scholarly journals THE BINDING OF MYOGLOBIN BY PLASMA PROTEIN

1960 ◽  
Vol 111 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Willoughby Lathem
Keyword(s):  
Plasma Protein ◽  
Binding Sites ◽  
Binding Capacity ◽  
Plasma Hemoglobin ◽  
Renal Threshold ◽  
Dog Plasma ◽  
Beta Globulin ◽  
Maximal Binding

When added to dog plasma in vitro and in vivo, myoglobin was bound to plasma protein in a concentration which, maximally, averaged 21 ± 6 mg. per cent. Electrophoretically, bound myoglobin was separated from free myoglobin and migrated between alpha-2 and beta globulin. The electrophoretic characteristics of protein-bound myoglobin were similar to, although not identical with, those of protein-bound hemoglobin. The maximal binding capacity of plasma for myoglobin was less than for hemoglobin, which averaged 123 mg. per cent. At concentrations below the maximal binding capacity, from 15 to 50 per cent of the myoglobin was in the free, unbound state, differing from hemoglobin which was completely bound at all concentrations below the binding capacity. When myoglobin and hemoglobin were added together to plasma, hemoglobin appeared to interfere with the binding of myoglobin or to replace it at the binding sites. Myoglobin, however, did not appear to interfere with the binding of hemoglobin. These observations suggested that myoglobin and hemoglobin were bound at least in part by the same protein. When myoglobin was given intravenously, free myoglobin was excreted in the urine, whereas protein-bound myoglobin was not excreted. This suggests that protein-binding contributes to or determines the apparent renal threshold to myoglobin.

scholarly journals Contribution of gangliosides to thyroxin binding with plasma membranes

1995 ◽  
Vol 41 (2) ◽  
pp. 28-30
Author(s):  
T. S. Saatov ◽  
F. Ya. Gulyamova ◽  
G. U. Usmanova
Keyword(s):  
Binding Sites ◽  
Plasma Membranes ◽  
Binding Capacity ◽  
Specific Binding ◽  
Brain Cell ◽  
Cell Recognition ◽  
High Affinity ◽  
Specific Binding Sites

Besides intracellular receptors of thyroid hormones, specific binding sites for T3 and T4 were detected on plasma membranes (PM) of some cells and a relationship between membrane reception .and lipid composition of membranes shown. The parameters of 125I-T4 binding to highly purified PM of hepatic and cerebral cells of rats were studied. The hepatic and cerebral cellular membranes were found to contain two sites of hormone binding each, one of these sites being characterized by a high affinity and low capacity, and the other by low affinity and a higher binding capacity. The association constant of highly affine site of hepatocyte membranes was found to be higher than that of brain cell membranes. T4 membranous receptors may be significant in the process of cell “recognition" by the hormone. In vivo and in vitro experiments with 125I-T4 and 14C-labeled thyroxin in ganglioside fractions showed appreciable binding of the hormone to Gm3 fraction, this evidently pointing to participation of this, ganglioside in T4 interaction with membrane receptor. It is possible that gangliosides situated on membranous surface are components of or function as receptors.

Plasma calcium distribution in relation to parathyroid function

1961 ◽  
Vol 200 (2) ◽  
pp. 341-344 ◽  
Author(s):  
Moira Breen ◽  
Smith Freeman
Keyword(s):  
Plasma Protein ◽  
Plasma Calcium ◽  
Total Plasma ◽  
Calcium Distribution ◽  
Parathyroid Function ◽  
Dog Plasma ◽  
Parathyroid Extract ◽  
Simple Mass

The plasma calcium was fractionated into protein-bound and free fractions by means of an ultracentrifuge in normal, hypoparathyroid and hyperparathyroid dogs and normal and hypoparathyroid rats. The proportion of the total plasma calcium that was diffusible was greater in normal and hypercalcemic animals than in the hypoparathyroid state. Recalcification of hypoparathyroid dog plasma in vitro gave a similar calcium distribution to that obtained when parathyroid extract was injected into hypoparathyroid dogs. Although the binding of calcium per gram of plasma protein increased both in vivo and in vitro as the concentration rose, the results did not conform to the simple mass law relationship as usually expressed. The evidence presented indicates that parathyroid function only influences the distribution of plasma calcium indirectly by regulating its concentration.

