light-induced switching
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Xanthophylls in light harvesting complexes perform a number of functions ranging from structural support to light-harvesting and photoprotection. In the major light harvesting complex of photosystem II in plants (LHCII), the innermost xanthophyll binding pockets are occupied by lutein molecules. The conservation of these sites within the LHC protein family suggests their importance in LHCII functionality. In the present work, we induced the photoprotective switch in LHCII isolated from the Arabidopsis mutant npq1lut2, where the lutein molecules are exchanged with violaxanthin. Despite the differences in the energetics of the pigments and the impairment of chlorophyll fluorescence quenching in vivo, we show that isolated complexes containing violaxanthin are still able to induce the quenching switch to a similar extent to wild type LHCII monomers. Moreover, the same spectroscopic changes take place, which suggest the involvement of the terminal emitter site (L1) in energy dissipation in both complexes. These results indicate the robust nature of the L1 xanthophyll binding domain in LHCII, where protein structural cues are the major determinant of the function of the bound carotenoid.
Závěrečná zpráva o řešení grantu Interní grantové agentury MZ ČR
171 l. : il., tab. ; 31 cm
Chceme porovnat dostupné fotosenzibilizátory pro maxilofaciální onkologii a vybrat optimální. tento porovnat randomizovanou prospektivní studií s konvenční terapií. Dále chceme kombinovat fotodynamickou terapii s fotodestrukcí výkonovými lasery a intersticiální laserovou hypertermií, abychom mužnili kompletní laserovou destrukci libovolného novotvaru. Takto vzniklá metoda bude testována v prospektivní randomizované studi 6 a 12 měsíců, tak aby mohla být komparována s konvečním postupem a aby mohl být stanoven teraqpeutický protokol. Výsledkem by měl být nový algoritmus onkochirurgie postavený na vyšším stupni selektivity, než je tomu u konveční onkochirurgie; We want to find optimal photosenzitizer for head and neck oncology due to comprasion of drugs.The winner will compared with conventional surgery results in randomized trial. We want improve results due to combination of laser ablation, hyperthermy and photodynamic therapy. This combination can be used as tool for complete elimination of cancer.We compare laser interstitial hyperthermy with interstitial This combination will verified in prospective randomised study for 6 and 12 month and compared with results of conventional therapy. The planned result can be a new algoritmus for complex oncologic therapy than conventional with improved results and selectivity.
- MeSH
- fotochemoterapie metody MeSH
- fotosenzibilizující látky MeSH
- indukovaná hypertermie MeSH
- kyselina aminolevulová MeSH
- laserová terapie s nízkou intenzitou světla metody MeSH
- lasery využití MeSH
- maxilofaciální abnormality terapie MeSH
- nádory hlavy a krku terapie MeSH
- Konspekt
- Stomatologie
- NLK Obory
- zubní lékařství
- onkologie
- technika lékařská, zdravotnický materiál a protetika
- NLK Publikační typ
- závěrečné zprávy o řešení grantu IGA MZ ČR
... Hall (United Kingdom).13 -- Rotating spark gap switched discharge TEA C02 laser with average power up ... ... Ghafori (Iran) 15 -- SESSI\' -- Solid Stc -- ON 3 id Slate Lasers I -- High average power Q-switched ... ... EUV light source by laser-produced plasma -- Y. ... ... Mendonga (Portugal) 177 -- Measurement of sub-15-fs laser pulses by a light-emitting diode -- M. ... ... Stournaras (Greece) 195 -- Study of laser-induced cavitation bubble in liquid nitrogen -- K. ...
