A bifunctional molecule that displays context-dependent cellular activity.
The cell-permeable dihydrofolate reductase inhibitor methotrexate was covalently linked to a ligand for the protein FKBP to create a bifunctional molecule called MTXSLF. The covalent tether between the two ligands was designed to be prohibitively short, so that unfavorable protein-protein interactions between DHFR and FKBP preclude formation of a trimeric complex. In vitro and in vivo experiments demonstrate that MTXSLF is an effective inhibitor of human DHFR, but that efficacy is decreased in the presence of human FKBP due to the high concentration of FKBP and its tight affinity for MTXSLF. MTXSLF also inhibits Plasmodium falciparum DHFR in vitro, but a low concentration of the weaker binding Plasmodium FKBP has no effect on the inhibitory potency of MTXSLF in vivo. These studies illustrate a potentially general strategy for modulating the biological activity of synthetic molecules that depends on the ligand-binding properties of a nontarget protein.
Braun
Patrick D
PD
Department of Chemistry, Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
Barglow
Katherine T
KT
Lin
Yun-Ming
YM
Akompong
Thomas
T
Briesewitz
Roger
R
Ray
Gregory T
GT
Haldar
Kasturi
K
Wandless
Thomas J
TJ
D000595:Amino Acid Sequence; D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D002460:Cell Line; D005260:Female; D005493:Folic Acid Antagonists / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D008024:Ligands; D008727:Methotrexate / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D008969:Molecular Sequence Data; D019696:Peptidylprolyl Isomerase; D010963:Plasmodium falciparum / Q000187:drug effects / Q000201:enzymology; D022021:Tacrolimus Binding Proteins / Q000737:chemistry / Q000378:metabolism; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism; D014599:Uterus / Q000166:cytology / Q000187:drug effects
D000962:Antimalarials; D005493:Folic Acid Antagonists; D008024:Ligands; D013762:Tetrahydrofolate Dehydrogenase; D022021:Tacrolimus Binding Proteins; C110054:FKBP10 protein, human; D019696:Peptidylprolyl Isomerase; D008727:Methotrexate