B. 为了不破坏蛋白之间的相互作用,洗涤步骤是否有需要注意的地方?
1. Washing beads gently.
2. Add glycerol to final 5% if necessary, it can make protein stable in some cases.
3. Add phosphase inhibitors if the PPI may relate to the statuse of protein phosphrylation.
1. You can decrease the concentration of salts and detergent, e.g. 50mM Tris HCl pH 7.5, 150 mM NaCl, 0. 1% Triton X-100/NP-40, and using 1/3-1/5 of proteinase/phosphase inhibitors after first washing because most non-binding proteins are washing away.
2. You can use linker reagent to treat sample if you are so worry about decrease of PPI.
具体操作步骤如下:1 蛋白用非变性裂解液(不含SDS)裂解,定量,加入HSP90一抗(rat),1mg蛋白对1ug的抗体量,4度摇床摇晃24h;
2 ug 抗体 would be better
2 加入珠子,500ug蛋白对应20ul 50%的珠子,4度摇床摇晃过夜;
25-40 ul 50%的珠子would be better. o/n is OK.
3 反应结束后4度2500r,3min离心,取出上清,珠子用PBS轻柔地清洗两边(用PBS是因为它只含盐,不含去垢剂,为了不破坏蛋白之间的相互作用),每次洗完4度2500r,3min离心,弃上清。
用PBS轻柔地清洗: when you write paper for publication, are you sure your reason can be accepted by reviewer?
4 清洗后的珠子加入Loading buffer 100度煮10min,电泳,western.
结果HSP9080%都能沉淀下来,但是和它结合的蛋白如AKT等非常少。郁闷。
Read this paper carefully
Proc Natl Acad Sci U S A. 2000 September 26; 97(20): 10832–10837作者: 莓菓333 时间: 2013-7-3 16:03