Receptors for insulin-like growth factor-I in plasma membranes isolated from bovine mesenteric arteries

1988 ◽  
Vol 117 (4) ◽  
pp. 428-434 ◽  
Author(s):  
Karin E. Bornfeldt ◽  
Hans J. Arnqvist ◽  
Hans H. Dahlkvist ◽  
Anna Skottner ◽  
Jarl E. S. Wikberg
Keyword(s):  
Plasma Membranes ◽  
Specific Binding ◽  
Polyacrylamide Gel Electrophoresis ◽  
Mesenteric Arteries ◽  
Binding Characteristics ◽  
Factor I ◽  
Reducing Conditions ◽  
Ic50 Value ◽  
Igf I ◽  
High Concentrations

Abstract. Binding of IGF-I to plasma membranes from bovine mesenteric arteries was studied. The maximal specific binding of IGF-I was found to be 7.4 ± 1.7% of total 125I-IGF-I added to the incubation medium. Unlabelled IGF-I displaced 125I-IGF-I with an IC50 value of 0.5 nmol/l and a maximal displacement of 64.2 ± 2.8% of total binding. The potency of insulin to displace 125I-IGF-I was 100–1000-fold lower. Crosslinking of 125I-IGF-I to the receptor with disuccinimidyl suberate, followed by SDS-polyacrylamide gel electrophoresis under reducing conditions showed an IGF-I binding protein with a molecular weight of 146000 Dalton. In summary, we have shown the presence of receptors for IGF-I in plasma membranes isolated from macrovessels. The binding characteristics and the size of the binding unit were found to be similar to those of the IGF-1 receptor found in cultured vascular smooth muscle cells. Furthermore, insulin at high concentrations was found to interact with the IGF-I receptor.

scholarly journals Photoaffinity labelling of a nitrobenzylthioinosine-binding polypeptide from cultured Novikoff hepatoma cells

1986 ◽  
Vol 236 (3) ◽  
pp. 665-670 ◽  
Author(s):  
W P Gati ◽  
J A Belt ◽  
E S Jakobs ◽  
J D Young ◽  
S M Jarvis ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Plasma Membranes ◽  
Specific Binding ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Hepatoma Cells ◽  
Nucleoside Transport ◽  
Facilitated Diffusion ◽  
Animal Cells ◽  
Novikoff Hepatoma

Site-specific binding of nitrobenzylthioinosine (NBMPR) to plasma membranes of some animal cells results in the inhibition of the facilitated diffusion of nucleosides. The present study showed that nucleoside transport in Novikoff UA rat hepatoma cells is insensitive to site-saturating concentrations of NBMPR. Equilibrium binding experiments demonstrated the presence of high-affinity sites for NBMPR in a membrane-enriched fraction from these cells. In the presence of uridine or dipyridamole, specific binding of NBMPR at these sites was inhibited. When Novikoff UA membranes were covalently labelled with [3H]NBMPR by using photoaffinity techniques, specifically bound radioactivity was incorporated exclusively into a polypeptide(s) with an apparent Mr of 72,000-80,000, determined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Covalent labelling of this polypeptide was abolished in the presence of excess nitrobenzylthioguanosine (NBTGR) and reduced in the presence of adenosine, uridine or dipyridamole. The apparent Mr of the NBMPR-binding polypeptide in Novikoff UA cells is significantly higher than that reported for corresponding polypeptides in other cell types (Mr 45,000-66,000). When membrane-enriched preparations from S49 mouse lymphoma cells were photolabelled and mixed with labelled NovikoffUA membrane-enriched preparations, gel electrophoresis resolved the NBMPR-binding polypeptides from the two preparations.

Influence of nutrition and bovine growth hormone (GH) on hepatic GH binding, insulin-like growth factor-I and growth of lambs

1991 ◽  
Vol 128 (2) ◽  
pp. 181-186 ◽  
Author(s):  
J. J. Bass ◽  
J. M. Oldham ◽  
S. C. Hodgkinson ◽  
P. J. Fowke ◽  
H. Sauerwein ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Growth Factor ◽  
Plasma Glucose ◽  
Specific Binding ◽  
Plasma Concentrations ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

