Isolation of an inhibitory insulin-like growth factor (IGF) binding protein from bone cell-conditioned medium: A potential local regulator of IGF action

Journal Article · Wed Nov 01 00:00:00 EST 1989 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.86.21.8338· OSTI ID:7165660

Mohan, S; Bautista, C M; Wergedal, J; Baylink, D J ^[1]

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1. Loma Linda Univ., CA (USA)

Inhibitory insulin-like growth factor binding protein (In-IGF-BP) has been purified to homogeneity from medium conditioned by TE89 human osteosarcoma cells by two different methods using Sephadex G-100 gel filtration, FPLC Mono Q ion-exchange, HPLC C{sub 4} reverse-phase, HPLC CN reverse-phase and affinity chromatographies. In-IGF-BP thus purified appeared to be homogeneous and unique by the following criteria. (i) N-terminal sequence analysis yielded a unique sequence (Asp-Glu-Ala-Ile-His-Cys-Pro-Pro-Glu-Ser-Glu-Ala-Lys-Leu-Ala). (ii) Amino acid composition of In-IGF-BP revealed marked differences with the amino acid compositions of other known PBs. (iii) In-IGF-BP exhibited a single band with molecular mass of 25 kDa under reducing conditions on sodium dodecyl sulfate/polyacrylamide gels. IGF-I and IGF-II but not insulin displaced the binding of {sup 125}I-labeled IGF-I or {sup 125}I-labeled IGF-II binding to In-IGF-BP. In-IGF-BP inhibited basal, IGF-stimulated bone cell proliferation and serum-stimulated bone cell proliferation. Forskolin increases synthesis of In-IGF-BP in TE85 human osteosarcoma cells in a dose-dependent manner. Based on these findings, the authors conclude that In-IGF-BP is a protein that has a unique sequence and significant biological actions on bone cells.

• OSTI ID: 7165660
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Vol. 86:21; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BONE CELLS
CELL PROLIFERATION
GROWTH FACTORS
RECEPTORS
MEMBRANE PROTEINS
AUTORADIOGRAPHY
AMINO ACID SEQUENCE
ELECTROPHORESIS
INSULIN
IODINE 125
ION EXCHANGE CHROMATOGRAPHY
OSTEOSARCOMAS
PURIFICATION
ANIMAL CELLS
BETA DECAY RADIOISOTOPES
CHROMATOGRAPHY
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
MITOGENS
MOLECULAR STRUCTURE
NEOPLASMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PROTEINS
RADIOISOTOPES
SARCOMAS
SEPARATION PROCESSES
SKELETAL DISEASES
SOMATIC CELLS
550201* - Biochemistry- Tracer Techniques