PULSE RADIOLYTIC STUDY OF THE OXIDATION REACTIONS OF URIC-ACID IN PRESENCE OF BOVINE SERUM-ALBUMIN - EVIDENCE OF POSSIBLE COMPLEX-FORMATIONIN THE TRANSIENT STATE

The pulse radiolytic and spectrophotometric study of uric acid in pres ence of bovine serum albumin (BSA) has been carried out. In the spectr ophotometric study there is no evidence for ground state interaction b etween BSA and uric acid. The oxidation reactions of uric acid in pres ence 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 spec trum which show two peaks at 330 and 360 nm. The peak at 360 nm is asc ribed due to weak complex formation between semioxidised BSA and uric acid radicals. The rate constant of CCl3OO. radical with uric acid inc reases with the increase in BSA concentration which is explained as pr otection of BSA by uric acid from radical attack. The Br-. radical att acks uric acid and BSA in a manner similar to CCl3OO. radical. The bim olecular rate constants for the reaction of Br radical with BSA and ur ic 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