Linked Life Data

10764735

Source:http://linkedlifedata.com/resource/pubmed/id/10764735

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
2000-8-16
pubmed:abstractText
The two mannose 6-phosphate (Man-6-P) binding domains of the insulin-like growth factor II/mannose 6-phosphate receptor (Man-6-P/IGF2R), located in extracytoplasmic repeats 1-3 and 7-9, are capable of binding Man-6-P with low affinity and glycoproteins that contain more than one Man-6-P residue with high affinity. High affinity multivalent ligand binding sites could be formed through two possible mechanisms: the interaction of two Man-6-P binding domains within one Man-6-P/IGF2R molecule or by receptor oligomerization. To discriminate between these mechanisms, truncated FLAG epitope-tagged Man-6-P/IGF2R constructs, containing one or both of the Man-6-P binding domains, were expressed in 293T cells, and characterized for binding of pentamannose phosphate-bovine serum albumin (PMP-BSA), a pseudoglycoprotein bearing multiple Man-6-P residues. A construct containing all 15 repeats of the Man-6-P/IGF2R extracytoplasmic domain bound PMP-BSA with the same affinity as the full-length receptor (K(d) = 0.54 nm) with a curvilinear Scatchard plot. The presence of excess unlabeled PMP-BSA increased the dissociation rate of pre-formed (125)I-PMP-BSA/receptor complexes, suggesting negative cooperativity in multivalent ligand binding and affirming the role of multiple Man-6-P/IGF2R binding domains in forming high affinity binding sites. Truncated receptors containing only one Man-6-P binding domain and mutant receptor constructs, containing an Arg(1325) --> Ala mutation that eliminates binding to the repeats 7-9 binding domain, formed high affinity PMP-BSA binding, but with reduced stoichiometries. Collectively, these observations suggest that alignment of Man-6-P binding domains of separate Man-6-P/IGF2R molecules is responsible for the formation of high affinity Man-6-P binding sites and provide functional evidence for Man-6-P/IGF2R oligomerization.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18638-46
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Mechanisms for high affinity mannose 6-phosphate ligand binding to the insulin-like growth factor II/mannose 6-phosphate receptor.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68198-4525, USA. rgmacdon@unmc.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't