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Team:Osaka/Project pga
From 2010.igem.org
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Gamma polyglutamic acid (γ-PGA) is a very interesting biopolymer that attracts attention in late years. | Gamma polyglutamic acid (γ-PGA) is a very interesting biopolymer that attracts attention in late years. | ||
| - | <br>It can be found in "natto", a | + | <br>It can be found in "natto",a traditional Japanese fermented food made from soybeans by <i>Bacillus subtilis</i> (formerly <i>Bacillus natto</i>). This healty food is very sticky.</br><p> |
<img src="https://static.igem.org/mediawiki/2010/6/6e/Natto2.png" height="180" width="230" alt="Fig.1/PGA" > | <img src="https://static.igem.org/mediawiki/2010/6/6e/Natto2.png" height="180" width="230" alt="Fig.1/PGA" > | ||
<img src="https://static.igem.org/mediawiki/2010/a/a5/Natto1.png" height="180" width="151" alt="Fig.2/PGA" > | <img src="https://static.igem.org/mediawiki/2010/a/a5/Natto1.png" height="180" width="151" alt="Fig.2/PGA" > | ||
| - | <p><br>In this sticky product secreted by | + | <p><br>In this sticky product secreted by <i>B. subtilis</i>, γ-PGA is contained.γ-PGA and its derivatives offer a wide range of unique applications including being used as thickener, humectant, drug carrier, biodegradable fibers, highly water absorbable hydrogels, biopolymer flocculants, and heavy metal absorber. ( Ing-Lung Shih <i>et al,.</i> 2001<a href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V24-43F8HMH-1&_user=9152734&_coverDate=09/30/2001&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000011799&_version=1&_urlVersion=0&_userid=9152734&md5=ca162614ee76294eb1dbebd32405ac00&searchtype=a#toc17">→</a>)</br> |
Most famous products of PGA is highly water absorbable hydrogels. Its PGA is from <i>B.natto</i>. PGA from<i>B.natto</i> have high ability to absorb and hold water. This character is strengthened by UV-crosslink among PGA chains and very useful to environmental problems. | Most famous products of PGA is highly water absorbable hydrogels. Its PGA is from <i>B.natto</i>. PGA from<i>B.natto</i> have high ability to absorb and hold water. This character is strengthened by UV-crosslink among PGA chains and very useful to environmental problems. | ||
<br>Further more, PGA is very safe, not having toxicity to animals.</br><p> | <br>Further more, PGA is very safe, not having toxicity to animals.</br><p> | ||
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<h3>PGA STRUCTURE</h3> | <h3>PGA STRUCTURE</h3> | ||
<img src="https://static.igem.org/mediawiki/2010/3/3f/PGAstructure.gif" alt="Fig.3/PGA"> | <img src="https://static.igem.org/mediawiki/2010/3/3f/PGAstructure.gif" alt="Fig.3/PGA"> | ||
| - | <br>(Ing-Lung Shih <i>et al,.</i> 2001<a href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V24-43F8HMH-1&_user=9152734&_coverDate=09/30/2001&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000011799&_version=1&_urlVersion=0&_userid=9152734&md5=ca162614ee76294eb1dbebd32405ac00&searchtype=a#toc17">→</a>)</br> | + | <br>( Ing-Lung Shih <i>et al,.</i> 2001<a href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V24-43F8HMH-1&_user=9152734&_coverDate=09/30/2001&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000011799&_version=1&_urlVersion=0&_userid=9152734&md5=ca162614ee76294eb1dbebd32405ac00&searchtype=a#toc17">→</a>)</br> |
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| - | <p>It is Dehydration-condensation reaction between gamma-position carboxyl group and alpha-position amino group of glutamate to compose PGA. | + | <p><br>It is Dehydration-condensation reaction between gamma-position carboxyl group and alpha-position amino group of glutamate to compose PGA . </br> |
| - | <br>Glutamate have chirality. Although almost glutamate exist in L-form, PGA don't have only L-form Glutamate but also D-form Glutamate. | + | Glutamate have chirality. Although almost glutamate exist in L-form in nature, PGA don't have only L-form Glutamate but also D-form Glutamate.The ratio with L and D depends on some factors, species, culture condition and so on. These factors effect on the degree of polymerization.</p><br> |
| - | The ratio with L and D depends on some factors, species, culture condition and so on. These factors effect on the degree of polymerization.</p><br> | + | |
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| + | <h3>POLY GLUTAMATE SYNTHETASE</h3> | ||
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| - | + | <br>Three genes ware required for a poly-gamma-glutamate synthetic system of <i>B. subtilis</i> IFO 3336 (<i>B. natto</i>), previously reported.The E. coli cloned these genes produced poly-gamma-glutamate extracellularly.( H. Misono <i>et al,.</i> 1999<a href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WBK-45V7V30-3&_user=9152734&_coverDate=09/16/1999&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000011799&_version=1&_urlVersion=0&_userid=9152734&md5=9cf8843cf0ce14d56845be2a633550c1&searchtype=a">→</a>)</br> | |
| + | Three genes, pgsA, pgsB, and pgsC, code three essential enzymes to creat and secrete PGA .Unfortunately, the roles of these enzymes are not confirmed, but the localizations are reported, all extracellularly. | ||
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Revision as of 18:47, 27 October 2010
Gamma polyglutamic acid
OVERVIEW
Gamma polyglutamic acid (γ-PGA) is a very interesting biopolymer that attracts attention in late years.
It can be found in "natto",a traditional Japanese fermented food made from soybeans by Bacillus subtilis (formerly Bacillus natto). This healty food is very sticky.
In this sticky product secreted by B. subtilis, γ-PGA is contained.γ-PGA and its derivatives offer a wide range of unique applications including being used as thickener, humectant, drug carrier, biodegradable fibers, highly water absorbable hydrogels, biopolymer flocculants, and heavy metal absorber. ( Ing-Lung Shih et al,. 2001→)
Most famous products of PGA is highly water absorbable hydrogels. Its PGA is from B.natto. PGA fromB.natto have high ability to absorb and hold water. This character is strengthened by UV-crosslink among PGA chains and very useful to environmental problems.
Further more, PGA is very safe, not having toxicity to animals.
PGA STRUCTURE
( Ing-Lung Shih et al,. 2001→)
It is Dehydration-condensation reaction between gamma-position carboxyl group and alpha-position amino group of glutamate to compose PGA .
Glutamate have chirality. Although almost glutamate exist in L-form in nature, PGA don't have only L-form Glutamate but also D-form Glutamate.The ratio with L and D depends on some factors, species, culture condition and so on. These factors effect on the degree of polymerization.
POLY GLUTAMATE SYNTHETASE
Three genes ware required for a poly-gamma-glutamate synthetic system of B. subtilis IFO 3336 (B. natto), previously reported.The E. coli cloned these genes produced poly-gamma-glutamate extracellularly.( H. Misono et al,. 1999→)
Three genes, pgsA, pgsB, and pgsC, code three essential enzymes to creat and secrete PGA .Unfortunately, the roles of these enzymes are not confirmed, but the localizations are reported, all extracellularly.
To increase the amount of PGA production, co-expression of glutamate racemase and PGS is needed.
PGS is originally localized in cell membrane, and proposed to produce PGA from D,L-Glutamic acid. Bacillus subtilis has enzymes to biodegrade PGA; however, E. coli does not. Therefore, we want E. coli to produce PGA for greening of the desert.
