Marker useful for detection and measurement of free radical damage and method

Abstract

The present invention teaches a marker useful for detection and measurement of free radical damage. Specifically, the invention takes advantage of alterations which occur to the N-terminus of the albumin molecule, a circulating protein in human blood, in the presence of free radicals. These alterations affect the ability of the N-terminus of the albumin molecule to bind metals. Methods for detecting and quantifying this alteration include evaluating and quantifying the cobalt binding capacity of an albumin containing sample, analysis and measurement of the ability of albumin to bind exogenous cobalt, detection and measurement of the presence of copper in a purified albumin sample and use of an immunological assay specific to the altered form of serum albumin which occurs following free radical damage. Also taught by the present invention is the use of the compound Asp-Ala-His-Lys-R (SEQ ID NO:1), wherein R is any chemical group capable of being detected when bound to any compound capable of binding to the N-terminus of naturally occurring albumin (including no additional chemical group), for detection and quantification of the marker. Methods of the present invention also include use of the marker as a 'biochemical tag,' thereby allowing for sensitive detection and measurement of the efficacy of clinical drugs and therapeutics which result in the generation of free radicals, such as Photofrin® (porfimer sodium), or which act to limit free-radical damage. The marker also acts as a 'biological tag' of a process implicated in a wide array of diseases and sequelae and, accordingly, may be used to test for the occurrence or non-occurrence of such diseases and sequelae. One such disease is ischemia.