전문가 기술 지원 씨 제이슨 아드 킨스에게 감사드립니다.

1. 탈지 상업 글 리아 딘 <ol><li> 눈금 실린더 아세톤 150 ㎖를 측정하고 250 mL의 삼각 플라스크에 붓는다. <ol><li> RT에서 자석 교반기 스핀 막대로 교반하면서 상업적 글 리아 딘 분말 30g을 추가한다. 알루미늄 호일로 플라스크의 입구를 밀봉하고, 후드에서 O / N 감동을 계속. </li></ol></li><li> 필터 종이와 솔루션을 여과. <ol><li> 신선한 아세톤 (약 50 ㎖)로 여과 액을 씻으십시오. 10 분은 아세톤 배출 할 수 있도록 방치하자. </li><li> 이러한 세포 배양 사각 접시로 큰 접시 아래 여과지와 함께 여과 전송. 잔류 아세톤의 증발 속도를 느리게하는 큰 필터 종이 전체 접시를 커버. </li><li> 여과 액은 후드 O의 /의 N 완전히 건조하도록 허용합니다. 실온에서 밀폐 용기에 탈지 글 리아 딘을 저장합니다. </li></ol></li></ol> 정제 된 글 리아 딘 2. 준비 <ol><li> WA 150㎖의 측정눈금 실린더 터와 1,000 ㎖의 삼각 플라스크에 붓는다. <ol><li> 엉망 실린더와 무수 에탄올 350 ml의 측정과 동일한 1,000 ㎖의 삼각 플라스크에 붓는다. 더 버블이 혼합 용액으로부터 발생되지 않을 때까지 스핀 바 - (1,000 RPM 800) 격렬하게 교반 하였다. </li></ol></li><li> 교반하면서, 탈지 상업 글 리아 딘 분말 20g을 추가합니다. 중간에 공기가 들어 덩어리의 형성을 피하기 위해 한번에 소량으로 글 리아 딘을 추가한다. O / N 교반에 보관하십시오. </li><li> 1,000 ml의 혼란 실린더에 전체 솔루션을 전송합니다. 이틀 동안 서 보자. 이 시간 동안, 불순물들은 상기 실린더의 바닥에 침전 될 것이다. </li><li> 피펫으로 회전 증발기에 뜨는을 전송하고, 가능한 한 상층 액에서 에탄올을 제거합니다. 에탄올의 비율이 감소함에 따라, 글 리아 딘 집계과 솔루션에 표시됩니다. </li><li> 메탄올 회전 / 침지하여 솔루션을 포함 글 리아 딘 집계를 고정/ 드라이 아이스 혼합물 및 동결 건조 진공 -70 ° C에서. 동결 건조하기 전에, 전체 솔루션은 액체없이 고정되어 있는지 확인합니다. 주 : 동결 건조 된 글 리아 딘이 다공성 고체를 형성 할 것이다. </li><li> 박격포와 유 봉 동결 건조 글 리아 딘을 분쇄하고, 고급 전원 (&lt;0.5 mm)를 얻기 위해 커피 분쇄기로 분쇄. 실온에서 밀폐 용기 및 저장에 제품을 전송합니다. </li></ol> 글 리아 딘과 ECA 3. 중합 반응 <ol><li> 무게 밸런스, 용기의 섬광 유리 병을 (부피가 약 20 ml의 경우) 놓습니다. scitillation 유리 병에 3.2 g 증류수 및 6.8 g 무수 에탄올을 추가합니다. </li><li> 유리 병에 자기 스핀 바 (20 × 3mm)를 넣어 자석 교반기로의 섬광 유리 병을 이동하고 적극적으로 저어 - 공기 거품이 에탄올 혼합물로부터 생성되지 않을 때까지 (800 1,000 RPM을). </li><li> 교반하면서 유리 병에 4 N 염산 40 μl를 추가합니다. STI는 동안 유리 병에 글 리아 딘 20mg을 추가<html> rring와 글 리아 딘의 분말을 완전히 에탄올의 혼합물에 용해 될 때까지 교반을 계속. </li><li> 1,000 rpm으로 - 교반 속도가 여전히 800 동안 ECA 100 ㎕ - 확인한 후 글 리아 딘 솔루션은 육안에 분명하다, 천천히 (80)를 추가합니다. <ol><li> 500 rpm으로 교반 속도를 낮추고, 그리고 1 시간 동안 계속 교반 하였다. 반응이 진행됨에 따라, 중합 반응이 진행 중임을 나타내는 탁도를 관찰한다. </li></ol></li><li> 반응이 종료되면, 원심 분리 튜브에 용액을 전송하고, 상기 튜브의 무게 균형. 20 분 동안 10,000 × g으로의 반응 생성물을 원심 분리기. 이 기간 동안, 측면 제품 침전물과 나노 입자는 supernantant에 남아 있습니다. 부산물의 주요 성분은 PACA 단독 중합체이다. </li><li> 원심 분리 후, 섬광 유리 병 (또는 밀폐 용기)에 피펫으로 제조 된 나노 입자 현탁액 (뜨는)를 전송하고 실온에서 보관합니다. </li></ol>제품의 제목 &quot;&gt; 4. 특성 <ol><li> 20 ㎖ 섬광 유리 병에 3.2 g의 물과 6.8 g 무수 에탄올을 혼합하여 68 중량 % 에탄올 10 g을 준비하고 더 거품이 혼합 용액에서 생성되지 않을 때까지 저어. <ol><li> 교반하면서 혼합 용액에 4 N 염산 40 μl를 추가합니다. 교반하면서 제조 된 에탄올 용액에 나노 입자 현탁액의 50 μl를 추가합니다. </li></ol></li><li> 상기 제조 된 샘플 용액을 사용하여 동적 광산란 (DLS)을 가진 나노 입자의 크기를 측정하고, 제조자의 지시에 따른다. 주 : 최종 제품의 크기가 작은 200nm 이하이어야한다. 이 200nm보다 큰 경우, 제품이 장기간 안정적 일 수 없다. 채용 된 ECA 신선한하지 않을 경우 더 큰 나노 입자가 생성된다. </li></ol> 제품 5. 시험 <ol><li> 그러한 손 거울 유리판을 준비한다. 비누 물 유리 기판의 표면을 세척 할 것. 아르 자형흐르는 물과 유리 기판의 표면 INSE. 세척 된 표면을 건조하거나 다음 단계 건조하지 않고 사용합니다. </li><li> 유리판의 일부에 3.6에서 수득 한 나노 입자 현탁액)을 스프레이하고, 즉시 흐르는 물 표면을 씻어 낸다. </li><li> 유리판의 표면에 순수를 분무. 코팅되지 않은 표면이 분명하다 동안 코팅 (나노 입자 현탁액을 분무) 표면 유지 물 층을 준수하십시오. </li></ol>

