A Th ermodyn amic Study on the Binding of Huma n Serum Albumin with Beta Cyclodextrin

The application of isothermal titration calorimetry method and fluorescence spectru m, UV-visible spectrum t o determining the pro perties effe ct of BetaCyclodextrin (β-CD) on human serum albumin (HAS) is described in this pa per. Our measureme nts provide useful informa tion about the binding of β-CD to human se rum albumin (HSA) that is important for potenti al clinical applications of this agent. Binding properties of β-CD is the subjec t of this paper. Variations of UV-Vis spectrum and fluore scence spec trum of HAS can help us to investig ate the changes that ar e created i n protein str ucture. It w as shown that β-CD h as quite a strong ability to quench t he fluorescence launching from HSA by re acting with it and formin g a certain k ind of new compound.The thermodynam ics of the interaction between β-CD with HAS, host-guest S tructure complex, in the presence of β-CD (۳۵.۲۴۲ mM) was investigated at pH ۷ by iso thermal titration calorimetry. A new solvation m odel was used to reproduce the enthalpies of HSA interaction β-CD within a broad range of comple x concentration in the presence of β-CD (۳۵.۲۴۲ mM). The solvation parameters attained from the ne w model was attributed to the structural change and biolo gical activity of HSA. From the binding parameters for the interaction of β-CD and HS A suggeste d that electrostatic interaction w as the predominant intermo lecular forces stabilizing the co mplex. On the other h and in presence of β-CD the binding parameters recovered from the new equation are not a ttributed to a structural change of HSA and its biological activity due to low concen tration β-CD interacti on and vice versa .

کلیدواژه ها:

Human serum albumin ، Cyclodextrins ، Fluorescence ، Isothermal titration calorimetry ، Binding parameters.