Effect of insulin on the hepatic production of insulin-like growth factor-binding protein-1 (IGFBP-1), IGFBP-3, and IGF-I in insulin-dependent diabetes.

1994 ◽  
Vol 79 (3) ◽  
pp. 872-878 ◽  
Author(s):  
K Brismar ◽  
E Fernqvist-Forbes ◽  
J Wahren ◽  
K Hall
Keyword(s):  
Growth Factor ◽  
Binding Protein ◽  
Insulin Dependent Diabetes ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Igf I ◽  
Insulin Dependent ◽  
Igfbp 3

Radioimmunoassay of insulin-like growth factor-binding protein-6 in human serum and other body fluids

1992 ◽  
Vol 134 (1) ◽  
pp. 133-139 ◽  
Author(s):  
R. C. Baxter ◽  
H. Saunders
Keyword(s):  
Cerebrospinal Fluid ◽  
Growth Factor ◽  
Human Serum ◽  
Follicular Fluid ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Igf I ◽  
The Mean ◽  
Igfbp 3

ABSTRACT A radioimmunoassay has been established for the insulin-like growth factor-binding protein, IGFBP-6, isolated from a human transformed fibroblast cell-line. The binding proteins IGFBP-I and IGFBP-3 did not cross-react, but both IGF-I and IGF-II markedly inhibited IGFBP-6 tracer binding to antiserum. This inhibition, greater for IGF-II than for IGF-I, was fully reversed by the addition of IGFBP-3 to sequester the IGFs. After fractionation of human serum and follicular fluid samples by gel chromatography, interference in the radioimmunoassay by fractions corresponding to the 150 kDa IGF-IGFBP complex could be eliminated by IGFBP-3. The equivalent fractions from cerebrospinal fluid and amniotic fluid fractionation did not interfere in the assay. The mean IGFBP-6 level in adult human serum was 0·221 ±0·110 mg/l, with values significantly higher in men than women, and slightly decreased in pregnancy. Similar values were seen in umbilical cord serum and in amniotic and follicular fluid samples, while the mean level in cerebrospinal fluid was slightly lower, 0·152±0·049 mg/l. This assay will facilitate studies on the regulation of IGFBP-6 production, and its role as an IGF carrier. Journal of Endocrinology (1992) 134, 133–139

The ovine pancreatic protein which binds insulin-like growth factor binding protein-3 is procarboxypeptidase A

1996 ◽  
Vol 150 (1) ◽  
pp. 51-56 ◽  
Author(s):  
P J Fowke ◽  
S C Hodgkinson
Keyword(s):  
Growth Factor ◽  
Cell Surface ◽  
Binding Protein ◽  
Binding Activity ◽  
Insulin Like Growth Factor ◽  
Surface Binding ◽  
Factor Binding ◽  
Amino Terminal ◽  
Igf I ◽  
Igfbp 3

Abstract Insulin-like growth factor binding protein-3 (IGFBP-3) is known to modulate the actions of insulin-like growth factors (IGF)-I and -II at the level of the cell. Proposed mechanisms include association of IGFBP-3 with cell surface proteoglycan, with cell surface binding proteins, proteolysis and/or internalization of IGFBP-3. In previous studies we have characterized a protein of 40 kDa in extracts of ovine pancreas and muscle which binds IGFBP-3 on ligand blot analyses. This paper reports the identity of the pancreatic species as procarboxypeptidase A (peptidyl-l-amino acid hydrolase, E.C. 3.4.17.1; proCPA). Identity was established by amino terminal sequence analysis, binding studies with pure bovine carboxypeptidase A (CPA) and observations that the binding activity was present in pancreatic secretions consistent with the role of proCPA as a secretory zymogen. The binding activity was inhibited by unlabelled IGFBP-3 at high doses (10 μg/ml) and reduced but not abolished by preincubation of 125I-IGFBP-3 with excess IGF-I. Digestion of 125I-IGFBP-3 with mature CPA produced a 26 kDa product. Modification of IGFBP-3 by CPA or binding to proCPA may provide a mechanism for modulation of IGFBP activity and hence IGF action. Journal of Endocrinology (1996) 150, 51–56