1st ed. 209 s. ; 30 cm
Recently nanoparticle enhanced Laser Induced Breakdown Spectroscopy (NELIBS) is getting a growing interest as an effective alternative method for improving the analytical performance of LIBS. On the other hand, the plasmonic effect during laser ablation can be used for a different task rather than elemental analysis. In this paper, the dependence of NELIBS emission signal enhancement on nanoparticle-protein solutions dried on a reference substrate (metallic titanium) was investigated. Two proteins were studied: Human Serum Albumin (HSA) and Cytochrome C (CytC). Both proteins have a strong affinity for the gold nanoparticles (AuNPs) due to the bonding between the single free exterior thiol (associated with a cysteine residue) and the gold surface to form a stable protein corona. Then, since the protein sizes are vastly different, a different number of protein units is needed to cover AuNP surface to form a protein layer. The NP-protein solution was dropped and dried onto the titanium substrate. Then the NELIBS signal enhancement of Ti emission lines was correlated to the solution characteristics as determined with Dynamic Light Scattering (DLS), Surface Plasmon Resonance (SPR) spectroscopy and Laser Doppler Electrophoresis (LDE) for ζ-potential determination. Moreover, the dried solutions were studied with TEM (Transmission Electron Microscopy) for the inspection of the inter-particle distance. The structural effect of the NP-protein conjugates on the NELIBS signal reveals that NELIBS can be used to determine the number of protein units required to form the nanoparticle-protein corona with good accuracy. Although the investigated NP-protein systems are simple cases in biological applications, this work demonstrates, for the first time, a different use of NELIBS that is beyond elemental analysis and it opens the way for sensing the nanoparticle protein corona.
- MeSH
- kovové nanočástice * MeSH
- lasery MeSH
- lidé MeSH
- proteinová korona * MeSH
- spektrální analýza MeSH
- zlato MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
... Choice of Fixation Light: Network Competition 33 -- 2.3. ... ... Short Term Memory of the First Light 33 -- B. ... ... Match-Induced Reset of the TPM 207 -- 9.5. Design of a Predictive Command Network 210 -- 9.6. ... ... Parietal Light-Sensitive and Saccade Neurons 218 -- 9.9. ... ... Learning and Competition from a Vector-Based Map 254 to a Light-Based Map -- 11.3. ...
Advances in psychology ; 30
xvi, 336 stran : ilustrace ; 23 cm
- Konspekt
- Psychologie
- NLK Obory
- oftalmologie
- psychologie, klinická psychologie
- NLK Publikační typ
- kolektivní monografie
Light is one of the most important factor influencing plant growth and development all through their life cycle. One of the well-known light-regulated processes is de-etiolation, i.e. the switch from skotomorphogenesis to photomorphogenesis. The hormones cytokinins (CKs) play an important role during the establishment of photomorphogenesis as exogenous CKs induced photomorphogenesis of dark-grown seedlings. Most of the studies are conducted on the plant model Arabidopsis, but no or few information are available for important crop species, such as tomato (Solanum lycopersicum L.). In our study, we analyzed for the first time the endogenous CKs content in tomato hypocotyls during skotomorphogenesis, photomorphogenesis and de-etiolation. For this purpose, two tomato genotypes were used: cv. Rutgers (wild-type; WT) and its corresponding mutant (7B-1) affected in its responses to blue light (BL). Using physiological and molecular approaches, we identified that the skotomorphogenesis is characterized by an endoreduplication-mediated cell expansion, which is inhibited upon BL exposure as seen by the accumulation of trancripts encoding CycD3, key regulators of the cell cycle. Our study showed for the first time that iP (isopentenyladenine) is the CK accumulated in the tomato hypocotyl upon BL exposure, suggesting its specific role in photomorphogenesis. This result was supported by physiological experiments and gene expression data. We propose a common model to explain the role and the relationship between CKs, namely iP, and endoreduplication during de-etiolation and photomorphogenesis.
