. 44, 3322-3327 (2000).</li><li>Okusu, H., Ma, D., Nikaido, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=AcrAB+efflux+pump+plays+a+major+role+in+the+antibiotic+resistance+phenotype+of+Escherichia+coli+multiple-antibiotic-resistance+(Mar)+mutants.">AcrAB efflux pump plays a major role in the antibiotic resistance phenotype of Escherichia coli multiple-antibiotic-resistance (Mar) mutants.</a> J. Bacteriol. 178, 306-308 (1996).</li><li>Srikumar, R., Kon, T., Gotoh, N., Poole, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+Pseudomonas+aeruginosa+multidrug+efflux+pumps+MexA-MexB-OprM+and+MexC-MexD-OprJ+in+a+multidrug-sensitive+Escherichia+coli+strain.">Expression of Pseudomonas aeruginosa multidrug efflux pumps MexA-MexB-OprM and MexC-MexD-OprJ in a multidrug-sensitive Escherichia coli strain.</a> Antimicrob. Agents Chemother. 42, 65-71 (1998).</li><li>Tikhonova, E. B., Zgurskaya, H. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=AcrA,+AcrB,+and+TolC+of+Escherichia+coli+Form+a+Stable+Intermembrane+Multidrug+Efflux.">AcrA, AcrB, and TolC of Escherichia coli Form a Stable Intermembrane Multidrug Efflux.</a> Complex. J. Biol. Chem. 279, 32116-3224 (2004).</li><li>Yoneyama, H., Ocakatan, A., Tsuda, M., Nakae, T. <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+mex-gene+products+in+antibiotic+extrusion+in+Pseudomonas+aeruginosa.">The role of mex-gene products in antibiotic extrusion in Pseudomonas aeruginosa.</a> Biochem. Biophys. Res. Commun. 233, 611-618 (1997).</li><li>Berger, B. W., Gendron, C. M., Robinson, C. R., Kaler, E. W., Lenhoff, A. 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+role+of+protein+and+surfactant+interactions+in+membrane-protein+crystallization.">The role of protein and surfactant interactions in membrane-protein crystallization.</a> Acta. Crystallogr. D Biol. Crystallogr. 61, 724-730 (2005).</li><li>Jones, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surfactants+in+membrane+solubilisation.">Surfactants in membrane solubilisation.</a> Int. J. Pharm. 177, 137-159 (1999).</li><li>Maire, M. l. e., Champeil, P., Moller, J. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interaction+of+membrane+proteins+and+lipids+with+solubilizing+detergents.">Interaction of membrane proteins and lipids with solubilizing detergents.</a> Biochim. Biophys. Acta. 1508, 86-111 (2000).</li><li>Miroux, B., Walker, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Over-production+of+proteins+in+Escherichia+coli:+mutant+hosts+that+allow+synthesis+of+some+membrane+proteins+and+globular+proteins+at+high+levels.">Over-production of proteins in Escherichia coli: mutant hosts that allow synthesis of some membrane proteins and globular proteins at high levels.</a> J. Mol. Biol. 260, 289-298 (1996).</li></ol>

No conflicts of interest declared.

