@article {1165,
	title = {The structural and dynamic basis of Ets-1 DNA binding autoinhibition},
	journal = {Journal of Biological Chemistry},
	volume = {280},
	number = {8},
	year = {2005},
	note = {ISI Document Delivery No.: 902DTTimes Cited: 19Cited Reference Count: 73},
	month = {Feb},
	pages = {7088-7099},
	type = {Article},
	abstract = {The transcription factor Ets-1 is regulated by the allosteric coupling of DNA binding with the unfolding of an alpha-helix (HI-1) within an autoinhibitory module. To understand the structural and dynamic basis for this autoinhibition, we have used NAIR spectroscopy to characterize Ets-1DeltaN301, a partially inhibited fragment of Ets-1. The NMR-derived Ets-1DeltaN301 structure reveals that the autoinhibitory module is formed predominantly by the hydrophobic packing of helices from the N-terminal (HI-1, HI-2) and C-terminal (114, 115) inhibitory sequences, along with H1 of the intervening DNA binding ETS domain. The intramolecular interactions made by HI-1 in Ets-1DeltaN301 are similar to the intermolecular contacts observed in the crystal structure of an Ets-1DeltaN300 dimer, confirming that the latter represents a domain-swapped species. N-15 relaxation studies demonstrate that the backbone of the N-terminal inhibitory sequence is mobile on the nanosecond-picosecond and millisecond-microsecond time scales. Furthermore, hydrogen exchange measurements reveal that amide protons in helices HI-I and HI-2 exchange with water at rates only similar to15- and similar to75-fold slower, respectively, than predicted for an unfolded polypeptide. These findings indicate that inhibitory helices are only marginally stable even in the absence of DNA. The energetic coupling of DNA binding with the facile unfolding of the labile HI-1 provides a mechanism for modulating Ets-1 DNA binding activity via protein partnerships, post-translational modifications, or mutations. Ets-1 autoinhibition illustrates how conformational equilibria within structural domains can regulate macromolecular interactions.},
	keywords = {BACKBONE DYNAMICS, CHEMICAL-EXCHANGE, DIPOLAR COUPLINGS, Ets-1, GROUP HYDROGEN-EXCHANGE, HIGH-RESOLUTION, MURINE, N-15 NMR RELAXATION, POINTED DOMAIN, SECONDARY STRUCTURE, SIDE-CHAINS},
	isbn = {0021-9258},
	url = {<Go to ISI>://000227332700099},
	author = {Lee, G. M. and Donaldson, L. W. and Pufall, M. A. and Kang, H. S. and Pot, I. and Graves, B. J. and McIntosh, L. P.}
}
@article {3692,
	title = {Speciation of aluminum in biological systems},
	journal = {Journal of Toxicology and Environmental Health},
	volume = {48},
	number = {6},
	year = {1996},
	note = {ISI Document Delivery No.: VE144Times Cited: 99Cited Reference Count: 131Research Issues in Aluminum Toxicity WorkshopJUL, 1995VANCOUVER, CANADA},
	month = {Aug},
	pages = {543-568},
	type = {Proceedings Paper},
	abstract = {As a {\textquoteright}{\textquoteright}hard{\textquoteright}{\textquoteright} trivalent metal ion, Al3+ binds strongly to oxygen-donor ligands such as citrate and phosphate. The aqueous coordination chemistry of Al is complicated by the tendency of many Al complexes to hydrolyze and form polynuclear species, many of which are sparingly soluble. Thus there is considerable variation among the Al stability constants reported for several important ligands. The complexity in the aqueous chemistry of Al has also affected Al toxicity studies, which have often utilized poorly characterized Al stock solutions. Serum fractionation studies show that most Al is protein bound, primarily to the serum iron transport protein transferrin. Albumin appears to play little, if any, role in serum transport. There is little agreement as to the speciation of the remaining low-molecular-mass fraction of serum Al. The lability of the Al3+ ion precludes the simple separation and identification of individual Al complexes. Computational methods are available for detailed computer calculations of the Al speciation in serum, but efforts in this area have been severely hampered by the uncertainties regarding the stability constants of the low molecular mass Al complexes with Citrate, phosphate, and hydroxide. Specific recommendations for further research on Al speciation include: (1) Determine more accurate Al stability constants with critical low molecular mass ligands such as citrate and phosphate; (2) supplement traditional potentiometric studies on Al complexes with data from other techniques such as Al-27-NMR and accelerator mass spectrometry with Al-26; (3) develop new methods for generating reliable linear free energy relationships for Al complexation; (4) determine equilibrium and rate constants for Al binding to transferrin al 37 degrees C; (5) confirm the possible formation of low-molecular-mass Al-protein complexes following desferrioxamine therapy; (6) continue research efforts to incorporate kinetic considerations into the present equilibrium speciation calculations; (7) improve methods for preparing chemically well-defined stock solutions for toxicological studies; (8) incorporate more detailed speciation data into studies on Al toxicity and pharmacokinetics; and (9) incorporate more detailed speciation data into future epidemiological studies on the relationship between Al toxicity and various water quality parameters.},
	keywords = {ALZHEIMERS-DISEASE, DIETARY CONSTITUENTS, DRINKING-WATER, GASTROINTESTINAL ABSORPTION, HUMAN-SERUM TRANSFERRIN, MURINE, NEUROBLASTOMA-CELLS, POTENTIAL, PROTEIN-BINDING, SIGNIFICANCE INVIVO, SIZE-EXCLUSION CHROMATOGRAPHY, THERAPEUTIC CHELATING-AGENTS},
	isbn = {0098-4108},
	url = {<Go to ISI>://A1996VE14400005},
	author = {Harris, W. R. and Berthon, G. and Day, J. P. and Exley, C. and Flaten, T. P. and Forbes, W. F. and Kiss, T. and Orvig, Chris and Zatta, P. F.}
}
