1l24
From Proteopedia
(New page: 200px<br /><applet load="1l24" size="450" color="white" frame="true" align="right" spinBox="true" caption="1l24, resolution 1.7Å" /> '''ENHANCED PROTEIN THER...) |
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| - | [[Image:1l24.jpg|left|200px]]<br /><applet load="1l24" size=" | + | [[Image:1l24.jpg|left|200px]]<br /><applet load="1l24" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1l24, resolution 1.7Å" /> | caption="1l24, resolution 1.7Å" /> | ||
'''ENHANCED PROTEIN THERMOSTABILITY FROM SITE-DIRECTED MUTATIONS THAT DECREASE THE ENTROPY OF UNFOLDING'''<br /> | '''ENHANCED PROTEIN THERMOSTABILITY FROM SITE-DIRECTED MUTATIONS THAT DECREASE THE ENTROPY OF UNFOLDING'''<br /> | ||
==Overview== | ==Overview== | ||
| - | It is proposed that the stability of a protein can be increased by | + | It is proposed that the stability of a protein can be increased by selected amino acid substitutions that decrease the configurational entropy of unfolding. Two such substitutions, one of the form Xaa----Pro and the other of the form Gly----Xaa, were constructed in bacteriophage T4 lysozyme at sites consistent with the known three-dimensional structure. Both substitutions stabilize the protein toward reversible and irreversible thermal denaturation at physiological pH. The substitutions have no effect on enzymatic activity. High-resolution crystallographic analysis of the proline-containing mutant protein (Ala-82----Pro) shows that its three-dimensional structure is essentially identical with the wild-type enzyme. The overall structure of the other mutant enzyme (Gly-77----Ala) is also very similar to wild-type lysozyme, although there are localized conformational adjustments in the vicinity of the altered amino acid. The combination of a number of such amino acid replacements, each of which is expected to contribute approximately 1 kcal/mol (1 cal = 4.184 J) to the free energy of folding, may provide a general strategy for substantial improvement in the stability of a protein. |
==About this Structure== | ==About this Structure== | ||
| - | 1L24 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4]. Active as [http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17] Full crystallographic information is available from [http:// | + | 1L24 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4]. Active as [http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1L24 OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Lysozyme]] | [[Category: Lysozyme]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Matthews, B | + | [[Category: Matthews, B W.]] |
[[Category: Nicholson, H.]] | [[Category: Nicholson, H.]] | ||
[[Category: hydrolase (o-glycosyl)]] | [[Category: hydrolase (o-glycosyl)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:40:24 2008'' |
Revision as of 11:40, 21 February 2008
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ENHANCED PROTEIN THERMOSTABILITY FROM SITE-DIRECTED MUTATIONS THAT DECREASE THE ENTROPY OF UNFOLDING
Overview
It is proposed that the stability of a protein can be increased by selected amino acid substitutions that decrease the configurational entropy of unfolding. Two such substitutions, one of the form Xaa----Pro and the other of the form Gly----Xaa, were constructed in bacteriophage T4 lysozyme at sites consistent with the known three-dimensional structure. Both substitutions stabilize the protein toward reversible and irreversible thermal denaturation at physiological pH. The substitutions have no effect on enzymatic activity. High-resolution crystallographic analysis of the proline-containing mutant protein (Ala-82----Pro) shows that its three-dimensional structure is essentially identical with the wild-type enzyme. The overall structure of the other mutant enzyme (Gly-77----Ala) is also very similar to wild-type lysozyme, although there are localized conformational adjustments in the vicinity of the altered amino acid. The combination of a number of such amino acid replacements, each of which is expected to contribute approximately 1 kcal/mol (1 cal = 4.184 J) to the free energy of folding, may provide a general strategy for substantial improvement in the stability of a protein.
About this Structure
1L24 is a Single protein structure of sequence from Bacteriophage t4. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.
Reference
Enhanced protein thermostability from site-directed mutations that decrease the entropy of unfolding., Matthews BW, Nicholson H, Becktel WJ, Proc Natl Acad Sci U S A. 1987 Oct;84(19):6663-7. PMID:3477797
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