Long-term treatment of Laron type dwarfs with insulin-like growth factor-1 increases serum insulin-like growth factor-binding protein-3 in the absence of growth hormone activity

1993 ◽  
Vol 128 (2) ◽  
pp. 144-149 ◽  
Author(s):  
Hannah Kanety ◽  
Avraham Karasik ◽  
Beatrice Klinger ◽  
Aviva Silbergeld ◽  
Zvi Laron
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Binding Protein ◽  
Serum Insulin ◽  
Continuous Treatment ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Long Term Treatment ◽  
Igf I ◽  
Igfbp 3

Insulin-like growth factor binding protein-3 (IGFBP-3) is the major carrier of insulin-like growth factor I (IGF-1) in serum, and its production is growth hormone (GH) dependent. It is unclear whether in humans IGFBP-3 production is directly regulated by GH or mediated via IGF-I. We addressed this question in six patients with Laron-type dwarfism, a syndrome characterized by the absence of GH receptor activity (LTD), who were chronically treated with recombinant IGF-I. Analysis of the electrophoretic profiles of serum IGFBPs in these patients by Western ligand blotting revealed an extremely low IGFBP-3 level. A striking progressive increase in serum IGFBP-3 was observed with continuous treatment, despite the absence of GH action. In LTD children, serum IGFBP-3 increased up to 19-fold after six months of therapy and equalled levels observed in controls, whereas in adult LTD patients the increase was smaller. A rise in serum levels of 34, 30 and 24 kDa BPs (presumably IGFBP-2, -1 and -4, respectively was also noted with chronic IGF-I therapy. This proof of GH-independent induction of IGFBP-3 by IGF-1 may be a major advantage in the therapeutic use of biosynthetic IGF-I in several types of short stature children.

scholarly journals Ligand-binding characteristics of recombinant amino- and carboxyl-terminal fragments of human insulin-like growth factor-binding protein-3

2001 ◽  
Vol 169 (1) ◽  
pp. 123-133 ◽  
Author(s):  
M Galanis ◽  
SM Firth ◽  
J Bond ◽  
A Nathanielsz ◽  
AA Kortt ◽  
...  
Keyword(s):  
Growth Factor ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Amino Terminal ◽  
Terminal Domain ◽  
Igf I ◽  
Igf Binding ◽  
Carboxyl Terminal ◽  
Igfbp 3

Insulin-like growth factor-binding protein-3 (IGFBP-3) is a member of a family of structurally conserved proteins (IGFBP-1 to -6) which act as carriers and regulators of the mitogenic peptide hormones IGF-I and IGF-II. Members of the IGFBP family share conserved cysteine-rich amino- and carboxyl-terminal regions. The amino-terminal domain of these proteins is recognised to contain an IGF-binding determinant, but evidence to support a binding site in the carboxyl-terminal region of the protein is less rigorous. To further investigate this, we have synthesised both the amino-terminal (residues 1-88; N-88) and carboxyl-terminal (residues 165-264; C-165) domains of human IGFBP-3 in bacteria, as fusion proteins with a carboxyl-terminal FLAG peptide. Although only C-165 showed binding to IGF-I and -II by solution-binding assays, both N-88 and C-165 demonstrated binding to IGF-I and -II by biosensor analysis albeit with reduced affinities compared with full-length IGFBP-3. Only the carboxyl-terminal fragment (C-165) was able to form hetero-trimeric complexes with IGF-I and the acid-labile subunit (ALS). We conclude that the carboxyl-terminal domain of IGFBP-3 contains an IGF-binding determinant and can form ternary complexes with ALS.

Insulin-like growth factor binding protein (IGFBP-3), an inhibitor of serum growth factors other than IGF-I and -II

1992 ◽  
Vol 153 (1) ◽  
pp. 15-21 ◽  
Author(s):  
L. Liu ◽  
J. Delbé ◽  
C. Blat ◽  
J. Zapf ◽  
L. Harel
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Igf I ◽  
Igfbp 3
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