Computer Aided Design of Polygalacturonase II from aspergillus niger
ABSTRACT: Pectin is a complex polysaccharide found in the cell walls of plants and consisting mainly of esterified D-galacturonic acid resides in �-(1-4) chain. In production of fruit juice, pectin contributes to fruit juice viscosity, thereby reducing the juice production and increasing the filt...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
IIUM Press
2011
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/14652/ http://irep.iium.edu.my/14652/ http://irep.iium.edu.my/14652/1/CAD_PG_II_-_IIUMEJ_2011.pdf |
| Summary: | ABSTRACT: Pectin is a complex polysaccharide found in the cell walls of plants and
consisting mainly of esterified D-galacturonic acid resides in �-(1-4) chain. In production
of fruit juice, pectin contributes to fruit juice viscosity, thereby reducing the juice
production and increasing the filtration time. Polygalacturonase improves the juice
production process by rapid degradation of pectin. In this project we have designed a
novel polygalacturonase enzyme using computer aided design approaches. The three
dimension structure of polygalacturonase is first modeled on the basis of the known
crystal structure. The active site in this enzyme is identified by manual and automated
docking methods. Lamarckian genetic algorithm is used for automated docking and the
active site is validated by comparing with existing experimental data. This is followed
by in silico mutations of the enzymes and the automated docking process is repeated
using the mutant enzymes. The strength of the binding of the ligands inside the active
site is evaluated by computing the binding score using Potential Mean Force (PMF)
method. The in silico mutations R256Q and K258N are found to decrease the binding
strength of the ligand at the active site, indicating lowering of enzyme activity, which is
consistent with the experimental results. Hence in silico mutations can be used to design
new polygalacturonase enzymes with improved enzyme activity. |
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