Thermodynamics of target peptide recognition by calmodulin and a calmodulin analogue: implications for the role of the central linker

FEBS Letters

Bhattacharya, Alok¹  Gopal, B.²  Moorthy, Anu K.²  Satish, P.R.²  Bhattacharya, Sudha³  Murthy, M.R.N.²  Surolia, A.² 

[1] School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067, India;Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India;School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110 067, India

关键词: Calmodulin;    Calcium binding protein;    Isothermal titration calorimetry;    Melittin;    Mastoparan;    CAM;    calmodulin;    CaBP;    calcium binding protein;    ITC;    isothermal titration calorimetry;    ANS;    8-anilino-1-naphthalene-sulphonic acid;    MOPS;    3-[N-morpholino]propane-sulphonic acid;    smMLCK;    smooth muscle-myosin light chain kinase;   

DOI  :  10.1016/S0014-5793(99)01380-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The thermodynamics of interaction of two model peptides melittin and mastoparan with bovine brain calmodulin (CAM) and a smaller CAM analogue, a calcium binding protein from Entamoeba histolytica (CaBP) in 10 mM MOPS buffer (pH 7.0) was examined using isothermal titration calorimetry (ITC). These data show that CAM binds to both the peptides and the enthalpy of binding is endothermic for melittin and exothermic for mastoparan at 25°C. CaBP binds to the longer peptide melittin, but does not bind to mastoparan, the binding enthalpy being endothermic in nature. Concurrently, we also observe a larger increase in α-helicity upon the binding of melittin to CAM when compared to CaBP. The role of hydrophobic interactions in the binding process has also been examined using 8-anilino-1-naphthalene-sulphonic acid (ANS) binding monitored by ITC. These results have been employed to rationalize the energetic consequences of the binding reaction.

【 授权许可】

Unknown