Takeuchi Y, Birckbichler P J, Patterson M K
Banyu Tsukuba Research Institute, Ibaraki, Japan.
Experientia. 1995 Apr 15;51(4):339-42. doi: 10.1007/BF01928891.
We show that gamma-immunoglobulin (IgG) binds calmodulin (CaM) in a Ca(2+)-independent manner, with Kd value of (1.7 +/- 0.5) x 10(-7) M. A single IgG molecule maximally bound 10 CaM molecules. The binding is to the heavy chain or Fab portion, but not the Fc portion, of the IgG molecules. Ca2+ greatly diminished the interaction between IgG and CaM, with IC50 = 8-9 microM. These data give a novel insight into protein-protein interactions.
我们发现，γ-免疫球蛋白（IgG）以不依赖Ca²⁺的方式结合钙调蛋白（CaM），解离常数（Kd）值为（1.7±0.5）×10⁻⁷M。单个IgG分子最多可结合10个CaM分子。这种结合发生在IgG分子的重链或Fab部分，而非Fc部分。Ca²⁺可显著减弱IgG与CaM之间的相互作用，半数抑制浓度（IC50）为8 - 9微摩尔。这些数据为蛋白质 - 蛋白质相互作用提供了新的见解。
