Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
49
pubmed:dateCreated
2002-12-4
pubmed:abstractText
Erythropoietin (EPO) is a cytokine produced by the kidney whose function is to stimulate red blood cell production in the bone marrow. Previously, it was shown that the affinity of EPO for its receptor, EPOR, is inversely related to the sialylation of EPO carbohydrate. To better understand the properties of EPO that modulate its receptor affinity, various glycoforms were analyzed using surface plasmon resonance. The system used has been well characterized and is based on previous reports employing an EPOR-Fc chimera captured on a Protein A surface. Using three variants of EPO containing different levels of sialylation, we determined that sialic acid decreased the association rate constant (k(on)) about 3-fold. Furthermore, glycosylated EPO had a 20-fold slower k(on) than nonglycosylated EPO, indicating that the core carbohydrate also negatively impacted k(on). The effect of electrostatic forces on EPO binding was studied by measuring binding kinetics in varying NaCl concentrations. Increasing NaCl concentration resulted in a slower k(on) while having little impact on k(off), suggesting that long-range electrostatic interactions are primarily important in determining the rate of association between EPO and EPOR. Furthermore, the glycosylation content (i.e., nonglycosylated vs glycosylated, sialylated vs desialylated) affected the overall sensitivities of k(on) to [NaCl], indicating that sialic acid and the glycan itself each impact the overall effect of these electrostatic forces.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14524-31
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Glycosylation of erythropoietin affects receptor binding kinetics: role of electrostatic interactions.
pubmed:affiliation
BioResearch Technologies and Proteins, Lilly Research Laboratories, Eli Lilly and Co., Indianapolis, Indiana 46285, USA.
pubmed:publicationType
Journal Article