Introduction: Cyanidin a compound found in fruits , is the derivative from flavonoid and flavanone . Due to in antioxidant property , cyanidin may help prevent a variety of free oxygen radical related disease , including cancer and cardiovascular disease. Human serum albumin is the protein that predominates in the blood plasma and is the carrier of several endogenous and exogenous compound. Human transferrin is glycoprotein of about 80 KDa with the characteristic property of requiring the a synergistic anion. In the present study on the interaction of HSA with HTF in the presence of CYA should prove helpful determining
Methods: Fluorescence resonance energy transfer (FRET) is a powerful tool to determine distances between chromophores bound to macromolecules, since the efficiency of the energy transfer from an initially exited donor to an acceptor strongly depends on the distance between the two dye molecules. The three dimensional coordinates of HSA and HTF were obtained from protein data bank (PDB). The structure of CYA was designed and energy minimized using MM method in MOE 2015.
Results: Further elucidating the quenching mechanism of HSA-HTF induced by CYA , the data were analyzed with stern _ volmer equation : F0/F : 1 + Ksv [Q] . Where F0 and F1 are the relative fluorescence intensities in the absence and presence of quencher respectively , [Q] is the quencher concentration , Ksv is the stern _ volmer quenching constant. Ksv values obtained were decreased with increased the temperature .FRET arise when the emission spectrum of donor overlaps with absorption spectrum of acceptor . The distance between the donor and acceptor was calculated to the foster theory .In addition the donor to acceptor distance r<8 nm revealed the static quenching mechanism in the interaction. The experimental observation were followed by docking studies where HSA and HTF was docked to CYA and in both the binary and ternary system to determine the changes in the binding affinity and binding site in the HSA and HTF
Conclusion: This manuscript describes the exploration of the binding of HSA and HTF to CYA by FRET and molecular modelling techniques. The changes of the protein conformation upon binding were determined by FRET and docking .This study proves that HSA and HTF forms complex with CYA , The calculated binding constant suggests a stable and possibly biologically relevant interaction