Re: [ccp4bb] Oligomer which lacks conformational cooperativity

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

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Subject: Oligomer which lacks conformational cooperativity
From: Jacob Keller j-keller2 {- at -} MD {- dot -} NORTHWESTERN {- dot -} EDU
Date: 2007-08-15

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Subject: Re: Oligomer which lacks conformational cooperativity
From: Jacob Keller j-keller2 {- at -} MD {- dot -} NORTHWESTERN {- dot -} EDU
Date: 2007-08-15

Subject: Re: Oligomer which lacks conformational cooperativity
From: Daniel Schlieper daniel {- dot -} schlieper {- at -} TUXOMANIA {- dot -} NET
Date: 2007-08-15

Hi Jacob,

as far as I understand it, proteins also oligomerise to share a stable
core. For example, some proteins form tetramers and minimise the material
needed to form a scaffold around their active centres. Could that be the
case for your protein as well?

Best regards, Daniel
--
Daniel Schlieper, PhD email: daniel.schlieper@tuxomania.net
Molecular Motors Group phone: +44 1883 722306 (x 305)
Marie Curie Research Institute fax : +44 1883 714375
The Chart, Oxted RH8 0TL, UK web : http://mc11.mcri.ac.uk

On Wed, 15 Aug 2007, Jacob Keller wrote:

> Sorry about this not being exactly CCP4 related, but I think it is still of general interest to the
> structural biology community:
>
> I am dealing with a membrane protein which seems, on the surface, to present a contradiction:
>
> We know from western blots and other data that this protein forms oligomers vehemently, which are
> all but impervious to monomerization under the most ruthless conditions--we cannot completely
> monomerize it. We have tried DTT, EDT, BME, all concentrations of SDS, PFO, temperature, and salt,
> and in various combinations (further suggestions are welcome.) Suffice it to say, this thing is a
> bona fide vicious oligomer.
>
> Here is the paradox: the functional data, on the surface, seem to imply that the protein acts
> independently, as if a monomer, without being influenced by its (tight) oligomeric partners, even
> though we think the functional mechanism is a conformational change. Is such a thing observed in
> the biochemical world? Are there any homo-oligomeric proteins out there, membrane-bound or
> otherwise, which exhibit conformational changes, and yet the protomers do not influence each other?
>
> If so, if the oligomerization has no functional significance, and the subunits do not exhibit
> crosstalk, what on earth is the reason for their oligomerization?
>
> All hypotheses and especially references would be greatly appreciated,
>
> Jacob Keller
>
>
> ***********************************
> Jacob Keller
> Northwestern University
> 6541 N. Francisco #3
> Chicago IL 60645
> (847)467-4049
> j-keller2@northwestern.edu
> ***********************************
>

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

Previous message:
Subject: Oligomer which lacks conformational cooperativity
From: Jacob Keller j-keller2 {- at -} MD {- dot -} NORTHWESTERN {- dot -} EDU
Date: 2007-08-15

Next message:
Subject: Re: Oligomer which lacks conformational cooperativity
From: Jacob Keller j-keller2 {- at -} MD {- dot -} NORTHWESTERN {- dot -} EDU
Date: 2007-08-15