ABSTRACT The effect on young lambs of 0·25 mg recombinant bovine GH (bGH)/kg per day on plasma concentrations of insulin-like growth factor-I (IGF-I), glucose, specific hepatic GH binding and body composition changes was examined at two levels of nutrition (lucerne pellets; 3 and 1·7% of body weight/day). Lambs on low levels of nutrition had low plasma IGF-I (P < 0·001). Plasma concentrations of IGF-I were increased by bGH treatment at both levels of nutrition, with the high nutrition group showing the greatest IGF-I response after 3 and 40 days of bGH treatment. Plasma glucose, after 40 days, was higher overall (P < 0·05) in lambs on high nutrition. bGH treatment increased plasma glucose, with the response being greater in the well-fed lambs. Specific binding of GH to liver membranes was highest in lambs on high nutrition and on bGH treatment; no significant interaction between nutrition and bGH treatment was detected, indicating that specific binding of GH was increased proportionally by bGH at both nutritional levels. The major change in body composition was the reduced level of fatness in lambs treated with bGH. There was no significant effect of bGH on body weight although bGH treatment tended to increase weight gain of well-fed lambs and decreased weight loss of poorly nourished lambs. The results show that, although there was a significant (P < 0·05) bGH/nutrition interaction for IGF-I there was no such interaction for body weight/components or specific GH binding to the liver. The results indicate that an increase in plasma IGF-I does not necessarily result in increases in growth or changes in carcass composition. Journal of Endocrinology (1991) 128, 181–186

scholarly journals Characterization of the Binding of Adenosine Diphosphate to Human Platelet Membranes

1977 ◽  
Author(s):  
C. Legrand ◽  
B. Bauvois ◽  
J. P. Caen
Keyword(s):  
Binding Sites ◽  
Plasma Membranes ◽  
Specific Binding ◽  
Adenosine Diphosphate ◽  
Affinity Constant ◽  
Membrane Bound ◽  
High Concentrations ◽  
Kinetics Of

ADP-mediated platelet aggregation is a routinely employed test but its mechanism is poorly understood. The aim of this study was to compare the binding of ADP to plasma membranes isolated from normal platelets and thrombasthenic platelets (which do not aggregate with ADP). Binding of ADP to isolated membranes was assayed by incubation with 14C-ADP followed by Mill i pore filtration. In standard conditions, 14C-ADP was not transformed and non specific binding represented lessthan 3 % of the total binding. Using 1 μM 14C-ADP, the binding has been shown to be a rapid (t 1/2 = 2 mn 30 sec), saturable and reversible phenomenon at 37° C. The existence of a major population of binding sites, with an affinity constant Ka = 0.43 (+ 0.1) χ 106M-1, has been demonstrated. The kinetics of the binding was normal with membranes Tsolated from the platelets of 4 thrombasthenic patients and the affinity constant, when determined, was in the normal range. Dissociation of the membrane-bound 14C-ADP occurred rapidly at 37° C (t l/2c≃3mn) when samples were diluted enough (dilution 1 : 100 was currently employed) to avoid rebinding of the radioligand. Accelerated dissociation (t 1/2 ≃ 1 mn) was observed when the dilution was performed in the presence of an excess of unlabeled ADP, suggesting the existence of negatively cooperative site-site interactions among the ADP binding sites. This effect was only observed at high concentrations of ADP (> 10–5M) and its eventual role in vivo remains to be established. Two thrombasthenic membrane preparations studied in the same way dissociated as did the control membranes.

The binding of insulin-like growth factor II to the erythroleukemia cell line K562

1984 ◽  
Vol 4 (12) ◽  
pp. 1071-1077 ◽  
Author(s):  
Michael Tally ◽  
Tang Xin-Zhi ◽  
Gösta Enberg ◽  
Kerstin Hall
Keyword(s):  
Growth Factor ◽  
Cell Line ◽  
Specific Binding ◽  
Affinity Constant ◽  
Scatchard Analysis ◽  
Insulin Like Growth Factor ◽  
Factor Ii ◽  
Igf I ◽  
Erythroleukemia Cell ◽  
High Concentrations

The erythroleukemia cell line K562 was previously shown to have specific binding sites for insulin but not for insulin-like growth factor I (IGF-I). In this study the presence of specific receptors for insulin-like growth factor II (IGFqI) is established. Scatchard analysis of the competition curve for IGF-II disclosed a non-cooperative binding kinetic with a calculated affinity constant of 2.4 × 108 M−1 and a receptor number of 4.8 × 104 sites/cell. IGF-I displayed 10% crossreactivity over the IGF-II receptor but insulin did not crossreact at all. Instead insulin, present in high concentrations, enhanced the binding of IGF-II. The presence of IGF II but not IGF-I receptors makes the K562 cell line suitable for studying properties of the type-2 receptor.

