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From: "Dr. Artem Evdokimov" <eudokima@mail.ncifcrf.gov>
Organization: NCI-FCRDC PSB-MCL Protein Engineering
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Subject: Re: Salt bridges
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Date: Sun, 29 Apr 2001 14:39:40 -0400
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You could try scanning calorimetry in D2O and D2O/H2O mixtures, however
interpreting these results would be quite tricky.

NMR might work, but you most likely won't be able to observe the protons
of the salt bridge directly (high exchange) more likely to observe the
changes in other nuclei of the residues involved in the bridge(s),
especially if you play with pH and other variables. If the protein
crystallizes then your best bet is still doing the structure - it is not
as difficult as it may seem (with a known starting structure, provided
that crystals of the mutant behave well, it only takes 1-2 days to
obtain the structure of the mutant).

Artem

Mavrommatis Kostas wrote:
> 
> Hi everybody,
> does anybody knows if there is an experimental method for identifying the
> formation of a salt bridge, apart from structural studies?
> I have some mutants of a protein that are supposed to form different number
> of salt bridges and I want to verify this.
> Is there a way to do this by using chaotropic salts or DSC? or something
> else?
> 
> I thank you in advance.

-- 
|Dr. Artem Evdokimov   Protein Engineering |
| NCI-Frederick        Tel. (301)846-5401  |
|              FAX (301)846-7148           |
|        eudokima@mail.ncifcrf.gov         |
|      http://www.ncifcrf.gov/plague       |


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