Wang H X, Ng T B
Department of Microbiology, China Agricultural University, Beijing and State Key Laboratory for Agrobiotechnology, Beijing, China.
Biochem Biophys Res Commun. 2006 Mar 31;342(1):349-53. doi: 10.1016/j.bbrc.2006.01.109. Epub 2006 Jan 31.
A simple purification protocol, involving ion exchange chromatography on DEAE-cellulose and CM-cellulose and fast protein liquid chromatography-gel filtration on Superdex 75, was employed to isolate a Kunitz-type trypsin inhibitor with antifungal activity and a novel lectin from Pseudostellaria heterophylla roots. Both the trypsin inhibitor and the lectin were unadsorbed on DEAE-cellulose and adsorbed on CM-cellulose. They could be separated from one another by gel filtration on Superdex 75 in which the 36-kDa lectin appeared as the first peak and the 20.5-kDa trypsin inhibitor as the second peak. P. heterophylla trypsin inhibitor exhibited a trypsin inhibitory potency similar to that of soybean trypsin inhibitor. It also demonstrated antifungal activity toward Fusarium oxysporum like aprotinin and Kunitz-type trypsin inhibitors from soybeans and lima beans. P. heterophylla lectin was devoid of antifungal activity and exhibited low thermostability and also lability in the presence of acid and alkali. The novel aspects of the present report include demonstration of antifungal activity in Kunitz-type trypsin inhibitors and isolation of a novel lectin as well as a trypsin inhibitor from roots.
采用一种简单的纯化方案，包括在DEAE-纤维素和CM-纤维素上进行离子交换色谱以及在Superdex 75上进行快速蛋白质液相色谱-凝胶过滤，从太子参根部分离出一种具有抗真菌活性的Kunitz型胰蛋白酶抑制剂和一种新型凝集素。胰蛋白酶抑制剂和凝集素在DEAE-纤维素上均不被吸附，而在CM-纤维素上被吸附。通过在Superdex 75上进行凝胶过滤可将它们彼此分离，其中36 kDa的凝集素作为第一个峰出现，20.5 kDa的胰蛋白酶抑制剂作为第二个峰出现。太子参胰蛋白酶抑制剂表现出与大豆胰蛋白酶抑制剂相似的胰蛋白酶抑制效力。它还对尖孢镰刀菌表现出抗真菌活性，类似于抑肽酶以及来自大豆和利马豆的Kunitz型胰蛋白酶抑制剂。太子参凝集素没有抗真菌活性，表现出较低的热稳定性，并且在酸碱存在下也不稳定。本报告的新内容包括证明Kunitz型胰蛋白酶抑制剂具有抗真菌活性，以及从根部分离出一种新型凝集素和一种胰蛋白酶抑制剂。
