Re: [ccp4bb] Negative density around C of COO-

Protein crystallography Programs for crystallography X-ray detectors
Basic tutorials:
Protein Peptide

CCP4bb navigation

CCP4bb <-- 2008 <-- May 2008 <-- 05 May 2008

Previous message:
Subject: Re: Negative density around C of COO-
From: Kevin P Madauss kevin {- dot -} p {- dot -} madauss {- at -} GSK {- dot -} COM
Date: 2008-05-05

Next message:
Subject: Summary: Negative density around COOH
From: Narayanan Ramasubbu ramasun1 {- at -} UMDNJ {- dot -} EDU
Date: 2008-05-05

Subject: Re: Negative density around C of COO-
From: Roger Rowlett rrowlett {- at -} MAIL {- dot -} COLGATE {- dot -} EDU
Date: 2008-05-05

Narayanan Ramasubbu wrote:
> Dear all:
> I am noticing that in some of my structures, at 1.5 A resolution, 1)
> there is some negative density around the C of the carboxyl groups.
> 2) I also notice the negative density around S in a disulfide region. It
> is as though the disulfide is broken.
>
> Could some body enlighten me on this feature?
>
Synchrotron radiation can cause free radical mediated damage to
proteins. The most frequently observed consequences are decarboxlation
of Asp and Glu, and the breakage of disulfide bonds. See, for example,
Wiek et al. (2000) PNAS 97, 623-628, and Leiros et al. (2001) Acta
Cryst. D 57, 488-497.

Cheers,

--
------------------------------------------------------------------------
Roger S. Rowlett
Professor
Colgate University Presidential Scholar
Department of Chemistry
Colgate University
13 Oak Drive
Hamilton, NY 13346

tel: (315)-228-7245
ofc: (315)-228-7395
fax: (315)-228-7935
email: rrowlett@mail.colgate.edu

CCP4bb navigation

CCP4bb <-- 2008 <-- May 2008 <-- 05 May 2008

Previous message:
Subject: Re: Negative density around C of COO-
From: Kevin P Madauss kevin {- dot -} p {- dot -} madauss {- at -} GSK {- dot -} COM
Date: 2008-05-05

Next message:
Subject: Summary: Negative density around COOH
From: Narayanan Ramasubbu ramasun1 {- at -} UMDNJ {- dot -} EDU
Date: 2008-05-05