In addition to multidrug resistance, many vital cellular activities, including ion transport, cell-cell communication, vesicle transport, maintenance of cellular structure, and host-pathogen interactions, involve proteins that are embedded in the cell membrane. Transmembrane proteins make up over 30% of known proteins and are the targets for the majority of pharmaceuticals in use today. The improper folding or activity of transmembrane proteins lead to important genetic diseases, including cystic fibrosis and diabetes. I...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>SDS sample buffer</td>
<td>&nbsp;</td>
<td>Biorad</td>
<td>161-0737</td>
<td>&nbsp;</td>
<tr>
<td>C43(DE3) E. coli strain</td>
<td>&nbsp;</td>
<td>Lucigen</td>
<td>60345-1</td>
<td>&nbsp;</td>
<tr>
<td>kanamycin sulfate</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>K4378</td>
<td>&nbsp;</td>
<tr>
<td>2XYT media</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>BP2466-2</td>
<td>&nbsp;</td>
<tr>
<td>LB media</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>AC61189-5000</td>
<td>&nbsp;</td>
<tr>
<td>IPTG</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>I6758</td>
<td>&nbsp;</td>
<tr>
<td>DNaseI</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>BP3226-1</td>
<td>&nbsp;</td>
<tr>
<td>Lysozyme</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>L7651</td>
<td>&nbsp;</td>
<tr>
<td>Complete EDTA-free protease inhibitor tablets</td>
<td>&nbsp;</td>
<td>Roche</td>
<td>11 873 580 001</td>
<td>&nbsp;</td>
<tr>
<td>NaP monobasic</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>S6566</td>
<td>&nbsp;</td>
<tr>
<td>NaP dibasic</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>S5136</td>
<td>&nbsp;</td>
<tr>
<td>NaCl</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>S6191</td>
<td>&nbsp;</td>
<tr>
<td>MgCl2</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>M1028</td>
<td>&nbsp;</td>
<tr>
<td>Glycerol</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>BP229-1</td>
<td>&nbsp;</td>
<tr>
<td>n-dodecyl-&beta;-D-maltopyranoside</td>
<td>&nbsp;</td>
<td>Anatrace</td>
<td>D310</td>
<td>&nbsp;</td>
<tr>
<td>15ml tubes</td>
<td>&nbsp;</td>
<td>Corning</td>
<td>430052</td>
<td>&nbsp;</td>
<tr>
<td>See-Saw Rocker</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>SSL 4</td>
<td>&nbsp;</td>
<tr>
<td>Talon metal affinity resin</td>
<td>&nbsp;</td>
<td>Clontech</td>
<td>635503</td>
<td>&nbsp;</td>
<tr>
<td>imidazole</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>I5513</td>
<td>&nbsp;</td>
<tr>
<td>10% polyacrylamide SDS PAGE gels</td>
<td>&nbsp;</td>
<td>BioRad</td>
<td>161-1454</td>
<td>&nbsp;</td>
<tr>
<td>Tris/glycine/SDS PAGE running buffer</td>
<td>&nbsp;</td>
<td>BioRad</td>
<td>161-0732</td>
<td>&nbsp;</td>
<tr>
<td>Kaleidascope prestained molecular weight markers</td>
<td>&nbsp;</td>
<td>BioRad</td>
<td>161-0324</td>
<td>&nbsp;</td>
<tr>
<td>Superose 12 30/10 column</td>
<td>&nbsp;</td>
<td>GEHealthcareSuperose</td>
<td>12 10/300 GL</td>
<td>&nbsp;</td>
<tr>
<td>Amicon centrifugal concentrator</td>
<td>&nbsp;</td>
<td>Millipore</td>
<td>UFC801024</td>
<td>&nbsp;</td>
<tr>
<td>Syringe filter</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>SLFG R04 NL</td>
<td>&nbsp;</td>
<tr>
<td>Fernbach flasks</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>09-552-39</td>
<td>&nbsp;</td>
<tr>
<td>Shaker to hold Fernbach flasks</td>
<td>&nbsp;</td>
<td>Fisher Scientific</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Akta system</td>
<td>&nbsp;</td>
<td>GE Healthcare</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>J6 Large scale centrifuge with JLA-8.1000 rotor</td>
<td>&nbsp;</td>
<td>Beckman</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>1 l centrifuge bottles</td>
<td>&nbsp;</td>
<td>Beckman</td>
<td>969329</td>
<td>&nbsp;</td>
<tr>
<td>RC-5 centrifuge</td>
<td>&nbsp;</td>
<td>ThermoScientific</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>SS34 fixed-angle rotor and tubes</td>
<td>&nbsp;</td>
<td>ThermoScientific</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Sorvall floor model Ultracentrifuge</td>
<td>&nbsp;</td>
<td>ThermoScientific</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>T647.5 rotor and tubes with caps</td>
<td>&nbsp;</td>
<td>ThermoScientific</td>
<td>08322</td>
<td>&nbsp;</td>
<tr>
<td>French Pressure Cell</td>
<td>&nbsp;</td>
<td>ThermoScientific</td>
<td>FA-032</td>
<td>&nbsp;</td>		</tbody>
		</table>
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expression, detergent solubilization, and purification of a membrane transporter, the mexb multidrug resistance protein

Multidrug resistance (MDR), the ability of a cancer cell or pathogen to be resistant to a wide range of structurally and functionally unrelated anti-cancer drugs or antibiotics, is a current serious problem in public health. This multidrug resistance is largely due to energy-dependent drug efflux pumps. The pumps expel anti-cancer drugs or antibiotics into the external medium, lowering their intracellular concentration below a toxic threshold. We are studying multidrug resistance in Pseudomonas aeruginosa, an opportunistic bacterial pathogen that causes infections in patients with many types of injuries or illness, for example, burns or cystic fibrosis, and also in immuno-compromised cancer, dialysis, and transplantation patients. The major MDR efflux pumps in P. aeruginosa are tripartite complexes comprised of an inner membrane proton-drug antiporter (RND), an outer membrane channel (OMF), and a periplasmic linker protein (MFP) 1-8. The RND and OMF proteins are transmembrane proteins. Transmembrane proteins make up more than 30% of all proteins and are 65% of current drug targets. The hydrophobic transmembrane domains make the proteins insoluble in aqueous buffer. Before a transmembrane protein can be purified, it is necessary to find buffer conditions containing a mild detergent that enable the protein to be solubilized as a protein detergent complex (PDC) 9-11. In this example, we use an RND protein, the P. aeruginosa MexB transmembrane transporter, to demonstrate how to express a recombinant form of a transmembrane protein, solubilize it using detergents, and then purify the protein detergent complexes. This general method can be applied to the expression, purification, and solubilization of many other recombinantly expressed membrane proteins. The protein detergent complexes can later be used for biochemical or biophysical characterization including X-ray crystal structure determination or crosslinking studies.

Watch this Scientific Journal Video about Expression, Detergent Solubilization, and Purification of a Membrane Transporter, the MexB Multidrug Resistance Protein at JoVE.com

Expression, Detergent Solubilization, and Purification of a Membrane Transporter, the MexB Multidrug Resistance Protein

In this protocol we demonstrate the expression, solubilization, and purification of a recombinantly expressed membrane protein, MexB, as a soluble protein detergent complex. MexB is a multidrug resistance membrane transporter from the opportunistic bacterial pathogen Pseudomonas aeruginosa.

Multidrug resistance (MDR), the ability of a cancer cell or pathogen to be resistant to a wide range of structurally and functionally unrelated ...

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21.1K visualizações.  University of Illinois Chicago - UIC. Neste protocolo que demonstram a expressão, solubilização e purificação de uma proteína de membrana recombinantemente expressas, MexB, como um complexo proteína solúvel detergente. MexB é um transportador de membrana multirresistência do oportunista Pseudomonas aeruginosa bacteriana patogênica.