title: Efficient synthesis of human type alpha transforming growth factor: its physical and biological characterization.
abstract: Human transforming growth factor type alpha (TGF-alpha) was synthesized by a stepwise solid-phase method with an overall yield of 26%. Synthetic TGF-alpha, consisting of 50 amino acid residues deduced from a cDNA precursor sequence, was purified in a single HPLC step. The homogeneity and primary structure were confirmed by several criteria including Edman degradation and mass spectrometry. Synthetic TGF-alpha was as active as murine epidermal growth factor in binding to the epidermal growth factor receptor and in stimulation of anchorage-dependent and of anchorage-independent growth of normal indicator cells in culture. Synthetic TGF-alpha stimulated plasminogen activator production in A 431 and HeLa cells; the stimulation was similar to that induced by epidermal growth factor. Furthermore, synthetic human TGF-alpha showed similar immunoreactivity when compared with rat TGF-alpha. Thus, the 50-amino acid TGF-alpha is likely to be the bioactive principle produced and secreted by tumor cell lines.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D004815:Epidermal Growth Factor / Q000378:metabolism; D006801:Humans; D013058:Mass Spectrometry; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis / Q000138:chemical synthesis* / Q000494:pharmacology; D010960:Plasminogen Activators / Q000096:biosynthesis; D015291:Transforming Growth Factors
chemical_list: D000596:Amino Acids; D010455:Peptides; D004815:Epidermal Growth Factor; D015291:Transforming Growth Factors; D010960:Plasminogen Activators