No abstract

Patients suffering from myocardial ischemia reportedly exhibit reduced in vitro binding of exogenous Co 21 to the N-terminal of human serum albumin (HSA). The purpose of our investigation was to simulate changes in the N-terminus of HSA that may account for these ischemia-induced modifications to the cobalt binding site. HPLC, LC-MS and 1 H NMR analyses have shown that the N-terminal region of HSA Asp-Ala-His-Lys binds the transition metals Co 21 and Ni 21 . Synthetic peptides with the first 2±12 amino acids of the HSA sequence demonstrated that the first three amino acids, Asp-Ala-His, are essential for strong binding of cobalt. Modification of the N-terminus peptide of HSA by way of N-acetylation or the deletion of one or more amino acid resulted in no binding of cobalt. Because the degradation of the susceptible, specific transition metal binding site of HSA may account for the decreased cobalt binding observed during ischemic events, an assay that detects this reduced binding could be useful in the diagnosis of ischemia.

No abstract

The overall redox potential of a cell is primarily determined by oxidizable/reducible chemical pairs, including glutathione–glutathione disulfide, reduced thioredoxin–oxidized thioredoxin, and NAD+–NADH (and NADP–NADPH). Current methods for evaluating oxidative stress rely on detecting levels of individual byproducts of oxidative damage or by determining the total levels or activity of individual antioxidant enzymes. Oxidation–reduction potential (ORP), on the other hand, is an integrated, comprehensive measure of the balance between total (known and unknown) pro-oxidant and antioxidant components in a biological system. Much emphasis has been placed on the role of oxidative stress in chronic diseases, such as Alzheimer's disease and atherosclerosis. The role of oxidative stress in acute diseases often seen in the emergency room and intensive care unit is considerable. New tools for the rapid, inexpensive measurement of both redox potential and total redox capacity should aid in introducing a new body of literature on the role of oxidative stress in acute illness and how to screen and monitor for potentially beneficial pharmacologic agents.