<ol>
	<li>Vauthier, C., Dubernet, C., Fattal, E., Pinto-Alphandary, H., Couvreur, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poly(alkylcyanoacrylates)+as+biodegradable+materials+for+biomedical+applications.">Poly(alkylcyanoacrylates) as biodegradable materials for biomedical applications.</a> Adv. Drug Deliver. Rev. 55, 519-548 (2003).</li><li>Wieser, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemistry+of+gluten+proteins.">Chemistry of gluten proteins.</a> Food Microbiol. 24, 115-119 (2007).</li><li>Bietz, J. A., Wall, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identity+of+high+molecular+weight+gliadin+and+ethanol+soluble+glutenin+subunits+of+wheat:+Relation+to+gluten+structure.">Identity of high molecular weight gliadin and ethanol soluble glutenin subunits of wheat: Relation to gluten structure.</a> Cereal Chem. 57, 415-421 (1980).</li><li>Kim, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+composites+by+using+gliadin+as+a+bonding+material.">Production of composites by using gliadin as a bonding material.</a> J. Cereal Sci. 54, 168-172 (2011).</li><li>Kim, S., Kim, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+gliadin-poly(ethyl+cyanoacrylate)+nanoparticles+for+hydrophilic+coating.">Production of gliadin-poly(ethyl cyanoacrylate) nanoparticles for hydrophilic coating.</a> J. Nanopart. Res. 16, 1-10 (2014).</li><li>Behan, N., Birkinshaw, C., Clarke, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poly+n-butyl+cyanoacrylate+nanoparticles:+a+mechanistic+study+of+polymerisation+and+particle+formation.">Poly n-butyl cyanoacrylate nanoparticles: a mechanistic study of polymerisation and particle formation.</a> Biomaterials. 22, 1335-1344 (2001).</li><li>Nicolas, J., Couvreur, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+poly(alkyl+cyanoacrylate)-based+colloidal+nanomedicines.">Synthesis of poly(alkyl cyanoacrylate)-based colloidal nanomedicines.</a> Wiley Interdiscip. Rev. Nanomed. Nanobiotechnol. 1, 111-127 (2009).</li><li>Kim, S., Evans, K., Biswas, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+BSA-poly(ethyl+cyanoacrylate)+nanoparticles+as+a+coating+material+that+improves+wetting+property.">Production of BSA-poly(ethyl cyanoacrylate) nanoparticles as a coating material that improves wetting property.</a> Colloid Surface. B. 107, 68-75 (2013).</li><li>Lander, L. M., Siewierski, L. M., Brittain, W. J., Vogler, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+systematic+comparison+of+contact+angle+methods.">A systematic comparison of contact angle methods.</a> Langmuir. 9, 2237-2239 (1993).</li><li>Davies, J., Nunnerley, C. S., Brisley, A. C., Edwards, J. C., Finlayson, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+Dynamic+Contact+Angle+Profile+Analysis+in+Studying+the+Kinetics+of+Protein+Removal+from+Steel+Glass,+Polytetrafluoroethylene,+Polypropylene,+Ethylenepropylene+Rubber,+and+Silicone+Surfaces.">Use of Dynamic Contact Angle Profile Analysis in Studying the Kinetics of Protein Removal from Steel Glass, Polytetrafluoroethylene, Polypropylene, Ethylenepropylene Rubber, and Silicone Surfaces.</a> J. Colloid Interf. Sci. 182, 437-443 (1996).</li><li>Giolando, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nano-crystals+of+titanium+dioxide+in+aluminum+oxide:+A+transparent+self-cleaning+coating+applicable+to+solar+energy.">Nano-crystals of titanium dioxide in aluminum oxide: A transparent self-cleaning coating applicable to solar energy.</a> Sol. Energy. 97, 195-199 (2013).</li></ol>

Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer.

There are several critical steps in the production of the nanoparticle suspension. If the purified gliadin contains impurities, the reaction with ECA will produce side products. Although these unwanted products can be removed from the reaction medium during the centrifugation stage, it lowers the yield of the major product. If the gliadin solution prepared during experimental step 2.3) does not show clear separation between supernatant and precipitate after two days, the solution needs to stand for longer time. Using fre...

The goal of this article is to show the protocol for the preparation of nanoparticle suspension that modifies the wetting property of materials by a simple spray. The presented nanoparticle suspension is made from alkyl cyanoacrylate1 and a cereal protein, gliadin2,3. During the manufacturing process, protein aggregates are formed in aqueous ethanol4. Subsequent reaction with monomer (alkyl cyanoacrylate) produces the nanoparticle that is comprised of a protein core surrounded by linear polymer chains [poly(alkyl cyanoacrylate)]5.
Poly(alkyl cyanoacrylate)s are biodegradable and have been used for the production of nanoparticles via emulsion polymerization6. This reaction is spontaneously initiated by the hydroxyl groups dissociated from water or by other nucleophilic groups in the reaction medium7. In the case of the reaction presented in this article, the amine groups on the surface of protein aggregates initiate the polymerization reaction of alkyl cyanoacrylate monomers5,8. As a result of this reaction, nanoparticles are formed in the reaction medium. The core of the nanoparticle is protein aggregates and the outer layer is poly(alkyl cyanoacrylate) (PACA) chains. The prepared nanoparticle has a strong affinity on most materials (more precisely, any material which PACA can adsorb to) and adheres onto their surface to form a thin coating on a nanometer scale. A simple spray coating instantly turns the surface of the materials hydrophilic.
Gliadin is one of the main fractions of gluten, which is in the endosperms of wheat. Gliadins are mainly monomeric proteins with molecular weights around 28,000 - 55,000. Non-covalent bonds such as hydrogen bonds, ionic bonds and hydrophobic bonds are responsible for the aggregation of gliadins2. Although gliadin is chosen as a reactant in this article, many other proteins can also be used for the same purpose. However, the reaction condition needs to be modified accordingly because the condition for inducing aggregation is dependent on the type of protein to be employed8. Compared with other proteins, gliadin is more readily available, purification is simple, and production cost is low. Although ethyl cyanoacrylate (ECA) is chosen as a monomer for the presented reaction, other alkyl cyanoacrylates can also be used for the same reaction. The reason for choosing ECA is that it is readily available at low cost.

