[ccp4bb] protein degradation in crystal

2013-01-16 Thread LISA
Hi All, I have an 36KD protein which can be crystallize in two days. Most of the crystals are very big. But all cystals have poor resolution,lower than 3.8 A. I picked some crystals, washed them in the mother solution and then run SDS-PAGE. It is surprised to find that different cystals have

Re: [ccp4bb] protein degradation in crystal

2013-01-16 Thread jens Preben Morth
Dear Lisa It is not uncommon to see breakdown products when you run crystals on gel. Espesially if they are older crystals, sometimes you even see higher molecular bands, these are probably due to intra molecular cross links formed over time. If you are worried about stability, try to

Re: [ccp4bb] protein degradation in crystal

2013-01-16 Thread John Domsic
Hi Lisa, Speed is definitely a big factor here. With a protein I work with I can get large crystals in myriad conditions that only diffract to about 4-5 Ang. What I ended up doing was taking these crystals and seeding entire screens. I found that not only would crystals appear sooner but it

Re: [ccp4bb] protein degradation in crystal

2013-01-16 Thread David Schuller
Were the crystals which run different on gels from the same drop, or separate drops? Yes, it is possible that the protein is being cleaved in the crystal (self-cleavage?); but it may also be that it is being cleaved in the mother liquor, and that crystallization is enriching one form or

Re: [ccp4bb] protein degradation in crystal

2013-01-16 Thread David Schuller
Were the crystals which run different on gels from the same drop, or separate drops? Yes, it is possible that the protein is being cleaved in the crystal (self-cleavage?); but it may also be that it is being cleaved in the mother liquor, and that crystallization is enriching one form or

Re: [ccp4bb] protein degradation in crystal

2013-01-16 Thread Herman . Schreuder
used for crystallization. Herman From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of John Domsic Sent: Wednesday, January 16, 2013 2:22 PM To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] protein degradation

Re: [ccp4bb] protein degradation in crystal

2013-01-16 Thread Tom Murray-Rust
@JISCMAIL.AC.UK *Subject:* Re: [ccp4bb] protein degradation in crystal Hi Lisa, Speed is definitely a big factor here. With a protein I work with I can get large crystals in myriad conditions that only diffract to about 4-5 Ang. What I ended up doing was taking these crystals and seeding entire

Re: [ccp4bb] protein degradation in crystal

2013-01-16 Thread Joe Chen
*Subject:* Re: [ccp4bb] protein degradation in crystal Hi Lisa, Speed is definitely a big factor here. With a protein I work with I can get large crystals in myriad conditions that only diffract to about 4-5 Ang. What I ended up doing was taking these crystals and seeding entire screens. I