24小时热门版块排行榜    

查看: 5697  |  回复: 18
当前只显示满足指定条件的回帖,点击这里查看本话题的所有回帖

yanhui8558

金虫 (小有名气)

[求助] his标签蛋白纯化,不挂柱 已有1人参与

我一直在用大肠杆菌表达一个蛋白激酶,用pet21a载体,用过超声破碎和先溶菌酶处理和超声处理破碎。结果蛋白主要在沉淀中,上清中的量不多但还可以,主要问题是不怎么挂镍柱,用PBS平衡柱子,PH8.0, 30mM咪唑洗杂蛋白,250mM咪唑洗脱,跑蛋白电泳和western都是穿过液和上清条带都差不多,很苦恼,有没有高人指点一下啊。
回复此楼

» 收录本帖的淘帖专辑推荐

蛋白质生物学实验经验

» 猜你喜欢

» 本主题相关价值贴推荐,对您同样有帮助:

已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

ybs007

金虫 (小有名气)

【答案】应助回帖

★ ★
silicare(金币+2): 2011-07-14 12:40:55
yanhui8558(金币+1): 2011-07-14 17:01:43
很有可能是你融合的蛋白改变了构象,将6His包裹起来不能与镍柱亲和。由于你用的是pET-21a,貌似只有C端的6His,所以要么更换载体,或者更换其他的纯化标签,比如T7标签。
平生我自知
4楼2011-07-14 10:27:08
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
查看全部 19 个回答

zx1984

木虫 (正式写手)


amisking(金币+1): 鼓励应助 2011-07-11 20:14:00
我用pet28a载体表达蛋白,也用超声破碎和和先溶菌酶处理后超声处理破碎,和你一样的情况,也是不挂镍柱。后来用wash buffer浓度梯度洗也不好。很郁闷。
2楼2011-07-11 19:13:05
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

nnxqwei

至尊木虫 (职业作家)

【答案】应助回帖

yanhui8558(金币+1): 2011-07-12 09:35:27
确定纯化条件没有问题的条件下,考虑换一下6His的位置吧,把原来 的N端换到C端!!
3楼2011-07-12 03:21:44
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

jyh024

木虫 (正式写手)

