Abstract: The invention relates to a purified growth factor protein which is obtained from Spirometra mansonoides, and a pharmaceutical composition which includes the same. The protein has a molecular weight of 27,500 and an isoelectric point of 4.5. The amino acid sequence has been characterized as well as the DNA sequence which encodes it.

Abstract: PDGF B-chain polypeptides characterized by the substitution or deletion of a lysine or arginine residue at position 27, 28, 32, 79, 80 or 81 of native B-chain are disclosed. Also disclosed are PDGF-like proteins containing the B-chain polypeptides. The polypeptides and proteins may be produced through the use of cultured cells transfected or transformed to express DNA molecules that encode the polypeptides. The PDGF-like proteins are useful as components of cell culture media and for accelerating the healing of wounds.

Abstract: A method for selecting novel proteins such as growth hormone and antibody fragment variants having altered binding properties for their respective receptor molecules is provided. The method comprises fusing a gene encoding a protein of interest to the carboxy terminal domain of the gene III coat protein of the filamentous phage M13. The gene fusion is mutated to form a library of structurally related fusion proteins that are expressed in low quantity on the surface of a phagemid particle. Biological selection and screening are employed to identify novel ligands useful as drug candidates. Disclosed are preferred phagemid expression vectors and selected human growth hormone variants.