scholarly journals PENAMBAHAN PROTEIN INSULIN LIKE GROWTH FACTOR-I COMPLEX DALAM PENGENCER PEMBEKUAN SEMEN TERHADAP KUALITAS SPERMATOZOA KAMBING PADA WAKTU EKUILIBRASI

2011 ◽  
Vol 5 (2) ◽  
Author(s):  
Suherni Susilowati ◽  
Tatik Hernawati
Keyword(s):  
Growth Factor ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Plasma Séminal ◽  
Igf I ◽  
Native Polyacrylamide Gel Electrophoresis ◽  
Growth Factor I

Penelitian ini bertujuan mengisolasi protein Insulin Like Growth Factor-I (IGF-I) complex untuk meningkatkan kualitas semen beku kambing pada waktu ekuilibrasi setelah penambahan protein IGF-I complex. Penelitian ini terdiri atas 2 tahap yaitu isolasi protein IGF-I complex dari plasma seminal kambing dan aplikasi terhadap prosesing pembekuan semen. Pada tahap pertama dilakukan identifikasi IGF-I complex dengan menggunakan gel native polyacrylamide gel electrophoresis dan isolasi IGF-I complex. Pada tahap kedua dilakukan aplikasi penambahan protein IGF-I complex pada prosesing semen beku. Semen dikoleksi dengan menggunakan vagina buatan dan kemudian disentrifus selama 5 menit dengan kecepatan 1800 rpm. Kemudian semen dibagi menjadi tiga kelompok. Pada kelompok I, II, dan III ditambahkan protein IGF-I complex masing-masing 0, 12, dan 618 ng/ 3X10 sperma. Selanjutnya dilakukan ekuilibrasi selama 1 jam dan dilanjutkan dengan evaluasi motilitas, viabilitas, dan membran sperma. Hasil penelitian menunjukkan perbedaaan motilitas, viabilitas, dan membran sperma yang signifikan (P<0,05) di antara tiga kelompok perlakuan. Dapat disimpulkan bahwa penambahan protein IGF-I complex dapat meningkatkan kualitas semen beku kambing pada fase ekuilibrasi.

scholarly journals The biosynthesis of glucagon in perfused rat pancreas

1973 ◽  
Vol 134 (2) ◽  
pp. 473-480 ◽  
Author(s):  
Kevin J. O'Connor ◽  
Adrian Gay ◽  
Norman R. Lazarus
Keyword(s):  
Molecular Weight ◽  
Specific Binding ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Leucine Incorporation ◽  
Perfused Rat Pancreas ◽  
Rat Pancreas ◽  
Extractable Protein ◽  
High Concentrations ◽  
Glucagon Immunoreactivity

The biosynthesis of glucagon was studied by using the recirculated, isolated perfused rat pancreas. [3H]Tryptophan was initially incorporated into acid–ethanol-extractable protein, which on gel filtration was eluted with a molecular weight of about 9000 and contained a small amount of glucagon immunoreactivity. With longer incubation [3H]tryptophan incorporation into a second peak was obtained in an identical position with that of the majority of rat glucagon immunoreactivity. This peak of labelled protein exhibited migration characteristics on polyacrylamide-gel electrophoresis identical with those of rat glucagon and was identified as newly synthesized glucagon by demonstration of specific binding and dissociation behaviour with glucagon antibodies. The incorporation of [3H]tryptophan into acid–ethanol-extractable protein was inhibited by cycloheximide. High concentrations of glucose increased [3H]tryptophan incorporation into high-molecular-weight protein but decreased incorporation into proteins smaller than cytochrome c. The pattern of [3H]leucine incorporation into protein was similar to that of [3H]tryptophan.

The presence of classical insulin-like growth factor (IGF) type-I and -II receptors on mouse osteoblasts: autocrine/paracrine growth effect of IGFs?

1990 ◽  
Vol 125 (2) ◽  
pp. 271-277 ◽  
Author(s):  
M. C. Slootweg ◽  
C. M. Hoogerbrugge ◽  
T. L. de Poorter ◽  
S. A. Duursma ◽  
S. C. van Buul-Offers
Keyword(s):  
Growth Factor ◽  
Specific Binding ◽  
Growth Effect ◽  
Classical Type ◽  
Type I ◽  
Specific Binding Sites ◽  
Reducing Conditions ◽  
Receptor Sites ◽  
Igf I ◽  
Paracrine Actions

