Linked Life Data

6323494

Source:http://linkedlifedata.com/resource/pubmed/id/6323494

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1984-5-11
pubmed:abstractText
In a previous report we demonstrated that phosphorylated oligosaccharides isolated from acid hydrolases were subject to pinocytosis by phosphomannosyl receptors present on the cell surface of human fibroblasts [9]. However, limiting quantities of oligosaccharides precluded detailed comparison of the kinetics of pinocytosis of these phosphorylated oligosaccharides to those of the acid hydrolases from which they were derived. In this report we present studies comparing the kinetics of pinocytosis of acid hydrolases from NH4Cl-induced fibroblast secretions with those of concanavalin A-binding glycopeptides prepared from them by pronase digestion. The uptake of both secretion acid hydrolases and 125I-labeled glycopeptides was linear for at least 3 hr, saturable, inhibited competitively by mannose 6-phosphate, and destroyed by prior treatment of the ligand with alkaline phosphatase. The inhibition constants of excess unlabeled glycopeptide for the uptake of 125I-labeled glycopeptides (Ki of 1.5 X 10(-6) M) and for the uptake of secretion acid hydrolases (Ki of 2.2 X 10(-6) M) were remarkably similar. Furthermore, the Ki for mannose 6-phosphate inhibition of pinocytosis of glycopeptide uptake (3 X 10(-5) M) compares closely to that previously determined for the pinocytosis of intact "high-uptake" acid hydrolases (3-6 X 10(-5) M). "High-uptake" fractions of both ligands were prepared and quantified by affinity chromatography on immobilized phosphomannosyl receptors purified from bovine liver. Only 10% of the concanavalin A-binding glycopeptides bound to the immobilized phosphomannosyl receptors, while 80% of the acid hydrolases from which they were prepared bound and were eluted with 10 mM mannose 6-phosphate. However, the fraction of each type of ligand that binds to the immobilized phosphomannosyl receptors accounts for all the uptake activity of that ligand.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0730-2312
pubmed:author
pubmed:issnType
Print
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
69-86
pubmed:dateRevised
2008-8-22
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Comparative kinetics of phosphomannosyl receptor-mediated pinocytosis of fibroblast secretion acid hydrolases and glycopeptides prepared from them.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't