scholarly journals Evidence concerning the mechanism of insulin-receptor interaction and the structure of the insulin receptor from biological properties of covalently linked insulin dimers

1983 ◽  
Vol 216 (3) ◽  
pp. 687-694 ◽  
Author(s):  
M A Tatnell ◽  
R H Jones ◽  
K P Willey ◽  
A Schüttler ◽  
D Brandenburg
Keyword(s):  
Insulin Receptor ◽  
Plasma Membranes ◽  
Gel Filtration ◽  
Biological Properties ◽  
Receptor Interaction ◽  
Cross Linking ◽  
Receptor Complex ◽  
Biological Responses ◽  
Rat Liver Plasma Membranes ◽  
Covalently Linked

Covalently linked insulin dimers have been prepared by cross-linking two insulin monomers with a flexible suberoyl chain at either the B1 phenylalanine or the B29 lysine residue. Binding potencies of dimers determined by inhibition of binding of 125I-insulin to isolated rat liver plasma membranes or adipocytes were 2.5-7-fold greater than their abilities to stimulate lipogenesis in adipocytes. Rates of liver plasma-membrane-associated degradation of labelled insulin and dimers, measured by gel filtration, were similar at 37 degrees C. Binding and lipogenesis potencies of dimers prepared by substitution of each monomeric half of an asymmetrical dimer with desoctapeptide insulin, an almost inactive derivative, implicated the B1-cross-linked monomeric half as predominantly interacting with the insulin receptor. These results suggest that (1) dimers bind univalently to a bivalent insulin-receptor complex, in which the two individual binding subunits are arranged with anti-parallel symmetry and (2) the mechanism by which insulin binds and initiates its biological responses requires a conformational change within the insulin-receptor complex and/or in the insulin molecule for full biological expression.

Large-cluster and combined fluorescent and gold immunoprobes

1996 ◽  
Vol 54 ◽  
pp. 892-893
Author(s):  
Richard D. Powell ◽  
James F. Hainfeld ◽  
Carol M. R. Halsey ◽  
David L. Spector ◽  
Shelley Kaurin ◽  
...  
Keyword(s):  
Metal Cluster ◽  
Sulfonyl Chloride ◽  
Gel Filtration ◽  
Cross Linking ◽  
Site Specific ◽  
Fab Fragments ◽  
Cluster Label ◽  
Covalently Linked ◽  
Texas Red ◽  
Fold Excess

Two new types of covalently linked, site-specific immunoprobes have been prepared using metal cluster labels, and used to stain components of cells. Combined fluorescein and 1.4 nm “Nanogold” labels were prepared by using the fluorescein-conjugated tris (aryl) phosphine ligand and the amino-substituted ligand in the synthesis of the Nanogold cluster. This cluster label was activated by reaction with a 60-fold excess of (sulfo-Succinimidyl-4-N-maleiniido-cyclohexane-l-carboxylate (sulfo-SMCC) at pH 7.5, separated from excess cross-linking reagent by gel filtration, and mixed in ten-fold excess with Goat Fab’ fragments against mouse IgG (obtained by reduction of F(ab’)2 fragments with 50 mM mercaptoethylamine hydrochloride). Labeled Fab’ fragments were isolated by gel filtration HPLC (Superose-12, Pharmacia). A combined Nanogold and Texas Red label was also prepared, using a Nanogold cluster derivatized with both and its protected analog: the cluster was reacted with an eight-fold excess of Texas Red sulfonyl chloride at pH 9.0, separated from excess Texas Red by gel filtration, then deprotected with HC1 in methanol to yield the amino-substituted label.

scholarly journals Quantitative Aspects of the Insulin-Receptor Interaction in Liver Plasma Membranes

