A transforming growth factor. beta. (TGF-. beta. ) receptor from human placenta exhibits greater affinity for TGF-. beta. 2 than for TGF-. beta. 1
- Biotechnology Research Institute, Montreal, Quebec (Canada)
Affinity-labeling techniques have been used to identify three types of high-affinity receptors for transforming growth factor {beta} (TGF-{beta}) on the surface of many cells in culture. Here the authors demonstrate that membrane preparations from tissue sources may also be used as an alternative system for studying the binding properties of TGF-{beta} receptors. Using a chemical cross-linking technique with {sup 125}I-TGF-{beta}1 and {sup 125}I-TGF-{beta}2 and bis(sulfosuccinimidyl)suberate (BS{sup 3}), they have identified and characterized two high-affinity binding components in membrane preparations derived from human term placenta. The larger species, which migrates as a diffuse band of molecular mass 250-350 kDa on sodium dodecyl sulfate-polyacrylamide electrophoresis gels, is characteristic of the TGF-{beta} receptor type III, a proteoglycan containing glycosaminoglycan (GAG) chains of chondroitin and heparan sulfate. The smaller species of molecular mass 140 kDa was identified as the core glycoprotein of this type III receptor by using the techniques of enzymatic deglycosylation and peptide mapping. Competition experiments, using {sup 125}I-TGF-{beta}1 or {sup 125}I-TGF-{beta}2 and varying amounts of competing unlabeled TGF-{beta}1 or TGF-{beta}2, revealed that both the placental type III proteoglycan and its core glycoprotein belong to a novel class of type III receptors that exhibit a greater affinity for TGF-{beta}2 than for TGF-{beta}1. This preferential binding of TGF-{beta}2 to placental type III receptors suggests differential roles for TGF-{beta}2 and TGF-{beta} 1 in placental function.
- OSTI ID:
- 5596688
- Journal Information:
- Biochemistry; (United States), Vol. 30:17; ISSN 0006-2960
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GROWTH FACTORS
RECEPTORS
MEMBRANE PROTEINS
AUTORADIOGRAPHY
CELL DIFFERENTIATION
CELL PROLIFERATION
ELECTROPHORESIS
GLYCOPROTEINS
IODINATION
IODINE 125
PLACENTA
SODIUM IODIDES
ALKALI METAL COMPOUNDS
BETA DECAY RADIOISOTOPES
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
FETAL MEMBRANES
HALIDES
HALOGEN COMPOUNDS
HALOGENATION
INORGANIC PHOSPHORS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODIDES
IODINE COMPOUNDS
IODINE ISOTOPES
ISOTOPES
MEMBRANES
MITOGENS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PHOSPHORS
PROTEINS
RADIOISOTOPES
SODIUM COMPOUNDS
550201* - Biochemistry- Tracer Techniques