FCP の浄化支援ありがとうラナ Adeel アフマド。教授クラウディア Büchel は役に立つ議論のため認められている原稿を読む。この作品は LD (DI1956-1/1) にドイツ語研究財団および LD へフェオドル ・ リュネン フェローシップのフンボルト財団によって支えられました。

著者が明らかに何もありません。

FCP リポソーム天然脂質組成と分光学的性質を調査するための便利なシンプルで再現性のあるツールを提供するの in vitro 。FCP リポソームの脂質環境は、自然の状態に近い実験結果を生じ、チラコイド膜内状況に似ています。
FCP アンテナのモデル システムとしてc. meneghinianaを使用していくつかの利点があります。それは比較的速い成長、他の珪藻のモデル種...

珪藻など光合成生物必要があります刻 々 変化する光条件に対処し、光合成効率を維持し、過剰な光によって写真酸化ダメージから保護する高度順化のメカニズムと対応します。光合成真核生物の主要な光保護プロセスは高エネルギー焼入れ (qE) の光ストレス条件1,2 の下で非光化学の焼入 (NPQ) への主要な貢献として発生する吸収光 ,3。光の収穫アンテナ複合体 (LHC) は、励起エネルギー移動経路の調節に関与しています。高い光に応答低pH葉緑体ルーメン、集光状態を急冷状態からアンテナ システム スイッチを誘発しました。このエネルギー散逸状態は、光酸化からのダメージを与える (PS) とチラコイド膜の他の複合体を保護します。光合成真核生物で qEは通常、2 つの要因1,2,3によって誘導します。要因の一つは、特殊な集光性タンパク質低pHに応答します。PsbS 蛋白質はより高い植物4qEを誘導します。LhcSRs5、PsbS 活動によって変調は、緑藻6で qEを誘発します。珪藻では、構造的に LHCSRs7,8,9,10に関連している Lhcx のような蛋白質を所有しています。
QEの 2 番目の要素は、アンテナのカロテノイドが de エポキシ化によって写真保護形式に変換、エポキシ化によって元に戻さキサントフィル サイクルです。植物や緑藻、ビオラキサンチンはゼアキサンチンに変換されます。珪藻の diadinoxanthin は NPQ11の程度と相関し、diatoxanthin に変換されます。珪藻集光アンテナはそれは進化植物と藻類の LHCs に関連するいくつかの特性を所有しています。光の写真の保護するために収穫からスイッチが非常に高速と NPQ 容量は植物12に比べて高い。これは珪藻が13海洋純一次生産量の 45% までに責任がある方法でさまざまな生態学的ニッチの非常に成功した 1 つの理由があります。したがって、光収穫系珪藻は光合成研究の興味深いオブジェクトです。
珪藻、峰 meneghinianaの中心の種は、チラコイド本質的な集光性色素にちなんで彼らのシステムを所有しているようなバインド - フコキサンチン、クロロフィル a と c、それゆえ FCP. 集光性タンパク質、FCPs などいくつかの膜層を構成するチラコイド膜システムに埋め込まれます。珪藻は、3 つのチラコイドのバンドを形作る。この複合体チラコイド膜で分子レベルで研究するが困難な状況です。さらに、多くのコンポーネントは、集光性 (上記参照) の規制に貢献します。したがって、さまざまな方法で複合体は、n-ドデシル-β-D-maltopyranoside (β-DDM)、膜可溶化が FCP 複合体をそのまま維持など、穏やかな洗剤を使用して膜から分離しました。可溶化された FCP を使用して分子内エネルギー転送14,15,16,17を調査する多くの分光学的研究を行った。しかし、この前者のアプローチは、エネルギー転送の規制が他のアンテナ複合体やダメージを与えると励起子相互作用を必要とするので、限られていた。したがって、これらの種類の研究が複合体間の相互作用が失われるためにを可溶化された錯体を実施できません。
