Journal
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY
Volume 102, Issue 1, Pages 1-10Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.jphotobiol.2010.08.010
Keywords
beta-Lactoglobulin; Fluorescence resonance energy transfer; ANS; Lifetime decay; Acetylation; Succinylation
Categories
Funding
- UGC-CAS (Govt. of INDIA) of Jadavpur University, Kolkata
- CSIR
Ask authors/readers for more resources
In accordance with the recent reports by Ng et al. (2001) [12] and Pellengrini et al. (2001) [13], that acetylated and succinylated beta-lg has a potent HIV-I and HIV-II type enzyme inhibitory activity, a spectro-fluoremetric approach has been made to understand the mode of interactions playing the key role in inhibition process. In this article, interactions between lysine modified bovine beta-lactoglobulin (beta-lg) and a hydrophobic fluorescence probe, 1-anilinonapthalene-8-sulfonate (ANS), have been studied with the help of fluorescence resonance energy transfer (FRET) process. Lysine residues of beta-lg were modified by acetylation and succinylation. Tryptophan-19 of intact beta-lg efficiently transfers energy to ANS, whereas in derivatives, it unexpectedly failed to promote energy transfer in spite of being more solvent exposed with an appreciable overlap integral. Efficient fluorescence resonance energy transfer (FRET) is a consequence of good overlap between emission and absorption spectra of donor and acceptor respectively. Therefore, linearity of this relationship becomes questionable in case of modified bio-molecules. Furthermore, time resolved studies showed that in the derivatives, hydrophobic cavities of beta-lg were collapsed so that ANS failed to recognize the deep interior pockets leading to the loss of longer lifetime component. Modifications also prohibited the ionic association through surface leading to the loss of shorter lifetime component. Hence, chemical modification destabilizes beta-lg conformations that affect FRET and interactions are strictly electrostatic. (C) 2010 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available