The cold-active, chloride-dependent a-amylase from Pseudoalteromonas haloplanktis (AHA) is one of the best characterized psychrophilic enzymes, and shares high sequence and structural similarity with its mesophilic porcine counterpart (PPA). An atomic detail comparative analysis was carried out by performing more than 60 ns of multiple-replica explicit-solvent molecular dynamics simulations on the two enzymes in order to characterize the differences in ensemble properties and dynamics in solution between the two homologues. We find in both enzymes high flexibility clusters in the surroundings of the substrate-binding groove, primarily involving the long loops that protrude from the main domain's barrel structure. These loops are longer in PPA and extend further away from the core of the barrel, where the active site is located: essential fluctuations in PPA mainly affect the highly solvent-accessible portions of these loops, whereas AHA is characterized by greater flexibility in the immediate surroundings of the active site. Furthermore, detailed analysis of active- site dynamics has revealed that elements previously identified through X-ray crystallography as involved in substrate binding in both enzymes undergo concerted motions that may be linked to catalysis. © 2009 American Chemical Society.

Pasi, M., Riccardi, L., Fantucci, P., DE GIOIA, L., Papaleo, E. (2009). Dynamic Properties of a Psychrophilic alpha-Amylase in Comparison with a Mesophilic Homologue. JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL, 113(41), 13585-13595 [10.1021/jp900790n].

Dynamic Properties of a Psychrophilic alpha-Amylase in Comparison with a Mesophilic Homologue

PASI, MARCO;FANTUCCI, PIERCARLO;DE GIOIA, LUCA;PAPALEO, ELENA
2009

Abstract

The cold-active, chloride-dependent a-amylase from Pseudoalteromonas haloplanktis (AHA) is one of the best characterized psychrophilic enzymes, and shares high sequence and structural similarity with its mesophilic porcine counterpart (PPA). An atomic detail comparative analysis was carried out by performing more than 60 ns of multiple-replica explicit-solvent molecular dynamics simulations on the two enzymes in order to characterize the differences in ensemble properties and dynamics in solution between the two homologues. We find in both enzymes high flexibility clusters in the surroundings of the substrate-binding groove, primarily involving the long loops that protrude from the main domain's barrel structure. These loops are longer in PPA and extend further away from the core of the barrel, where the active site is located: essential fluctuations in PPA mainly affect the highly solvent-accessible portions of these loops, whereas AHA is characterized by greater flexibility in the immediate surroundings of the active site. Furthermore, detailed analysis of active- site dynamics has revealed that elements previously identified through X-ray crystallography as involved in substrate binding in both enzymes undergo concerted motions that may be linked to catalysis. © 2009 American Chemical Society.
Articolo in rivista - Articolo scientifico
protein chemistry
English
13585
13595
Pasi, M., Riccardi, L., Fantucci, P., DE GIOIA, L., Papaleo, E. (2009). Dynamic Properties of a Psychrophilic alpha-Amylase in Comparison with a Mesophilic Homologue. JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL, 113(41), 13585-13595 [10.1021/jp900790n].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/10235
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