アンテナ規制の重要な機能は、アンテナとチラコイド膜18のダメージを与える「分子クラウディング」です。以前は、単純なアプローチは、この効果をシミュレートするために実施された体外。アンテナ複合体のランダムな集約につながる洗剤が削除されました。いくつかの合理的なデータは、このアプローチの17,19によって得られた、洗剤除去体内の状況を反映していない、複合体は通常第三に対話していないのでいくつかの制限があります。構造体です。
リポソームを用いる元の制限のいくつかを克服します。第三構造は完全にそのままです。リポソーム膜はアンテナ複合体の準ネイティブ環境を提供します。膜は、リポソームの内部を外部環境から分離します。これらの手段では、リポソームは、輸送過程については同様のイオン ・ pH 勾配の研究の 2 つの反応区画を提供します。さらに、チラコイド膜の研究のため実験システムのパラメーターをより簡単に制御できます。リポソームは、既に光合成錯体を研究する優れたツールであること示されていた。過去の主要な焦点だった植物 LHC LHC II20に変更後の脂質組成の影響を調べた。他のアプローチで異なる LHC II 間の蛋白質蛋白質の相互作用は調査21だったまた、緑の藻でいくつかの研究を行った LHC22の間自発的なクラスタ リングについて説明します。、水生生物の生態系の珪藻の重要性を考慮した珪藻のアンテナ複合体に比較的少数の研究を行った。2 つの研究は、FCP アンテナ23と FCP の応答性の電気化学的勾配24にクラスタ リングが示した中心峰 meneghinianaのアンテナ複合体を検討しました。したがって、リポソーム、珪藻アンテナ相互作用とほぼネイティブ条件で規制を勉強する優れたツールです。リポソーム、脂質、リポソーム サイズ、密度などの多くの条件からの汎用性と周囲の水相を制御できます。さらに、メソッドのサンプルの少量が必要です。実験システムは、堅牢かつ再現性が高い。リポソームの区分により pH を勉強して、アンテナ複合体の調節に重要なイオン勾配要因。
ここでは、 c. meneghinianaから FCP アンテナ複合体の単離とその自然なチラコイド脂質リポソームについて述べる。また、可溶化された FCP の分光特性評価の模範的なデータを提供し、リポソームの FCP との比較します。メソッドは、知識と Gundermann と Büchel 2012 年23ナタリら2016年22アフマドと Dietzel 2017 年の24の改善から得られる標準化されたプロトコルをまとめたものです。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/58017/58017fig1.jpg"> 図 1: ワークフローの模式図。( 1) 細胞の成長、混乱およびショ糖密度勾配; 次の FCP 分離チラコイド分離を説明する段落 1 を参照C. m.-峰 meneghiniana細胞。(2) 2 と octylglycoside (OG) 脂質界面活性剤ミセルの創造、自然チラコイド脂質混合物 (MGDG、DGDG SQDG) の調製は項で説明します。定義された脂質ミセルの大きさは、定義された孔径の膜を用いた押出によって実現されます。FCP と脂質ミセルが定義済みの脂質で統一: タンパク質比や OG と β DDM の洗剤は削除を介して制御される透析 FCP プロテオリポソームを形成します。<a href="https://www.jove.com/files/ftp_upload/58017/58017fig1large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。

