RE: [ccp4bb]: Thermostability vs Structure

["Flip Hoedemaeker" <hoedemae@chem.leidenuniv.nl>]

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Hi Francisco,

I'm afraid there's no simple answer to your complex question. In General,
you have to carefully look at all aa substitutions between a thermophile
enzyme and its no-thermophile homologue. You could find generally
stabilising substitutions, like gly-->ala, or ala-->pro for instance, but
some stabilising mutations are hard to explain.

Flip

-----Original Message-----
From: owner-ccp4bb@dl.ac.uk [mailto:owner-ccp4bb@dl.ac.uk]On Behalf Of
Francisco J. Enguita
Sent: Tuesday, December 04, 2001 12:53
To: ccp4bb@dl.ac.uk
Subject: [ccp4bb]: Thermostability vs Structure


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Dear all :

Sorry for posting this non-CCP4 question.

I am dealing with a structure of an oxidase. I have relatively decent
data till 1.7 A, and the model is practically refined. The protein is
very thermostable with a half life of 2 hours at 80ºC.

I have compared the structure with other "normal" oxidases, and I am not
able to find suitable differences to explain thermostability in terms of
structure. I have analyzed presence of disulfide bridges, salt bridges,
packing , etc ..

Is/was anybody dealing with a similar problem ?. What should be the
factors to analyze for the explanation of thermostability ?

Best regards

Francisco



============================================

Francisco J. Enguita, Ph.D.
Protein Crystallography laboratory
Instituto de Tecnologia Química e Biológica
Ap. 127
2781-901 Oeiras
PORTUGAL
Phone : 351-21-4469669
Fax : 351-21-4411277
E-mail : fenguita@itqb.unl.pt

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