Difference between revisions of "Team:HokkaidoU Japan/Circularization"

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<div id="Overview"><img src="https://static.igem.org/mediawiki/2016/f/fa/T--HokkaidoU_Japan--overview.png"  
 
<div id="Overview"><img src="https://static.igem.org/mediawiki/2016/f/fa/T--HokkaidoU_Japan--overview.png"  
 
width="270px" height="90px" alt="overview"></div>
 
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<p>酵素は科学の発展に不可欠な存在であるが、自身の性質上、熱や pH によって失活してしまう
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<p>Although enzymes are essential for the development of science, they can only be used under certain conditions due to its nature that it inactivates depending on the temperature and pH. Ways to gain enzymes that are stable against such conditions include investigation of microorganisms that survive under extreme environments, improvement of the activation using amino acid substitution, compartmentalization of the enzymes, and circularization of polypeptides. When enzymes are heated or the pH changed, linear-type enzymes are denatured and deactivated. On the other hand, with circularized enzymes, it is believed that since the ends of the polypeptide are joined and protected, the tertiary structure is less likely to be broken and the activation kept. This year, we attempted in the circularization of proteins using self-assembling peptide(SAP) and zip-up linker.</p>
ので使用できる条件が限られてしまう。熱や pH に対して安定な酵素を得るには極限環境下で生
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息する微生物の探索、アミノ酸置換による活性向上、酵素の区画化などの他にポリペプチドを環
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<p>The SAPs we used are RADA-16 and P11-4. These are both artificially created amphiphilic SAPs, consisting of amino acid sequence RADARADARADARADA and QQRFEWEFEQQ respectively. They self-assemble under suitable physiochemical conditions due to the polar amino acids and hydrophobic interaction.</p>
状化させる方法がある。熱を加えたり pH を変化させたりすると,線状型酵素は変性し,失活す
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る一方で,環状化させた酵素ではタンパクの末端同士が結合して保護されているため,立体構造
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<p>By creating a construction as shown in Fig.2, the self-assembling region(SAR) and the region containing the SAP interact, thus bringing closer the zip-up linkers on the N-terminal and the C-terminal.</p>
が崩れにくく,活性が保たれると考えられている。我々は今年、自己組織化ペプチド(SAP)と
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zip-up linker を使用してタンパク質の環状化に挑んだ。
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<p>The zip-up linker plays a vital role in the creation of the covalent bond essential for the circularization of proteins. This consists of amino acid sequence of CWEGGGCGGGCGGGCSALCGGGCGGGCGGG, and is composed of repetition of 3 glycine and 1 cysteine residues. We are hoping that the zip-up linker on the N and C terminal are brought closer by the SAR, and that the cysteine residues form disulfide bonds from the SAR as if to zip up the ends.</p>
我々が今回用いた SAP は RADA-16 I と P11-4 というものである。これらは両親媒性のペプチ
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ドであり、RADA-16 I は RADARADARADARADA、P11-4 は QQRFEWEFEQQ というアミノ
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<p>Since the distance between the N-terminal and the C-terminal varies depending on the protein, it is essential that a linker of an appropriate length is chosen. This would usually mean that it is necessary to change the linker depending on the protein that is to be circularized. However, our zip-up linker has enough GGGC sequence so that only the flexible part of the linker form disulfide bonds, thus preventing deformation of the tertiary structure. This means that a suitable length of the linker will be used to suit the structure of each protein, enabling this zip-up linker to be applied to various proteins regardless of its structure.
酸配列を持つ人工的に開発された SAP である。自身のアミノ酸の電荷や疎水性相互作用などに
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</p>
よりそれぞれに合った物理化学的条件下で自己集合する。
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Fig.2 のようなコンストラクトを作成すると SAP が含まれた領域、自己組織化領域(SAR)が
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互いに相互作用して近づくことで、同時にタンパク質の N 末端と C 末端にある zip-up linker 同
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士を近づけることができる。
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zip-up linker はタンパク質の環状化に必要な共有結合形成に重要な役割を果たす。これは
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CWEGGGCGGGCGGGCSALCGGGCGGGCGGG というアミノ酸配列を持ち、グリシン残基 3
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つとシステイン残基 1 つの繰り返しからなるリンカーである。SAR の働きにより N 末端と C 末
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端の zip-up linker が近づき、システイン残基同士でジスルフィド結合を形成し、それぞれの結合
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は zipper を閉めるように SAR から近い部分から生じることを期待している。
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また、タンパク質を環状化させる際、N 末端と C 末端の距離によって使用するリンカーの長さ
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を変える必要があるので、リンカーの長さを考慮することは本来不可欠である。つまり通常は環
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状化させたいタンパク質が違えば使用するリンカーも変更させなければならない。しかし我々が
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提案する zip-up linker GGGC の繰り返し配列を始めから十分な長さ用意しており、立体構造
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を無理に変化させるような部分にはジスルフィド結合は形成されずに、自由度の高い部分のみが
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結合を形成するのでタンパク質に合った linker の適切な長さを分子に選ばせることができると
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考えられる。つまり、多くのタンパク質に対してこの zip-up linker を応用できるということである。</p>
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<div id="Methods"><img src="https://static.igem.org/mediawiki/2016/2/2c/T--HokkaidoU_Japan--methods.png"  
 
