Cabrillat H, Galizzi J P, Djossou O, Arai N, Yokota T, Arai K, Banchereau J
UNICET, Laboratory for Immunological Research, Dardilly, France.
Biochem Biophys Res Commun. 1987 Dec 31;149(3):995-1001. doi: 10.1016/0006-291x(87)90507-9.
Purified human recombinant interleukin 4 (IL-4) was radio iodinated to high specific radioactivity without loss of biological activity. 125I-IL-4 bound specifically to the Burkitt lymphoma Jijoye cells and other cell lines. Jijoye cells showed a high affinity for 125I-IL-4 (Kd approximately equal to 7 10(-11) M) and displayed 1200-1400 specific receptors per cell at 4 degrees C or 37 degrees C. The equilibrium dissociation constant (Kd) corresponds to the IL-4 concentration which induces 50% maximal expression of the low affinity IgE receptor (Fc epsilon RL/CD23) on Jijoye cells. At 4 degrees C the rate constant of association K1 is 1.7 x 10(6) M-1 s-1 and the rate contant of dissociation k -1 is 1.3 x 10(-4) s-1 (t 1/2 = 91 min.) No human recombinant lymphokines other than IL-4 were able to compete for the binding of 125I-IL-4 to its receptor.
纯化的人重组白细胞介素4（IL-4）被放射性碘化至高比放射性，且生物活性未丧失。125I-IL-4特异性结合至伯基特淋巴瘤Jijoye细胞及其他细胞系。Jijoye细胞对125I-IL-4表现出高亲和力（解离常数Kd约等于7×10⁻¹¹ M），在4℃或37℃时每个细胞显示有1200 - 1400个特异性受体。平衡解离常数（Kd）对应于诱导Jijoye细胞上低亲和力IgE受体（FcεRII/CD23）最大表达量50%时的IL-4浓度。在4℃时，结合速率常数K1为1.7×10⁶ M⁻¹ s⁻¹，解离速率常数k⁻¹为1.3×10⁻⁴ s⁻¹（半衰期t₁/₂ = 91分钟）。除IL-4外，没有其他的人重组淋巴因子能够竞争125I-IL-4与其受体的结合。
