Effects of Temperature and Additives on the Thermal Stability of Glucoamylase from Aspergillus niger

Liu, Yang; Meng, Zhaoli; Shi, Ruilin; Zhan, Lin; Hu, Wei; Xiang, Hongyu; Xie, Qiuhong

doi:10.4014/jmb.1406.06045

Cited by 10 publications

(7 citation statements)

References 35 publications

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“…Far-UV CD spectral measurement was performed as described previously [22]. The CD spectra in the range of 195–240 nm were determined on a JASCO J-715 spectropolarimeter (Jasco, Tokyo, Japan) at room temperature.…”

Section: Methodsmentioning

confidence: 99%

Improved scFv Anti-LOX-1 Binding Activity by Fusion with LOX-1-Binding Peptides

Xie

2017

BioMed Research International

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The oxidized low-density lipoprotein receptor-1 (LOX-1) targeted single-chain variable fragment (scFvs) is a promising molecule for the targeted delivery of imaging and therapeutic molecules of atherosclerotic diseases; however, its applications are limited by the inherent low antigen affinity. In this study, the three-dimensional (3D) model of the anti-LOX-1 scFv was constructed and its docking with the LOX-1 protein was developed. To improve the LOX-1-binding activity, the anti-LOX-1 scFv was designed to fuse with one of three LOX-1-binding heptapeptides, LTPATAI, FQTPPQL, and LSIPPKA, at its N-terminus and C-terminus and in the linker region, which have different LOX-1-binding interfaces with the anti-LOX-1 scFv analyzed by an array of computational approaches. These scFv/peptide fusions were constructed, successfully expressed in Brevibacillus choshinensis hosts, and purified by a two-step column purification process. The antigen binding activity, structural characteristics, thermal stability, and stability in serum of these fusion proteins were examined. Results showed that the scFv with N-terminal fusing peptides proteins demonstrated increased LOX-1-binding activity without decrease in stability. These findings will help increase the application efficacy of LOX-1 targeting scFv in LOX-1-based therapy.

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Section: Methodsmentioning

confidence: 99%

Improved scFv Anti-LOX-1 Binding Activity by Fusion with LOX-1-Binding Peptides

Xie

2017

BioMed Research International

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“…Moreover, at a higher concentration of glycerol, the protein residual activity was reduced, compared to lower concentrations. High concentrations of viscosity-generating solutes can affect the enzyme s Michaelis-Menten constant [40][41][42], therefore affecting the catalytic efficiency [42,43]. However, the effect of glycerol was different when samples of rPON2 were stored in 20% glycerol at −20 °C.…”

Section: Protein Stabilizationmentioning

confidence: 99%

The Human Paraoxonase 2: An Optimized Procedure for Refolding and Stabilization Facilitates Enzyme Analyses and a Proteomics Approach

Lampitella,

Marone,

Achanta

et al. 2024

Molecules

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The human paraoxonase 2 (PON2) is the oldest member of a small family of arylesterase and lactonase enzymes, representing the first line of defense against bacterial infections and having a major role in ROS-associated diseases such as cancer, cardiovascular diseases, neurodegeneration, and diabetes. Specific Post-Translational Modifications (PTMs) clustering nearby two residues corresponding to pon2 polymorphic sites and their impact on the catalytic activity are not yet fully understood. Thus, the goal of the present study was to develop an improved PON2 purification protocol to obtain a higher amount of protein suitable for in-depth biochemical studies and biotechnological applications. To this end, we also tested several compounds to stabilize the active monomeric form of the enzyme. Storing the enzyme at 4 °C with 30 mM Threalose had the best impact on the activity, which was preserved for at least 30 days. The catalytic parameters against the substrate 3-Oxo-dodecanoyl-Homoserine Lactone (3oxoC12-HSL) and the enzyme ability to interfere with the biofilm formation of Pseudomonas aeruginosa (PAO1) were determined, showing that the obtained enzyme is well suited for downstream applications. Finally, we used the purified rPON2 to detect, by the direct molecular fishing (DMF) method, new putative PON2 interactors from soluble extracts of HeLa cells.

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“…It indicates that the high temperature associated with extreme pH (in relation to the optimum conditions) promotes the loss of enzymatic activity (Vandersall, Cameron, Nairn, Yelenosky, & Wodzinski, 1995;Liu et al, 2015). Liu et al (2015) demonstrated that heating at temperatures ≥ 70°C promotes unfolding of the α-helix, which is often correlated with the loss of activity. In addition, at high temperatures, tryptophan residues were partially exposed, indicating changes in the tertiary structure of the enzyme.…”

Section: Determination Of Amyloglucosidase Activity and Optimum Ph Anmentioning

confidence: 99%

Ultrasound processing of amyloglucosidase: impact on enzyme activity, stability and possible industrial applications

et al. 2020

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This study evaluated the effect of ultrasound processing as a pre-treatment of amyloglucosidase on the enzymatic activity and stability. The activity was evaluated under optimal (65°C/ pH = 4.5) and non-optimal conditions of temperature and pH and its stability was evaluated during storage at 8°C. The enzyme solution was processed at 9.5 W L-1, 40 kHz, 23°C and at pH 3.5, 4.5, and 5.5, for up to 120 min. The activity was measured at 35, 65 and 80°C. The US process was able to increase, reduce or not alter the enzymatic activity, depending on the conditions applied. These modifications depended on the pH of the enzyme solution, the ultrasound processing time and the activity temperature. In different ultrasound conditions, mainly at 35 and 65°C, the enzyme activity did not change, demonstrating that this technology can be used for other purposes, such as microbial inactivation, without affecting the enzyme. The activity increase (up to 15%) occurred under non-optimal pH and temperature conditions (pH 3.5 or 5.5/ 80°C), suggesting that ultrasound promoted stabilization and enzymatic protection. This result is interesting in the starch saccharification, which requires the enzymatic reaction at high temperatures. Therefore, such results can increase the application range of this enzyme in different industrial applications.

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Effects of Temperature and Additives on the Thermal Stability of Glucoamylase from Aspergillus niger

Cited by 10 publications

References 35 publications

Improved scFv Anti-LOX-1 Binding Activity by Fusion with LOX-1-Binding Peptides

Improved scFv Anti-LOX-1 Binding Activity by Fusion with LOX-1-Binding Peptides

The Human Paraoxonase 2: An Optimized Procedure for Refolding and Stabilization Facilitates Enzyme Analyses and a Proteomics Approach

Ultrasound processing of amyloglucosidase: impact on enzyme activity, stability and possible industrial applications

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