TY - JOUR
T1 - Binding and fluorescence resonance energy transfer (FRET) of ruthenium(II)-bipyridine-calixarene system with proteins-experimental and docking studies
AU - Mareeswaran, P. Muthu
AU - Maheshwaran, D.
AU - Babu, E.
AU - Rajagopal, S.
N1 - Funding Information:
Acknowledgement We thank Prof. P. Ramamurthy, National Centre for Ultrafast Processes, University of Madras, Taramani, Chennai for his help in excited state lifetime studies. We thank Prof. S. Krishnasamy, School of Biotechnology, Madurai Kamaraj University for his help in the docking studies. We thank UGC-UPE for financial support. We thank Dr. M. Vairamani, IICT, Hyderabad for his help in taking HR-MS.
PY - 2012/9/1
Y1 - 2012/9/1
N2 - The investigation of the interaction of ruthenium (II)-bipyridine-tert- butylcalix[4]arene complexes (Rubc2 and Rubc3) with proteins (BSA and ovalbumin) using absorption, emission, excited state lifetime and circular dichroism techniques and by docking studies show that luminophore-receptor system bind strongly with proteins. An enhancement of absorption as well as emission intensity of Ru(II)-calixarene complexes in the presence of proteins, but the quenching of the emission intensity of proteins in the presence of Ru(II)-calixarene complexes are the interesting observations. The enhancement of emission intensity of Ru (II)-calixarene complex, in the presence of proteins, is due to the fluorescence resonance energy transfer (FRET) from protein to Ru(II)-calixarene complex. Among the two Ru (II)-calixarene complexes synthesized Rubc3 has more efficient binding and energy transfer than Rubc2 and BSA, with a large cavity size, has the advantage for binding over ovalbumin. Docking studies reveal that the presence of tertbutylcalix[ 4]arene moiety in Ru(II)-calixarene complexes facilitates binding with proteins. After the binding of Rubc2 and Rubc3 with proteins, the nearby fluorophores present in proteins are in optimal distance from the ruthenium centre for efficient FRET process to occur.
AB - The investigation of the interaction of ruthenium (II)-bipyridine-tert- butylcalix[4]arene complexes (Rubc2 and Rubc3) with proteins (BSA and ovalbumin) using absorption, emission, excited state lifetime and circular dichroism techniques and by docking studies show that luminophore-receptor system bind strongly with proteins. An enhancement of absorption as well as emission intensity of Ru(II)-calixarene complexes in the presence of proteins, but the quenching of the emission intensity of proteins in the presence of Ru(II)-calixarene complexes are the interesting observations. The enhancement of emission intensity of Ru (II)-calixarene complex, in the presence of proteins, is due to the fluorescence resonance energy transfer (FRET) from protein to Ru(II)-calixarene complex. Among the two Ru (II)-calixarene complexes synthesized Rubc3 has more efficient binding and energy transfer than Rubc2 and BSA, with a large cavity size, has the advantage for binding over ovalbumin. Docking studies reveal that the presence of tertbutylcalix[ 4]arene moiety in Ru(II)-calixarene complexes facilitates binding with proteins. After the binding of Rubc2 and Rubc3 with proteins, the nearby fluorophores present in proteins are in optimal distance from the ruthenium centre for efficient FRET process to occur.
KW - BSA
KW - Docking studies
KW - FRET
KW - Ovabumin
KW - Ruthenium(II)-bipyridine-calixarene complexes
UR - http://www.scopus.com/inward/record.url?scp=84865203007&partnerID=8YFLogxK
U2 - 10.1007/s10895-012-1074-9
DO - 10.1007/s10895-012-1074-9
M3 - Article
C2 - 22699809
AN - SCOPUS:84865203007
SN - 1053-0509
VL - 22
SP - 1345
EP - 1356
JO - Journal of Fluorescence
JF - Journal of Fluorescence
IS - 5
ER -