EPR spectroscopic investigation of membrane protein structure and folding on light harvesting complex LHCIIb

Structure and folding of membrane proteins are important issues in molecular and cell biology. In this work new approaches are developed to characterize the structure of folded, unfolded and partially folded membrane proteins. These approaches combine site-directed spin labeling and pulse EPR techniques. The major plant light harvesting complex LHCIIb was used as a model system. Measurements of longitudinal and transversal relaxation times of electron spins and of hyperfine couplings to neighboring nuclei by electron spin echo envelope modulation(ESEEM) provide complementary information about the local environment of a single spin label. By double electron electron resonance (DEER) distances in the nanometer range between two spin labels can be determined. The results are analyzed in terms of relative water accessibilities of different sites in LHCIIb and its geometry. They reveal conformational changes as a function of micelle composition. This arsenal of methods is used to study protein folding during the LHCIIb self assembly and a spatially and temporally resolved folding model is proposed. The approaches developed here are potentially applicable for studying structure and folding of any protein or other self-assembling structure if site-directed spin labeling is feasible and the time scale of folding is accessible to freeze-quench techniques.

Molecular crosstalk between a chemical and a biological stressor and consequences on disease manifestation in rainbow trout.

The aim of the present study was to examine the molecular and organism reaction of rainbow trout, Oncorhynchus mykiss, to the combined impact of two environmental stressors. The two stressors were the myxozoan parasite, Tetracapsuloides bryosalmonae, which is the etiological agent of proliferative kidney disease (PKD) and a natural stressor to salmonid populations, and 17β-estradiol (E2) as prototype of estrogen-active chemical stressors in the aquatic environment. Both stressors, the parasite and estrogenic contaminants, co-exist in Swiss rivers and are discussed as factors contributing to the decline of Swiss brown trout populations over the last decades. Using a microarray approach contrasting parasite-infected and non-infected rainbow trout at low or high estrogen levels, it was observed that molecular response patterns under joint exposure differed from those to the single stressors. More specifically, three major response patterns were present: (i) expression responses of gene transcripts to one stressor are weakened by the presence of the second stressor; (ii) expression responses of gene transcripts to one stressor are enhanced by the presence of the second stressor; (iii) expression responses of gene transcripts at joint treatment are dominated by one of the two stressors. Organism-level responses to concurrent E2 and parasite treatment - assessed through measuring parasite loads in the fish host and cumulative mortalities of trout - were dominated by the pathogen, with no modulating influence of E2. The findings reveal function- and level-specific responses of rainbow trout to stressor combinations, which are only partly predictable from the response to the single stressors.

Bibli oteka dli a chteni i a : zhurnal slovesnosti, nauk, khudozhestv, promyshlennosti, novostei i mod.

Editors: O.I. Senkovskii , 1934-1857; A.V. Druzhinin, 1858-1860; A.F. Pisemskii , 1861-1862; P.D. Boborykin, 1863-1865.

Stabat Mater.

Mode of access: Internet.

Populi︠a︡rnyĭ kurs politicheskoĭ ėkonomii.

Mode of access: Internet.

Svod botanicheskikh terminov, vstri e chai u shchikhsi a v Russkoi botanicheskoi literaturi e /

"K 'Trudam Bi u ro po prikladnoi botaniki e ' Uchenago Komiteta Trafnago Upravleni i a Zemleustroi stva i Zemledi e li i a , izdavaemym pod redakt s i ei Zavi e d. Bi u ro Rob. Ed. Regeli a "

Puteshestvi e v Turkestan /

Includes bibliographical references and indexes.

Velikai︠a︡ reforma : russkoe obshchestvo i krestʹi︠a︡nskīĭ vopros v proshlom i nastoi︠a︡shchem /

"I︠U︡bileĭnoe izd. [19 fevr. 1861-1911]."

Russkiĭ knizhnyĭ znak /

Six hundred copies have been printed, of these two hundred on special paper.

Russkai︠a︡ karikatura.

[1] V.F. Timm.--2. Otechestvennai︠a︡ voĭna: Terebenev, Venet︠s︡īanov, Ivanov.--3. A.O. Orlovskiĭ.

Izbrannyi͡a stikhotvorenii͡a /

Poems.

東部蒙古 続蒙古及蒙古人

Mode of access: Internet.

Stabat Mater. Partitur für das grosse Orchester, und mit Choeren instrumentirt

For solo voices (SA), chorus (SATB) and orchestra; originally for SA, 2 violins, viola, and figured bass.

Povi͡e︡sti i razskazy A.N. Pleshcheeva /

Photocopy.

Svi͡e︡di͡e︡nii͡a︡ o grafi͡e︡ Aleksi͡e︡i͡e︡ Andreevichi͡e︡ Arakcheevi͡e︡ /

Bibliographical footnotes.