<table><tbody><tr><td>500 ml centrifuge vials</td><td></td><td></td><td></td></tr><tr><td>high speed centrifuge</td><td>Heraeus</td><td></td><td></td></tr><tr><td>Bead Mill VI 2</td><td>Edmund-B&amp;uuml;hler (edmund-buehler.de)</td><td></td><td>newer version: Vibrogen-Zellm&amp;uuml;hle Vl 6</td></tr><tr><td>Silibeads S 400 &amp;micro;m</td><td>Sigmund-Lindner.com</td><td>5223-7</td><td></td></tr><tr><td>Silibeads S 1,-1,3 mm</td><td>Sigmund-Lindner.com</td><td>4504</td><td></td></tr><tr><td>VitraPOR filter funnel - por1</td><td>ROBU GmbH</td><td>21121</td><td></td></tr><tr><td>polycarbonate ultracentrifuagtion vials (30 mL) for T-865</td><td>Beranek Laborger&amp;auml;te (Laborgeraete-beranek.de)</td><td>314348</td><td></td></tr><tr><td>Ultracentrifuge Discovery 90SE</td><td>Sorvall</td><td>n.a.</td><td></td></tr><tr><td>rotor T 865</td><td>ThermoFisher Scientific (thermofisher.com)</td><td>51411</td><td></td></tr><tr><td>Neubauer Cell Counter Chamber (improved)</td><td>Carl Roth Laborbedarf (Carlroth.com)</td><td>T729.1</td><td></td></tr><tr><td>Zeiss Mikroskop Primostar (7)</td><td>Optik-Pro (optik-pro.de)</td><td>51428</td><td></td></tr><tr><td>optical glass cuvettes (6040-OG)</td><td>Hellma Analytics (hellma-analytics.com)</td><td>&quot;6040-10-10&quot;</td><td></td></tr><tr><td>V-630 UV-VIS Spectrophotometer (incl. software)</td><td>Jasco (jasco.de)</td><td>V-630</td><td></td></tr><tr><td>n-Dodecyl-&amp;beta;-D-Maltopyranoside</td><td>ANATRACE (anatrace.com)</td><td>D310LA</td><td></td></tr><tr><td>Ultra-Clear tubes 17 ml for AH629</td><td>Beranek Laborger&amp;auml;te (Laborgeraete-beranek.de)</td><td>344061</td><td></td></tr><tr><td>rotor AH629-17-mL</td><td>ThermoFisher Scientific (thermofisher.com)</td><td>54285</td><td></td></tr><tr><td>Membrane concentrator_Centriprep 30 kDa cutoff</td><td>Millipore (merckmillipore.com)</td><td>4307</td><td></td></tr><tr><td>Biometra Minigel-Twin</td><td>Analytik Jena AG (analytik-jena.de)</td><td>846-010-100</td><td></td></tr><tr><td>Silver Stain Plus Kit</td><td>Bio-Rad (bio-rad.com)</td><td>1610449</td><td></td></tr><tr><td>libre office spread sheet</td><td>The document foundation</td><td>https://de.libreoffice.org/download/libreoffice-still/</td><td></td></tr><tr><td>special glass cuvettes for fluorescence (101-0S)</td><td>Hellma Analytics (hellma-analytics.com)</td><td>101-10-20</td><td></td></tr><tr><td>Spectrofluorometer FP-6500 (incl. Software)</td><td>Jasco (jasco.de)</td><td>FP-6500</td><td></td></tr><tr><td>SDS-loading buffer Roti-Load</td><td>ROTH (carlroth.com)</td><td>K929.1</td><td></td></tr><tr><td>n-octyl &amp;beta;-D-glucopyranoside</td><td>ANATRACE (anatrace.com)</td><td>O311</td><td></td></tr><tr><td>Monogalactosyl Diaclyglycerol (MGDG)</td><td>Larodan AB (larodan.com)</td><td>59-1300</td><td>make stock solution in chloroform</td></tr><tr><td>Digalactosyl Diacylglycerol (DGDG)</td><td>Larodan AB (larodan.com)</td><td>59-1310</td><td>make stock solution in chloroform</td></tr><tr><td>Sulphoquinovosyl Diacylglycerol (SQDG)</td><td>Larodan AB (larodan.com)</td><td>59-1230</td><td>make stock solution in chloroform</td></tr><tr><td>L-alpha-Phosphatidylglycerol (PG)</td><td>Larodan AB (larodan.com)</td><td>37-0150</td><td>make stock solution in chloroform</td></tr><tr><td>L-&amp;alpha;-Phosphatidylcholine</td><td>Sigma-Aldrich (sigmaaldrich.com)</td><td>P3782 SIGMA</td><td>make stock solution in chloroform</td></tr><tr><td>sonicator bath S-50TH</td><td>Sonicor (getmedonline.com</td><td>SONICOR-S-50TH</td><td></td></tr><tr><td>mini-Extruder</td><td>Avanti Polar Lipids (Avanti.com)</td><td>610000</td><td></td></tr><tr><td>Nuleopore polycarbonate membrane</td><td>Avanti Polar Lipids (Avanti.com)</td><td>610005</td><td></td></tr><tr><td>dialysis membrane Visking 14 kDa cutoff</td><td>ROTH (carlroth.com)</td><td>0653.1</td><td>boil in destilled water before use</td></tr><tr><td>Biobeads SM2 Adsorbent</td><td>Biorad (Bio-rad.com)</td><td>152-3920</td><td></td></tr><tr><td>sucrose epichlorhydrin copolymer - Ficoll 400</td><td>Sigma-Aldrich (sigmaaldrich.com)</td><td>F4375</td><td></td></tr><tr><td>Polycarbonate ultracentrifuagtion vials (2.7 mL) for TFT 80.4</td><td>Beranek Laborger&amp;auml;te (Laborgeraete-beranek.de)</td><td>252150</td><td></td></tr><tr><td>rotor TFT 80.4</td><td>Millipore (merckmillipore.com)</td><td>54356</td><td></td></tr><tr><td>&lt;strong&gt;&lt;em&gt;material listed in order of appearance &lt;/em&gt;&lt;/strong&gt;</td><td></td><td></td><td>&lt;em&gt;For specific safety instructions please refer to material safety sheets and repective manuals.&lt;br /&gt;Standard lab material and substances are not listed.&lt;/em&gt;</td></tr></tbody></table>