<table border="0" cellpadding="0" cellspacing="0" width="580">
	<tbody>
		<tr height="85">
			<td height="85" style="height:85px;width:143px;">Ethyl cyanoacrylate (ECA) monomer</td>
			<td style="width:113px;">K&#38;R International (Laguna Niguel, CA)</td>
			<td style="width:107px;">I-1605</td>
			<td style="width:219px;">Any pure ECA can be used.</td>
		</tr>
		<tr height="106">
			<td height="106" style="height:106px;width:143px;">Gliadin</td>
			<td style="width:113px;">MGP Ingredients, Inc (Atchison, KS)</td>
			<td style="width:107px;">Gift from the company</td>
			<td style="width:219px;">Gliadin can be purchased from Sigma-Aldrich (cat #: G3375-25G). Instead of gliadin, any commercial&#160; gluten can be used.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:143px;">HCl</td>
			<td style="width:113px;">Any</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any reagent grade chemical can be used.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:143px;">Acetone</td>
			<td style="width:113px;">Any</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any reagent grade chemical can be used.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:143px;">Methanol</td>
			<td style="width:113px;">Any</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any reagent grade chemical can be used.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:143px;">Ethanol (100%)</td>
			<td style="width:113px;">Any</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any reagent grade chemical can be used.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:143px;">Filter paper</td>
			<td style="width:113px;">Any</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any grade filter paper larger than 10 cm can be used.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:143px;">Cell culture square dish</td>
			<td style="width:113px;">Any</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any dish larger than 20 cm x 20 cm can be used.</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:143px;">Coffee grinder</td>
			<td style="width:113px;">Any</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any coffee grinder can be used.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:143px;">Rotary evaporator</td>
			<td style="width:113px;">Any</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any rotary evaporator can be used.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:143px;">Freeze Dryer</td>
			<td style="width:113px;">Any</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any freeze dryer that can reach - 70&#176;C can be used.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:143px;">Centrifuge</td>
			<td style="width:113px;">Any</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any centrifuge that can apply 1000 x g can be used.</td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:143px;">Magnetic stirrer</td>
			<td style="width:113px;">Any</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any magnetic stirrer that can turn spin bar to 1000 RPM can be used.</td>
		</tr>
		<tr height="85">
			<td height="85" style="height:85px;width:143px;">Dynamic Light Scattering (DLS)</td>
			<td style="width:113px;">Brookhaven Instruments Corporation</td>
			<td style="width:107px;">NanoBrook Omni Zeta Potential Analyzer</td>
			<td style="width:219px;">DLS from any company can be used.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:143px;">Scanning Electron Microscope (SEM)</td>
			<td style="width:113px;">Carl Zeiss Inc.</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any SEM can be used.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:143px;">Dynamic Contact Angle (DCA)</td>
			<td style="width:113px;">Thermo Cahn Instruments</td>
			<td style="width:107px;"></td>
			<td style="width:219px;">Any DCA can be used.</td>
		</tr>
	</tbody>
</table>

a protocol for the production of gliadin-cyanoacrylate nanoparticles for hydrophilic coating

이 문서는 간단한 스프레이 코팅함으로써 친수성으로 소수성 표면을 변경 단백질 계 나노 입자의 생산을위한 프로토콜을 제공한다. 이러한 나노 입자는 곡류 단백질 (글 리아 딘) 분자의 표면 상에 알킬, 시아 노 아크릴 레이트의 중합 반응에 의해 제조된다. 시아 노 아크릴 레이트는 알킬기가 물질의 표면에인가 될 때 즉각적으로 RT에서 중합 단량체이다. 그 중합 반응은 수분을 포함하는 표면에 약 염기성 또는 구핵 종의 미량으로 개시된다. 중합 후에 니트릴 기는 폴리 (알킬 시아 노 아크릴 레이트)의 중추이기 때문에, 중합 된 알킬 시아 노 아크릴 레이트는 오브젝트 물질과 강한 친 화성을 나타낸다. 그들은 시아 노 아크릴 레이트의 중합을 개시 할 수 아민 그룹을 포함하기 때문에 단백질이 중합 개시제로서 작동합니다. 응집 된 단백질은 개시제로서 사용되는 경우, 단백질 응집물은 소수성 둘러싸여폴리 (알킬 시아 노 아크릴 레이트) 알킬, 시아 노 아크릴 레이트의 중합 반응 후의 체인. 실험 조건을 제어함으로써, 나노 미터 범위의 입자가 제조된다. 생성 된 나노 입자를 용이하게 유리, 금속, 플라스틱, 목재, 피혁, 직물을 포함하여 대부분의 재료의 표면에 흡착. 재료의 표면이 생성 된 나노 입자 현탁액을 분무하고, 물로 세정하는 경우, 나노 입자의 미셀 구조의 형태를 변경하고, 친수성 ​​단백질은 공기에 노출된다. 그 결과, 나노 입자 표면에 코팅 된 친수성으로 변화시킨다.

