PMID- 20346348
OWN - NLM
STAT- MEDLINE
DCOM- 20100513
LR  - 20131121
IS  - 1090-2104 (Electronic)
IS  - 0006-291X (Linking)
VI  - 394
IP  - 4
DP  - 2010 Apr 16
TI  - Organization and dynamics of tryptophans in the molten globule state of bovine 
      alpha-lactalbumin utilizing wavelength-selective fluorescence approach: 
      comparisons with native and denatured states.
PG  - 1082-6
LID - 10.1016/j.bbrc.2010.03.130 [doi]
AB  - Bovine alpha-lactalbumin (BLA) is known to be present in molten globule form in 
      its apo-state (i.e., Ca(2+) depleted state). We explored the organization and 
      dynamics of the functionally important tryptophan residues of BLA in native, 
      molten globule and denatured states utilizing the wavelength-selective 
      fluorescence approach. We observed red edge excitation shift (REES) of 7 nm for 
      the tryptophans in native BLA. Interestingly, we show here that BLA tryptophans 
      exhibit considerable REES (8 nm) in its molten globule state. Taken together, 
      these results indicate that tryptophan residues in BLA in native as well as 
      molten globule states experience motionally restricted environment. We further 
      show that even the denatured form of BLA exhibits a modest REES of 3 nm, 
      indicating that the tryptophans are shielded from bulk solvent, even when 
      denatured, due to the presence of residual structure around tryptophan(s). This 
      is further supported by wavelength-dependent changes in fluorescence anisotropy 
      and lifetime for BLA tryptophans. These novel results constitute one of the first 
      reports of REES in the molten globule state of proteins, and could provide vital 
      insight into the role of tryptophans in the function of BLA in its molten globule 
      state in particular, and other partially ordered proteins in general.
CI  - 2010 Elsevier Inc. All rights reserved.
FAU - Chaudhuri, Arunima
AU  - Chaudhuri A
AD  - Centre for Cellular and Molecular Biology, Council of Scientific and Industrial 
      Research, Uppal Road, Hyderabad 500 007, India.
FAU - Haldar, Sourav
AU  - Haldar S
FAU - Chattopadhyay, Amitabha
AU  - Chattopadhyay A
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20100324
PL  - United States
TA  - Biochem Biophys Res Commun
JT  - Biochemical and biophysical research communications
JID - 0372516
RN  - 8DUH1N11BX (Tryptophan)
RN  - 9013-90-5 (Lactalbumin)
SB  - IM
MH  - Animals
MH  - Cattle
MH  - Circular Dichroism
MH  - Fluorescence
MH  - Lactalbumin/*chemistry
MH  - Luminescent Measurements
MH  - Protein Denaturation
MH  - Protein Folding
MH  - Tryptophan/*chemistry
EDAT- 2010/03/30 06:00
MHDA- 2010/05/14 06:00
CRDT- 2010/03/30 06:00
PHST- 2010/03/11 00:00 [received]
PHST- 2010/03/20 00:00 [accepted]
PHST- 2010/03/30 06:00 [entrez]
PHST- 2010/03/30 06:00 [pubmed]
PHST- 2010/05/14 06:00 [medline]
AID - S0006-291X(10)00594-2 [pii]
AID - 10.1016/j.bbrc.2010.03.130 [doi]
PST - ppublish
SO  - Biochem Biophys Res Commun. 2010 Apr 16;394(4):1082-6. doi: 
      10.1016/j.bbrc.2010.03.130. Epub 2010 Mar 24.