Thermal stability of matrix protein from Newcastle disease virus

Int J Biol Macromol. 2013 Oct:61:390-5. doi: 10.1016/j.ijbiomac.2013.07.019. Epub 2013 Aug 2.

Abstract

The thermal stability of the matrix protein (M protein) of Newcastle disease virus (NDV) has been investigated using high-sensitivity differential scanning calorimetry (DSC) at pH 7.4. The thermal folding/unfolding of M protein at this pH value is a reversible process involving a highly cooperative transition between folded and unfolded monomers with a transition temperature (Tm) of 63 °C, an unfolding enthalpy, ΔH(Tm), of 340 kcal mol(-1), and the difference in heat capacity between the native and denatured states of the protein, ΔCp, of 5.1 kcal K(-1) mol(-1). The heat capacity of the native state of the protein is in good agreement with the values calculated using a structure-based parameterization, whereas the calculated values for the hypothetical fully-unfolded state of the protein is higher than those determined experimentally. This difference between the heat capacity of denatured M protein and the heat capacity expected for an unstructured polypeptide of the same sequence, together with the data derived from the heat-induced changes in the steady-state fluorescence of the protein, indicates that the polypeptide chain maintains a significant amount of residual structure after thermal denaturation.

Keywords: APS; ASA; DSC; N,N,N′,N′-tetramethyl-ethylenediamine.; NDV; Newcastle disease virus; Newcastle disease virus matrix protein; Structural-based statistical thermodynamic analysis; TEMED; Thermal stability; accessible surface area; ammonium persulfate; differential scanning calorimetry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calorimetry, Differential Scanning
  • Hydrogen-Ion Concentration
  • Newcastle disease virus / chemistry*
  • Protein Stability
  • Thermodynamics
  • Viral Matrix Proteins / chemistry*
  • Viral Matrix Proteins / isolation & purification

Substances

  • Viral Matrix Proteins