Interaction of Myoglobin with Cationic and Nonionic Surfactant in Phosphate Buffer Media
Satyajit Mondal, Maria Luz Raposo, Gerardo Prieto, Soumen Ghosh
Journal of Chemical and Engineering Data
Interaction of myoglobin with cationic surfactants hexadecyltrimethylammonium bromide (HTAB), gemini surfactant 16-2-16 (dimethylene-1,2-bis(hexadecyldimethylammonium bromide)) and nonionic surfactant Mega 10 (N-decanoyl-N-methylglucamine) have been studied in phosphate buffer at pH 7.4 using surface tension, UV–visible, fluorescence, and circular dichroism spectroscopies and differential scanning calorimetry. With increasing concentration of HTAB, metal ion of the heme group changes its spin states; but in case of 16-2-16 and Mega 10, spin change does not occur. Fluorescence spectra clearly denote the unfolding process in HTAB media. With increasing HTAB concentration, α-helicity of myoglobin decreases with the appearance of β-sheet and random coil more rapidly than other two surfactants. Melting temperature of myoglobin is reduced drastically upon interaction with HTAB than their corresponding gemini and nonionic surfactants.
Circular dichroism, Protein folding, Secondary structure, Thermodynamics, Biochemistry