Methods for expressing a variety of biologically active PDGF analogs in eucaryotic cells are disclosed. The methods generally comprise introducing into a eucaryotic host cell a DNA construct capable of directing the expression and secretion of biologically active PDGF analogs in eucaryotic cells. The DNA construct contains a transcriptional promoter followed downstream by a suitable DNA sequence. The DNA sequence may encode a protein substantially homologous or identical to the A-chain or the B-chain of PDGF, or a portion thereof, or an A-B heterodimer. In addition, a portion of the DNA sequence may encode at least a portion of the A-chain, while another portion encodes at least a portion of the B-chain of PDGF. Eucaryotic cells transformed with these DNA constructs are also disclosed. Methods of promoting the growth of mammalian cells, comprising incubating the cells with a biologically active PDGF analog expressed by a eucaryotic host cell transformed with such a DNA construct, are also disclosed.
Dimeric proteins having substantially the same biological activity as PDGF are also disclosed. More specifically, the proteins may have two polypeptide chains, one of the chains being a mosaic of amino acid sequences substantially identical to portions of the A- or B-chains of PDGF, the second of the chains being substantially homologous to either the A-chain or the B-chain of PDGF, or each of the chains may be substantially identical to the A-chain of PDGF. Altematively, each of the two polypeptide chains may be a mosaic of amino acid sequences as described above. In addition, proteins comprising polypeptides that are variants or derivatives of the A- or B-chains of PDGF are also disclosed. Therapeutic compositions containing these proteins and methods for enhancing the wound-healing process in warm-blooded animals are also disclosed.
本发明公开了在真核细胞中表达各种
生物活性 PDGF 类似物的方法。这些方法一般包括将能够引导
生物活性 PDGF 类似物在真核细胞中表达和分泌的 DNA 构建体导入真核宿主细胞。DNA 构建体包含一个转录启动子,其下游是一个合适的 DNA 序列。DNA 序列可编码与 PDGF 的 A 链或 B 链基本同源或相同的蛋白质,或其一部分,或 A-B 异源二聚体。此外,DNA 序列的一部分可编码至少一部分 PDGF 的 A 链,而另一部分可编码至少一部分 PDGF 的 B 链。还公开了用这些 DNA 构建体转化的真核细胞。此外,还公开了促进哺乳动物细胞生长的方法,包括将细胞与用这种 DNA 构建体转化的真核宿主细胞表达的具有
生物活性的 PDGF 类似物一起培养。
还公开了与 PDGF 具有基本相同
生物活性的二聚体蛋白质。更具体地说,这些蛋白质可以有两条
多肽链,其中一条
多肽链是与 PDGF 的 A 链或 B 链部分基本相同的
氨基酸序列的拼接,第二条
多肽链与 PDGF 的 A 链或 B 链基本同源,或者每条
多肽链都与 PDGF 的 A 链基本相同。或者,两条
多肽链中的每一条都可以是上述
氨基酸序列的混合体。此外,还公开了包含 PDGF A 链或 B 链变体或衍
生物的
多肽的蛋白质。还公开了含有这些蛋白质的治疗组合物和增强温血动物伤口愈合过程的方法。