1mgo
From Proteopedia
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caption="1mgo, resolution 1.20Å" /> | caption="1mgo, resolution 1.20Å" /> | ||
'''Horse Liver Alcohol Dehydrogenase Phe93Ala Mutant'''<br /> | '''Horse Liver Alcohol Dehydrogenase Phe93Ala Mutant'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The relationship between substrate mobility and catalysis was studied with | + | The relationship between substrate mobility and catalysis was studied with wild-type and Phe93Ala (F93A) horse liver alcohol dehydrogenase (ADH). Wild-type ADH binds 2,3,4,5,6-pentafluorobenzyl alcohol in one position as shown by X-ray results, and (19)F NMR shows five resonances for the fluorines of the bound alcohol. The two meta-fluorines exchange positions with a rate constant of about 4 s(-1), indicating that mobility (ring flipping) of the benzyl alcohol is relatively restricted. The wild-type enzyme binds 2,3-difluorobenzyl alcohol in two alternative conformations that are related by a ring flip and a small translation of the fluorinated benzene ring, and the (19)F NMR spectrum shows three resonances for the two bound fluorines, consistent with the two orientations. Phe-93 interacts with the bound benzyl alcohols, and the F93A substitution decreases the rate constants for hydride transfer for benzyl alcohol oxidation and benzaldehyde reduction by 7.4- and 130-fold, respectively. The structure of F93A ADH crystallized with NAD(+) and 2,3,4,5,6-pentafluorobenzyl alcohol is similar to the structure of the wild-type enzyme complex except that the pentafluorobenzyl alcohol is not found in one position. The (19)F NMR spectrum of the F93A ADH-NAD(+)-pentafluorobenzyl alcohol complex shows three resonances for the bound fluorines. Line shape analysis of the spectrum suggests the bound pentafluorobenzyl ring undergoes rapid ring-flipping at about 20 000 s(-1). The F93A substitution greatly increases the mobility of the benzyl alcohol but modestly and differentially decreases the probability that the substrate is preorganized for hydride transfer. |
==About this Structure== | ==About this Structure== | ||
| - | 1MGO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Equus_caballus Equus caballus] with ZN, NAD, PFB and MPD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Alcohol_dehydrogenase Alcohol dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.1 1.1.1.1] Full crystallographic information is available from [http:// | + | 1MGO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Equus_caballus Equus caballus] with <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=NAD:'>NAD</scene>, <scene name='pdbligand=PFB:'>PFB</scene> and <scene name='pdbligand=MPD:'>MPD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Alcohol_dehydrogenase Alcohol dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.1 1.1.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MGO OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Equus caballus]] | [[Category: Equus caballus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Plapp, B | + | [[Category: Plapp, B V.]] |
| - | [[Category: Rubach, J | + | [[Category: Rubach, J K.]] |
[[Category: MPD]] | [[Category: MPD]] | ||
[[Category: NAD]] | [[Category: NAD]] | ||
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[[Category: substrate binding site]] | [[Category: substrate binding site]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:54:57 2008'' |
Revision as of 11:54, 21 February 2008
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Horse Liver Alcohol Dehydrogenase Phe93Ala Mutant
Overview
The relationship between substrate mobility and catalysis was studied with wild-type and Phe93Ala (F93A) horse liver alcohol dehydrogenase (ADH). Wild-type ADH binds 2,3,4,5,6-pentafluorobenzyl alcohol in one position as shown by X-ray results, and (19)F NMR shows five resonances for the fluorines of the bound alcohol. The two meta-fluorines exchange positions with a rate constant of about 4 s(-1), indicating that mobility (ring flipping) of the benzyl alcohol is relatively restricted. The wild-type enzyme binds 2,3-difluorobenzyl alcohol in two alternative conformations that are related by a ring flip and a small translation of the fluorinated benzene ring, and the (19)F NMR spectrum shows three resonances for the two bound fluorines, consistent with the two orientations. Phe-93 interacts with the bound benzyl alcohols, and the F93A substitution decreases the rate constants for hydride transfer for benzyl alcohol oxidation and benzaldehyde reduction by 7.4- and 130-fold, respectively. The structure of F93A ADH crystallized with NAD(+) and 2,3,4,5,6-pentafluorobenzyl alcohol is similar to the structure of the wild-type enzyme complex except that the pentafluorobenzyl alcohol is not found in one position. The (19)F NMR spectrum of the F93A ADH-NAD(+)-pentafluorobenzyl alcohol complex shows three resonances for the bound fluorines. Line shape analysis of the spectrum suggests the bound pentafluorobenzyl ring undergoes rapid ring-flipping at about 20 000 s(-1). The F93A substitution greatly increases the mobility of the benzyl alcohol but modestly and differentially decreases the probability that the substrate is preorganized for hydride transfer.
About this Structure
1MGO is a Single protein structure of sequence from Equus caballus with , , and as ligands. Active as Alcohol dehydrogenase, with EC number 1.1.1.1 Full crystallographic information is available from OCA.
Reference
Mobility of fluorobenzyl alcohols bound to liver alcohol dehydrogenases as determined by NMR and X-ray crystallographic studies., Rubach JK, Plapp BV, Biochemistry. 2002 Dec 31;41(52):15770-9. PMID:12501206
Page seeded by OCA on Thu Feb 21 13:54:57 2008
Categories: Alcohol dehydrogenase | Equus caballus | Single protein | Plapp, B V. | Rubach, J K. | MPD | NAD | PFB | ZN | Alcohol | Dehydrogenase | Mutant | Nicotinamide coenzyme | Substrate binding site
