A differential scanning calorimetric study of Newcastle disease virus: identification of proteins involved in thermal transitions.
The irreversible thermal denaturation of Newcastle disease virus was investigated using different techniques including high-sensitivity differential scanning calorimetry, thermal gel analysis intrinsic fluorescence, and neuraminidase activity assays. Application of a successive annealing procedure to the scanning calorimetric endotherm of Newcastle disease virus furnished four elementary thermal transitions below the overall endotherm; these were further identified as coming from the denaturation of each viral protein. The shape of these transitions, as well as their scanrate dependence, was explained by assuming that thermal denaturation takes place according to the kinetic scheme N-->(k)D, where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation; N is the native state; and D is the denatured state. On the basis of this model, activation energy values were calculated. The data obtained with the other methods used in this work support the proposed two-state kinetic model.
Shnyrov
V L
VL
Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Spain.
Zhadan
G G
GG
Cobaleda
C
C
Sagrera
A
A
Muñoz-Barroso
I
I
Villar
E
E
D002152:Calorimetry, Differential Scanning; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D009439:Neuraminidase / Q000378:metabolism; D009522:Newcastle disease virus / Q000737:chemistry* / Q000502:physiology; D011489:Protein Denaturation; D013050:Spectrometry, Fluorescence; D013696:Temperature; D013816:Thermodynamics; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism
D014759:Viral Envelope Proteins; D014764:Viral Proteins; D009439:Neuraminidase