Structural and functional characterization of full-length heparin-binding growth associated molecule.
Heparin-binding growth-associated molecule (HB-GAM) was purified from adult bovine brain and chicken heart. The yield of HB-GAM is increased by 5- to 10-fold when 250 mM NaCl is added to the homogenization buffer, indicating that HB-GAM may exist as a complex with an insoluble component of the tissue. The complete amino acid sequence of the brain-derived HB-GAM was established by automated Edman degradation of the intact protein and chemically or enzymatically derived fragments. The mass of bovine HB-GAM as determined by plasma desorption time-of-flight mass spectrometry is 15,291 mass units, which compares favorably with the calculated mass of 15,289 based on the amino acid sequence. Therefore, HB-GAM has not undergone any major post-translational modifications other than cleavage of the signal peptide. These results indicate that previous amino acid sequence analysis of this protein was carried out using truncated HB-GAM. Full-length HB-GAM is not a mitogen for Balb/3T3 clone A31, Balb MK, NRK, or human umbilical vein endothelial cells. HB-GAM does, however, have adhesive properties and neurite extension activity for chick embryo cerebral cortical derived neurons when presented to these cells as a substrate. HB-GAM had little neurite extension activity when presented as a soluble factor.
Hampton
B S
BS
American Red Cross, Laboratory of Molecular Biology, Jerome H. Holland Laboratory for the Biomedical Sciences, Rockville, Maryland 20855.
Marshak
D R
DR
Burgess
W H
WH
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001923:Brain Chemistry; D002352:Carrier Proteins / Q000737:chemistry* / Q000302:isolation & purification; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002645:Chickens; D016207:Cytokines / Q000737:chemistry* / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D006133:Growth Substances / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D051379:Mice; D008934:Mitogens / Q000494:pharmacology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009206:Myocardium / Q000737:chemistry; D016501:Neurites / Q000187:drug effects / Q000502:physiology; D012965:Sodium Chloride
D002352:Carrier Proteins; D016207:Cytokines; D006133:Growth Substances; D008934:Mitogens; C066845:pleiotrophin; D012965:Sodium Chloride