Walter R D
Biochim Biophys Acta. 1976 Mar 11;429(1):137-46. doi: 10.1016/0005-2744(76)90036-x.
A nucleoside-dependent protein kinase (EC 2.7.1.37) was partially purified from Trypanosoma gambiense, the pathogenic agent of sleeping sickness. This enzyme catalyzes the phosphorylation of histone and protamine. Various nucleosides at the concentration of 10(-4) M stimulated the histone kinase activity about two-fold, whereas cyclic AMP and cyclic GMP were without effect. The pH-optimum for histone phosphorylation was at about pH 7.0. The enzyme activity absolutely depends on Mg2+, Mn2+ or Co2+. The apparent Km-value for histone was 0.3 mg/ml and those for ATP were 2 - 10(-4) M and 6 - 10(-5) M in the absence or presence of 10(-4) M adenosine respectively. IDP and ADP complete with ATP. The inhibition constants were calculated to be 2 - 10(-4) M and 2.5 - 10(-4) M, respectively. The molecular weight of the histone kinase was found to be 95 000 by gel filtration and 88 000 by sedimentation in a sucrose gradient.
从昏睡病的病原体冈比亚锥虫中部分纯化出一种核苷依赖性蛋白激酶（EC 2.7.1.37）。该酶催化组蛋白和鱼精蛋白的磷酸化。浓度为10^(-4) M的各种核苷可使组蛋白激酶活性提高约两倍，而环磷酸腺苷（cAMP）和环磷酸鸟苷（cGMP）则无此作用。组蛋白磷酸化的最适pH约为7.0。酶活性绝对依赖于Mg2+、Mn2+或Co2+。在不存在或存在10^(-4) M腺苷的情况下，组蛋白的表观Km值为0.3 mg/ml，ATP的表观Km值分别为2×10^(-4) M和6×10^(-5) M。肌苷二磷酸（IDP）和二磷酸腺苷（ADP）与ATP竞争。计算出的抑制常数分别为2×10^(-4) M和2.5×10^(-4) M。通过凝胶过滤法测得组蛋白激酶的分子量为95000，通过蔗糖梯度沉降法测得为88000。
