兔肌肉磷酸果糖激酶在pH 7.0时的自我缔合：化学计量学

Self-association of rabbit muscle phosphofructokinase at pH 7.0: stoichiometry.

作者信息

Hesterberg L K, Lee J C

出版信息

Biochemistry. 1981 May 12;20(10):2974-80. doi: 10.1021/bi00513a040.

Abstract

The self-association of rabbit muscle phosphofructokinase at pH 7.0 was investigated by velocity sedimentation. The process was demonstrated to be in a rapid, dynamic equilibrium. The concentration dependence of the weight-average sedimentation coefficient was monitored within the range of 10-750 microgram/mL. The sedimentation properties of phosphofructokinase were analyzed by theoretical simulations or an associating system in rapid equilibrium. In the absence of any ligands and at a temperature of 23 degrees C, the simplest computed model which gives the best fit between theoretical and experimental points can be described as progressive association of monomer in equilibrium or formed from tetramer in equilibrium or formed from 16-mer with apparent equilibrium constants K4 = 5.06 X 10(5) (mL/mg)3 and K16 = 3.25 X 10(23) (mL/mg)15. However, at 5 degrees C, the equilibrium was altered and can best be described as monomer in equilibrium or formed from dimer in equilibrium or formed from tetramer in equilibrium or formed from 16-mer.

摘要

通过速度沉降法研究了兔肌磷酸果糖激酶在pH 7.0时的自缔合作用。结果表明该过程处于快速的动态平衡中。在10 - 750微克/毫升的浓度范围内监测了重均沉降系数的浓度依赖性。通过理论模拟或快速平衡中的缔合体系分析了磷酸果糖激酶的沉降性质。在没有任何配体且温度为23℃的情况下，能使理论点与实验点最佳拟合的最简单计算模型可描述为单体在平衡中逐步缔合，或由四聚体在平衡中形成，或由16聚体形成，其表观平衡常数K4 = 5.06×10⁵（毫升/毫克）³和K16 = 3.25×10²³（毫升/毫克）¹⁵。然而，在5℃时，平衡发生了改变，最好描述为单体在平衡中，或由二聚体在平衡中形成，或由四聚体在平衡中形成，或由16聚体形成。