Kushida Yo, Shigeno Masanori, Yamaguchi Masahiko
Department of Organic Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai, 980-8578 (Japan).
Chemistry. 2015 Sep 21;21(39):13788-92. doi: 10.1002/chem.201501474. Epub 2015 Aug 3.
Sulfonamidohelicene tetramer (M)-1 exhibits a concentration threshold and amplification phenomena in solution during helix-dimer formation from a random-coil. The (M)-tetramer is a random-coil below a threshold concentration, and the concentration of the helix-dimer is irreversibly amplified once the threshold concentration is exceeded. For example, a 15% increase in (M)-tetramer total concentration from 0.6 to 0.7 mM induces an 8-fold increase in the concentration of the helix-dimer, being 8:0.15=53-fold amplification, under temperature oscillation conditions between 47 and 49 °C. Experiments without oscillation also exhibit concentration amplification. The threshold and amplification phenomenon involves concentration hysteresis, being away from equilibrium, and self-catalysis. On the basis of this study, a proposal on how a biological cell senses concentration changes of a chemical substance is provided.
磺酰胺并四苯四聚体（M）-1在溶液中从无规卷曲形成螺旋二聚体的过程中表现出浓度阈值和放大现象。（M）-四聚体在阈值浓度以下是无规卷曲，一旦超过阈值浓度，螺旋二聚体的浓度就会不可逆地放大。例如，在47至49°C的温度振荡条件下，（M）-四聚体总浓度从0.6 mM增加15%至0.7 mM会导致螺旋二聚体浓度增加8倍，即8:0.15 = 53倍放大。无振荡的实验也表现出浓度放大。阈值和放大现象涉及浓度滞后、远离平衡和自催化。基于这项研究，提出了关于生物细胞如何感知化学物质浓度变化的建议。
