@article { ISI:000253896400027,
	title = {Steady state and time-resolved fluorescence studies of a hemagglutinin from Moringa oleifera},
	journal = {Journal of Fluorescence},
	volume = {18},
	number = {2},
	year = {2008},
	month = {MAR},
	pages = {479-485},
	publisher = {SPRINGER/PLENUM PUBLISHERS},
	address = {233 SPRING ST, NEW YORK, NY 10013 USA},
	abstract = {<p>The saccharide binding and conformational characterization of a hemagglutinin, a low molecular weight protein from the seeds of Moringa oleifera was studied using steady state and time resolved fluorescence. The lectin binds sugars LacNAc (K-a = 1380 M-1) and fructose (K-a = 975 M-1), as determined by the fluorescence spectroscopy. It has a single tryptophan per monomer which is exposed on the surface and is in a strong electropositive environment as revealed by quenching with iodide. Quenching of the fluorescence by acrylamide involved both static (K-s = 0.216 M-1) and collisional (K-sv= 8.19 M-1) components. The native protein showed two different lifetimes, tau(1) (1.6 ns) and tau(2) (4.36 ns) which decrease and get converted into a single one, (2.21 ns) after quenching with 0.15 M acrylamide. The bimolecular quenching constant, k(q) was 7.55 x 10(11) M-1 s(-1). ANS binding studies showed that the native protein has exposed hydrophobic patches which get further exposed at extreme acidic or alkaline pH. However, they get buried in the interior of the protein in presence of 1 M GdnHCl or urea.</p>},
	keywords = {ANS binding, fluorescence, Hemagglutinin, lifetime, Moringa oleifera, saccharide binding, Solute quenching},
	issn = {1053-0509},
	doi = {10.1007/s10895-007-0289-7},
	author = {Katre, Uma V. and Suresh, C. G. and Khan, Mohammad Islam and Gaikwad, Sushama M.}
}
@article { ISI:000264484400007,
	title = {Comparative studies of two araceous lectins by steady state and time-resolved fluorescence and CD spectroscopy},
	journal = {Journal of Fluorescence},
	volume = {19},
	number = {2},
	year = {2009},
	month = {MAR},
	pages = {239-248},
	publisher = {SPRINGER/PLENUM PUBLISHERS},
	address = {233 SPRING ST, NEW YORK, NY 10013 USA},
	abstract = {<p>Transitions in the tryptophan microenvironment and secondary structure of two monocot lectins from Sauromatum guttatum and Arisaema tortuosum under different denaturing conditions were studied by steady state and time resolved fluorescence and CD spectroscopy. The lectins exist as tetramers with a single tryptophan residue estimated per monomer, present in a polar environment. Quenching with ionic quenchers showed predominantly electropositive environment for tryptophan residues. Acrylamide had maximum quenching effect. A decrease in KI quenching due to lectin denaturation indicated redistribution of charges as a result of possible conformational change. The two values for lifetimes of tryptophanyl population (1.2-1.4 and 6.3-6.4 ns) reduced substantially on quenching or denaturation. Similarly, both the lectins showed a drastic loss of secondary structure in 5 M Gdn-HCl or 6 M Urea or at pH 2.0 and below. For the first time araceous lectins, like legume lectins are shown to bind adenine. The presence of a compact structure at alkaline pH 10.0-12.0 was observed in CD spectra.</p>},
	keywords = {Araceae lectins, Denaturation, fluorescence, Lifetime spectroscopy, Secondary structure},
	issn = {1053-0509},
	doi = {10.1007/s10895-008-0409-z},
	author = {Dharker, Poorva N. and Gaikwad, Sushama M. and Suresh, C. G. and Dhuna, Vikram and Khan, Mohammad Islam and Singh, Jatinder and Kamboj, Sukhdev Singh}
}
