1gt6: Difference between revisions
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==Overview== | ==Overview== | ||
The binding of Thermomyces lanuginosa lipase and its mutants [TLL(S146A), TLL(W89L), TLL(W117F, W221H, W260H)] to the mixed micelles of, cis-parinaric acid/sodium taurodeoxycholate at pH 5.0 led to the quenching, of the intrinsic tryptophan fluorescence emission (300-380 nm) and to a, simultaneous increase in the cis-parinaric acid fluorescence emission, (380-500 nm). These findings were used to characterize the Thermomyces, lanuginosa lipase/cis-parinaric acid interactions occurring in the, presence of sodium taurodeoxycholate.The fluorescence resonance energy, transfer and Stern-Volmer quenching constant values obtained were, correlated with the accessibility of the tryptophan residues to the, cis-parinaric acid and with the lid opening ability of Thermomyces, lanuginosa lipase (and its .. | The binding of Thermomyces lanuginosa lipase and its mutants [TLL(S146A), TLL(W89L), TLL(W117F, W221H, W260H)] to the mixed micelles of, cis-parinaric acid/sodium taurodeoxycholate at pH 5.0 led to the quenching, of the intrinsic tryptophan fluorescence emission (300-380 nm) and to a, simultaneous increase in the cis-parinaric acid fluorescence emission, (380-500 nm). These findings were used to characterize the Thermomyces, lanuginosa lipase/cis-parinaric acid interactions occurring in the, presence of sodium taurodeoxycholate.The fluorescence resonance energy, transfer and Stern-Volmer quenching constant values obtained were, correlated with the accessibility of the tryptophan residues to the, cis-parinaric acid and with the lid opening ability of Thermomyces, lanuginosa lipase (and its mutants). TLL(S146A) was found to have the, highest fluorescence resonance energy transfer. In addition, a, TLL(S146A)/oleic acid complex was crystallised and its three-dimensional, structure was solved. Surprisingly, two possible binding modes (sn-1 and, antisn1) were found to exist between oleic acid and the catalytic cleft of, the open conformation of TLL(S146A). Both binding modes involved an, interaction with tryptophan 89 of the lipase lid, in agreement with, fluorescence resonance energy transfer experiments.As a consequence, we, concluded that TLL(S146A) mutant is not an appropriate substitute for the, wild-type Thermomyces lanuginosa lipase for mimicking the interaction, between the wild-type enzyme and lipids. | ||
==About this Structure== | ==About this Structure== | ||
1GT6 is a | 1GT6 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermomyces_lanuginosus Thermomyces lanuginosus] with OLA as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Triacylglycerol_lipase Triacylglycerol lipase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.3 3.1.1.3] Structure known Active Site: OLA. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1GT6 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: zymogen]] | [[Category: zymogen]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:36:55 2007'' | ||