isolating and incorporating light-harvesting antennas from diatom cyclotella meneghiniana in liposomes with thylakoid lipids

強く、植物、藻類、珪藻類の光合成能力は、葉緑体のチラコイド膜での転送プロセスを光収穫とエネルギーの高速かつ効率的な規制に依存します。集光珪藻のアンテナと呼ばれるフコキサンチン クロロフィル a/c 結合タンパク質 (FCP) が光の吸収に必要なと光合成反応に効率的に転送センター写真-過剰な光からの保護も同様。これら 2 つの関数の間のスイッチは、研究の長年問題です。これらの研究の多くは FCP で洗剤のミセルで行われています。相互作用の研究、FCP 錯体の非特異的凝集につながった、洗剤を削除されています。このアプローチで成果物と関連する生理学的データを区別するは難しいです。したがって、FCP や他の膜に埋もれた集光複合体についての有益な情報は、ネイティブ脂質環境に埋め込まれている場合、タンパク質間相互作用、エネルギー移動、他の分光学的特徴を研究することによって取得できます。主な利点は、リポソームが定義されているサイズと FCP のクラスタ リングの範囲を制御する定義された脂質・ タンパク質比ことです。さらに、集光性体内を調節する pH とイオン組成の変化は、簡単にシミュレートできます。チラコイド膜と比較してリポソームより均一なより少なく複雑な取得、分光学的データを理解して簡単に。プロトコルでは、FCP 分離精製、リポソーム調製と FCP の天然脂質リポソームへの取り込みの手順について説明します。一般的なアプリケーションからの結果が与えられ、議論。

プロトコルでは、峰 meneghiniana合計 FCP 画分の分離とネイティブ脂質リポソームに定款をについて説明します。チラコイドの分離は、再現性が高いが、チラコイド収量が変更します。結果が全ての顔料の 50% 以上が 1.1.4 のステップでリカバリする場合できます。80% 以上が最適です。
チラコイドの可溶化は、重要なス?...

Watch this Scientific Journal Video about Isolating and Incorporating Light-Harvesting Antennas from Diatom Cyclotella Meneghiniana in Liposomes with Thylakoid Lipids at JoVE.com

Isolating and Incorporating Light-Harvesting Antennas from Diatom Cyclotella Meneghiniana in Liposomes with Thylakoid Lipids

フコキサンチン クロロフィル a/c 結合タンパク質 (FCP) 珪藻を分離し、天然の脂質組成のイオン組成変化の励起エネルギー移動を研究するリポソームにそれらを組み込むのためのプロトコルを紹介します。

分離してチラコイド脂質リポソームの珪藻峰 Meneghinianaから光捕集アンテナを組み込む

The photosynthetic performance of plants, algae and diatoms strongly depends on the fast and efficient regulation of the light harvesting and energy ...

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Isolating and Incorporating Light-Harvesting Antennas from Diatom Cyclotella Meneghiniana in Liposomes with Thylakoid Lipids

Unit 1

Chloroplasts and Photosynthesis

SCIENTISTS IN ACTION

7.7K ビュー.  Goethe University. フコキサンチン クロロフィル a/c 結合タンパク質 (FCP) 珪藻を分離し、天然の脂質組成のイオン組成変化の励起エネルギー移動を研究するリポソームにそれらを組み込むのためのプロトコルを紹介します。

ビデオ: Isolating and Incorporating Light-Harvesting Antennas from Diatom Cyclotella Meneghiniana in Liposomes with Thylakoid Lipids

Using Scaffold Liposomes to Reconstitute Lipid-proximal Protein-protein Interactions In Vitro

Studies of integral membrane proteins in vitro are frequently complicated by the presence of a hydrophobic transmembrane domain. Further complicating these studies, reincorporation of detergent-solubilized membrane proteins into liposomes is a stochastic process where protein topology is impossible to enforce. This paper offers an alternative method to these challenging techniques that utilizes a liposome-based scaffold. Protein solubility is enhanced by deletion of the transmembrane domain, and these amino acids are replaced with a tethering moiety, such as a His-tag. This tether interacts with an anchoring group (Ni2+ coordinated by nitrilotriacetic acid (NTA(Ni2+)) for His-tagged proteins), which enforces a uniform protein topology at the surface of the liposome. An example is presented wherein the interaction between Dynamin-related protein 1 (Drp1) with an integral membrane protein, Mitochondrial Fission Factor (Mff), was investigated using this scaffold liposome method. In this work, we have demonstrated the ability of Mff to efficiently recruit soluble Drp1 to the surface of liposomes, which stimulated its GTPase activity. Moreover, Drp1 was able to tubulate the Mff-decorated lipid template in the presence of specific lipids. This example demonstrates the effectiveness of scaffold liposomes using structural and functional assays and highlights the role of Mff in regulating Drp1 activity.

Using Scaffold Liposomes to Reconstitute Lipid-proximal Protein-protein Interactions In Vitro

This paper describes a method for assessing the interactions and assemblies of integral membrane proteins in vitro with various partner factors in a lipid-proximal environment.

足場リポソームを使用することにより、脂質近位タンパク質 - タンパク質相互作用を再構成します<em&gt;インビトロ</em

Studies of integral membrane proteins in vitro are frequently complicated by the presence of a hydrophobic transmembrane domain. Further complicating ...

