R. Joshi et al., REDUCTION REACTIONS OF BOVINE SERUM-ALBUMIN AND LYSOZYME BY CO2- RADICAL IN POLYVINYL-ALCOHOL SOLUTION - A PULSE-RADIOLYSIS STUDY, Radiation physics and chemistry (1993), 53(2), 1998, pp. 171-176
Citations number
18
Categorie Soggetti
Nuclear Sciences & Tecnology","Chemistry Physical","Physics, Atomic, Molecular & Chemical
Pulse radiolytic reduction of bovine serum albumin (BSA) and lysozyme
by CO(2)radical anion radical in presence of polyvinyl alcohol (PVA)ha
s been studied. At pH 6.8 in presence of 2% (w/v) PVA, reduction of BS
A and lysozyme (both at 1 x 10(-4) mol dm(-3)) give an additional tran
sient peak at 390 nm along with the usual 420 nm peak. The bimolecular
rate constants for the reaction of CO(2)radical anion radical at pH 6
.8 +/- 0.2 with BSA are 2.7 x 10(8) and 7.13 x 10(8) dm(3) mol(-1) s(-
1) at 420 rim and 390 nm respectively. The same for lysozyme are 3.2 x
10(8) and 5.6 x 10(8) dm(3) mol(-1) s(-1) at 420 nm and 390 nm, respe
ctively. Dimethyl disulfide also gives 390 nm and 420 nm peaks in this
System upon reduction with CO(2)radical anion radical. The 390 nm pea
k is ascribed to the sulfenium radical (RSS(H)R), Studies on the varia
tion of pH suggests the protonation of RSSR- radical (420 nm) to form
RSS(H)R-. radical (390 nm) in this viscous media. The decay of RSS(H)R
-. radical occurs via formation of RS' radical and RS(H)S(H)R;;the fin
al product being RSH in both cases: (C) 1998 Elsevier Science Ltd. All
rights reserved.