Quinine and chloroquine differentially perturb heme monomer-dimer equilibrium.
Nuclear magnetic resonance (NMR) measurements of magnetic susceptibility have been utilized to study the equilibrium between two forms (high-spin monomer vs the antiferromagnetically coupled mu-oxo dimer) of ferriprotoporphyrin(IX) as a function of pH. The pH dependence of this equilibrium is significantly altered by the addition of either chloroquine or quinine. Chloroquine promotes the mu-oxo dimer whereas quinine promotes the monomer.
Casabianca
Leah B
LB
Department of Chemistry, Georgetown University, 37th and O Streets, NW, Washington, DC 20057, USA.
An
David
D
Natarajan
Jayakumar K
JK
Alumasa
John N
JN
Roepe
Paul D
PD
Wolf
Christian
C
de Dios
Angel C
AC
D002738:Chloroquine; D019281:Dimerization; D006418:Heme / Q000737:chemistry*; D006427:Hemin / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D011803:Quinine
D006418:Heme; D006427:Hemin; D002738:Chloroquine; D011803:Quinine