BibTex format
@phdthesis{Cardona:2010,
author = {Cardona, T},
title = {The Heterocysts of Nostoc punctiforme: from Proteomics to Energy Transfer},
url = {http://www.diva-portal.org/smash/record.jsf?pid=diva2:235774&dswid=978},
year = {2010}
}
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Citation
RIS format (EndNote, RefMan)
TY - THES
AB - The aim of this thesis is to provide a thorough characterization of the photosynthetic machinery from the heterocysts of Nostoc punctiforme strain ATCC 29133. In this thesis I describe the protocols I have optimized for the isolation of thylakoids from vegetative cells, the purification of heterocysts and the isolation of thylakoids from the purified heterocysts. The composition of the thylakoid membranes was studied by two dimensional electrophoresis and mass-spectrometry. Further insight into the functionality of the photosynthetic complexes was obtained by EPR, electron transport measurements through Photosystem II (PSII), and fluorescence spectroscopy. The proteome of the heterocysts thylakoids compared to that of the vegetative cell was found to be dominated by Photosystem I (PSI) and ATP-synthase complexes, both essential for keeping high nitrogenase activities. Surprisingly, we found a significant amount of assembled monomeric PSII complexes in the heterocysts thylakoid membranes. We measured in vitro light-driven electron transfer from PSII in heterocysts using an artificial electron donor, suggesting that under certain circumstances heterocysts might activate PSII. Parallel to my main research I also worked in a collaboration to elucidate the total proteome of Nostoc sp. strain 7120 and Nostoc punctiforme using quantitative shotgun proteomics. Several hundred proteins were quantified for both species. It was possible to trace the detailed changes that occurred in the energy and nitrogen metabolism of a heterocyst after differentiation. Moreover, the presence of PSII proteins identified in our membrane proteome was also confirmed and extended. Lastly, I studied how the heterocysts are capable of responding to variations in light quality as compared to vegetative cells. Using 77 K fluorescence spectroscopy on heterocysts and vegetative cells previously illuminated with light at specific wavelengths, I was able to demonstrate that heterocysts still possess a p
AU - Cardona,T
PY - 2010///
TI - The Heterocysts of Nostoc punctiforme: from Proteomics to Energy Transfer
UR - http://www.diva-portal.org/smash/record.jsf?pid=diva2:235774&dswid=978
UR - http://hdl.handle.net/10044/1/21753
ER -