Photophysical Studies on the Interaction of Acridinedione Dyes with Universal Protein Denaturant: Guanidine Hydrochloride
Photophysical studies of photoinduced electron transfer (PET) and non-PET based acridinedione dyes with guanidine hydrochloride (GuHCl) were carried out in water and methanol. Addition of GuHCl to photoinduced electron transfer (PET) based acridinedione dye (ADR 1) results in a fluorescence enhancement, whereas a non-PET based dye (ADR 2) shows no significant change in the fluorescence intensity and lifetime. Addition of GuHCl to ADR 1 dye in methanol results in single exponential decay behaviour, on the contrary a biexponential decay pattern was observed on the addition of GuHCl in water. Absorption and emission spectral studies of ADR 1 dye interaction with GuHCl reveals that the dye molecule is not in the protonated form in aqueous GuHCl solution, and the dye is confined to two distinguishable microenvironment in the aqueous phase. A large variation in the microenvironment around the dye molecule is created on the addition of GuHCl and this was ascertained by time-resolved area normalized emission spectroscopy (TRANES) and time-resolved emission spectroscopy (TRES). The dye molecule prefers to reside in the hydrophobic microenvironment, rather in the hydrophilic aqueous phase is well emphasized by time-resolved fluorescence lifetime studies. The mechanism of fluorescence enhancement of ADR 1 dye by GuHCl is attributed to the suppression of the PET process occuring through space.
KeywordsAcridinedione dyes Guanidine hydrochloride Photoinduced electron transfer Fluorescence enhancement Hydrogen-bonding
Financial support by DST-IRHPA and UGC-INNOVATIVE Programme is acknowledged. R.K thanks the UGC for providing the financial assistance.
- 1.Creighton TE (1992) Protein folding. Freeman, New YorkGoogle Scholar
- 2.Joly M (1965) A physiochemical approach on the denaturation of proteins. Academic, LondonGoogle Scholar
- 3.Michnik A, Sulkowska A (1997) Hydrogen-bonded interactions in alkylurea-and amide-D2O-gunanidine.HCl systems. J Mol Struct 410–411:17–21Google Scholar
- 4.Sato S, Sayid CJ, Raleigh DP (2003) The failure of simple empirical relationships to predict the viscocity of mixed aqueous solution of guanidine hydrochloride and glucose has important implications for the study of protein folding in [In Process Citation]. Protein Sci 9:1601–1603CrossRefGoogle Scholar
- 11.Cox RA (1968) The use of guanidinium chloride in the isolation of nucleic acids. In: Grossman L, Moldave K (eds) Methods in enzymology, vol 12. Academic, New York, pp 120–129Google Scholar
- 21.Kalyanasundaram K (1987) Photochemistry in microheterogeneous system. Academic, New YorkGoogle Scholar
- 22.Lakowicz JR (1999) Principles of fluorescence spectroscopy, 3rd edn. Kluwer Academic/Plenum, New YorkGoogle Scholar
- 25.Stryer L (1995) Biochemistry, 4th edn. Freeman, New YorkGoogle Scholar
- 30.Kumaran R, Ramamurthy P Photophysical studies of PET based acridinedionedyes with globular protein: Bovine Serum Albumin (BSA), Accepted for Publication in J. Luminescence (Lumin0-08-00192)Google Scholar
- 36.Connor DV, Phelps D (1984) Time correlated single photon counting. Academic, LondonGoogle Scholar
- 38.Bankar KV, Bhagat VR, Das R, Doraiswamy S, Ghangrekar AS, Kamat DS, Periasamy N, Srivatsavoy VJP, Venkataraman B (1989) Techniques for the study of fast chemical processes with half-times of the order of microseconds or less Indian. J Appl Phys 27(7–8):416–428Google Scholar
- 46.Gaussian 03 (2004) Revision B.04. Gaussian Inc, Wallingford CTGoogle Scholar