Pulse radiolytic study of the oxidation reactions of uric acid in presence of bovine serum albumin. Evidence of possible complex formation in the transient state

The pulse radiolytic and spectrophotometric study of uric acid in presence of bovine serum albumin (BSA) has been carried out. In the spectrophotometric study there is no evidence for ground state interaction between BSA and uric acid. The oxidation reactions of uric acid in presence and absence of BSA employing CCl3OO. and Br-. radicals have been carried out. In a composition of equal concentration of uric acid and BSA, the CCl3OO. and Br-. radicals produce a transient absorption spectrum which show two peaks at 330 and 360 nm. The peak at 360 nm is ascribed due to weak complex formation between semioxidised BSA and uric acid radicals. The rate constant of CCl3OO. radical with uric acid increases with the increase in BSA concentration which is explained as protection of BSA by uric acid from radical attack. The Br-. radical attacks uric acid and BSA in a manner similar to CCl3OO. radical. The bimolecular rate constants for the reaction of Br radical with BSA and uric acid have been found as 2.9 x 10(10) dm(3) mol(-1) s(-1) and 6.33 x 10(9) dm(3) mol(-1) s(-1), respectively. Copyright (C) 1997 Elsevier Science Ltd