In Vitro and in Vivo Comparison of Binding of 99m-Tc-Iabeled Anti-CEA MAb F33-104 with 99m-Tc-labeled Anti-CEA MAb BW431/26

1999 ◽  
Vol 38 (04) ◽  
pp. 115-119
Author(s):  
N. Oriuchi ◽  
S. Sugiyama ◽  
M. Kuroki ◽  
Y. Matsuoka ◽  
S. Tanada ◽  
...  
Keyword(s):  
Nude Mice ◽  
Binding Capacity ◽  
Colon Adenocarcinoma ◽  
Human Colon ◽  
Cell Binding ◽  
Vitro Binding ◽  
Labeling Method ◽  
Human Colon Adenocarcinoma

Summary Aim: The purpose of this study was to assess the potential for radioimmunodetection (RAID) of murine anti-carcinoembryonic antigen (CEA) monoclonal antibody (MAb) F33-104 labeled with technetium-99m (99m-Tc) by a reduction-mediated labeling method. Methods: The binding capacity of 99m-Tc-labeled anti-CEA MAb F33-104 with CEA by means of in vitro procedures such as immunoradiometric assay and cell binding assay and the biodistribution of 99m-Tc-labeled anti-CEA MAb F33-104 in normal nude mice and nude mice bearing human colon adenocarcinoma LS180 tumor were investigated and compared with 99m-Tc-labeled anti-CEA MAb BW431/26. Results: The in vitro binding rate of 99m-Tc-labeled anti-CEA MAb F33-104 with CEA in solution and attached to the cell membrane was significantly higher than 99m-Tclabeled anti-CEA MAb BW431/261 (31.4 ± 0.95% vs. 11.9 ± 0.55% at 100 ng/mL of soluble CEA, 83.5 ± 2.84% vs. 54.0 ± 2.54% at 107 of LS 180 cells). In vivo, accumulation of 99m-Tc-labeled anti-CEA MAb F33-104 was higher at 18 h postinjection than 99m-Tc-labeled anti-CEA MAb BW431/26 (20.1 ± 3.50% ID/g vs. 14.4 ± 3.30% ID/g). 99m-Tcactivity in the kidneys of nude mice bearing tumor was higher at 18 h postinjection than at 3 h (12.8 ± 2.10% ID/g vs. 8.01 ± 2.40% ID/g of 99m-Tc-labeled anti-CEA MAb F33-104, 10.7 ± 1.70% ID/g vs. 8.10 ± 1.75% ID/g of 99m-Tc-labeled anti-CEA MAb BW431/26). Conclusion: 99m-Tc-labeled anti-CEA MAb F33-104 is a potential novel agent for RAID of recurrent colorectal cancer.

Role of Apolipoprotein A-I in Protecting against Endotoxin Toxicity

2004 ◽  
Vol 36 (6) ◽  
pp. 419-424 ◽  
Author(s):  
Juan Ma ◽  
Xue-Ling Liao ◽  
Bin Lou ◽  
Man-Ping Wu
Keyword(s):  
Survival Time ◽  
Binding Capacity ◽  
Density Lipoprotein ◽  
Mtt Method ◽  
Apolipoprotein A ◽  
Plasma Fraction ◽  
Significant Difference ◽  
In Vivo Effects