나노 입자는 다양한 반응 조건으로 제조 할 수있다. 글 리아 딘 양식은 에탄올 함량 (5)의 넓은 범위에서 집계. 그러나, 응집체의 크기는 추가 층 (예., 중합 ECA)이이 집합에 추가되기 때문에 가능한 한 작게 할 필요가 있고,이 프로세스는 최종 크기가 더 크게된다. 입자의 최종 크기가 너무 크면, 입자가 불안정하고 쉽게 침전된다. 따라서, 68 % 에탄올 수용액?...

Watch this Scientific Journal Video about A Protocol for the Production of Gliadin-cyanoacrylate Nanoparticles for Hydrophilic Coating at JoVE.com

A Protocol for the Production of Gliadin-cyanoacrylate Nanoparticles for Hydrophilic Coating

This article presents a protocol for the production of protein-based nanoparticles that changes the hydrophobic surface to hydrophilic. The produced nanoparticle is an assembly of gliadin-cyanoacrylate diblock copolymers. Spray coating with the produced nanoparticle changes the surface of target material to a hydrophilic surface.

친수성 코팅 글 리아 딘 - 시아 노 아크릴 레이트 나노 입자의 생산을위한 프로토콜

This article presents a protocol for the production of protein-based nanoparticles that changes the hydrophobic surface to hydrophilic by a simple spray ...

a-protocol-for-production-gliadin-cyanoacrylate-nanoparticles-for

Research

JoVE Journal

Chemistry

6.8K 조회수.  USDA/ARS/NCAUR. This article presents a protocol for the production of protein-based nanoparticles that changes the hydrophobic surface to hydrophilic. The produced nanoparticle is an assembly of gliadin-cyanoacrylate diblock copolymers. Spray coating with the produced nanoparticle changes the surface of target material to a hydrophilic surface.

비디오: A Protocol for the Production of Gliadin-cyanoacrylate Nanoparticles for Hydrophilic Coating

Production of Disulfide-stabilized Transmembrane Peptide Complexes for Structural Studies

Physical interactions among the lipid-embedded alpha-helical domains of membrane proteins play a crucial role in folding and assembly of membrane protein complexes and in dynamic processes such as transmembrane (TM) signaling and regulation of cell-surface protein levels. Understanding the structural features driving the association of particular sequences requires sophisticated biophysical and biochemical analyses of TM peptide complexes. However, the extreme hydrophobicity of TM domains makes them very difficult to manipulate using standard peptide chemistry techniques, and production of suitable study material often proves prohibitively challenging. Identifying conditions under which peptides can adopt stable helical conformations and form complexes spontaneously adds a further level of difficulty. Here we present a procedure for the production of homo- or hetero-dimeric TM peptide complexes from materials that are expressed in E. coli, thus allowing incorporation of stable isotope labels for nuclear magnetic resonance (NMR) or non-natural amino acids for other applications relatively inexpensively. The key innovation in this method is that TM complexes are produced and purified as covalently associated (disulfide-crosslinked) assemblies that can form stable, stoichiometric and homogeneous structures when reconstituted into detergent, lipid or other membrane-mimetic materials. We also present carefully optimized procedures for expression and purification that are equally applicable whether producing single TM domains or crosslinked complexes and provide advice for adapting these methods to new TM sequences.

Biophysical and biochemical studies of interactions among membrane-embedded protein domains face many technical challenges, the first of which is obtaining appropriate study material. This article describes a protocol for producing and purifying disulfide-stabilized transmembrane peptide complexes that are suitable for structural analysis by solution nuclear magnetic resonance (NMR) and other analytical applications.

구조 연구 생산 이황화 - 안정화 Transmembrane의 펩타이드 단지

Physical  interactions among the lipid-embedded alpha-helical domains of membrane  proteins play a crucial role in folding and assembly of membrane ...

