Glu-370 in the large subunit influences the substrate binding, allosteric, and heat stability properties of potato ADP-glucose pyrophosphorylase

•Glu-370 of the LS AGPase is important for the proper binding of the effectors and substrate.•This residue is important for the heat stability of the potato AGPase. ADP-glucose pyrophosphorylase (AGPase) is a key allosteric enzyme in plant starch biosynthesis. Plant AGPase is a heterotetrameric enzy...

Full description

Saved in:
Bibliographic Details
Published in:Plant science (Limerick) 2016-11, Vol.252, p.125-132
Main Authors: Seferoglu, Ayse Bengisu, Gul, Seref, Dikbas, Ugur Meric, Baris, Ibrahim, Koper, Kaan, Caliskan, Mahmut, Cevahir, Gul, kavakli, Ibrahim Halil
Format: Article
Language:English
Subjects:
ADP-glucose pyrophosphorylase
Allosteric regulation
Binding Sites
Enzyme Stability
Glucose-1-Phosphate Adenylyltransferase - chemistry
Glucose-1-Phosphate Adenylyltransferase - physiology
Glycogen - biosynthesis
Hot Temperature
Kinetics
Models, Molecular
Mutagenesis, Site-Directed
Plant Proteins - chemistry
Plant Proteins - physiology
Protein stability
Protein Structure, Tertiary
Solanum tuberosum - enzymology
Solanum tuberosum - genetics
Starch - biosynthesis
Substrate Specificity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Glu-370 of the LS AGPase is important for the proper binding of the effectors and substrate.•This residue is important for the heat stability of the potato AGPase. ADP-glucose pyrophosphorylase (AGPase) is a key allosteric enzyme in plant starch biosynthesis. Plant AGPase is a heterotetrameric enzyme that consists of large (LS) and small subunits (SS), which are encoded by two different genes. In this study, we showed that the conversion of Glu to Gly at position 370 in the LS of AGPase alters the heterotetrameric stability along with the binding properties of substrate and effectors of the enzyme. Kinetic analyses revealed that the affinity of the LSE370GSSWT AGPase for glucose-1-phosphate is 3-fold less than for wild type (WT) AGPase. Additionally, the LSE370GSSWT AGPase requires 3-fold more 3-phosphogyceric acid to be activated. Finally, the LSE370GSSWTAGPase is less heat stable compared with the WT AGPase. Computational analysis of the mutant Gly-370 in the 3D modeled LS AGPase showed that this residue changes charge distribution of the surface and thus affect stability of the LS AGPase and overall heat stability of the heterotetrameric AGPase. In summary, our results show that LSE370 intricately modulate the heat stability and enzymatic activity of potato the AGPase.
ISSN:0168-9452
1873-2259
DOI:10.1016/j.plantsci.2016.07.007