生化学

In Vitro Reconstitution of Self-Organizing Protein Patterns on Supported Lipid Bilayers

Many aspects of the fundamental spatiotemporal organization of cells are governed by reaction-diffusion type systems. In vitro reconstitution of such systems allows for detailed studies of their underlying mechanisms which would not be feasible in vivo. Here, we provide a protocol for the in vitro reconstitution of the MinCDE system of Escherichia coli, which positions the cell division septum in the cell middle. The assay is designed to supply only the components necessary for self-organization, namely a membrane, the two proteins MinD and MinE and energy in the form of ATP. We therefore fabricate an open reaction chamber on a coverslip, on which a supported lipid bilayer is formed. The open design of the chamber allows for optimal preparation of the lipid bilayer and controlled manipulation of the bulk content. The two proteins, MinD and MinE, as well as ATP, are then added into the bulk volume above the membrane. Imaging is possible by many optical microscopies, as the design supports confocal, wide-field and TIRF microscopy alike. In a variation of the protocol, the lipid bilayer is formed on a patterned support, on cell-shaped PDMS microstructures, instead of glass. Lowering the bulk solution to the rim of these compartments encloses the reaction in a smaller compartment and provides boundaries that allow mimicking of in vivo oscillatory behavior. Taken together, we describe protocols to reconstitute the MinCDE system both with and without spatial confinement, allowing researchers to precisely control all aspects influencing pattern formation, such as concentration ranges and addition of other factors or proteins, and to systematically increase system complexity in a relatively simple experimental setup.

In Vitro Reconstitution of Self-Organizing Protein Patterns on Supported Lipid Bilayers

We provide a protocol for in vitro self-organization assays of MinD and MinE on a supported lipid bilayer in an open chamber. Additionally, we describe how to enclose the assay in lipid-clad PDMS microcompartments to mimic in vivo conditions by reaction confinement.

体外自己組織化人工脂質膜上のタンパク質パターンの再構成

Many aspects of the fundamental spatiotemporal organization of cells are governed by reaction-diffusion type systems. In vitro reconstitution of such ...

Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays

Chloroplasts are the organelles in green plants responsible for carrying out numerous essential metabolic pathways, most notably photosynthesis. Within the chloroplasts, the thylakoid membrane system houses all the photosynthetic pigments, reaction center complexes, and most of the electron carriers, and is responsible for light-dependent ATP synthesis. Over 90% of chloroplast proteins are encoded in the nucleus, translated in the cytosol, and subsequently imported into the chloroplast. Further protein transport into or across the thylakoid membrane utilizes one of four translocation pathways. Here, we describe a high-yield method for isolation of transport-competent thylakoids from peas (Pisum sativum), along with transport assays through the three energy-dependent cpTat, cpSec1, and cpSRP-mediated pathways. These methods enable experiments relating to thylakoid protein localization, transport energetics, and the mechanisms of protein translocation across biological membranes.

We present protocols herein for high-yield isolation of physiologically active thylakoids and protein transport assays for the chloroplast twin arginine translocation (cpTat), secretory (cpSec1), and signal recognition particle (cpSRP) pathways.

生理活性とエネルギー依存性タンパク質輸送アッセイでの使用の分離

Chloroplasts are the organelles in green plants responsible for carrying out numerous essential metabolic pathways, most notably photosynthesis. Within ...

Formation of Biomembrane Microarrays with a Squeegee-based Assembly Method

Lipid bilayer membranes form the plasma membranes of cells and define the boundaries of subcellular organelles. In nature, these membranes are heterogeneous mixtures of many types of lipids, contain membrane-bound proteins and are decorated with carbohydrates. In some experiments, it is desirable to decouple the biophysical or biochemical properties of the lipid bilayer from those of the natural membrane. Such cases call for the use of model systems such as giant vesicles, liposomes or supported lipid bilayers (SLBs). Arrays of SLBs are particularly attractive for sensing applications and mimicking cell-cell interactions. Here we describe a new method for forming SLB arrays. Submicron-diameter SiO2 beads are first coated with lipid bilayers to form spherical SLBs (SSLBs). The beads are then deposited into an array of micro-fabricated submicron-diameter microwells. The preparation technique uses a "squeegee" to clean the substrate surface, while leaving behind SSLBs that have settled into microwells. This method requires no chemical modification of the microwell substrate, nor any particular targeting ligands on the SSLB. Microwells are occupied by single beads because the well diameter is tuned to be just larger than the bead diameter. Typically, more 75% of the wells are occupied, while the rest remain empty. In buffer SSLB arrays display long-term stability of greater than one week. Multiple types of SSLBs can be placed in a single array by serial deposition, and the arrays can be used for sensing, which we demonstrate by characterizing the interaction of cholera toxin with ganglioside GM1. We also show that phospholipid vesicles without the bead supports and biomembranes from cellular sources can be arrayed with the same method and cell-specific membrane lipids can be identified.