【答案】应助回帖

★ ★ ★
yanhui8558(金币+2): 2011-07-14 17:02:13
lstt09nk(金币+3): 辛苦,感谢交流,欢迎常来 2011-07-17 20:22:27
The reasons may be:
•  Elution conditions are too mild (histidine-tagged protein still bound):
Elute with an increasing imidazole gradient or decreasing pH to
determine the optimal elution conditions.
• The protein has precipitated in the column: Try detergents or changed
NaCl concentration or elute under denaturing (unfolding) conditions
(use 4–8 M urea or 4–6 M Gua-HCl) to remove precipitated proteins. For
the next experiment, decrease amount of sample, or decrease protein
concentration by eluting with a linear imidazole gradient instead of
imidazole steps.
• Nonspecific hydrophobic or other interaction: Add a nonionic
detergent to the elution buffer (e.g. 0.2% Triton X-100) or change the NaCl
concentration.
• Concentration of imidazole in the sample and/or binding buffer is too
high: The protein is found in the flowthrough material. Decrease the
imidazole concentration.
• Target protein may not be histidine-tagged as expected: Verify DNA
sequence of the gene. Analyze samples taken before and after induction
of expression with, for example, anti-His antibodies in Western blotting.
• Histidine-tag may be insufficiently exposed: The protein is found in the
flowthrough material. Perform purification of unfolded protein in urea or
Gua-HCl as for inclusion bodies.
5楼2011-07-14 16:44:28
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[找工作] 售SCI一区T0P文章,我:8O.55.1.O.5.4,科目齐全,可+急 +6 s3fFTmArrBt6 2026-09-13 6/300 2026-09-17 23:28 by cuPZTDXS3VOd
[硕博家园] 售一区SCI文章T0P,我:8O.551.O54,科目全,可十急 +7 LwdutQ8HoqWP 2026-09-13 7/350 2026-09-17 22:53 by cuPZTDXS3VOd
[考研] 售SCI一区文章,我:8.O.551.O.5.4,科目全,可伽急 +8 QUjhNVAcOSff 2026-09-13 9/450 2026-09-17 22:05 by cuPZTDXS3VOd
[有机交流] 各位大神,目前国内有哪些比较好用的逆合成软件? 20+3 zapen 2026-09-15 7/350 2026-09-17 16:40 by 北京莱茵编辑
[考研] 售SCI一区T0P文章,我:8.O.55.1.O54,科目全,可伽急 +3 5BDX0d0WFp7t 2026-09-15 3/150 2026-09-17 16:27 by 0ngsZVSCTS7z
[硕博家园] 售SCI一区文章,我:8.O.551.O.5.4,科目全,可伽急 +3 mibUvS8DDCwf 2026-09-15 3/150 2026-09-17 16:03 by 0ngsZVSCTS7z
[考研] 售SCI一区文章,我:8.O.55.1.O.54,科目齐全,可伽急 +6 Aj1rhIDL5ixY 2026-09-14 6/300 2026-09-17 14:17 by ObVzqQQh1rrE
[找工作] 售SCI文章,我:8O.5.5.1O.54,科目全,可十急 +3 23jxep3nCNZb 2026-09-14 3/150 2026-09-17 13:39 by ObVzqQQh1rrE
[考研] 售SCI一区T0P文章,我:8O.55.1.O.54,科目全,可伽急 +6 23jxep3nCNZb 2026-09-14 6/300 2026-09-17 13:29 by ObVzqQQh1rrE
[找工作] 售SCI一区T0P文章,我:8.O.55.1.O54,科目全,可伽急 +5 s3fFTmArrBt6 2026-09-14 6/300 2026-09-17 12:29 by ObVzqQQh1rrE
[找工作] 售SCI一区文章,我:8O5.5.1.O5.4,科目全,可伽急 +8 3n8v2C8RimXI 2026-09-13 8/400 2026-09-17 11:27 by UAIjTRMuUFoj
[公派出国] 售SCI文章,我:8O5.5.1.O.54,科目齐全,可+急 +3 23jxep3nCNZb 2026-09-14 3/150 2026-09-17 03:52 by k06BKNblrGRH
[考研] 售SCI-T0P文章,我:8O.5.5.1.O.54,科目齐全,可+急 +5 6F5UbRU2I5hL 2026-09-14 5/250 2026-09-17 03:14 by Tql5LQhh5rLK
[考研] 售SCI文章,我:8O5.5.1.O.54,科目齐全,可+急 +6 6F5UbRU2I5hL 2026-09-14 6/300 2026-09-17 03:14 by Tql5LQhh5rLK
[找工作] 售SCI一区T0P文章,我:8.O.55.1.O.5.4,科目全,可+急 +6 6F5UbRU2I5hL 2026-09-14 6/300 2026-09-17 03:04 by Tql5LQhh5rLK
[考研] 售SCI一区文章,我:8O5.5.1.O5.4,科目全,可伽急 +4 23jxep3nCNZb 2026-09-14 4/200 2026-09-16 21:03 by MHf40yA0Uhyb
[考研] 售SCI一区T0P文章,我:8.O.55.1.O.5.4,科目全,可+急 +4 s3fFTmArrBt6 2026-09-13 6/300 2026-09-16 16:00 by i3KBRD19ERkG
[硕博家园] 售SCI一区T0P文章,我:8.O55.1.O.54,科目全,可十急 +5 s3fFTmArrBt6 2026-09-14 5/250 2026-09-15 16:35 by CgyNCDVNhGVg
[公派出国] 售SCI一区T0P文章,我:8O.55.1.O.5.4,科目齐全,可+急 +4 3n8v2C8RimXI 2026-09-13 5/250 2026-09-15 14:58 by CgyNCDVNhGVg
[教师之家] 售SCI文章,我:8O.5.5.1O.54,科目全,可十急 +3 6F5UbRU2I5hL 2026-09-14 3/150 2026-09-15 08:14 by C79jjtjAKjEn
信息提示
请填处理意见