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The Human Urinary Epidermal Growth Factor (EGF) Precursor
- Source :
- Journal of Biological Chemistry. 270:27954-27960
- Publication Year :
- 1995
- Publisher :
- Elsevier BV, 1995.
-
Abstract
- In this report, we describe the isolation from human urine of a predominant 160-kDa epidermal growth factor (EGF)-immunoreactive glycoprotein that exhibits affinity for heparin. The purification procedure involved concentration and dialysis of 20-30-liter batches of fresh urine on a high capacity ultrafiltration apparatus followed by chromatography on DEAE-Sephacel, heparin-agarose, and Sephacryl S-300. A nearly homogeneous preparation of 160-kDa protein was obtained with a yield of approximately 1 mg of 160-kDa protein from 25 liters of urine. The amino-terminal sequence of the purified 160-kDa protein, H2N-SAPQHXSXPEGTXA-, matched residues 21-34 of the predicted sequence of human prepro-EGF and established that the 160 kDa protein (pro-EGF) is a product of the prepro-EGF gene. Characterization of the carboxyl terminus of the purified protein by digestion with carboxypeptidase B and by immunoblotting with antisera against synthetic carboxyl-terminal and juxtatransmembrane peptides of prepro-EGF indicated that the carboxyl terminus has been truncated at an arginine residue that corresponds, most likely, to the carboxyl-terminal arginine of the EGF moiety. The intact 160-kDa pro-EGF is biologically active as evidenced by its specific binding to the EGF receptor and activation of the EGF receptor tyrosine kinase in A-431 cell membranes. Purified pro-EGF competitively inhibited the binding of 125I-EGF to human fibroblasts, and it stimulated the proliferation of these cells in culture. When immobilized onto culture dishes, the heparin-binding pro-EGF appeared to function both as an adhesion molecule and as a growth factor for serum-free mouse embryo cells.
- Subjects :
- chemistry.chemical_classification
Arginine
Growth factor
medicine.medical_treatment
Cell Biology
Biology
Biochemistry
Molecular biology
Receptor tyrosine kinase
Amino acid
chemistry
Cell culture
Epidermal growth factor
biology.protein
medicine
Receptor
Molecular Biology
Peptide sequence
hormones, hormone substitutes, and hormone antagonists
Subjects
Details
- ISSN :
- 00219258
- Volume :
- 270
- Database :
- OpenAIRE
- Journal :
- Journal of Biological Chemistry
- Accession number :
- edsair.doi...........3ba8434e5b66e8ac4e348a57e216a7fd