Effect of pressure on pulse radiolysis reduction of proteins.
Pulse radiolysis experiments were performed on proteins under pressure. Whereas many spectroscopic techniques have shown protein modifications at different pressure ranges, the present measurements performed using the water radiolysis allowed to generate radical species and to study the mechanisms implied in their reactions with proteins. This work gives the first results obtained on the effects of pressure on the rate constants of the proteins reduction by the hydrated electron at pressures up to 100 MPa. The reaction with the hydrated electron was investigated on two classes of protein: the horse myoglobin and the mussel metallothioneins. We have successively studied the influence of the pH value of metmyoglobin solutions (pH 6, 7 and 8) and the influence of the metals nature (Zn,Cu,Cd) bound to metallothioneins. For both protein, whatever the experimental conditions, the pressure does not influence the value of the reduction rate constant in the investigated range (0.1-100 MPa).
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Laboratoire Claude Fréjacques (URA 331 CEA/CNRS), DSM/DRECAM/Service de Chimie Moléculaire, CEA Saclay, 91191-Gif sur Yvette cedex, France.
Baldacchino
Gérard
G
Cosson
Richard P
RP
Coppo
Michèle
M
Trehen
Catherine
C
Vigneron
Georges
G
Renault
Jean Philippe
JP
Pin
Serge
S
D000818:Animals; D049872:Bivalvia; D017665:Hydroxyl Radical / Q000737:chemistry / Q000378:metabolism; D008668:Metallothionein / Q000737:chemistry* / Q000378:metabolism; D009211:Myoglobin / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D011312:Pressure; D011675:Pulse Radiolysis / Q000295:instrumentation; D013481:Superoxides / Q000737:chemistry / Q000378:metabolism
D009211:Myoglobin; D013481:Superoxides; D017665:Hydroxyl Radical; D008668:Metallothionein