Dear CCP4 colleagues,
We have a protein that is composed of two domains
connected by a short peptide linker. We have some indirect evidence showing
that the two domains may somehow move against each other when exposed to
different pH. It is unlikely to have any obvious secondary structure
Hi,
Sorry for the off-CCP4 question. Crystallographers are now doing everything...
We are looking for a fluorescent dye that will be turned on, or increase
signal, when pH goes from neutral to acidic. More specifically, we would like
to monitor the internalization of a protein into the
Hi,
We are trying to express a protein in insect cells as secreted. However, the
yield is VERY low using either pFastBAC or pAcGP67A. We have tried many
different constructs and this is the only one that at least expresses. I wonder
whether anyone knows how to improve. Many thanks.
Best,
Hi,
Sorry for the off topic question. I am looking for helps from someone who is
familiar with Centramate from Pall. We recently bought one and try to use it
for concentrating insect media with secreted proteins. Here is some more
information:
Pump: MasterFlex Console drive
Pump head:
Hi,
We would like to order two peptides for co-crystallizaiton. I notice that there
is a big price jump for peptide over 95% pure and over 98% pure. Do you think
95% purity is good enough? Another choice is to order crude peptides and purify
by ourselves. Crude peptide is much cheaper. But we
Hi there,
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Sorry for the off topic questions. We need your feedback.
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We are expressing a rat protein in insect cells. It is expressed as a secreted
protein with an N-terminal 6xHis tag. We can get about 4 mg of it from 1L
culture and everything looked quite normal at the very
Hi,
I have been trying to express a rat protein in bacteria. The MBP-fusion
expressed at very high level (~ 40 mg/L) while the GST-fusion and His-tag only
gave inclusion bodies. The problem is that all protein runs in the void volume
on a size-exclusion column (s-200, hepes, pH 7.4, 200
Hi,
I am wondering whether there is a way to turn a membrane protein with known
crystal structure into a water soluble protein by systematic mutagenesis. I
guess it should be doable if we introduce enough hydrophilic residues on the
surface. Has anyone tested this crazy idea before? Thank
Hi,
I am working on a 60 kDa C. elegans protein that is predicted to be mostly
alpha-helix. It is over-expressed in E.coli and the yield is about 1 mg/L of
cell culture. The CD spec at 4 degree showed the presence of dominant
alpha-helix. However, we dont have any functional assay to