RCSB PDB - 4Q8Y: Crystal structure of 2-hydroxyisoquinoline-1(2H)-thione bound to human carbonic anhydrase II (original) (raw)
Exploring the influence of the protein environment on metal-binding pharmacophores.
[Martin, D.P.](/search?q=citation.rcsb%5Fauthors:Martin, D.P.), [Blachly, P.G.](/search?q=citation.rcsb%5Fauthors:Blachly, P.G.), [McCammon, J.A.](/search?q=citation.rcsb%5Fauthors:McCammon, J.A.), [Cohen, S.M.](/search?q=citation.rcsb%5Fauthors:Cohen, S.M.)
(2014) J Med Chem 57: 7126-7135
PubMed Abstract:
The binding of a series of metal-binding pharmacophores (MBPs) related to the ligand 1-hydroxypyridine-2-(1H)-thione (1,2-HOPTO) in the active site of human carbonic anhydrase II (hCAII) has been investigated. The presence and/or position of a single methyl substituent drastically alters inhibitor potency and can result in coordination modes not observed in small-molecule model complexes. It is shown that this unexpected binding mode is the result of a steric clash between the methyl group and a highly ordered water network in the active site that is further stabilized by the formation of a hydrogen bond and favorable hydrophobic contacts. The affinity of MBPs is dependent on a large number of factors including donor atom identity, orientation, electrostatics, and van der Waals interactions. These results suggest that metal coordination by metalloenzyme inhibitors is a malleable interaction and that it is thus more appropriate to consider the metal-binding motif of these inhibitors as a pharmacophore rather than a "chelator". The rational design of inhibitors targeting metalloenzymes will benefit greatly from a deeper understanding of the interplay between the variety of forces governing the binding of MBPs to active site metal ions.
Organizational Affiliation:
Departments of Chemistry and Biochemistry, ‡Pharmacology, and §Howard Hughes Medical Institute, University of California, San Diego , 9500 Gilman Drive, MC 0358, La Jolla, California 92093, United States.