Supported lipid bilayers and natural membrane particles are convenient systems that can approximate the properties of cell membranes and be incorporated in a variety of analytical strategies. Here we demonstrate a method for preparing microarrays composed of supported lipid bilayer-coated SiO2 beads, phospholipid vesicles or natural membrane particles.

スキージベースアセンブリ法による生体膜マイクロアレイの形成

Lipid bilayer membranes form the plasma membranes of cells and define the boundaries of subcellular organelles. In nature, these membranes are ...

生物工学

Self-Assembly of Hybrid Lipid Membranes Doped with Hydrophobic Organic Molecules at the Water/Air Interface

Because of their unique properties, including an ultrathin thickness (3-4 nm), ultrahigh resistivity, fluidity and self-assembly ability, lipid bilayers can be readily functionalized and have been used in various applications such as bio-sensors and bio-devices. In this study, we introduced a planar organic molecule: copper (II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (CuPc) to dope lipid membranes. The CuPc/lipid hybrid membrane forms at the water/air interface by self-assembly. In this membrane, the hydrophobic CuPc molecules are located between the hydrophobic tails of lipid molecules, forming a lipid/CuPc/lipid sandwich structure. Interestingly, an air-stable hybrid lipid bilayer can be readily formed by transferring the hybrid membrane onto a Si substrate. We report a straightforward method for incorporating nanomaterials into a lipid bilayer system, which represents a new methodology for the fabrication of biosensors and biodevices.

We report a protocol for producing a hybrid lipid membrane at the water/air interface by doping the lipid bilayer with copper (II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (CuPc) molecules. The resulting hybrid lipid membrane has a lipid/CuPc/lipid sandwich structure. This protocol can also be applied to the formation of other functional nanomaterials.

水/空気界面で疎水性有機分子をドープしたハイブリッド脂質膜の自己集合

Because of their unique properties, including an ultrathin thickness (3-4 nm), ultrahigh resistivity, fluidity and self-assembly ability, lipid bilayers ...

化学

Purification of Active Photosystem I-Light Harvesting Complex I from Plant Tissues

This method is used to isolate Photosystem I (PSI) together with the Light Harvesting Complex I (LHCI), its native antenna, from plants. PSI-LHCI is a large membrane protein complex coordinating hundreds of light harvesting and electron transport factors and is the most efficient light harvesting system found in nature. Photons absorbed by the four LHCA antenna proteins that make up LHCI are transferred through excitonic interaction to the PSI core reaction center and are used to facilitate light-driven charge separation across the thylakoid membrane, providing reducing power and energy for carbon fixation in photoautotrophic organisms. The high quantum efficiency of PSI makes this complex an excellent model to study light-driven energy transfer. In this protocol, plant tissue is mechanically homogenized, and the chloroplasts are separated from the bulk cellular debris by filtration and centrifugation. The isolated chloroplasts are then osmotically lysed, and the thylakoid membranes are recovered via centrifugation and solubilized using the detergent n-dodecyl-beta-maltoside. The solubilized material is loaded onto an anion exchange column to collect most of the chlorophyll-containing complexes. Larger complexes are precipitated from the solution, resuspended in a small volume, and loaded on sucrose gradients to separate the major chlorophyll-containing complexes. The resulting sucrose gradient fractions are characterized to identify the band of interest containing PSI-LHCI. This protocol is highly similar to the protocol used in the crystallization of plant PSI-LHCI with some simplifications and relies on methods developed over the years in the lab of Nathan Nelson.

<meta charset="utf8"></head><body>植物組織からの活性光化学系I-Light Harvesting Complex Iの精製

This protocol describes the isolation of Photosystem I (PSI) - Light Harvesting Complex I (LHCI) from plant tissues. PSI along with PSII is responsible for the conversion of light to chemical energy in oxygenic photoautotrophs and has a quantum efficiency of ~1, making it a target for studying light-driven energy transfer.

植物組織からの活性光化学系I-Light Harvesting Complex Iの精製

This method is used to isolate Photosystem I (PSI) together with the Light Harvesting Complex I (LHCI), its native antenna, from plants. PSI-LHCI is a ...