연구

화학

Thin-layer Chromatographic (TLC) Separations and Bioassays of Plant Extracts to Identify Antimicrobial Compounds

A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the chromatograms to microbial suspensions (e.g. fungi or bacteria in broth or agar), allowing time for the microbes to grow in a humid environment, and visualizing zones with no microbial growth.&#160;The effectiveness of this screening method, known as bioautography, depends on both the quality of the chromatographic separation and the care taken with microbial culture conditions.&#160;This paper describes standard protocols for TLC and contact bioautography&#160;with a novel application to amino acid-fermenting bacteria. The extract is separated on flexible (aluminum-backed) silica TLC plates, and bands are visualized under ultraviolet (UV) light.&#160;Zones are cut out and incubated face down onto agar inoculated with the test microorganism.&#160;Inhibitory bands are visualized by staining the agar plates with tetrazolium red.&#160;The method is applied to the separation of red clover (Trifolium pratense cv. Kenland) phenolic compounds and their screening for activity against Clostridium sticklandii, a hyper ammonia-producing bacterium (HAB) that is native to the bovine rumen.&#160;The TLC methods apply to many types of plant extracts&#160;and other bacterial species (aerobic or anaerobic), as well as fungi, can be used as test organisms if culture conditions are modified to fit the growth requirements of the species.

Thin-layer Chromatographic TLC Separations and Bioassays of Plant Extracts to Identify Antimicrobial Compounds

Methods are described for thin-layer chromatographic (TLC) separation of plant extracts and contact bioautography to identify antibacterial metabolites. The methods are applied to the screening of red clover phenolic compounds inhibiting hyper&#160;ammonia-producing bacteria (HAB) native to the bovine rumen.

A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the ...

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like oligomeric clusters of these yellow nanoparticles of narrow size distribution are synthesized under ambient conditions via two methods. The delay-time method controls the number of subunits in the oligoclusters by varying the time between the addition of HAuCl4 to alkaline solution and the subsequent addition of reducing agent, NaSCN. The yellow oligoclusters produced range in size from ~3 to ~25 nm. This size range can be further extended by an add-on method utilizing hydroxylated gold chloride (Na+[Au(OH4-x)Clx]-) to auto-catalytically increase the number of subunits in the as-synthesized oligocluster nanoparticles, providing a total range of 3 nm to 70 nm. The crude oligocluster preparations display narrow size distributions and do not require further fractionation for most purposes. The oligoclusters formed can be concentrated &#62;300 fold without aggregation and the crude reaction mixtures remain stable for weeks without further processing. Because these oligomeric clusters can be concentrated before derivatization they allow expensive derivatizing agents to be used economically. In addition, we present two models by which predictions of particle size can be made with great accuracy.

We describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles via the reduction of chloroauric acid (HAuCl4) with sodium thiocyanate (NaSCN). The oligoclusters have a narrow size distribution and can be produced with a wide range of sizes and surface coats.

주변 조건에 따라 금 나노 입자의 안정 올리고머 클러스터의 크기 제어 합성을위한 간단한 방법

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like ...

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

Molecules bearing trifluoromethoxy (OCF3) group often show desired pharmacological and biological properties. However, facile synthesis of trifluoromethoxylated aromatic compounds remains a formidable challenge in organic synthesis. Conventional approaches often suffer from poor substrate scope, or require use of highly toxic, difficult-to-handle, and/or thermally labile reagents. Herein, we report a user-friendly protocol for the synthesis of methyl 4-acetamido-3-(trifluoromethoxy)benzoate using 1-trifluoromethyl-1,2-benziodoxol-3(1H)-one (Togni reagent II). Treating methyl 4-(N-hydroxyacetamido)benzoate (1a) with Togni reagent II in the presence of a catalytic amount of cesium carbonate (Cs2CO3) in chloroform at RT afforded methyl 4-(N-(trifluoromethoxy)acetamido)benzoate (2a). This intermediate was then converted to the final product methyl 4-acetamido-3-(trifluoromethoxy)benzoate (3a) in nitromethane at 120 &#176;C. This procedure is general and can be applied to the synthesis of a broad spectrum of ortho-trifluoromethoxylated aniline derivatives, which could serve as useful synthetic building blocks for the discovery and development of new pharmaceuticals, agrochemicals, and functional materials.

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

An operationally simple procedure for the synthesis of ortho-trifluoromethoxylated aniline derivatives via a two-step sequence of O-trifluoromethylation of N-aryl-N-hydroxyacetamide followed by thermally induced intramolecular OCF3-migration is reported.

의 합성을위한 프로토콜<em&gt; 직교</em&gt; -trifluoromethoxylated 아닐린 파생 상품

Molecules bearing trifluoromethoxy (OCF3) group often show desired pharmacological and biological properties. However, facile synthesis of ...

