Hi Jon
           there is no surface exposed cysteine nearby which can potentially 
make disulfide bond with the modified cysteine intramolecularily.

Dhiraj
________________________________
From: Jon Cooper <jon.b.coo...@protonmail.com>
Sent: Sunday, November 1, 2020 7:41 AM
To: Srivastava, Dhiraj <dhiraj-srivast...@uiowa.edu>; CCP4BB@JISCMAIL.AC.UK 
<CCP4BB@JISCMAIL.AC.UK>
Subject: Re: [ccp4bb] Cysteine oxidation product

Hello,

does the protein you added cysteine to (I assume you mean by mutagenesis) have 
another cysteine which could make an intra molecular disulphide with it? That 
would probably not show on non-reducing SDS?

Best wishes, Jon Cooper



-------- Original Message --------
On 31 Oct 2020, 15:58, Srivastava, Dhiraj < dhiraj-srivast...@uiowa.edu> wrote:

Hi All
        I added an extra cysteine residue to one of my protein interactions 
partners and somehow it increased the affinity in the absence of reducing agent 
however in the presence of reducing agent, the affinity is same. there is no 
disulfide bond formation between the two interaction partner as in non-reducing 
SDS-PAGE, I see the molecular weights corresponding to only the individual 
proteins and not the sum of two.
Does anyone has ever seen this? at pH 8.0, what is the probability that a 
surface exposed cysteine will have a net negative charge and still not very 
reactive? can it exist as thiolate, sulfinate or sulfonate ion? is there any 
such example in literature that anyone knows?

Thank you
Dhiraj

________________________________

To unsubscribe from the CCP4BB list, click the following link:
https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1

########################################################################

To unsubscribe from the CCP4BB list, click the following link:
https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1

This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list 
hosted by www.jiscmail.ac.uk, terms & conditions are available at 
https://www.jiscmail.ac.uk/policyandsecurity/

Reply via email to