Open AccessX‐Ray Investigation of the Binding of 1,10‐Phenanthroline and Imidazole to Horse‐Liver Alcohol Dehydrogenase
Author(s) -
BOIWE Torne,
BRÄNDEN CarlIvar
Publication year - 1977
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1977.tb11655.x
Subject(s) - imidazole , zinc , phenanthroline , alcohol dehydrogenase , crystallography , molecule , chemistry , resolution (logic) , atom (system on chip) , oxidoreductase , electron density , stereochemistry , alcohol , enzyme , electron , physics , biochemistry , organic chemistry , quantum mechanics , artificial intelligence , computer science , embedded system
We have studied the binding of two inhibitor molecules, imidazole and 1,10‐phenanthroline, to liver alcohol dehydrogenase by crystallographic methods. X‐ray data for the imidazole complex were collected to 0.29‐nm resolution and for the 1,10‐phenanthroline complex to 0.45‐nm resolution. In both cases we found only one peak in the difference electron density maps close to the active zinc atom. The peak corresponding to 1,10‐phenanthroline overlaps the site of the density of the zinc‐bound water in the apoenzyme and the imidazole density partly overlaps this density. We can not discern any additional peaks close to the zinc atom which would correspond to new positions of bound water. We thus conclude that both these inhibitors bind to the catalytic zinc atom and that upon binding they displace the water molecule that is firmly bound to this zinc atom in the apoenzyme. We do not see any structural changes in the remaining part of the molecule.