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{{Refimprove|date=June 2010}} |
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{{Refimprove|date=June 2010}} |
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{{drugbox |
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{{drugbox |
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| IUPAC_name = <nowiki>N-[4-amino-1-[[1-[[4-amino-1-oxo-1-[[6,9,18-tris |
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| IUPAC_name = <nowiki>N-[4-amino-1-[[1-[[4-amino-1-oxo-1-[[6,9,18-tris |
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amino]butan-2-yl]amino]-3-hydroxy-1-oxobutan-2-yl] |
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amino]butan-2-yl]amino]-3-hydroxy-1-oxobutan-2-yl] |
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amino]-1-oxobutan-2-yl]-6-methyloctanamide</nowiki> |
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amino]-1-oxobutan-2-yl]-6-methyloctanamide</nowiki> |
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| image = Polymyxin B Sulfate.png |
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| image = Polymyxin B1.svg |
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| image2 = polymyxin B2.svg |
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| CAS_number = 1405-20-5 |
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| CAS_number = 1405-20-5 |
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| ATC_prefix = A07 |
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| ATC_prefix = A07 |
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'''Polymyxin B''' is an antibiotic primarily used for resistant ] infections. It is derived from the bacterium Bacillus polymyxa. Polymyxin B sulfate has a bactericidal action against almost all gram-negative bacilli except the ] group. Polymyxins bind to the cell membrane and alter its structure, making it more permeable. The resulting water uptake leads to cell death. They are cationic, basic proteins that act like detergents (]s). Side-effects include neurotoxicity and acute renal tubular necrosis. It is commonly used in the topical first-aid preparation ]. |
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'''Polymyxin B''' is an antibiotic primarily used for resistant ] infections. It is derived from the bacterium '']''. Polymyxin B is a mixture of two closely related compounds, polymyxin B1 and polymxin B2. It has a bactericidal action against almost all gram-negative bacilli except the ] group. Polymyxins bind to the cell membrane and alter its structure, making it more permeable. The resulting water uptake leads to cell death. They are cationic, basic proteins that act like detergents (]s). Side-effects include neurotoxicity and acute renal tubular necrosis. It is commonly used in the topical first-aid preparation ]. |
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# Family of polypeptides with attached fatty acid; ] ] at physiological pH, both hydrophilic and hydrophobic properties |
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#Family of polypeptides with attached fatty acid; ] ] at physiological pH, both hydrophilic and hydrophobic properties |
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# Bactericidal for ]; little to no effect on ], since cell wall is too thick to permit access to membrane |
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#Bactericidal for ]; little to no effect on ], since cell wall is too thick to permit access to membrane |
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==Mechanism of action== |
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==Mechanism of action== |
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# Alters ] permeability by binding to a negatively charged site in the lipopolysaccharide layer, which has an electrostatic attraction for the positively charged amino groups in the cyclic peptide portion (this site normally is a binding site for calcium and magnesium counter ions); the result is a destabilized outer membrane |
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#Alters ] permeability by binding to a negatively charged site in the lipopolysaccharide layer, which has an electrostatic attraction for the positively charged amino groups in the cyclic peptide portion (this site normally is a binding site for calcium and magnesium counter ions); the result is a destabilized outer membrane |
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# Fatty acid portion dissolves in hydrophobic region of ] and disrupts membrane integrity |
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#Fatty acid portion dissolves in hydrophobic region of ] and disrupts membrane integrity |
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# Leakage of cellular molecules, inhibition of cellular respiration |
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#Leakage of cellular molecules, inhibition of cellular respiration |
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# Binds and inactivates endotoxin<ref name="pmid17201926">{{cite journal |author=Cardoso LS, Araujo MI, Góes AM, Pacífico LG, Oliveira RR, Oliveira SC |title=Polymyxin B as inhibitor of LPS contamination of Schistosoma mansoni recombinant proteins in human cytokine analysis |journal=Microb. Cell Fact. |volume=6 |issue= |pages=1 |year=2007 |pmid=17201926 |pmc=1766364 |doi=10.1186/1475-2859-6-1 |url=http://www.microbialcellfactories.com/content/6//1}}</ref> |
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#Binds and inactivates endotoxin<ref name="pmid17201926">{{cite journal |author=Cardoso LS, Araujo MI, Góes AM, Pacífico LG, Oliveira RR, Oliveira SC |title=Polymyxin B as inhibitor of LPS contamination of Schistosoma mansoni recombinant proteins in human cytokine analysis |journal=Microb. Cell Fact. |volume=6 |issue= |pages=1 |year=2007 |pmid=17201926 |pmc=1766364 |doi=10.1186/1475-2859-6-1 |url=http://www.microbialcellfactories.com/content/6//1}}</ref> |
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# Relative absence of selective toxicity: nonspecific for cell membranes of any type, highly toxic |
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#Relative absence of selective toxicity: nonspecific for cell membranes of any type, highly toxic |
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==Research application== |
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==Research application== |
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# In addition to its antibiotic function, polymix B has been used to clear endotoxin contamination in reagents. |
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In addition to its antibiotic function, polymix B has been used to clear endotoxin contamination in reagents. |
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==References== |
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==References== |
In addition to its antibiotic function, polymix B has been used to clear endotoxin contamination in reagents.
