Wang H, Ng T B
Department of Microbiology, China Agricultural University, Beijing, China.
Biochem Biophys Res Commun. 2001 Nov 23;289(1):120-4. doi: 10.1006/bbrc.2001.5963.
A deoxyribonuclease distinct from the previously isolated asparagus ribosome-inactivating proteins, possessing a molecular weight of 30 kDa and requiring a pH of 7.5 for optimum hydrolytic activity toward herring sperm DNA, was isolated from Asparagus officinalis seeds. The isolation procedure involved extraction with saline, (NH(4))(2)SO(4) precipitation, ion-exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion-exchange chromatography on CM-Sepharose, and FPLC gel filtration on Superdex 75. The doxyribonuclease was unadsorbed onto DEAE-cellulose and Affi-gel blue gel and adsorbed onto CM-Sepharose. It exhibited the novel N-terminal sequence, GIEVIKIREL. The deoxyribonuclease was purified to a specific activity of 1584 units/mg. It was devoid of ribonuclease, protease, and HIV-1 reverse transcriptase-inhibitory activities. However, it inhibited cell-free translation in a rabbit reticulocyte lysate system with an IC(50) of 20 microM. It exhibited antifungal activity toward Botrytis cinerea but not toward Fusarium oxysporum and Mycosphaerella arachidicola.
从芦笋种子中分离出一种脱氧核糖核酸酶，它与先前分离的芦笋核糖体失活蛋白不同，分子量为30 kDa，对鲱鱼精DNA具有最佳水解活性时需要pH 7.5。分离过程包括用盐水提取、硫酸铵沉淀、在DEAE-纤维素上进行离子交换色谱、在Affi-凝胶蓝胶上进行亲和色谱、在CM-琼脂糖凝胶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。该脱氧核糖核酸酶不吸附在DEAE-纤维素和Affi-凝胶蓝胶上，而是吸附在CM-琼脂糖凝胶上。它具有新的N端序列GIEVIKIREL。该脱氧核糖核酸酶纯化后的比活性为1584单位/毫克。它没有核糖核酸酶、蛋白酶和HIV-1逆转录酶抑制活性。然而，它在兔网织红细胞裂解物系统中抑制无细胞翻译，IC50为20 μM。它对灰葡萄孢具有抗真菌活性，但对尖孢镰刀菌和落花生球腔菌没有抗真菌活性。
