Hanneken A, Ying W, Ling N, Baird A
Department of Molecular and Cellular Growth Biology, Whittier Institute for Diabetes and Endocrinology, La Jolla, CA 92037.
Proc Natl Acad Sci U S A. 1994 Sep 13;91(19):9170-4. doi: 10.1073/pnas.91.19.9170.
We have purified three acidic (FGF-1) and basic (FGF-2) fibroblast growth factor binding proteins (FGF-BP1, FGF-BP2, and FGF-BP3) from human plasma and calf serum and demonstrate the presence of these circulating FGF-BPs in blood. Each are truncated forms of the high-affinity FGF receptor (FGFR-1). FGF-BP1 and FGF-BP2 have estimated molecular masses of 70-85 kDa and 55-60 kDa, respectively, and are detected by using 125I-labeled FGF-2 ligand blotting. Immunoblotting with four distinct antibodies to FGFR-1 reveals that FGF-BP1 and FGF-BP2 are immunologically and biochemically related to the extracellular domain of FGFR-1. Reverse-phase HPLC chromatography resolves FGF-BP2 into two proteins with estimated molecular masses of 55 kDa and 60 kDa. Protein sequencing of the amino terminus of FGF-BP2 and FGF-BP3 reveals identity with the extracellular domain of the two-IgG-loop form of human FGFR-1. The FGF-BPs do not require heparin to bind FGF-2 on affinity columns, but heparin does enhance their recovery from blood. These FGF-BPs may play an important physiological role in regulating the biological activity of FGF and the other members of the FGF family of growth factors.
我们已从人血浆和小牛血清中纯化出三种酸性（FGF-1）和碱性（FGF-2）成纤维细胞生长因子结合蛋白（FGF-BP1、FGF-BP2和FGF-BP3），并证明血液中存在这些循环FGF-BP。它们均为高亲和力成纤维细胞生长因子受体（FGFR-1）的截短形式。FGF-BP1和FGF-BP2的估计分子量分别为70 - 85 kDa和55 - 60 kDa，通过使用125I标记的FGF-2配体印迹法进行检测。用四种针对FGFR-1的不同抗体进行免疫印迹分析表明，FGF-BP1和FGF-BP2在免疫和生化方面与FGFR-1的细胞外结构域相关。反相高效液相色谱法将FGF-BP2分离为两种估计分子量分别为55 kDa和60 kDa的蛋白质。对FGF-BP2和FGF-BP3氨基末端的蛋白质测序显示，它们与人FGFR-1的双IgG环形式的细胞外结构域相同。FGF-BP在亲和柱上结合FGF-2时不需要肝素，但肝素确实能提高它们从血液中的回收率。这些FGF-BP可能在调节FGF及FGF家族其他生长因子的生物活性方面发挥重要的生理作用。
