Nicola N A, Metcalf D
Walter and Eliza Hall Institute of Medical Research, P.O. Royal Melbourne Hospital, Victoria, Australia.
Growth Factors. 1988;1(1):29-39. doi: 10.3109/08977198809000244.
The kinetic parameters involved in determining the steady-state interaction of Multi-CSF with FDCP-1 cells at 37 degrees C have been determined by kinetic analysis under steady-state conditions and by curve-fitting the rate of approach to steady-state conditions. The two methods are in substantial agreement and yield values of Vr = 28 receptors/cell/min for the rate of appearance of receptors at the cell surface, ke and kt = 0.061 min-1 and 0.0044 min-1 for the rate constants of internalization of occupied and unoccupied receptors, respectively, kh = 0.008 min-1 for the rate constant of degradation of internalized ligand, ka = 2.9 X 10(8) M-1 min-1 for the rate constant of association and kd = 0.11 min-1 for the rate constant of dissociation of ligand with receptor. Analysis of steady-state conditions indicated that Multi-CSF caused substantial down-regulation of surface receptors and that considerably more Multi-CSF was inside the cell than at the cell surface. The implications of these results for utilization rates of Multi-CSF by FDCP-1 cells and the relationship of receptor occupancy to biological activity are discussed.
通过在稳态条件下进行动力学分析以及对达到稳态条件的速率进行曲线拟合，确定了在37摄氏度下多集落刺激因子（Multi-CSF）与FDCP-1细胞稳态相互作用所涉及的动力学参数。这两种方法结果基本一致，得出细胞表面受体出现速率Vr = 28个受体/细胞/分钟，占据和未占据受体内化速率常数ke和kt分别为0.061分钟-1和0.0044分钟-1，内化配体降解速率常数kh = 0.008分钟-1，配体与受体结合速率常数ka = 2.9×10(8) M-1分钟-1，配体与受体解离速率常数kd = 0.11分钟-1。稳态条件分析表明，多集落刺激因子导致表面受体大量下调，且细胞内的多集落刺激因子比细胞表面的多得多。讨论了这些结果对FDCP-1细胞利用多集落刺激因子的速率以及受体占据与生物活性关系的影响。
