Coordination chemistry of metals in medicine: target sites for bismuth

Bismuth compounds are used for the treatment of gastrointestinal disorders and may also be useful for the treatment of other diseases. Bi(III) exhibits a highly variable coordination number (3-10) and often an irregular coordination geometry. The coordination chemistry of Bi(III) with carboxylates and aminocarboxylates is dominated by intermolecular interactions which leads to polymeric structures. Bi(III) binds strongly to the thiolate sulfur of the tripeptide glutathione, however these adducts are also kinetically labile which allows rapid translocation of Bi(III) inside cells. The major biological target for Bi(III) appears to be proteins and enzymes; BL(III) binds: to both Zn(II) sites (e.g. metallothionein) and Fe(III) sites (e.g. transferrin and lactoferrin) in proteins and enzymes and inhibits the bacterial Ni enzyme urease. (C) 1999 Elsevier Science S.A. All rights reserved.