TY  - JOUR
A1  - Rosenkranz, Peter
A1  - Schmidt, Hartmut
T1  - On the mechanism of the acridine orange sensitized photodynamic inactivation of lysozyme. I. Basic kinetics
T2  - Zeitschrift für Naturforschung, C
N2  - The kinetics of the photodynamic desactivation of lysozyme in presence of acridine orange as the sensitizer have been investigated in detail varying oxygen, protein, dye concentration, ionic strength and pH value. The kinetics can be approximately described as an over all pseudo-first- order rate process. Changing the solvent from water to D2O or by quenching experiments in pres­ence of azide ions it could be shown that the desactivation of lysozyme is caused exclusively by singlet oxygen. The excited oxygen occurs via the triplet state of the dye with a rate constant considerably lower than that to be expected for a diffusionally controlled reaction. Singlet oxygen reacts chemically (desactivation, k=2.9 × 107 ᴍ-1 sec-1) and physically (quenching process, k = 4.1 × 108 ᴍ-1sec-1) with the enzyme. The kinetical analysis shows that additional chemical reactions between singlet oxygen and lysozyme would have only little influence on the kinetics of the desactivation as long as their products would be enzymatically active and their kinetical constants would be less than about 1 × 108 ᴍ-1 sec-1.
KW  - Photodynamic Effect
KW  - Singlet Oxygen
KW  - Lysozyme
KW  - Acridine Orange
KW  - Kinetics
Y1  - 2014
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/72159
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-721593
SN  - 0939-5075
SN  - 1865-7125
VL  - 31.1976
IS  - 1-2
SP  - 29
EP  - 39
PB  - Verlag der Zeitschrift für Naturforschung
CY  - Tübingen
ER  -