POSTULATED MODE OF ACTION OF METALS ON PURIFIED HUMAN ALA-DEHYDRATASE (EC 4-2-1-24)

  • 1 January 1977
    • journal article
    • research article
    • Vol. 27  (9-10) , 358-361
Abstract
The effects of 12 metals at various concentrations ranging from 10-4-10-7 M were studied on .delta.-aminolevulinic acid dehydratase 9000-fold (ALA-D), isolated and purified from human red cells. Zn, a constitutive element of the enzyme, behaves as an activator at low concentration and an inhibitor at higher concentrations. The same effect is noted with Al, Cd, Hg and Sn. The Mn has a poor inhibitory action. Cu and Pb are powerful inhibitors of the enzyme. The other metals studied had no noticable effect on ALA-D. These results agree with the following hypothesis: according to their structure, metals would bind the enzyme in one or several allosteric sites and induce an allosteric transposition to the active or inactive enzyme form.

This publication has 0 references indexed in Scilit: