Linked Life Data

6361024

Source:http://linkedlifedata.com/resource/pubmed/id/6361024

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
1984-2-14
pubmed:abstractText
Insulin receptors from turkey erythrocyte plasma membranes were solubilized in nondenaturing detergents (Triton X-100 and sodium deoxycholate). Their hydrodynamic properties were determined by sedimentation analyses in H2O and D2O, and gel filtration on Sepharose 4B. Two specific insulin-binding species are observed after velocity sedimentation in linear sucrose density gradients: peaks I and II. In Triton X-100, the sedimentation coefficient (s20,w), partial specific volume (Vc), and Stokes radius (a) for peaks I and II are, respectively, 10.2 +/- 0.5 S and 6.6 +/- 0.5 S, 0.75 +/- 0.02 ml/g, and 0.76 +/- 0.02 ml/g, and 89 +/- 3 A and 76 +/- 3 A, to yield Mr = 410,000 +/- 75,000 and 235,000 +/- 55,000, respectively, for the protein-Triton X-100 complex. The corresponding values in deoxycholate solution are: 10.7 +/- 0.5 S and 6.9 +/- 0.5 S, 0.71 +/- 0.03 ml/g and 0.70 +/- 0.04 ml/g, and 86 +/- 3 A and 69 +/- 3 A for peaks I and II, respectively, to yield 360,000 +/- 65,000 and 180,000 +/- 45,000, respectively, for the molecular weight of the protein-deoxycholate complex. These data are consistent with a model whereby each receptor species binds to one micelle of the appropriate detergent. In agreement with this model, it was also found that, in both Triton X-100 and deoxycholate, concentrations higher than the critical micellar concentration are required in order to maintain discrete receptor species in solution. At concentrations below the critical micellar concentration, the receptors aggregate to a broad band that sediments faster than 11.3 S. This is typical of membrane proteins that are stabilized in solution by insertion into detergent micelles. Based on these results, the protein molecular weights of peaks I and II are estimated to be 355,000 +/- 65,000 and 180,000 +/- 45,000, respectively. When membranes are treated with the reducing agent dithiothreitol, peak I is converted to peak II. This fact, together with the estimates obtained for the protein molecular weights of the two receptor species, suggests that peak I is a disulfide-linked dimer of peak II. The sedimentation characteristics of insulin receptors in many different cell types appear to be similar. As with turkey erythrocytes, detergent extracts of membranes from rat liver contained two native receptor species whose sedimentation coefficients were similar to peaks I and II. However, in all the other cell types examined, including rat adipocytes, rat heart muscle, 3T3-L1 adipocytes, 3T3-C2 fibroblasts, and FAO hepatoma cells, peak I (the native dimer) was the predominant species observed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
258
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14992-9
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Structural characterization of insulin receptors. I. Hydrodynamic properties of receptors from turkey erythrocytes.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.