Modulation of the Binding Affinity of Myelopoietins for the Interleukin-3 Receptor by the Granulocyte Colony-Stimulating Factor Receptor Agonist
| Autor: | Yatin R. Gokarn, Edward E. Remsen, Yiqing G. Feng, Joseph B. Monahan, Cindy Jarvis, Roger J. Schilling, Barbara K. Klein, William F. Hood, Joseph K. Welply, Jeng-Jong J. Shieh, John P. Mckearn, William D. Joy, Joseph O. Polazzi |
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| Rok vydání: | 2001 |
| Předmět: |
Agonist
Magnetic Resonance Spectroscopy Light medicine.drug_class Recombinant Fusion Proteins Hematopoietic Cell Growth Factors Binding Competitive Biochemistry Beta-1 adrenergic receptor Granulocyte Colony-Stimulating Factor Tumor Cells Cultured medicine Enzyme-linked receptor Humans 5-HT5A receptor Protease-activated receptor 2 Chemistry Circular Dichroism Molecular biology Peptide Fragments Receptors Interleukin-3 Recombinant Proteins Kinetics Competitive antagonist Interleukin-21 receptor Mutation Receptors Granulocyte Colony-Stimulating Factor Chromatography Gel Biophysics Interleukin-3 Interleukin 1 receptor type I |
| Zdroj: | Biochemistry. 40:13598-13606 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi010590t |
| Popis: | Myelopoietins (MPOs) are a family of recombinant chimeric proteins that are both interleukin-3 (IL-3) receptor and granulocyte colony-stimulating factor (G-CSF) receptor agonists. In this study, MPO molecules containing one of three different IL-3 receptor agonists linked with a common G-CSF receptor agonist have been examined for their IL-3 receptor binding characteristics. Binding to the alpha-subunit of the IL-3 receptor revealed that the affinity of the MPO molecules was 1.7-3.4-fold less potent than those of their individual cognate IL-3 receptor agonists. The affinity decrease was reflected in the MPO chimeras having approximately 2-fold slower dissociation rates and 2.7-5.5-fold slower association rates than the corresponding specific IL-3 receptor agonists alone. The affinity of binding of the MPO molecules to the heteromultimeric alphabeta IL-3 receptor expressed on TF-1 cells was either 3-, 10-, or 42-fold less potent than that of the individual cognate IL-3 receptor agonist. Biophysical data from nuclear magnetic resonance, near-UV circular dichroism, dynamic light scattering, analytical ultracentrifugation, and size exclusion chromatography experiments determined that there were significant tertiary structural differences between the MPO molecules. These structural differences suggested that the IL-3 and G-CSF receptor agonist domains within the MPO chimera may perturb one another to varying degrees. Thus, the differential modulation of affinity observed in IL-3 receptor binding may be a direct result of the magnitude of these interdomain interactions. |
| Databáze: | OpenAIRE |
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