title: Mutational effect of structural parameters on coiled-coil stability of proteins.
abstract: Understanding the parameters that influence the melting temperature of coiled-coils (CC) and their stability is very important. We have analyzed 45 CC mutants of DNA binding protein, electron transport protein, hydrolase, oxidoreductase, and transcription factors. Many mutants have been observed at Tm = 40 °C-60 °C with ΔS = 9-11 kcal/°C mol, ΔG = -400 to -450 kcal/mol, and Keq = 0.98-1.03. The multiple regression analysis of Tm reveals that influences of thermodynamic parameters are strong (R = 0.97); chemical parameters are moderate (R = 0.63); and the geometrical parameters are negligible (R = 0.19). The combination of all these three parameters exhibits a little higher influence on Tm (R = 0.98). From the analysis, it has been concluded that the thermodynamic parameters alone are very important in stability studies on protein coil mutants. Besides, the derived regression model would have been useful for the reliable prediction of the melting temperature of coil mutants.
authors.affiliation: Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India. ; Department of Biotechnology, Anna University-BIT Campus, Tiruchirappalli, Tamil Nadu, India.
authors.forename: Amutha Selvaraj
authors.initials: AS
authors.lastname: Maheshwari
authors.affiliation: Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India.
authors.forename: Govindaraju
authors.initials: G
authors.lastname: Archunan
keywords: coil propensity; compactness; equilibrium constant; free energy change; melting temperature; solvent accessibility; structural parameters; van’t Hoff enthalpy