Marec J, Keprtová J, Spurná V, Minárová E, Michl J
Neoplasma. 1978;25(1):37-46.
Isologous and heterologous 3H-DNA (optimum concentration 25 microgram/ml of medium) are incorporated into L-cells from the medium during short-term incubation (up to 60 min). The incorporation of DNA is stimulated by a protein complex from calf serum--the growth-promoting alpha-globulin (GPAG) in the concentration 0.8 mg/ml of medium), which is rapidly taken into cells by pinocytosis. GPAG increases the frequency of incorporation of exogenous 3H-DNA into L-cells and the quantity of DNA incorporated. The quantity of 3H-DNA incorporated is further increased on the incubation of L-cells in a medium containing the complex 3H-DNA + GPAG, which is formed by the joint preincubation of the two components at 37 degrees C (20 hr); under these conditions the quantity of DNA incorporated is 150% greater than when 3H-DNA is used alone. GPAG acts as an activator of exogenous DNA transfer, stimulates its pinocytosis by the cells, and at the same time accelerates its intracellular transfer to the cell nuclei.
在短期培养（长达60分钟）过程中，同源和异源3H-DNA（培养基中的最佳浓度为25微克/毫升）从培养基中被整合到L细胞中。小牛血清中的一种蛋白质复合物——促生长α球蛋白（GPAG，培养基浓度为0.8毫克/毫升）能刺激DNA的整合，它通过胞饮作用迅速进入细胞。GPAG增加了外源3H-DNA整合到L细胞中的频率以及整合的DNA量。在含有3H-DNA + GPAG复合物的培养基中培养L细胞时，整合的3H-DNA量进一步增加，该复合物是由两种成分在37℃下共同预孵育（20小时）形成的；在这些条件下，整合的DNA量比单独使用3H-DNA时多150%。GPAG作为外源DNA转移的激活剂，刺激细胞对其进行胞饮作用，同时加速其在细胞内转移至细胞核。