1974 ◽  
Vol 249 (7) ◽  
pp. 2249-2257 ◽  
Author(s):  
C. Ronald Kahn ◽  
Pierre Freychet ◽  
Jesse Roth ◽  
David M. Neville
Keyword(s):  
Insulin Receptor ◽  
Plasma Membranes ◽  
Receptor Interaction ◽  
Liver Plasma Membranes

scholarly journals Evidence for regulated dimerization of cell-cell adhesion molecule (C-CAM) in epithelial cells

1996 ◽  
Vol 320 (3) ◽  
pp. 847-853 ◽  
Author(s):  
Irene HUNTER ◽  
Hiroki SAWA ◽  
Magnus EDLUND ◽  
Björn ÖBRINK
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cells ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Plasma Membranes ◽  
Immunoglobulin Superfamily ◽  
Dimer Formation ◽  
Rat Liver Plasma Membranes ◽  
Self Association ◽  
Covalently Linked

C-CAM is a Ca2+-independent cell adhesion molecule (CAM) belonging to the immunoglobulin superfamily. Addition of chemical cross-linkers to isolated rat liver plasma membranes, intact epithelial cells and purified preparations of C-CAM stabilized one major C-CAM-containing product whose apparent molecular mass was approximately twice that of the C-CAM monomer. The failure to detect additional proteins after cleavage of the cross-linked species demonstrated that C-CAM exists as non-covalently linked dimers both in solution and on the cell surface. Dimerization occurred to the same extent in adherent monolayers and in single cell populations, indicating that dimer formation was the result of cis- interactions within the membranes of individual cells. Using isoform-specific anti-peptide antibodies, both C-CAM1 and C-CAM2 were found to be involved in dimerization, forming predominantly homo-dimeric species. Both calmodulin and Ca2+ ionophore modulated the level of dimer formation, suggesting a role for regulated self-association in the functional activity of C-CAM.

scholarly journals Guanine nucleotide regulation of [3H]vasopressin binding to liver plasma membranes and solubilized receptors Evidence for the involvement of a guanine nucleotide regulatory protein

1986 ◽  
Vol 240 (2) ◽  
pp. 361-365 ◽  
Author(s):  
D Bojanic ◽  
J N Fain
Keyword(s):  
Plasma Membranes ◽  
Binding Capacity ◽  
Regulatory Protein ◽  
Gel Filtration ◽  
Molecular Size ◽  
Receptor Complex ◽  
Guanine Nucleotide ◽  
Guanine Nucleotide Binding Protein ◽  
Vasopressin Receptors ◽  
Guanine Nucleotide Regulatory Protein

A guanine nucleotide regulatory protein may be involved in vasopressin-receptor-mediated polyphosphoinositide breakdown in rat liver. Therefore we examined the effects of the non-hydrolysable guanine nucleotide guanosine 5′-[beta gamma-imido]triphosphate (p[NH]ppG) on [3H]vasopressin ([3H]AVP) binding to hepatic plasma membranes and detergent extracts. [3H]AVP bound to a single set of high-affinity binding sites in membranes. Addition of p[NH]ppG decreased the affinity of receptor binding without altering the maximal binding capacity. The rate of dissociation of [3H]AVP from membrane-bound receptors was also enhanced by p[NH]ppG. Solubilization of [3H]AVP-prelabelled membranes with dodecyl beta-D-maltoside resulted in a [3H]AVP-receptor complex that was unstable in solution. Incubation of these extracts for 5 min at 30 degrees C resulted in a 40% loss of bound [3H]AVP, whereas in the presence of p[NH]ppG there was a 54% loss. However, when membranes were prelabelled with [3H]AVP and p[NH]ppG and then solubilized, the resulting hormone-receptor complex was still temperature-labile but insensitive to the further addition of p[NH]ppG. The molecular size of soluble vasopressin receptors was estimated by gel filtration. The [3H]AVP-receptor complex was eluted as a single peak with an apparent molecular size of 258 kDa. However, no peak was detected when solubilized extract was made from membranes prelabelled with [3H]AVP and p[NH]ppG, suggesting that this receptor complex had dissociated during chromatography. It is possible therefore that the high-Mr complex contains the hormone, its receptor and a guanine nucleotide binding protein.

