Re: [ccp4bb] DDM

2012-03-27 Thread Daniel Picot
It is important to distinguish between the solubilisation and the purification steps: 1) During the solubisation step you need to care about the lipid/detergent ratio. The amount (not the concentration) of detergent (i.e. in non monomeric form, the detergent above the cmc) is important. You may

Re: [ccp4bb] DDM

2012-03-26 Thread Ho Leung Ng
Actually, DDM is the most successfully used detergent for membrane protein crystallization. See Newstead et al, Protein Sci. 17:466. But yes, the rule of thumb is that detergents that form smaller micelles give better diffracting crystals, but are more destabilizing. Ho Ho Leung Ng University of

Re: [ccp4bb] DDM

2012-03-26 Thread Edward A. Berry
If I recall correctly cytochrome oxidase, which I believe was the first protein purified with DDM, requires about 10x cmc in column buffers to keep it soluble. Check for papers from 1970's or 80's by S. Ferguson-Miller. Cytochrme bc1 complex, on the other hand, is perfectly clear in 1 cmc and can

Re: [ccp4bb] DDM

2012-03-26 Thread Joao Dias
.AC.UK Subject: [ccp4bb] DDM Hi All, Has anyone had any luck purifying membrane proteins with DDM (n-dodecyl-D-maltoside) using concentration of detergent ~1-2 x CMC ? (Its CMC is very low: 0.009%). I would like to keep it as low as possible, so I don't have too much DDM around when I

Re: [ccp4bb] DDM

2012-03-26 Thread Das, Debanu
bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Katarzyna Rudzka Sent: Monday, March 26, 2012 10:17 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] DDM Hi All, Has anyone had any luck purifying membrane proteins with DDM (n-dodecyl-D-maltoside) using concentration of detergent ~1-2 x CMC

Re: [ccp4bb] DDM

2012-03-26 Thread Kelly Daughtry
I generally use 1 - 2% DDM for extraction only, but lower the concentration to 0.01% for following steps (i.e. NiNTA and gel filtration). The excess DDM is washed away by using a lower concentration in your wash and elution buffers. Kelly *** Ke

Re: [ccp4bb] DDM

2012-03-26 Thread yybbll
Hi, I used 0.017% or 0.012%. My protein is very stable at this concentration. Good luck. Lin 2012-03-26 yybbll Hi All, Has anyone had any luck purifying membrane proteins with DDM (n-dodecyl-D-maltoside) using concentration of detergent ~1-2 x CMC ? (Its CMC is very low: 0.009%).

[ccp4bb] DDM

2012-03-26 Thread Katarzyna Rudzka
Hi All, Has anyone had any luck purifying membrane proteins with DDM (n-dodecyl-D-maltoside) using concentration of detergent ~1-2 x CMC ? (Its CMC is very low: 0.009%). I would like to keep it as low as possible, so I don't have too much DDM around when I get to the crystallization step. I wond

Re: [ccp4bb] DDM crystals

2012-01-11 Thread Jacob Keller
What exactly is your question--I saw tons of "crystals" of DDM and PEGs, I think especially P400, if I recall correctly. JPK On Wed, Jan 11, 2012 at 7:12 AM, Patrick Loll wrote: > Does anyone have any experience with formation of crystals of dodecyl > maltoside in the presence of PEG? > Pat > >

[ccp4bb] DDM crystals

2012-01-11 Thread Patrick Loll
Does anyone have any experience with formation of crystals of dodecyl maltoside in the presence of PEG? Pat --- Patrick J. Loll, Ph. D. Professor of Biochemistry & Molecular Biology Director, Biochemistry Gradu

Re: [ccp4bb] DDM artifacts?

2008-05-23 Thread Ed Pozharski
> ps. in passing, it seems like it would be a great idea to get together an > excel database of all false-positive results (e.g. phosphate salt crystals) > commonly found in the usual crystal screens. One could then search it to see > whether one's current crystallization conditions have be vill

Re: [ccp4bb] DDM artifacts?

2008-05-23 Thread R.M. Garavito
Jacob, I doubt that the spherulites formed in the presence of detergents are "primary" detergent phenomenon. However, detergent micelles and the protein-detergent aggregates (please don't say protein-detergent micelles) will condense (phase) out in the presence of high salt or polymers t

[ccp4bb] DDM artifacts?

2008-05-22 Thread Jacob Keller
Sorry for this non-CCP4 question, but I know no better venue to ask this: Do people see detergent spherulites or other artifacts in crystal screens in the presence of dodecyl-maltoside or other detergents? Are there any papers about this? I have seen some papers talking about the relationships