Interaction of singlet oxygen with bovine serum albumin and the role of the protein nano-compartmentalization

RODRIGO E. GIMÉNEZ; VERONIKA VARGOVÁ; VALENTINA REY; M. BEATRIZ ESPECHE TURBAY; INÉS ABATEDAGA; FAUSTINO E. MORÁN VIEYRA; VERÓNICA I. PAZ ZANINI; JUAN H. MECCHIA ORTIZ; NÉSTOR E. KATZ; VERONIKA OSTATNA; CLAUDIO D. BORSARELLI

FREE RADICAL BIOLOGY AND MEDICINE

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2016 vol. 94 p. 99 - 99

0891-5849

inglet molecular oxygen (1O2) contributes to protein damage triggering biophysical and biochemical changes that can be related with aging and oxidative stress. Serum albumins, such as bovine serum albumin (BSA), are abundant proteins in blood plasma with different biological functions. This paper presents a kinetic and spectroscopic study of the 1O2-mediated oxidation of BSA using the tris(2,2′-bipyridine)ruthenium(II) cation [Ru(bpy)3]2þ as sensitizer. BSA quenches efficiently 1O2 with a total (chemicalþphysical interaction) rate constant ktBSA=7.3(+/-0.4) 10(8 )M-1 s-1, where the chemical pathway represented 37% of the interaction. This efficient quenching by BSA indicates the participation of several reactive residues. MALDI-TOF MS analysis of intact BSA confirmed that after oxidation by 1O2, the mass protein increased the equivalent of 13 oxygen atoms. Time-resolved emission spectra analysis of BSA established that Trp residues were oxidized to N′-for