A Simple and Efficient Protocol for the Catalytic Insertion Polymerization of Functional Norbornenes

Norbornene can be polymerized by a variety of mechanisms, including insertion polymerization whereby the double bond is polymerized and the bicyclic nature of the monomer is conserved. The resulting polymer, polynorbornene, has a very high glass transition temperature, Tg, and interesting optical and electrical properties. However, the polymerization of functional norbornenes by this mechanism is complicated by the fact that the endo substituted norbornene monomer has, in general, a very low reactivity. Furthermore, the separation of the endo substituted monomer from the exo monomer is a tedious task. Here, we present a simple protocol for the polymerization of substituted norbornenes (endo:exo ca. 80:20) bearing either a carboxylic acid or a pendant double bond. The process does not require that both isomers be separated, and proceeds with low catalyst loadings (0.01 to 0.02 mol%). The polymer bearing pendant double bonds can be further transformed in high yield, to afford a polymer bearing pendant epoxy groups. These simple procedures can be applied to prepare polynorbornenes with a variety of functional groups, such as esters, alcohols, imides, double bonds, carboxylic acids, bromo-alkyls, aldehydes and anhydrides.

We describe the catalytic insertion polymerization of 5-norbornene-2-carboxylic acid and 5-vinyl-2-norbornene to form functional polymers with a very high glass transition temperature.

기능 노보 넨의 촉매 삽입 중합을위한 간단하고 효율적인 프로토콜

Norbornene can be polymerized by a variety of mechanisms, including insertion polymerization whereby the double bond is polymerized and the bicyclic ...

A Protocol for Safe Lithiation Reactions Using Organolithium Reagents

Organolithium reagents are powerful tools in the synthetic chemist&#39;s toolbox. However, the extreme pyrophoric nature of the most reactive reagents warrants proper technique, thorough training, and proper personal protective equipment. To aid in the training of researchers using organolithium reagents, a thorough, step-by-step protocol for the safe and effective use of tert-butyllithium on an inert gas line or within a glovebox is described. As a model reaction, preparation of lithium tert-butyl amide by the reaction of tert-butyl amine with one equivalent of tert-butyl lithium is presented.

The safe and proper use of organolithium reagents is described.

유기 리튬 시약을 사용하여 안전 리튬 화의 반응을위한 프로토콜

Organolithium reagents are powerful tools in the synthetic chemist&#39;s toolbox. However, the extreme pyrophoric nature of the most reactive reagents ...

An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group

Here, we demonstrate a detailed protocol for the radiosynthesis of a 125I-labeled azide prosthetic group and its application to the efficient radiolabeling of DBCO-group-functionalized gold nanoparticles using a copper-free click reaction. Radioiodination of the stannylated precursor (2) was carried out by using [125I]NaI and chloramine T as an oxidant at room temperature for 15 min. After HPLC purification of the crude product, the purified 125I-labeled azide (1) was obtained with high radiochemical yield (75 &plusmn; 10%, n = 8) and excellent radiochemical purity (&gt;99%). For the synthesis of radiolabeled 13-nm-sized gold nanoparticles, the DBCO-functionalized gold nanoparticles (3) were prepared by using a thiolated polyethylene glycol polymer. A copper-free click reaction between 1 and 3 gave the 125I-labeled gold nanoparticles (4) with more than 95% of radiochemical yield as determined by radio-thin-layer chromatography (radio-TLC). These results clearly indicate that the present radiolabeling method using a strain-promoted copper-free click reaction will be useful for the efficient and convenient radiolabeling of DBCO-group-containing nanomaterials.

An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group

A detailed procedure for the synthesis of a 125I-labeled azide and the radiolabeling of dibenzocyclooctyne (DBCO)-group-conjugated, 13-nm-sized gold nanoparticles using a copper-free click reaction is described.

를 사용하여 금 나노 입자의 효율적인 방사성 표지를위한 최적화 된 프로토콜<sup&gt; (125)</sup&gt; I-표시 아 지드 보철 그룹

Here, we demonstrate a detailed protocol for the radiosynthesis of a 125I-labeled azide prosthetic group and its application to the efficient ...

The MPLEx Protocol for Multi-omic Analyses of Soil Samples

Mass spectrometry (MS)-based integrated metaproteomic, metabolomic, and lipidomic (multi-omic) studies are transforming our ability to understand and characterize microbial communities in environmental and biological systems. These measurements are even enabling enhanced analyses of complex soil microbial communities, which are the most complex microbial systems known to date. Multi-omic analyses, however, do have sample preparation challenges, since separate extractions are typically needed for each omic study, thereby greatly amplifying the preparation time and amount of sample required. To address this limitation, a 3-in-1 method for the simultaneous extraction of metabolites, proteins, and lipids (MPLEx) from the same soil sample was created by adapting a solvent-based approach. This MPLEx protocol has proven to be both simple and robust for many sample types, even when utilized for limited quantities of complex soil samples. The MPLEx method also greatly enabled the rapid multi-omic measurements needed to gain a better understanding of the members of each microbial community, while evaluating the changes taking place upon biological and environmental perturbations.

