Re: [ccp4bb] Solvent content of membrane protein crystals

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

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Subject: Solvent content of membrane protein crystals
From: Savvas Savvides savvas {- dot -} savvides {- at -} UGENT {- dot -} BE
Date: 2007-09-22

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From: James Whisstock James {- dot -} Whisstock {- at -} MED {- dot -} MONASH {- dot -} EDU {- dot -} AU
Date: 2007-09-22

Subject: Re: Solvent content of membrane protein crystals
From: Edward Berry eaberry {- at -} LBL {- dot -} GOV
Date: 2007-09-22

I would use a very general definition for "solvent",
including disordered detergent and lipids.
As you know in many cases ordered detergents and lipids
have been modeled in the coordinates, so they are part of
the model not the solvent. In some cases I think waters
should be included in the model not solvent- say for
structural waters buried in the protein at least.

Ed

Savvas Savvides wrote:

> Dear colleagues,
>
> in estimating the solvent content of membrane protein crystals it would
> only seem reasonable that micelle size should also be taken into
> account. Depending on the aggregation number and MW of a given
> detergent, the concentation of detergent used, and the buffer
> conditions, one may have micelles on the order of 15-25 kDa or even
> 35-50 kDa for detergents with alkyl chains of more than 10 carbons.
>
> However, when I took a look in a handful of papers reporting Matthews'
> numbers for membrane protein crystals, it became apparent that only the
> protein MW is used in such estimates. I am beginning to wonder if one
> should even bother reporting a Matthews number for a membrane protein
> crystal given the uncertainties surrounding size and role of micelles
> in crystal packing.
>
> Any thoughts on this?
>
> best wishes
> Savvas

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Solvent content of membrane protein crystals
From: Savvas Savvides savvas {- dot -} savvides {- at -} UGENT {- dot -} BE
Date: 2007-09-22

Next message:
Subject: Re: worst mr probes
From: James Whisstock James {- dot -} Whisstock {- at -} MED {- dot -} MONASH {- dot -} EDU {- dot -} AU
Date: 2007-09-22