Investigating the structural properties of the active conformation BTL2 of a lipase from Geobacillus thermocatenulatus in toluene using molecular dynamic simulations and engineering BTL2 via in-silico mutation

2018-09-01
Yenenler, Asli
Venturini, Alessandro
Burduroğlu, Hüseyin Cahit
SEZERMAN, Osman Uğur
The discovery or development of thermoalkalophilic lipases that show high levels of catalytic activity in organic solvents would have important industrial ramifications. However, this goal is yet to be achieved because organic solvents induce structural changes in lipases that suppress their catalytic abilities. A deep understanding of these structural changes to lipases in the presence of organic solvents is required before strategies can be devised to stop them from occurring. In this work, we investigated the effects of an organic reaction medium, toluene, on the structure of the Bacillus thermocatenulatus lipase BTL2 using MD simulation. The main aims were to identify the regions of the protein that are particularly sensitive to the presence of an organic solvent, and how the presence of a hydrophobic medium affects the overall stability of the enzyme. Upon analyzing how the behavior of the enzyme differed in aqueous and hydrophobic media, it was found that many significant zones of the protein suffer in the presence of an organic solvent, which increases the rigidity of the system. This was readily apparent when we investigated important noncovalent interactions (salt bridges) and probed how distances between the atoms of the catalytic triad Ser114, Asp318, and His359 change in the presence of toluene. Moreover, the high tendency for the system to destabilize in toluene was explained by the results of FoldX calculations. Calculations showed that the addition of a small amount of water to the hydrophobic reaction environment should restore the required flexibility of BTL2. The insights gained from the analysis of our simulations allowed us to propose a modification of BTL2, the G116P mutation, that should result in the structural behavior of BTL2 in organic solvent being closer to that of BTL2 in water.
JOURNAL OF MOLECULAR MODELING

Suggestions

Evaluating environmental impacts of a solvent recovery unit in a chemical factory by using life cycle assessment
Hakyemez, Gizem; Dilek, Filiz Bengü; Department of Environmental Engineering (2016)
In this study, Life Cycle Assessment (LCA) Technique was used to analyze the possible environmental impacts of the Solvent Recovery Unit (SRU) of a chemical factory. Firstly, the impact assessment of the SRU where a solvent of dimethylacetamide (DMAc) is currently being recovered by distillation, was performed using LCA with the help of SimaPro software, Eco-Indicator 99 method. Functional unit of the analysis was set as 1 kg of waste solvent recovered. Secondly, the case in which a solvent of dimethyl sulf...
Investigation on indigenous bacteria for individual BTEX degradation potentials and relative pathways used
Yavaş, Alper; İçgen, Bülent; Parlaktuna, Mahmut; Department of Biotechnology (2018)
Monoaromatic hydrocarbons including benzene, toluene, ethylbenzene and xylene collectively called as BTEX are found in the composition of crude oil and gasoline as an additive and thought to be the most serious contaminants of soil and groundwater. It is expected that indigenous bacteria isolated from petroleum hydrocarbon contaminated sites probably have degradation potential for the BTEX compounds. In this study, out of 22, 19 bacterial strains were selected as potential degraders for at least one of the ...
Investigating the mechanical properties of single walled carbon nanotube reinforced epoxy composite through finite element modelling
Zuberi, Muhammad Jibran Shahzad; Esat, Volkan (2015-03-15)
Varying experimental results on the mechanical properties of carbon nanotube reinforced polymer composites (CNTRPs) have been reported due to the complexities associated with the characterization of material properties in nano-scale. Insight into the issues associated with CNTRPs may be brought through computational techniques time- and cost-effectively. In this study, finite element models are generated in which single walled carbon nanotube models are embedded into the epoxy resin. For modelling interface...
INVESTIGATION OF PHOTOFERMENTATIVE POLY-HYDROXYBUTYRATE (PHB) AND HYDROGEN PRODUCTION VIA RHODOBACTER CAPSULATUS
Hoşafcı, Ertan; Bayramoğlu, Tuba Hande; Koku, Harun; Department of Environmental Engineering (2023-1-26)
The aim of this thesis study is to investigate factors affecting hydrogen (H2) and poly-hydroxybutyrate (PHB) production via photofermentation using two strains of Rhodobacter capsulatus species. To this purpose, three experimental designs were set up, namely Set 1, Set 2 and Set 3. In Set 1, various approaches in pretreatment of bacterial biomass were investigated. For R. capsulatus Wild Type (WT) strain, employment of different pretreatment methods did not make a significant difference, where an average ...
EVALUATION OF PYRITIC TAILINGS FROM A COPPER CONCENTRATION PLANT FOR CALCAREOUS SODIC SOIL RECLAMATION
TOZSİN, Gülşen; Arol, Ali İhsan; ÇAYCI, GÖKHAN (2014-01-01)
This study was aimed to investigate the feasibility to use waste pyrite and sulphuric acid produced from waste pyrite for the reclamation of calcareous sodic soils. The final aim is to displace Na from an exchange complex and replace it with Ca, leading to a decrease in pH and exchangeable sodium percentage (ESP) and an improvement of soil structure. A fertility of the soil may also be enhanced by this technique since waste pyrite can be rich in several micronutrients. An additional advantage to this strate...
Citation Formats
A. Yenenler, A. Venturini, H. C. Burduroğlu, and O. U. SEZERMAN, “Investigating the structural properties of the active conformation BTL2 of a lipase from Geobacillus thermocatenulatus in toluene using molecular dynamic simulations and engineering BTL2 via in-silico mutation,” JOURNAL OF MOLECULAR MODELING, pp. 0–0, 2018, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/89511.