- MeSH
- buněčný cyklus účinky léků genetika MeSH
- cyklin D3 genetika metabolismus MeSH
- cytokininy metabolismus MeSH
- endoreduplikace fyziologie účinky záření MeSH
- fylogeneze MeSH
- hypokotyl fyziologie účinky záření MeSH
- isopentenyladenosin metabolismus MeSH
- morfogeneze fyziologie účinky záření MeSH
- ploidie MeSH
- rostlinné proteiny genetika metabolismus MeSH
- semenáček fyziologie účinky záření MeSH
- Solanum lycopersicum fyziologie účinky záření MeSH
- světlo MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Plants harvest photons for photosynthesis using light-harvesting complexes (LHCs)-an array of chlorophyll proteins that can reversibly switch from harvesting to energy-dissipation mode to prevent over-excitation and damage of the photosynthetic apparatus. In unicellular algae and lower plants this process requires the LHCSR proteins which senses over-acidification of the lumen trough protonatable residues exposed to the thylakoid lumen to activate quenching reactions. Further activation is provided by replacement of the violaxanthin ligand with its de-epoxidized product, zeaxanthin, also induced by excess light. We have produced the ppLHCSR1 protein from Physcomitrella patens by over-expression in tobacco and purified it in either its violaxanthin- or the zeaxanthin-binding form with the aim of analyzing their spectroscopic properties at either neutral or acidic pH. Using femtosecond spectroscopy, we demonstrated that the energy dissipation is achieved by two distinct quenching mechanism which are both activated by low pH. The first is present in both ppLHCSR1-Vio and ppLHCSR1-Zea and is characterized by 30-40ps time constant. The spectrum of the quenching product is reminiscent of a carotenoid radical cation, suggesting that the pH-induced quenching mechanism is likely electron transfer from the carotenoid to the excited Chl a. In addition, a second quenching channel populating the S1 state of carotenoid via energy transfer from Chl is found exclusively in the ppLHCSR1-Zea at pH5. These results provide proof of principle that more than one quenching mechanism may operate in the LHC superfamily and also help understanding the photoprotective role of LHCSR proteins and the evolution of LHC antennae.
- MeSH
- biologické modely MeSH
- chlorofyl metabolismus MeSH
- fotosyntéza * genetika účinky záření MeSH
- geneticky modifikované rostliny genetika metabolismus účinky záření MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- mechy genetika metabolismus účinky záření MeSH
- přenos energie MeSH
- spektrální analýza MeSH
- světlosběrné proteinové komplexy genetika metabolismus účinky záření MeSH
- tabák genetika metabolismus účinky záření MeSH
- transport elektronů MeSH
- vazba proteinů MeSH
- xanthofyly metabolismus MeSH
- zeaxanthiny metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The transition from vegetative to reproductive phases is the most fundamental and tightly controlled switch in the life of flowering plants. The short-day plant Chenopodium rubrum is a fast cycling annual plant lacking a juvenile phase. It can be induced to flowering at the seedling stage by exposure to a single period of darkness. This floral induction may then be cancelled by a short pulse of red light at midnight called night break (NB), which also inhibits the floral activator FLOWERING LOCUS T LIKE 1 (CrFTL1). We performed a comparative transcriptomic study between C. rubrum seedlings treated by NB and ones growing through uninterrupted night, and found about six hundred differentially expressed genes, including the B-BOX DOMAIN (BBX) genes. We focused on the CrBBX19 and BOLTING TIME CONTROL 1 (BTC1) genes, homologous to the upstream regulators of the BvFT2, a floral inducer in sugar beet. The transcription patterns of the two genes were compatible with their putative role as a sensor of the dark period length optimal for flowering (CrBBX19), and a signal of lights-on (CrBTC1), but the participation of other genes cannot be excluded. The expression profiles of CrBBX19 and the homolog of the core endogenous clock gene LATE ELONGATED HYPOCOTYL (LHY) were highly similar, which suggested their co-regulation.
... by Chemicals 373 Mutations Induced by Radiation 378 Mutations Induced by Transposable Genetic Elements ... ... VIRUSES 615 D’Hérelle’s Dream of Treating Dysentery in Humans by Phage Therapy 615 Constitutive, Inducible ... ... Lambda Lytic Pathway Genes During Lysogeny 631 The Lambda Lytic Regulatory Cascade 634 The Lambda Switch ... ... Lymphocyte Differentiation 740 -- Lambda Light Chain Genes Assembled from Two Gene Segments 740 Kappa ... ... Light Chain Genes Assembled from Three Gene Segments 740 Heavy Chain Genes Assembled from Four Gene ...
2nd ed. xviii, 876 s. : il.