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy

In the ubiquitous process of membrane fusion the opening of a fusion pore establishes the first connection between two formerly separate compartments. During neurotransmitter or hormone release via exocytosis, the fusion pore can transiently open and close repeatedly, regulating cargo release kinetics. Pore dynamics also determine the mode of vesicle recycling; irreversible resealing results in transient, &#34;kiss-and-run&#34; fusion, whereas dilation leads to full fusion. To better understand what factors govern pore dynamics, we developed an assay to monitor membrane fusion using polarized total internal reflection fluorescence (TIRF) microscopy with single molecule sensitivity and ~15 msec time resolution in a biochemically well-defined in vitro system. Fusion of fluorescently labeled small unilamellar vesicles containing v-SNARE proteins (v-SUVs) with a planar bilayer bearing t-SNAREs, supported on a soft polymer cushion (t-SBL, t-supported bilayer), is monitored. The assay uses microfluidic flow channels that ensure minimal sample consumption while supplying a constant density of SUVs. Exploiting the rapid signal enhancement upon transfer of lipid labels from the SUV to the SBL during fusion, kinetics of lipid dye transfer is monitored. The sensitivity of TIRF microscopy allows tracking single fluorescent lipid labels, from which lipid diffusivity and SUV size can be deduced for every fusion event. Lipid dye release times can be much longer than expected for unimpeded passage through permanently open pores. Using a model that assumes retardation of lipid release is due to pore flickering, a pore &#34;openness&#34;, the fraction of time the pore remains open during fusion, can be estimated. A soluble marker can be encapsulated in the SUVs for simultaneous monitoring of lipid and soluble cargo release. Such measurements indicate some pores may reseal after losing a fraction of the soluble cargo.

Here, we present a protocol to detect single, SNARE-mediated fusion events between liposomes and supported bilayers in microfluidic channels using polarized TIRFM, with single molecule sensitivity and ~15 msec time resolution. Lipid and soluble cargo release can be detected simultaneously. Liposome size, lipid diffusivity, and fusion pore properties are measured.

偏光TIRF顕微鏡によって監視マイクロ流体フローセル内のテザー支持された二分子層​​を持つシングルプロテオリポソー​​ムのSNARE媒介性の融合

In the ubiquitous process of membrane fusion the opening of a fusion pore establishes the first connection between two formerly separate compartments. ...

神経科学

Examining BCL-2 Family Function with Large Unilamellar Vesicles

The BCL-2 (B cell CLL/Lymphoma) family is comprised of approximately twenty proteins that collaborate to either maintain cell survival or initiate apoptosis1. Following cellular stress (e.g., DNA damage), the pro-apoptotic BCL-2 family effectors BAK (BCL-2 antagonistic killer 1) and/or BAX (BCL-2 associated X protein) become activated and compromise the integrity of the outer mitochondrial membrane (OMM), though the process referred to as mitochondrial outer membrane permeabilization (MOMP)1. After MOMP occurs, pro-apoptotic proteins (e.g., cytochrome c) gain access to the cytoplasm, promote caspase activation, and apoptosis rapidly ensues2.
In order for BAK/BAX to induce MOMP, they require transient interactions with members of another pro-apoptotic subset of the BCL-2 family, the BCL-2 homology domain 3 (BH3)-only proteins, such as BID (BH3-interacting domain agonist)3-6. Anti-apoptotic BCL-2 family proteins (e.g., BCL-2 related gene, long isoform, BCL-xL; myeloid cell leukemia 1, MCL-1) regulate cellular survival by tightly controlling the interactions between BAK/BAX and the BH3-only proteins capable of directly inducing BAK/BAX activation7,8. In addition, anti-apoptotic BCL-2 protein availability is also dictated by sensitizer/de-repressor BH3-only proteins, such as BAD (BCL-2 antagonist of cell death) or PUMA (p53 upregulated modulator of apoptosis), which bind and inhibit anti-apoptotic members7,9. As most of the anti-apoptotic BCL-2 repertoire is localized to the OMM, the cellular decision to maintain survival or induce MOMP is dictated by multiple BCL-2 family interactions at this membrane.
 Large unilamellar vesicles (LUVs) are a biochemical model to explore relationships between BCL-2 family interactions and membrane permeabilization10. LUVs are comprised of defined lipids that are assembled in ratios identified in lipid composition studies from solvent extracted Xenopus mitochondria (46.5% phosphatidylcholine, 28.5% phosphatidylethanoloamine, 9% phosphatidylinositol, 9% phosphatidylserine, and 7% cardiolipin)10. This is a convenient model system to directly explore BCL-2 family function because the protein and lipid components are completely defined and tractable, which is not always the case with primary mitochondria. While cardiolipin is not usually this high throughout the OMM, this model does faithfully mimic the OMM to promote BCL-2 family function. Furthermore, a more recent modification of the above protocol allows for kinetic analyses of protein interactions and real-time measurements of membrane permeabilization, which is based on LUVs containing a polyanionic dye (ANTS: 8-aminonaphthalene-1,3,6-trisulfonic acid) and cationic quencher (DPX: p-xylene-bis-pyridinium bromide)11. As the LUVs permeabilize, ANTS and DPX diffuse apart, and a gain in fluorescence is detected. Here, commonly used recombinant BCL-2 family protein combinations and controls using the LUVs containing ANTS/DPX are described.

