Lead-binding proteins - a way to understand lead toxicity?

Abstract

espite the vast liter ature on lead toxicity [1], little is known about the biochemical mechanisms responsible for the toxicity of lead and other metals. The general assumption is that lead interacts with the function of enzymes, signal systems and membranes, probably by binding to certain sites of proteins. Recent studies in the labor atory in Lund have shown a remarka ble specificity for the binding of lead to certain red blood cell proteins, such as δaminolevulinic acid dehydratase (ALAD) [2]. This binding causes inhibition of the enzymatic activity. The inhibition of ALAD activity by lead has been known since the 1960s, but there are also other, as yet unidentified, lead-binding proteins. By identifying the proteins prone to bind lead , we may be able to understand lead toxicity better; identify enzymatic or other biological processes affected; find markers of lead exposure and effects; identify individuals especially sensiti ve to the metal; figure out candidates for antidotes; and under stand how lead is transported within the cell and in the bod y. The same principle should hold true for other toxic metals as well.