Seno M, Sasada R, Kurokawa T, Igarashi K
Biotechnology Research Laboratories, Takeda Chemical Industries Ltd, Osaka, Japan.
Eur J Biochem. 1990 Mar 10;188(2):239-45. doi: 10.1111/j.1432-1033.1990.tb15395.x.
The carboxyl-terminal sequence of basic fibroblast growth factor (bFGF) is rich in basic amino acid residues, a common characteristic amongst fibroblast growth factors, and is considered to contribute greatly to the binding to negatively charged extracellular matrixes such as heparin. To study the relationship between the affinity for heparin and the carboxyl-terminal structure of bFGF, amino- or carboxyl-terminal truncated molecules were produced in Escherichia coli using recombinant DNA techniques. These terminally truncated bFGFs were applied to a heparin-affinity HPLC column. Truncation of more than six amino acid residues from the carboxyl-terminal made the bFGF produced in E. coli markedly difficult to solubilize and weakened its affinity for heparin, though bFGF having up to 46 amino acids removed showed significant stimulation of the DNA synthesis of BALB/c3T3 cells. This stimulation of the DNA synthesis was also recognized by the bFGF having 40 amino acids removed from its amino-terminal, while the affinity of this peptide for heparin has been shown to be equal to that of the mature bFGF (146 amino acids). These results show that the affinity of bFGF for heparin depends significantly on its carboxyl-terminal structure and that the essential part for receptor binding is present between Asp41 and Ser100. Moreover, it suggests that the Phe139Leu140Pro141, present in all members of the FGF family, contributes greatly to the stable structure of the intact molecule.
碱性成纤维细胞生长因子（bFGF）的羧基末端序列富含碱性氨基酸残基，这是成纤维细胞生长因子的一个共同特征，并且被认为对与带负电荷的细胞外基质如肝素的结合有很大贡献。为了研究bFGF对肝素的亲和力与其羧基末端结构之间的关系，使用重组DNA技术在大肠杆菌中产生了氨基或羧基末端截短的分子。将这些末端截短的bFGF应用于肝素亲和HPLC柱。从羧基末端截去六个以上氨基酸残基使得在大肠杆菌中产生的bFGF明显难以溶解，并削弱了其对肝素的亲和力，尽管截去多达46个氨基酸的bFGF对BALB/c3T3细胞的DNA合成仍有显著刺激作用。从氨基末端截去40个氨基酸的bFGF对DNA合成的这种刺激作用也得到了认可，而该肽对肝素的亲和力已被证明与成熟bFGF（146个氨基酸）的亲和力相当。这些结果表明，bFGF对肝素的亲和力在很大程度上取决于其羧基末端结构，并且受体结合的关键部分存在于Asp41和Ser100之间。此外，这表明存在于FGF家族所有成员中的Phe139Leu140Pro141对完整分子的稳定结构有很大贡献。