Biochemically-defined large unilamellar vesicles (LUVs) are a convenient model system to analyze BCL-2 family interactions with immediate implications in better understanding the mitochondrial pathway of apoptosis. A method to produce LUVs, along with standard BCL-2 family protein combinations and controls to examine LUV permeabilization, are presented.

大型単層小胞とBcl-2ファミリーの機能を調べる

The BCL-2 (B cell CLL/Lymphoma) family is comprised of approximately twenty proteins that collaborate to either maintain cell survival or initiate ...

生物学

On-Chip Octanol-Assisted Liposome Assembly for Bioengineering

Microfluidics is a widely used tool to generate droplets and vesicles of various kinds in a controlled and high-throughput manner. Liposomes are simplistic cellular mimics composed of an aqueous interior surrounded by a lipid bilayer; they are valuable in designing synthetic cells and understanding the fundamentals of biological cells in an in vitro fashion and are important for applied sciences, such as cargo delivery for therapeutic applications. This article describes a detailed working protocol for an on-chip microfluidic technique, octanol-assisted liposome assembly (OLA), to produce monodispersed, micron-sized, biocompatible liposomes. OLA functions similarly to bubble blowing, where an inner aqueous (IA) phase and a surrounding lipid-carrying 1-octanol phase are pinched off by surfactant-containing outer fluid streams. This readily generates double-emulsion droplets with protruding octanol pockets. As the lipid bilayer assembles at the droplet interface, the pocket spontaneously detaches to give rise to a unilamellar liposome that is ready for further manipulation and experimentation. OLA provides several advantages, such as steady liposome generation (&#62;10 Hz), efficient encapsulation of biomaterials, and monodispersed liposome populations, and requires very small sample volumes (~50 &#181;L), which can be crucial when working with precious biologicals. The study includes details on microfabrication, soft-lithography, and surface passivation, which are needed to establish OLA technology in the lab. A proof-of-principle synthetic biology application is also shown by inducing the formation of biomolecular condensates inside the liposomes via transmembrane proton flux. It is anticipated that this accompanying video protocol will facilitate the readers to establish and troubleshoot OLA in their labs.

The present protocol describes octanol-assisted liposome assembly (OLA), a microfluidic technique to generate biocompatible liposomes. OLA produces monodispersed, micron-sized liposomes with efficient encapsulation, allowing immediate on-chip experimentation. This protocol is anticipated to be particularly suitable for synthetic biology and synthetic cell research.

分離してチラコイド脂質リポソームの珪藻峰 Meneghinianaから光捕集アンテナを組み込む

要約

さらに動画を探す

この動画の章

足場リポソームを使用することにより、脂質近位タンパク質 - タンパク質相互作用を再構成します

体外自己組織化人工脂質膜上のタンパク質パターンの再構成

生理活性とエネルギー依存性タンパク質輸送アッセイでの使用の分離

スキージベースアセンブリ法による生体膜マイクロアレイの形成

水/空気界面で疎水性有機分子をドープしたハイブリッド脂質膜の自己集合

植物組織からの活性光化学系I-Light Harvesting Complex Iの精製

植物組織からの活性光化学系I-Light Harvesting Complex Iの精製

偏光TIRF顕微鏡によって監視マイクロ流体フローセル内のテザー支持された二分子層を持つシングルプロテオリポソームのSNARE媒介性の融合

大型単層小胞とBcl-2ファミリーの機能を調べる

バイオエンジニアリングのためのオンチップオクタノール支援リポソームアセンブリ

分離してチラコイド脂質リポソームの珪藻峰 Meneghinianaから光捕集アンテナを組み込む

要約

さらに動画を探す

この動画の章

足場リポソームを使用することにより、脂質近位タンパク質 - タンパク質相互作用を再構成します

体外自己組織化人工脂質膜上のタンパク質パターンの再構成

生理活性とエネルギー依存性タンパク質輸送アッセイでの使用の分離

スキージベースアセンブリ法による生体膜マイクロアレイの形成

水/空気界面で疎水性有機分子をドープしたハイブリッド脂質膜の自己集合

植物組織からの活性光化学系I-Light Harvesting Complex Iの精製

植物組織からの活性光化学系I-Light Harvesting Complex Iの精製

偏光TIRF顕微鏡によって監視マイクロ流体フローセル内のテザー支持された二分子層​​を持つシングルプロテオリポソー​​ムのSNARE媒介性の融合

大型単層小胞とBcl-2ファミリーの機能を調べる

バイオエンジニアリングのためのオンチップオクタノール支援リポソームアセンブリ

偏光TIRF顕微鏡によって監視マイクロ流体フローセル内のテザー支持された二分子層を持つシングルプロテオリポソームのSNARE媒介性の融合