Binding energetics of the inhibitor cystatin to the cysteine proteinase actinidin.
The binding energetics of actinidin to chicken cystatin was determined from fluorometric titrations at different temperatures. It is shown that the association of actinidin with cystatin is both enthalpically and entropically driven, with a negative change in the heat capacity. The molecular basis of these contributions are analyzed within the framework of surface-area models, using a 3D model of the actinidin-cystatin complex, which was obtained using the x-ray structure of the homologous complex papain-stefin B as template.
Neria-Ríos
Maricela
M
Departamento de Química, Universidad Autónoma Metropolitana Iztapalapa, AP 55-534, México DF, México 09340.
Padilla-Zúñiga
Jaqueline
J
Garcia-Hernández
Enrique
E
Tello-Solís
Salvador R
SR
Zubillaga
Rafael A
RA
D029042:Actinidia / Q000378:metabolism; D000818:Animals; D002645:Chickens / Q000378:metabolism; D015891:Cystatins / Q000378:metabolism*; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000378:metabolism; D007700:Kinetics
D015891:Cystatins; D015853:Cysteine Proteinase Inhibitors; D003546:Cysteine Endopeptidases; C018745:actinidain