摘要
经ＤＥＡＥ－Ｓｅｐｈａｃｅｌ、ＵｌｔｒｏｇｅｌＡｃＡ ３４、Ｈｅｐｔｙｌａｍ ｉｎｅ－Ｓｅｐｈａｒｏｓｅ 和Ｂｉｏ Ｓｃａｌｅ Ｑ２等四步层析从牛脑皮层膜中同时纯化出抑制型Ｇ 蛋白（ｉｎｈｉｂｉｔｏｒｙ Ｇ ｐｒｏｔｅｉｎ， Ｇｉ）和Ｏ型Ｇ蛋白（ｏｔｈｅｒ Ｇ ｐｒｏ－ｔｅｉｎ， Ｇｏ）．对Ｇｏ 的选择性激活使Ｇｉ 和Ｇｏ 的分离大为简化，并使二者的大量制备成为可能．纯化的Ｇ 蛋白的ＳＤＳ－ＰＡＧＥ银染显示单一蛋白带，其结合［３５Ｓ］ＧＴＰγＳ的活性分别提高６８倍和１２４倍．用圆二色光谱法（ＣＤ）测量了纯化的Ｇ蛋白的二级结构．
Co purification of G i and G o from bovine cortex membranes was successfully performed by four steps of chromatography including DEAE Sephacel, Ultrogel AcA 34, Heptylamine Sepharose and Bio Scale Q 2. Selective activation of G o by AMF, a kind of G protein activator, accompanied with anion exchange chromatography greatly simplified the seperation of G i from G o and made possible the preparation of G i and G o on a large scale. The concentration of AMF and Lubrol PX was found to be essential for the separation of G i from G o by anion exchange chromatography. [ 35 S]GTP γS binding activities of the purified G i and G o were increased 68 folds and 124 folds respectively. High purity of the preparation was also showed by SDS PAGE visualized with silver staining. Secondary structure of the purified G i and G o was monitored by circular dichroism spectrophotometer. The CD spectra of the two G proteins were very similar.
出处
《中国生物化学与分子生物学报》
CAS
CSCD
1999年第6期937-942,共6页
Chinese Journal of Biochemistry and Molecular Biology
基金
中国科学院〈九五〉基础研究基金
