Linked Life Data

2897292

Source:http://linkedlifedata.com/resource/pubmed/id/2897292

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1988-7-14
pubmed:abstractText
The selective binding of somatostatin-28 (SS-28) to beta cells of hamster insulinoma was characterized using HPLC-purified 125I-[Leu8,D-Trp22,Tyr25]SS-28 or 125I-SS-28. A single class of high-affinity sites (Kd = 53 +/- 5 pM) was observed with a binding capacity of 2.85 pmol/mg membrane protein. A large number of relatively low-affinity sites was found also. The order of potency of different peptides to inhibit 125I-SS-28 binding is SS-28 greater than SS-14 greater than SMS-201-995 and the respective half-maximal inhibitory doses are 0.16 nM, 10 nM and 1000 nM. CCK8 and other active pancreatic peptides (glucagon, insulin, gastric inhibitory peptide, vasoactive intestinal peptide, oxyntomodulin) do not inhibit the SS-28 receptor binding. 125I-SS-28-labeled beta membranes were successfully cross-linked using either the cleavable cross-linker dithiobis(succinimidylpropionate) (1 mM) alone or with a heterobifunctional agent, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB). In both cases five molecular components were revealed, after polyacrylamide gel electrophoresis of the membrane proteins and autoradiography, with the following molecular mass: 196-kDa, 132 kDa, 69 kDa, 45 kDa and 28 kDa. The labeling of 196-kDa, 132-kDa and 45-kDa species was specific in that they could be inhibited by unlabeled SS-28. The major labeled species corresponds to the 132-kDa band and no change in the mobility of this HSAB covalently bound SS-28 receptor was found after addition of dithiothreitol, suggesting that this specific receptor does not contain interchain disulphide bonds. The molecular mass of SS-28 receptors differs markedly from that of guinea-pig pancreatic acinar membranes, where a single 93-kDa protein is identified as a 125I-SS-28 receptor site in comparative experiments. Both the binding kinetics and structural differences sustain the selective action of SS-28 in the endocrine pancreas.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
174
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
219-24
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Characterization of covalently cross-linked somatostatin receptors in hamster beta cell insulinoma.
pubmed:affiliation
Instituto di Clinica Medica, Università Cattolica, Roma.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't