Correlated fluorescence quenching and topographic mapping of Light-Harvesting Complex II within surface-assembled aggregates and lipid bilayers.
Correlated fluorescence quenching and topographic mapping of Light-Harvesting Complex II within surface-assembled aggregates and lipid bilayers.
复制标题
DOI：
10.1016/j.bbabio.2018.06.011
复制
发表时间：
2018-10
期刊：
影响因子：
--
通讯作者：
Johnson MP
中科院分区：
文献类型：
--
作者：
Adams PG;Vasilev C;Hunter CN;Johnson MP
捕光复合物II（LHCII）是一种叶绿素-蛋白质天线复合物，可有效吸收太阳能并将电子激发态转移到光系统I和II。在过量的光强度下，LHCII可以采取光保护状态，其中激发能量安全地消散为热，这一过程称为非光化学猝灭（NPQ）。在体内NPQ由包括跨膜ΔpH、PsbS蛋白和LHCII结合的玉米黄质的组合因素触发，导致LHCII荧光寿命显著缩短。在体外，洗涤剂溶液或蛋白脂质体中的LHCII可以通过操纵洗涤剂/蛋白质比、脂质/蛋白质比、pH或压力可逆地采用NPQ样状态。以前的光谱研究揭示了激子动力学和蛋白质构象的变化，伴随着淬火，然而，LHCII-LHCII相互作用还没有得到广泛的研究。在这里，我们相关的荧光寿命成像显微镜（FLIM）和原子力显微镜（AFM）的三聚体LHCII吸附到云母基板和操纵的环境，造成不同程度的淬火。AFM显示LHCII自组装到云母上形成2D聚集体（25-150 nm宽度）。FLIM确定这些聚集体中的LHCII处于淬灭状态，与溶液中的游离LHCII（2.2-3.9 ns）相比具有低得多的荧光寿命（~0.25 ns）。LHCII-LHCII相互作用被类囊体脂质或磷脂破坏，导致中间荧光寿命（0.6-0.9 ns）。据我们所知，这是第一次在体外相关的纳米级膜成像与LHCII淬灭。我们的研究结果表明，脂质可能在调节类囊体膜内LHCII-LHCII相互作用的程度以及NPQ激活的倾向方面发挥关键作用。光收集复合物II可以在云母表面上操作和淬灭，参见。NPQ。原子力显微镜显示，LHCII在云母上组装成小的2D聚集体。LHCII聚集体被高度淬灭，如荧光寿命显微镜所示。脂质引起重排的LHCII和中间水平的淬火。AFM和FLIM的相关性是连接结构和功能的有力策略。
Light-Harvesting Complex II (LHCII) is a chlorophyll-protein antenna complex that efficiently absorbs solar energy and transfers electronic excited states to photosystems I and II. Under excess light intensity LHCII can adopt a photoprotective state in which excitation energy is safely dissipated as heat, a process known as Non-Photochemical Quenching (NPQ). In vivo NPQ is triggered by combinatorial factors including transmembrane ΔpH, PsbS protein and LHCII-bound zeaxanthin, leading to dramatically shortened LHCII fluorescence lifetimes. In vitro, LHCII in detergent solution or in proteoliposomes can reversibly adopt an NPQ-like state, via manipulation of detergent/protein ratio, lipid/protein ratio, pH or pressure. Previous spectroscopic investigations revealed changes in exciton dynamics and protein conformation that accompany quenching, however, LHCII-LHCII interactions have not been extensively studied. Here, we correlated fluorescence lifetime imaging microscopy (FLIM) and atomic force microscopy (AFM) of trimeric LHCII adsorbed to mica substrates and manipulated the environment to cause varying degrees of quenching. AFM showed that LHCII self-assembled onto mica forming 2D-aggregates (25–150 nm width). FLIM determined that LHCII in these aggregates were in a quenched state, with much lower fluorescence lifetimes (~0.25 ns) compared to free LHCII in solution (2.2–3.9 ns). LHCII-LHCII interactions were disrupted by thylakoid lipids or phospholipids, leading to intermediate fluorescent lifetimes (0.6–0.9 ns). To our knowledge, this is the first in vitro correlation of nanoscale membrane imaging with LHCII quenching. Our findings suggest that lipids could play a key role in modulating the extent of LHCII-LHCII interactions within the thylakoid membrane and so the propensity for NPQ activation. Light-Harvesting Complex II can be manipulated & quenched on mica surfaces, cf. NPQ. LHCII assembles into small 2D aggregates on mica, shown by Atomic Force Microscopy. LHCII aggregates are highly quenched as shown by Fluorescence Lifetime Microscopy. Lipids caused rearrangement of LHCII and an intermediate level of quenching. Correlation of AFM and FLIM is a powerful strategy to link structure and function.
登录
查看更多内容
影响因子：
4.6
作者：
Adams PG;Swingle KL;Paxton WF;Nogan JJ;Stromberg LR;Firestone MA;Mukundan H;Montaño GA
通讯作者：
Montaño GA
影响因子：
3.4
作者：
Aitken, Colin Echeverria;Marshall, R. Andrew;Puglisi, Joseph D.
通讯作者：
Puglisi, Joseph D.
影响因子：
14.8
作者：
Croce, Roberta;van Amerongen, Herbert
通讯作者：
van Amerongen, Herbert
影响因子：
3.4
作者：
Crisafi, Emanuela;Pandit, Anjali
通讯作者：
Pandit, Anjali
影响因子：
56.9
作者：
Ahn, Tae Kyu;Avenson, Thomas J.;Fleming, Graham R.
通讯作者：
Fleming, Graham R.