H2020Индивидуална стипендия2015–2017

MeaSuRe · Following Protein Diffusion in Photosynthetic Membranes with Super Resolution

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2015-09-14 → 2017-10-23
Финансиране от ЕС: 177 599 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Движението на протеините, които улавят светлината в растителните мембрани, се проследява чрез специални наноантени. Това помага за по-доброто разбиране на процеса на фотосинтеза и може да се приложи при изследването на клетъчни мембрани.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Following Protein Diffusion in Photosynthetic Membranes with Super Resolution

The regulated diffusion of light-harvesting complexes in photosynthetic membranes is essential for photosynthesis. To date, however, little is understood about the mobility of these proteins through the highly crowded membrane environment. The light-harvesting complexes coordinate chlorophylls and are as such auto-fluorescent which makes fluorescence correlation spectroscopy (FCS) an attractive method to study their mobility. In this method the fluctuations in the fluorescence intensity when complexes move in and out of the diffraction-limited excitation spot is used to quantify the diffusion rates. However in the case of photosynthetic membranes there are two big challenges: 1) The concentration of the light-harvesting complexes in the membrane is extremely high, such that fluctuations are too small to observe. 2) The membrane dimensions are in the order of hundreds of nanometres which is the same as the diffraction limit of light, as such complexes will not diffuse in and out of the excitation spot. The aim of this project is to overcome these problems with the use of plasmonic nanoantennas which are able to confine light at the nanoscale. As a result only a small number of light-harvesting complexes will be excited, which will allow to measure fluctuations, and the excitation spot is smaller than the dimension of the membrane. This research is not only important for the understanding of photosynthesis, but the technique could also be applied to study cell membranes in general. Diffraction limited FCS was used to measure the diffusion rate of light-harvesting complexes. In the second step the plasmonic nanoantennas were used to reduce the excitation volume. Plasmonic nano-gap antennas inside a nanoaperture were used to have strongly localized excitation and little background illumination. As expected, the excitation volume was reduced. However, the reduction was only a factor ten while a reduction of 4000 has been observed for organic chromophores. A possible problem is the size of the light-harvesting complex of about ten nanometre which might hinder the access to the antenna hot-spot. Different gap sizes of the antenna were investigated, but the results did not improve. Therefore, instead of gap-antennas rod-shaped antennas were used. With these antennas the maximal photon emission rate of single light-harvesting complexes was enhanced by a factor of fifty and the number of photons emitted before photobleaching was enhanced by a factor of ten. These antenna are promising candidates to use in the study of light-harvesting complex diffusion in a crowded membrane. Due to a new job after 9 month the project was stopped, therefore the fellow could not finish the entire project.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

The regulated diffusion of light-harvesting complexes in photosynthetic membranes is essential for photosynthesis, for instance for the redistribution of light-harvesting complexes between Photosystems I and II. To date, however, little is understood about the mobility of these proteins through the highly crowded membrane environment. In contrast to the huge amount of structural research that has been performed on biomolecules in the past, research on the dynamics is lagging far behind. The major limitation is the fact that the nanometer size regime of biomolecules is not accessible by classical optical techniques owing to the diffraction limit of light. To overcome this problem, we propose to use plasmonic nanoantennas, which are able to confine light at the nanoscale. In combination with Fluorescence Correlation Spectroscopy (FCS) this will allow measuring protein mobility in photosynthetic membranes with high, tens of nanometers, resolution. Directional and functional protein movement will be induced by illumination of the chloroplasts using specific light conditions; simultaneously following the protein movement will give new insights in how plants optimize their light harvesting capacity under fluctuating light conditions. The new nanoantenna-FCS based method, which we will develop to measure the diffusion of membrane proteins with nanometer resolution, has the potential to become widely used for nanobioimaging and ultrasensitive biosensing.This research will be performed by Dr. E Wientjes in the Laboratory of Biophysics of Wageningen University led by photosynthesis expert Prof. H van Amerongen. A long-term collaboration will be started with Wientjes current supervisor Prof. NF van Hulst and Prof. MF Garcia-Parajo from the Institute of Photonic Sciences in Barcelona who are leading scientists in nanophotonics. The outcome of this project will provide biophysicists with a new method to study membrane protein dynamics with super resolution.

Оригинален текст от CORDIS (на английски).

Участници

WAGENINGEN UNIVERSITY · WageningenКоординаторНидерландия