Abstract High density lipoprotein (HDL) binds lipopolysaccharide (LPS or endotoxin) and neutralizes its toxicity. We investigated the function of Apolipoprotein A-I (ApoA-I), a major apolipoprotein in HDL, in this process. Mouse macrophages were incubated with LPS, LPS+ApoA-I, LPS+ApoA-I+LFF (lipoprotein-free plasma fraction d>1.210 g/ml), LPS+HDL, LPS+HDL+LFF, respectively. MTT method was used to detect the mortality of L-929 cells which were attacked by the release-out cytokines in LPS-activated macrophages. It was found that ApoA-I significantly decreased L-929 cells mortality caused by LPS treatment (LPS vs. LPS+ApoA-I, P<0.05) and this effect became even more significant when LFF was utilized (LPS vs. LPS+ApoA-I+LFF, P<0.01; LPS vs. LPS+HDL+LFF, P<0.01). There was no significant difference between LPS+ApoA-I+LFF and LPS+HDL+LFF treatment, indicating that ApoA-I was the main factor. We also investigated in vivo effects of ApoA-I on mouse mortality rate and survival time after LPS administration. We found that the mortality in LPS+ApoA-I group (20%) and in LPS+ApoA-I+LFF group (10%) was significantly lower than that in LPS group (80%) (P<0.05, P<0.01, respectively); the survival time was (43.20 ± 10.13) h in LPS+ApoA-I group and (46.80 ± 3.79) h in LPS+ApoA-I+LFF group, which were significantly longer than that in LPS group (16.25 ± 17.28) h (P<0.01). We also carried out in vitro binding study to investigate the binding capacity of ApoA-I and ApoA-I+LFF to fluorescence labeled LPS (FITC-LPS). It was shown that both ApoA-I and ApoA-I+LFF could bind with FITC-LPS, however, the binding capacity of ApoA-I+LFF to FITC-LPS (64.47 ± 8.06) was significantly higher than that of ApoA-I alone (24.35 ± 3.70) (P<0.01). The results suggest that: (1) ApoA-I has the ability to bind with and protect against LPS; (2) LFF enhances the effect of ApoA-I; (3) ApoA-I is the major contributor for HDL anti-endotoxin function.

scholarly journals Allergenic Characterization of New Mutant Forms of Pru p 3 as New Immunotherapy Vaccines

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
C. Gómez-Casado ◽  
M. Garrido-Arandia ◽  
P. Gamboa ◽  
N. Blanca-López ◽  
G. Canto ◽  
...  
Keyword(s):  
Food Allergy ◽  
Ex Vivo ◽  
Binding Capacity ◽  
Cross Reactivity ◽  
T Cell Epitopes ◽  
Native Form ◽  
Ige Binding ◽  
Pru P 3

Nowadays, treatment of food allergy only considered the avoidance of the specific food. However, the possibility of cross-reactivity makes this practice not very effective. Immunotherapy may exhibit as a good alternative to food allergy treatment. The use of hypoallergenic molecules with reduced IgE binding capacity but with ability to stimulate the immune system is a promising tool which could be developed for immunotherapy. In this study, three mutants of Pru p 3, the principal allergen of peach, were produced based on the described mimotope and T cell epitopes, by changing the specific residues to alanine, named asPru p 3.01, Pru p 3.02, andPru p 3.03.Pru p 3.01showed very similar allergenic activity as the wild type byin vitroassays. However,Pru p 3.02andPru p 3.03presented reduced IgE binding with respect to the native form, byin vitro,ex vivo,and in vivo assays. In addition,Pru p 3.03had affected the IgG4 binding capacity and presented a random circular dichroism, which was reflected in the nonrecognition by specific antibodies anti-Pru p 3. Nevertheless, bothPru p 3.02andPru p 3.03maintained the binding to IgG1 and their ability to activate T lymphocytes. Thus,Pru p 3.02andPru p 3.03could be good candidates for potential immunotherapy in peach-allergic patients.

The ADP/ATP carrier is the 32-kilodalton receptor for an NH2-terminally myristylated src peptide but not for pp60src polypeptide

1993 ◽  
Vol 13 (5) ◽  
pp. 3084-3092
Author(s):  
C T Sigal ◽  
M D Resh
Keyword(s):  
Binding Capacity ◽  
Membrane Binding ◽  
Mitochondrial Fraction ◽  
Fatty Acyl ◽  
Affinity Tag ◽  
Peptide Probe ◽  
The Cross ◽  
Docking Protein

Membrane binding of pp60src is initiated via its myristylated NH2 terminus. To identify a candidate pp60src docking protein or receptor in the membrane, a radiolabelled peptide corresponding to the pp60src NH2-terminal membrane binding domain was cross-linked to fibroblast membranes and found to specifically label a 32-kDa protein. This protein was purified by appending an affinity tag to the peptide probe so that the cross-linked complex could be isolated via affinity chromatography. Microsequencing indicated that the 32-kDa protein was the mitochondrial ADP/ATP carrier (AAC). This result was further confirmed by the ability of an antibody to the AAC to immunoprecipitate the cross-linked complex, by the ability of certain inhibitors of the AAC to block cross-linking, and by membrane fractionation to show that complex formation occurred essentially exclusively in the mitochondrial fraction. While the AAC bound the myristyl-src peptide in a specific manner both in vitro and in vivo, its localization to the inner membrane of the mitochondrion precludes its being a pp60src binding protein. An analysis of pp60v-src binding in vitro was consistent with this expectation. Thus, use of a myristyl-src peptide revealed an unexpected and previously unidentified binding capacity of the AAC, most likely related to the ability of long-chain fatty acyl coenzyme As to serve as AAC inhibitors. The amphipathic nature of the pp60src NH2 terminus suggests alternative strategies for uncovering pp60src membrane binding species.

