Differential scanning calorimetry of the irreversible thermal denaturation of cellulase from Streptomyces halstedii JM8.
High-sensitivity differential scanning calorimetry has been applied to characterize the irreversible thermal denaturation of a cellulase, 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 the native state, and D the denatured one. On the basis of this model, the values of the rate constant as a function of temperature and the activation energy were calculated. The analytical data obtained with the fluorescence method as well by measurement of the enzymatic activity temperature dependence support this two-state kinetic model.
Garda-Salas
A L
AL
Instituto de Microbiologia Bioquimica, Consejo Superior de Investigaciones Cientificas - Universidad de Salamanca, Spain.
Santamaria
R I
RI
Marcos
M J
MJ
Zhadan
G G
GG
Villar
E
E
Shnyrov
V L
VL
D002152:Calorimetry, Differential Scanning; D002266:Carboxymethylcellulose Sodium / Q000378:metabolism; D002480:Cellulase / Q000737:chemistry* / Q000378:metabolism; D005453:Fluorescence; D005947:Glucose / Q000032:analysis / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011489:Protein Denaturation; D013302:Streptomyces / Q000201:enzymology*; D013696:Temperature; D013816:Thermodynamics
D002480:Cellulase; D005947:Glucose; D002266:Carboxymethylcellulose Sodium