ABSTRACT Specific binding to and proliferative actions of insulinlike growth factors-I and -II (IGF-I and -II) on fetal mouse osteoblasts were tested. Membranes of mouse osteoblasts were shown by binding competition studies to possess specific binding sites for IGF-I and IGF-II. When IGF-I was used as a tracer, half-maximal displacement was obtained with 1·11 μg IGF-I/1 and with 14 μg IGF-II/1. Displacement of 125I-labelled IGF-I was accomplished with 2·33 μg IGF-II/1 and with 55 μg IGF-I/1. Affinity cross-linking showed bands of 130 kDa 125I-labelled IGF-I and 260 kDa 125I-labelled IGF-II under reducing conditions, further indicating the presence of classical type-I and -II receptor sites on mouse osteoblasts. Mitogenic effects of IGFs were weak; a combination with epidermal growth factor or fibroblast growth factor showed strong synergistic action however. The possibility of autocrine/paracrine actions of IGFs is discussed. Journal of Endocrinology (1990) 125, 271-277

Insulin and IGF I receptor-mediated Na+ transport in toad urinary bladders

1989 ◽  
Vol 257 (4) ◽  
pp. C612-C620 ◽  
Author(s):  
B. L. Blazer-Yost ◽  
M. Cox ◽  
R. Furlanetto
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
The Other ◽  
Na Transport ◽  
Renal Epithelium ◽  
Receptor Complexes ◽  
Factor I ◽  
Equilibrium Binding ◽  
Igf I ◽  
Specific Insulin ◽  
Toad Bufo

We compared the concentration dependence of insulin- and insulin-like growth factor I (IGF I)-stimulated Na+ transport with ligand-receptor affinities in the urinary bladder of the toad Bufo marinus. Threshold, half-maximal, and maximal natriferic concentrations of both peptides were approximately 0.1, 1, and 10 nM, respectively. Amiloride, but not ethyl isopropyl amiloride, (10(-5) M), abolished Na+ transport. Maximal responses to either peptide rendered the tissue insensitive to challenge with the other. Separate insulin and IGF I receptors were identified by equilibrium binding and polyacrylamide gel electrophoresis of cross-linked ligand-receptor complexes. For both peptides, half-maximal binding occurred at 3-10 nM; crossover binding to the other receptor occurred with 10- and 100-fold lower affinity. Thus, in this model "high-resistance" renal epithelium, 1) ligand binding to specific insulin and IGF I receptors stimulates transcellular Na+ flux, 2) the natriferic effects of insulin and IGF I apparently depend on activation of apical Na+ channels rather than Na+-H+ antiporters, and 3) the natriferic pathways activated by insulin and IGF I appear to converge subsequent to ligand-receptor binding but before the final transport ("effector") step(s).

In-vitro binding of gonadotrophin to fish ovary

1986 ◽  
Vol 111 (3) ◽  
pp. 407-413 ◽  
Author(s):  
Md. Jamal Uddin ◽  
S. Bhattacharya
Keyword(s):  
Plasma Membranes ◽  
Binding Capacity ◽  
Specific Binding ◽  
Ovarian Tissue ◽  
Silver Carp ◽  
Binding Studies ◽  
Binding Characteristics ◽  
Physiological Importance ◽  
Plot Analysis

ABSTRACT Binding of piscine and mammalian gonadotrophin to plasma membranes from the ovaries of a fish, the murrel (Channa punctatus), clearly suggests that the fish ovary possesses distinct and specific binding sites for both piscine and mammalian gonadotrophins. Maximum specific binding of 125I-labelled human chorionic gonadotrophin (125I-hCG) and 125I-labelled silver carp gonadotrophin (125I-scG) was obtained at 30 °C and pH 7·5 during 2 h of incubation. In competitive binding studies, binding of radiolabelled scG was effectively inhibited by piscine gonadotrophins while LH and hCG had less effect and FSH showed no inhibition. By using plasma membrane preparations from kidney, skeletal muscle, brain and ovary it could be shown that specific binding of radiolabelled gonadotrophins was restricted to ovarian tissue. Binding characteristics of both 125I-scG and 125I-hCG to a preparation of murrel ovarian plasma membranes showed saturability with high affinity and low capacity. Scatchard plot analysis gave a higher dissociation constant for hCG (Kd = 235 pmol/l) than for scG (Kd= 127 pmol/l). Maximum binding capacity of scG was about twofold higher (6·27 fmol/mg protein) than that of hCG (3·76 fmol/mg protein). An increase in gonadotrophin binding resulted in a greater formation of pregnenolone from cholesterol, indicating functional relevance. At a concentration of 8 mmol/l, Ca2+ markedly inhibited the binding of gonadotrophin. The physiological importance of this inhibition is discussed. J. Endocr. (1986) 111, 407–413

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