Interspersion of an unusual GCN4 activation site with a complex transcriptional repression site in Ty2 elements of Saccharomyces cerevisiae

1993 ◽  
Vol 13 (4) ◽  
pp. 2091-2103
Author(s):  
S Türkel ◽  
P J Farabaugh
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Binding Sites ◽  
Transcriptional Repression ◽  
Physiological Control ◽  
Reading Frame ◽  
Negative Region ◽  
Activation Site

Transcription of the Ty2-917 retrotransposon of Saccharomyces cerevisiae is modulated by a complex set of positive and negative elements, including a negative region located within the first open reading frame, TYA2. The negative region includes three downstream repression sites (DRSI, DRSII, and DRSIII). In addition, the negative region includes at least two downstream activation sites (DASs). This paper concerns the characterization of DASI. A 36-bp DASI oligonucleotide acts as an autonomous transcriptional activation site and includes two sequence elements which are both required for activation. We show that these sites bind in vitro the transcriptional activation protein GCN4 and that their activity in vivo responds to the level of GCN4 in the cell. We have termed the two sites GCN4 binding sites (GBS1 and GBS2). GBS1 is a high-affinity GCN4 binding site (dissociation constant, approximately 25 nM at 30 degrees C), binding GCN4 with about the affinity of a consensus UASGCN4, this though GBS1 includes two differences from the right half of the palindromic consensus site. GBS2 is more diverged from the consensus and binds GCN4 with about 20-fold-lower affinity. Nucleotides 13 to 36 of DASI overlap DRSII. Since DRSII is a transcriptional repression site, we tested whether DASI includes repression elements. We identify two sites flanking GBS2, both of which repress transcription activated by the consensus GCN4-specific upstream activation site (UASGCN4). One of these is repeated in the 12 bp immediately adjacent to DASI. Thus, in a 48-bp region of Ty2-917 are interspersed two positive and three negative transcriptional regulators. The net effect of the region must depend on the interaction of the proteins bound at these sites, which may include their competing for binding sites, and on the physiological control of the activity of these proteins.

Progastrin1–80stimulates growth of intestinal epithelial cells in vitro via high-affinity binding sites

2003 ◽  
Vol 284 (2) ◽  
pp. G328-G339 ◽  
Author(s):  
P. Singh ◽  
X. Lu ◽  
S. Cobb ◽  
B. T. Miller ◽  
N. Tarasova ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Binding Sites ◽  
Intestinal Epithelial Cells ◽  
Full Length ◽  
Intestinal Epithelial ◽  
Growth Effects ◽  
High Affinity ◽  
Significant Difference

Proliferation and carcinogenesis of the large intestinal epithelial cells (IEC) cells is significantly increased in transgenic mice that overexpress the precursor progastrin (PG) peptide. It is not known if the in vivo growth effects of PG on IEC cells are mediated directly or indirectly. Full-length recombinant human PG (rhPG1–80) was generated to examine possible direct effects of PG on IEC cells. Surprisingly, rhPG (0.1–1.0 nM) was more effective than the completely processed gastrin 17 (G17) peptide as a growth factor. Even though IEC cells did not express CCK1and CCK2receptors (-R), fluorescently labeled G17 and Gly-extended G17 (G-Gly) were specifically bound to the cells, suggesting the presence of binding proteins other than CCK1-R and CCK2-R on IEC cells. High-affinity ( Kd= 0.5–1.0 nM) binding sites for125I-rhPG were discovered on IEC cells that demonstrated relative binding affinity for gastrin-like peptides in the order PG ≥ COOH-terminally extended G17 ≥ G-Gly > G17 > *CCK-8 (* significant difference; P< 0.05). In conclusion, our studies demonstrate for the first time direct growth effects of the full-length precursor peptide on IEC cells in vitro that are apparently mediated by the high-affinity PG binding sites that were discovered on these cells.

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