Journal:Protein Science:4
From Proteopedia
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| - | <StructureSection load='' size='450' side='right' scene='10/1063617/009_fig_5b_png_def_jmol/1' caption='Acetylcholinesterase highlighting the 4A/3B motif'> | + | <sup></sup><StructureSection load='' size='450' side='right' scene='10/1063617/009_fig_5b_png_def_jmol/1' caption='Acetylcholinesterase highlighting the 4A/3B motif'> |
===Why is binding of a divalent metal cation to a structural motif containing four carboxylate residues not accompanied by a conformational change?=== | ===Why is binding of a divalent metal cation to a structural motif containing four carboxylate residues not accompanied by a conformational change?=== | ||
<big>Lushchekina, Weiner, Ashani, Emrizal, Firdaus-Raih, Silman & Sussman</big><ref>PMID: 39548604</ref> | <big>Lushchekina, Weiner, Ashani, Emrizal, Firdaus-Raih, Silman & Sussman</big><ref>PMID: 39548604</ref> | ||
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</jmol> between them. The stability of the 4D motif is attributed to adjacent positively charged residues (Lys325, Arg388, and Arg517), forming stabilizing salt bridges, leading to the newly named <scene name='10/1063617/009_fig_5b_png_def_jmol/1'>4A/3B motif</scene> (four acidic residues stabilized by three basic residues). | </jmol> between them. The stability of the 4D motif is attributed to adjacent positively charged residues (Lys325, Arg388, and Arg517), forming stabilizing salt bridges, leading to the newly named <scene name='10/1063617/009_fig_5b_png_def_jmol/1'>4A/3B motif</scene> (four acidic residues stabilized by three basic residues). | ||
| - | The study also identified additional metal-binding sites (His264 and His471 sites) in ''Tc''AChE through crystallographic analysis, but these appear to be weaker or crystallographic artifacts. Using metadynamics and molecular dynamics (MD) simulations with quantum potentials (QM/MM-MD), the binding strength of metal cations at the 4D site was compared to that of the 4D site in human fibrin-stabilizing factor (fXIIIa), which lacks stabilizing cationic residues. Results showed that while ''Tc''AChE’s 4A/3B motif maintains structural integrity upon metal binding/unbinding, the <scene name='10/1063617/009_fig_8a_new_jmol_def/1'>fXIIIa motif </scene> is stable in presence of a metal ion but <scene name='10/1063617/ | + | The study also identified additional metal-binding sites (His264 and His471 sites) in ''Tc''AChE through crystallographic analysis, but these appear to be weaker or crystallographic artifacts. Using metadynamics and molecular dynamics (MD) simulations with quantum potentials (QM/MM-MD), the binding strength of metal cations at the 4D site was compared to that of the 4D site in human fibrin-stabilizing factor (fXIIIa), which lacks stabilizing cationic residues. Results showed that while ''Tc''AChE’s 4A/3B motif maintains structural integrity upon metal binding/unbinding, the <scene name='10/1063617/009_fig_8a_new_jmol_def/1'>fXIIIa motif </scene> is stable in presence of a metal ion but <scene name='10/1063617/009_fig_8b_new_def_jmol/1'>explodes</scene> without a metal ions due to electrostatic repulsion. This is seen clearly in an |
<jmol> | <jmol> | ||
<jmolButton> | <jmolButton> | ||
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for(var i IN a) { | for(var i IN a) { | ||
script /wiki/scripts/10/1063617/009_fig_8a_new_jmol_def/1.spt; delay 0.5 | script /wiki/scripts/10/1063617/009_fig_8a_new_jmol_def/1.spt; delay 0.5 | ||
| - | script /wiki/scripts/10/1063617/ | + | script /wiki/scripts/10/1063617/009_fig_8b_new_def_jmol/1.spt; delay 0.5; |
} | } | ||
</script> | </script> | ||
Revision as of 09:26, 12 February 2025
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This page complements a publication in scientific journals and is one of the Proteopedia's Interactive 3D Complement pages. For aditional details please see I3DC.
