INVESTIGADORES
CORREA Nestor Mariano
artículos
Título:
A kinetic study of the photodynamic effect on tryptophan methyl ester and tryptophan octyl ester in DOPC vesicles
Autor/es:
POSADAZ A.; CORREA N.M.; BIASUTTI M. A.; GARCIA N. A.
Revista:
PHOTOCHEMISTRY AND PHOTOBIOLOGY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2010 vol. 86 p. 96 - 103
ISSN:
0031-8655
Resumen:
The photodynamic effect on tryptophan methyl ester (trpME)
and tryptophan octyl ester (trpOE), using the O2(1Dg)-photosensitizers
Rose Bengal (RB) and Perinaphthenone (PN) has
been studied in large unilamellar vesicles (LUVs) of the phospholipid
1,2-di-oleoyl-sn-glycero-3-phosphatidylcholine (DOPC)
by stationary photolysis and time-resolved methods. This work
reports on the influence of both the site (O2(1Dg)) generation and
the location of the tryptophan derivatives (trpD), on the
photo-oxidation process in a compartmentalized system. The
apparent rate constant values for chemical quenching of O2(1Dg)
by trpOE (kr,app), was higher in vesicles than in water. Also, the
ratio between apparent reactive and overall rate constant values
for the deactivation of O2(1Dg) (kr,app ⁄ kt,app), increases in
vesicles as compared with water, when the oxidative species is
generated in the lipidic region or at the interface. Nevertheless,
this quotient is lower than the corresponding value in water when
O2(1Dg) is generated in the aqueous pseudophase. For trpME,
the kr,app ⁄ kt,app values in vesicles and in water are quite similar,
confirming the fact that trpME is located in the water
pseudophase. Results are discussed in terms of relative protection
against O2(1Dg) attack in a microheterogeneous medium as
compared with water.2(1Dg)-photosensitizers
Rose Bengal (RB) and Perinaphthenone (PN) has
been studied in large unilamellar vesicles (LUVs) of the phospholipid
1,2-di-oleoyl-sn-glycero-3-phosphatidylcholine (DOPC)
by stationary photolysis and time-resolved methods. This work
reports on the influence of both the site (O2(1Dg)) generation and
the location of the tryptophan derivatives (trpD), on the
photo-oxidation process in a compartmentalized system. The
apparent rate constant values for chemical quenching of O2(1Dg)
by trpOE (kr,app), was higher in vesicles than in water. Also, the
ratio between apparent reactive and overall rate constant values
for the deactivation of O2(1Dg) (kr,app ⁄ kt,app), increases in
vesicles as compared with water, when the oxidative species is
generated in the lipidic region or at the interface. Nevertheless,
this quotient is lower than the corresponding value in water when
O2(1Dg) is generated in the aqueous pseudophase. For trpME,
the kr,app ⁄ kt,app values in vesicles and in water are quite similar,
confirming the fact that trpME is located in the water
pseudophase. Results are discussed in terms of relative protection
against O2(1Dg) attack in a microheterogeneous medium as
compared with water.2(1Dg)) generation and
the location of the tryptophan derivatives (trpD), on the
photo-oxidation process in a compartmentalized system. The
apparent rate constant values for chemical quenching of O2(1Dg)
by trpOE (kr,app), was higher in vesicles than in water. Also, the
ratio between apparent reactive and overall rate constant values
for the deactivation of O2(1Dg) (kr,app ⁄ kt,app), increases in
vesicles as compared with water, when the oxidative species is
generated in the lipidic region or at the interface. Nevertheless,
this quotient is lower than the corresponding value in water when
O2(1Dg) is generated in the aqueous pseudophase. For trpME,
the kr,app ⁄ kt,app values in vesicles and in water are quite similar,
confirming the fact that trpME is located in the water
pseudophase. Results are discussed in terms of relative protection
against O2(1Dg) attack in a microheterogeneous medium as
compared with water.2(1Dg)
by trpOE (kr,app), was higher in vesicles than in water. Also, the
ratio between apparent reactive and overall rate constant values
for the deactivation of O2(1Dg) (kr,app ⁄ kt,app), increases in
vesicles as compared with water, when the oxidative species is
generated in the lipidic region or at the interface. Nevertheless,
this quotient is lower than the corresponding value in water when
O2(1Dg) is generated in the aqueous pseudophase. For trpME,
the kr,app ⁄ kt,app values in vesicles and in water are quite similar,
confirming the fact that trpME is located in the water
pseudophase. Results are discussed in terms of relative protection
against O2(1Dg) attack in a microheterogeneous medium as
compared with water.kr,app), was higher in vesicles than in water. Also, the
ratio between apparent reactive and overall rate constant values
for the deactivation of O2(1Dg) (kr,app ⁄ kt,app), increases in
vesicles as compared with water, when the oxidative species is
generated in the lipidic region or at the interface. Nevertheless,
this quotient is lower than the corresponding value in water when
O2(1Dg) is generated in the aqueous pseudophase. For trpME,
the kr,app ⁄ kt,app values in vesicles and in water are quite similar,
confirming the fact that trpME is located in the water
pseudophase. Results are discussed in terms of relative protection
against O2(1Dg) attack in a microheterogeneous medium as
compared with water.2(1Dg) (kr,app ⁄ kt,app), increases in
vesicles as compared with water, when the oxidative species is
generated in the lipidic region or at the interface. Nevertheless,
this quotient is lower than the corresponding value in water when
O2(1Dg) is generated in the aqueous pseudophase. For trpME,
the kr,app ⁄ kt,app values in vesicles and in water are quite similar,
confirming the fact that trpME is located in the water
pseudophase. Results are discussed in terms of relative protection
against O2(1Dg) attack in a microheterogeneous medium as
compared with water.2(1Dg) is generated in the aqueous pseudophase. For trpME,
the kr,app ⁄ kt,app values in vesicles and in water are quite similar,
confirming the fact that trpME is located in the water
pseudophase. Results are discussed in terms of relative protection
against O2(1Dg) attack in a microheterogeneous medium as
compared with water.kr,app ⁄ kt,app values in vesicles and in water are quite similar,
confirming the fact that trpME is located in the water
pseudophase. Results are discussed in terms of relative protection
against O2(1Dg) attack in a microheterogeneous medium as
compared with water.2(1Dg) attack in a microheterogeneous medium as
compared with water.