Linked Life Data

8580082

Source:http://linkedlifedata.com/resource/pubmed/id/8580082

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1996-3-18
pubmed:abstractText
Studies on the binding of IL-2 to its receptor (IL-2R) have generally been limited to receptors expressed on cell surfaces. This has hampered detailed kinetic and mechanistic studies at the molecular level. We have prepared the soluble extracellular domains of all three receptor subunits (called alpha, beta and gamma) by recombinant techniques and have used these to perform detailed kinetic studies of their binding properties using the technique of surface plasmon resonance. We describe a novel approach whereby the receptors are assembled on an antibody surface, being held by an epitope engineered into the C-terminus of each of these domains. Thus the receptors are oriented naturally leading to homogeneous ligand binding kinetics. We have characterized the interactions of the heteromeric complexes of these subunits with mouse and human IL-2 and their analogs, as well as the recently discovered cytokine, IL-15. We have also studied the extracellular domains of the mouse receptor subunits for the first time and have used these as well as mouse-human hybrid receptors to probe the mechanism of assembly of these complexes. We show that no additional proteins are required to reproduce the properties of these complexes in vitro. In addition, kinetic studies with site-specific analogs of IL-2 and the mouse-human receptor hybrids clearly indicate that the extracellular domains of alpha and beta can together readily bind ligand with kinetic properties distinct from those of the constituent subunits. In contrast, a complex containing ligand and the extracellular domains of beta and gamma was comparatively difficult to assemble and required prolonged exposure to IL-2. Our method enabled us to calculate the stoichiometry of these complexes and to determine that anchoring these subunits is necessary to efficiently drive complex formation. The kinetic and equilibrium differences between the mouse and human receptor complexes, and between IL-2 and IL-15 binding to these receptors clarify the roles of the alpha and gamma subunits in the differential response of cells to different cytokines that may be present simultaneously in the environment.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0953-8178
pubmed:author
pubmed:issnType
Print
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1839-49
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Ligand binding kinetics of IL-2 and IL-15 to heteromers formed by extracellular domains of the three IL-2 receptor subunits.
pubmed:affiliation
DNAX Research Institute, Palo Alto, CA 94304-1104, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't