<div id="Methods"><img src="https://static.igem.org/mediawiki/2016/2/2c/T--HokkaidoU_Japan--methods.png"  
 
width="270px" height="90px" alt="methods"></div>
 
width="270px" height="90px" alt="methods"></div>

Revision as of 07:21, 6 October 2016

Team:HokkaidoU Japan - 2016.igem.org

 

Team:HokkaidoU Japan

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overview

Although enzymes are essential for the development of science, they can only be used under certain conditions due to its nature that it inactivates depending on the temperature and pH. Ways to gain enzymes that are stable against such conditions include investigation of microorganisms that survive under extreme environments, improvement of the activation using amino acid substitution, compartmentalization of the enzymes, and circularization of polypeptides. When enzymes are heated or the pH changed, linear-type enzymes are denatured and deactivated. On the other hand, with circularized enzymes, it is believed that since the ends of the polypeptide are joined and protected, the tertiary structure is less likely to be broken and the activation kept. This year, we attempted in the circularization of proteins using self-assembling peptide(SAP) and zip-up linker.

The SAPs we used are RADA-16 and P11-4. These are both artificially created amphiphilic SAPs, consisting of amino acid sequence RADARADARADARADA and QQRFEWEFEQQ respectively. They self-assemble under suitable physiochemical conditions due to the polar amino acids and hydrophobic interaction.

By creating a construction as shown in Fig.2, the self-assembling region(SAR) and the region containing the SAP interact, thus bringing closer the zip-up linkers on the N-terminal and the C-terminal.

The zip-up linker plays a vital role in the creation of the covalent bond essential for the circularization of proteins. This consists of amino acid sequence of CWEGGGCGGGCGGGCSALCGGGCGGGCGGG, and is composed of repetition of 3 glycine and 1 cysteine residues. We are hoping that the zip-up linker on the N and C terminal are brought closer by the SAR, and that the cysteine residues form disulfide bonds from the SAR as if to zip up the ends.

Since the distance between the N-terminal and the C-terminal varies depending on the protein, it is essential that a linker of an appropriate length is chosen. This would usually mean that it is necessary to change the linker depending on the protein that is to be circularized. However, our zip-up linker has enough GGGC sequence so that only the flexible part of the linker form disulfide bonds, thus preventing deformation of the tertiary structure. This means that a suitable length of the linker will be used to suit the structure of each protein, enabling this zip-up linker to be applied to various proteins regardless of its structure.

methods

ここに本文

modeling

ここに本文

results

ここに本文

conclusion

ここに本文