Glucagon from avian pancreatic islets: radioreceptor studies

1977 ◽  
Vol 55 (8) ◽  
pp. 915-918 ◽  
Author(s):  
Anthony K. Tung ◽  
Steven A. Rosenzweig ◽  
Piero P. Foa
Keyword(s):  
Molecular Weight ◽  
Pancreatic Islets ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Gel Filtration ◽  
Rat Plasma ◽  
Radioreceptor Assay ◽  
Isolated Islets ◽  
Liver Plasma Membranes ◽  
Rat Liver Plasma Membranes

Glucagon extracted from isolated islets of the pigeon was studied by means of Sephadex gel filtration. Radioreceptor assay, using rat liver plasma membranes and radioiodinated porcine glucagon, showed that the bulk of the activity eluted with glucagon (molecular weight 3500). Avian glucagon appeared to be less effective than porcine glucagon in inhibiting the binding of labeled porcine glucagon to rat plasma membranes.

scholarly journals Elucidation of the quaternary structure of the insulin receptor

1983 ◽  
Vol 212 (1) ◽  
pp. 79-84 ◽  
Author(s):  
M D Baron ◽  
P H Sönksen
Keyword(s):  
Insulin Receptor ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Quaternary Structure ◽  
Insulin Binding ◽  
Insulin Analogues ◽  
Cross Link ◽  
Disuccinimidyl Suberate ◽  
Rat Liver Plasma Membranes ◽  
Binding Subunit

Photoreactive insulin analogues specifically label predominantly one polypeptide in the insulin receptor of rat liver plasma membranes. We have used the bifunctional reagent disuccinimidyl suberate to cross-link this polypeptide to its neighbouring, but not necessarily labelled, subunits. The results of these studies show that (1) there are at least three types of subunit in the receptor, with apparent Mr (Mapp.) values of 65 000, 95 000 and 120 000; (2) the receptor appears to consist of two Mapp. 120 000, one Mapp. 95 000 and one Mapp. 65 000 subunits; (3) the Mapp. 65 000 subunit, which has not been previously reported, may be only loosely attached to the receptor, and does not interact directly with the insulin-binding subunit (M app. 120 000).

Biochemical Chgaracterization of Recombinant Baculovirus 373 K/E p53 Protein

2018 ◽  
Vol 9 (03) ◽  
pp. 20204-20223
Author(s):  
Maghsoudi, Hossein ◽  
U Pati
Keyword(s):  
Dna Binding ◽  
P53 Protein ◽  
Expression System ◽  
Gel Filtration ◽  
Recombinant Baculovirus ◽  
Baculovirus Expression System ◽  
Cross Linking ◽  
Mobility Shift ◽  
Dna Complexes ◽  
P53 Antibodies

In this study, we expressed and purified the recombinant baculovirus 373 K/E p53 protein in a baculovirus expression system to characterize this mutant and compare it with wild type p53. Gel- filtration chromatography and chemical cross-linking experiments indicated that purified recombinant baculovirus 373 K/E p53 protein assembles into multimeric forms ranging from tetramers to polymers. Gel-mobility shift assays and protein-DNA cross-linking studies demonstrated that the recombinant protein binds, to a consensus DNA target as a dimer but that additional p53 mutant molecules may then associate with the preformed p53-dimer-DNA complexes to form a larger p53_DNA complexes. These observations suggest that the p53 mutant tetramers and polymers that forms the minimal p53 mutant complex in solution dissociated upon DNA binding to form p53 mutant dimmer DNA complexes. The DNA binding activity of this mutant was then investigated using electrophoretic mobility shift assays as well as supershift assay with anti-p53 antibodies. Binding of the anti-p53 antibody PAb421to the oligomerization promoting domain on p53 stimulated the sequential formation of both the p53_dimer DNA and larger p53-DNA complexes

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