A protocol is presented for simultaneously extracting metabolites, proteins, and lipids from a single soil sample, allowing reduced sample preparation times and enabling multi-omic mass spectrometry analyses of samples with limited quantities.

멀티-omic 토양 샘플의 분석을 위한 MPLEx 프로토콜

Mass spectrometry (MS)-based integrated metaproteomic, metabolomic, and lipidomic (multi-omic) studies are transforming our ability to understand and ...

Automation of a Positron-emission Tomography (PET) Radiotracer Synthesis Protocol for Clinical Production

The development of new positron-emission tomography (PET) tracers is enabling researchers and clinicians to image an increasingly wide array of biological targets and processes. However, the increasing number of different tracers creates challenges for their production at radiopharmacies. While historically it has been practical to dedicate a custom-configured radiosynthesizer and hot cell for the repeated production of each individual tracer, it is becoming necessary to change this workflow. Recent commercial radiosynthesizers based on disposable cassettes/kits for each tracer simplify the production of multiple tracers with one set of equipment by eliminating the need for custom tracer-specific modifications. Furthermore, some of these radiosynthesizers enable the operator to develop and optimize their own synthesis protocols in addition to purchasing commercially-available kits. In this protocol, we describe the general procedure for how the manual synthesis of a new PET tracer can be automated on one of these radiosynthesizers and validated for the production of clinical-grade tracers. As an example, we use the ELIXYS radiosynthesizer, a flexible cassette-based radiochemistry tool that can support both PET tracer development efforts, as well as routine clinical probe manufacturing on the same system, to produce [18F]Clofarabine ([18F]CFA), a PET tracer to measure in vivo deoxycytidine kinase (dCK) enzyme activity. Translating a manual synthesis involves breaking down the synthetic protocol into basic radiochemistry processes that are then translated into intuitive chemistry &#34;unit operations&#34; supported by the synthesizer software. These operations can then rapidly be converted into an automated synthesis program by assembling them using the drag-and-drop interface. After basic testing, the synthesis and purification procedure may require optimization to achieve the desired yield and purity. Once the desired performance is achieved, a validation of the synthesis is carried out to determine its suitability for the production of the radiotracer for clinical use.

Automation of a Positron-emission Tomography PET Radiotracer Synthesis Protocol for Clinical Production

Positron-emission tomography (PET) imaging sites that are involved in multiple early clinical research trials need robust and versatile radiotracer manufacturing capabilities. Using the radiotracer [18F]Clofarabine as an example, we illustrate how to automate the synthesis of a radiotracer using a flexible, cassette-based radiosynthesizer and validate the synthesis for clinical use.

양전자 방출 단층 촬영 (PET) Radiotracer 합성 프로토콜의 임상 생산을 위한 자동화

The development of new positron-emission tomography (PET) tracers is enabling researchers and clinicians to image an increasingly wide array of biological ...

Gene-therapy Inspired Polycation Coating for Protection of DNA Origami Nanostructures

DNA origami nanostructures hold an immense potential to be used for biological and medical applications. However, low-salt conditions and nucleases in physiological fluids induce denaturation and degradation of self-assembled DNA nanostructures. In non-viral gene delivery, enzymatic degradation of DNA is overcome by the encapsulation of the negatively charged DNA in a cationic shell. Herein, inspired by gene delivery advancements, a simple, one-step and robust methodology is presented for the stabilization of DNA origami nanostructures by coating them with chitosan and linear polyethyleneimine. The polycation coating efficiently protects DNA origami nanostructures in Mg-depleted and nuclease-rich media. This method also preserves the full addressability of enzyme- and aptamer-based functionalization of DNA nanostructures.

Here, a protocol for the protection of DNA origami nanostructures in Mg-depleted and nuclease-rich media using natural cationic polysaccharide chitosan and synthetic linear polyethyleneimine (LPEI) coatings is presented.

유전자 치료 DNA 종이 접기 Nanostructures의 보호를 위한 Polycation 코팅을 영감

DNA origami nanostructures hold an immense potential to be used for biological and medical applications. However, low-salt conditions and nucleases in ...