@article { ISI:000271552400019,
	title = {Conformational characterization of human eukaryotic initiation factor 2 alpha: a single tryptophan protein},
	journal = {Biochemical and Biophysical Research Communications},
	volume = {390},
	number = {2},
	year = {2009},
	month = {DEC},
	pages = {273-279},
	publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE},
	address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA},
	abstract = {<p>The alpha-subunit of the human eukaryotic initiation factor 2 (heIF2 alpha), a GTP binding protein, plays a major role in the initiation of protein synthesis. During various cytoplasmic stresses, eIF2 alpha gets phosphorylated by eIF2 alpha-specific kinases resulting in inhibition of protein synthesis. The cloned and over expressed heIF2 alpha, a protein with a single tryptophan (trp) residue was examined for its conformational characteristics using steady-state and time-resolved tryptophan fluorescence, circular dichroism (CD) and hydrophobic dye binding. The steady-state fluorescence spectrum, fluorescence lifetimes (tau(1) = 1.13 ns and tau(2) = 4.74 ns) and solute quenching studies revealed the presence of trp conformers in hydrophobic and differential polar environment at any given time. Estimation of the alpha-helix and beta-sheet content showed: (i) more compact structure at pH 2.0, (ii) distorted alpha-helix and rearranged beta-sheet in presence of 4 M guanidine hydrochloride and (iii) retention of more than 50\% ordered structure at 95 degrees C. Hydrophobic dye binding to the protein with loosened tertiary structure was observed at pH 2.0 indicating the existence of a molten globule-like structure. These observations indicate the inherent structural stability of the protein under various denaturing conditions. (C) 2009 Elsevier Inc. All rights reserved.</p>},
	keywords = {Circular dichroism, heIF2 alpha, K562 cells, Molten globule, Steady-state and time-resolved fluorescence},
	issn = {0006-291X},
	doi = {10.1016/j.bbrc.2009.09.106},
	author = {Sreejith, R. K. and Yadav, Viveka Nand and Varshney, Nishant K. and Berwal, Sunil K. and Suresh, C. G. and Gaikwad, Sushama M. and Pal, Jayanta K.}
}
