Solution assembly of a soluble, heteromeric, high affinity interleukin-2 receptor complex.
In this study, we report the use of coiled-coil (leucine zipper) molecular recognition for the solution assembly of stable, high affinity, heteromeric interleukin-2 receptor complexes. Co-expression of interleukin-2 receptor alpha and beta extracellular domains (ectodomains), each fused to seven coiled-coil heptad repeats, resulted in the formation of heteromeric complexes that bound interleukin-2 in a cooperative fashion and with much higher affinity than similar homomeric complexes. The dissociation constants for these solution complexes are within the range of values reported for the comparable cell surface "pseudo high affinity" interleukin-2 receptor. Ligand-induced cross-linking of homomeric or heteromeric receptor subunits is the common signal transmission mechanism employed by hematopoietin receptors. Individual receptor ectodomains, however, often do not bind ligand with measurable affinity. This is the first study to demonstrate the feasibility of coiled-coil mediated preassembly of cytokine receptor complexes.
Wu
Z
Z
Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, New Hampshire 03755, USA.
Johnson
K W
KW
Goldstein
B
B
Choi
Y
Y
Eaton
S F
SF
Laue
T M
TM
Ciardelli
T L
TL
D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D002460:Cell Line; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011869:Radioligand Assay; D015375:Receptors, Interleukin-2 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012996:Solutions; D013601:T-Lymphocytes / Q000378:metabolism; D014461:Ultracentrifugation
D007376:Interleukin-2; D010446:Peptide Fragments; D015375:Receptors, Interleukin-2; D011993:Recombinant Fusion Proteins; D012996:Solutions