Piao Y F, Okabe T
Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
Cancer Res. 1990 Mar 15;50(6):1671-4.
Human granulocyte colony-stimulating factor (G-CSF) rapidly loses the biological activity and the receptor binding capacity following radioiodination. We have made a mutein of human G-CSF, KW-2228, in which Thr-1, Leu-3, Gly-4, Pro-5, and Cys-17 were respectively substituted with Ala, Thr, Tyr, Arg, and Ser; showed more potent G-CSF activity; and retained full biological activity and receptor binding capacity at least 2 weeks of radioiodination. G-CSF is an effective growth factor for the blasts of myeloid leukemia. Radioiodinated KW-2228 was prepared using solid-phase glucose oxidase-lactoperoxidase. Human leukemia cell lines and the blast cells from leukemia patients were examined for binding. High affinity binding sites were identified on myeloid cell lines and on the blasts obtained from acute myeloid leukemia patients. Scatchard analysis showed that a single binding site for G-CSF was observed (361-1688 receptors/cell; Kd 128-1400 pM). In contrast, specific binding of 125I-KW-2228 was not demonstrated on lymphoblastic cell lines or the blast cells of acute lymphoid leukemia or lymphoma. This difference was reflected in the effectiveness of G-CSF to stimulate colony formation in acute myeloid leukemia blasts, while G-CSF did not stimulate colony formation of the blast cells from acute lymphoid leukemia.
人粒细胞集落刺激因子（G-CSF）经放射性碘化后会迅速丧失生物活性和受体结合能力。我们制备了人G-CSF的一种突变体KW-2228，其中苏氨酸-1、亮氨酸-3、甘氨酸-4、脯氨酸-5和半胱氨酸-17分别被丙氨酸、苏氨酸、酪氨酸、精氨酸和丝氨酸取代；该突变体表现出更强的G-CSF活性；并且在放射性碘化至少2周后仍保留全部生物活性和受体结合能力。G-CSF是髓系白血病原始细胞的一种有效生长因子。使用固相葡萄糖氧化酶-乳过氧化物酶制备了放射性碘化的KW-2228。检测了人白血病细胞系和白血病患者的原始细胞的结合情况。在髓系细胞系和急性髓系白血病患者的原始细胞上鉴定出了高亲和力结合位点。Scatchard分析表明观察到了一个单一的G-CSF结合位点（361 - 1688个受体/细胞；解离常数128 - 1400 pM）。相比之下，在淋巴细胞系或急性淋巴细胞白血病或淋巴瘤的原始细胞上未显示出125I-KW-2228的特异性结合。这种差异反映在G-CSF刺激急性髓系白血病原始细胞集落形成的有效性上，而G-CSF不能刺激急性淋巴细胞白血病原始细胞的集落形成。
