Re: [ccp4bb] Off topic: His-tag purification

2012-01-16 Thread Tim Gruene
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Dear Theresa, you might also try changing the resin. I have worked on a protein which would no bind to Ni-NTA (Qiagen) at all but could greatly be purified when using Ni-IDA (then Pharmacia) instead. The protein expressed to about 60mg/l LB in E.

Re: [ccp4bb] Off topic: His-tag purification

2012-01-16 Thread Gregory T Costakes
- From: Theresa H. Hsu theresah...@live.com To: CCP4BB@JISCMAIL.AC.UK Sent: Sunday, January 15, 2012 1:23:33 PM Subject: [ccp4bb] Off topic: His-tag purification Hi all I have a His-tagged soluble protein (8 His residues added to 90 kDa protein) that do not bind to IMAC column based

[ccp4bb] AW: [ccp4bb] Off topic: His-tag purification

2012-01-16 Thread Metlitzky, Moritz, Dr.
/krappmannhttp://www.helmholtz-muenchen.de/en/toxi/krappmann From: Theresa H. Hsu theresah...@live.com To: CCP4BB@JISCMAIL.AC.UK Sent: Sunday, January 15, 2012 1:23:33 PM Subject: [ccp4bb] Off topic: His-tag purification Hi all I have a His-tagged soluble protein (8

Re: [ccp4bb] Off topic: His-tag purification

2012-01-16 Thread Luca Jovine
…alternatively, depending on what is the source of your protein, you might have to dialyze the (concentrated) sample before applying it to IMAC. Insect cell media, in particular, can be pretty good at stripping off Ni2+ from IMAC supports. HTH, Luca

[ccp4bb] Off topic: His-tag purification

2012-01-15 Thread Theresa H. Hsu
Hi all I have a His-tagged soluble protein (8 His residues added to 90 kDa protein) that do not bind to IMAC column based on flowthrough showing up with Western blott. Do you have suggestions to improve the binding? Binding condition is 50 mM Tris-HCl 8.0, 300 mM NaCl, 10 mM imidazole pH to

Re: [ccp4bb] Off topic: His-tag purification

2012-01-15 Thread Edward A. Berry
Maybe the His Tag is blocked by the folded protein. Try using 6M Guanidine-HCL and see if it sticks. Then you will need to find some way of refolding your protein, if you want to crystallize it. Theresa H. Hsu wrote: Hi all I have a His-tagged soluble protein (8 His residues added to 90 kDa

Re: [ccp4bb] Off topic: His-tag purification

2012-01-15 Thread Artem Evdokimov
Your protein is either misfolded/aggregated or the his tag is chewed off/never translated. You could try detergents etc. To improve the state of the protein but I would also doubl check sequence for early termination (assuming cterm) or protelysis. Artem On Jan 15, 2012 12:23 PM, Theresa H. Hsu

Re: [ccp4bb] Off topic: His-tag purification

2012-01-15 Thread Cécile Breyton
I addition to the suggestions of checking folding/aggregation/proteolysis, you might also want to try lowering the NaCl concentration. Whereas I like having some to prevent ion exchange effects on the IMAC column, I have had the case of a protein that does not bind if NaCl is present. Binds

Re: [ccp4bb] Off topic: His-tag purification

2012-01-15 Thread Artem Evdokimov
This likely means that your imac column is acting as an ion exchanger :-) On Jan 15, 2012 2:50 PM, Cécile Breyton cecile.brey...@ibs.fr wrote: I addition to the suggestions of checking folding/aggregation/**proteolysis, you might also want to try lowering the NaCl concentration. Whereas I like

Re: [ccp4bb] Off topic: His-tag purification

2012-01-15 Thread Xiaodi Yu
Xiaodi Date: Sun, 15 Jan 2012 18:23:33 + From: theresah...@live.com Subject: [ccp4bb] Off topic: His-tag purification To: CCP4BB@JISCMAIL.AC.UK Hi all I have a His-tagged soluble protein (8 His residues added to 90 kDa protein) that do not bind to IMAC column based on flowthrough

Re: [ccp4bb] Off topic: His-tag purification

2012-01-15 Thread Jodie Johnston
well to the Ni2+. Hope that helps Cheers Jodie From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Theresa H. Hsu [theresah...@live.com] Sent: Monday, 16 January 2012 7:23 a.m. To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Off topic: His-tag

Re: [ccp4bb] Off topic: His-tag purification

2012-01-15 Thread Theresa H. Hsu
On Sun, 15 Jan 2012 23:12:46 +, Xiaodi Yu uppsala@hotmail.com wrote: Another thing you can try is using Cu ion instead of Ni ion. It will fasten the binding. Can I know what is difference in binding chemistry of Ni, Cu, Co and Fe? Is there specific rule for binding affinity versus

Re: [ccp4bb] Off topic: His-tag purification

2012-01-15 Thread Artem Evdokimov
Typically affinity goes down in order cu ni co zn mg Artem On Jan 15, 2012 7:35 PM, Theresa H. Hsu theresah...@live.com wrote: On Sun, 15 Jan 2012 23:12:46 +, Xiaodi Yu uppsala@hotmail.com wrote: Another thing you can try is using Cu ion instead of Ni ion. It will fasten the