Single Residue Substitution at N-Terminal Affects Temperature Stability and Activity of L2 Lipase.

Noramirah Bukhari,Adam Thean Chor Leow,Fairolniza Mohd Shariff,Raja Noor Zaliha Raja Abd Rahman

doi:10.3390/molecules25153433

Noramirah Bukhari, Adam Thean Chor Leow + Show 2 more

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https://doi.org/10.3390/molecules25153433

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Journal: Molecules (Basel, Switzerland)	Publication Date: Jul 28, 2020
Citations: 8	License type: CC BY 4.0

Affiliation: Universiti Putra Malaysia

Abstract

Rational design is widely employed in protein engineering to tailor wild-type enzymes for industrial applications. The typical target region for mutation is a functional region like the catalytic site to improve stability and activity. However, few have explored the role of other regions which, in principle, have no evident functionality such as the N-terminal region. In this study, stability prediction software was used to identify the critical point in the non-functional N-terminal region of L2 lipase and the effects of the substitution towards temperature stability and activity were determined. The results showed 3 mutant lipases: A8V, A8P and A8E with 29% better thermostability, 4 h increase in half-life and 6.6 °C higher thermal denaturation point, respectively. A8V showed 1.6-fold enhancement in activity compared to wild-type. To conclude, the improvement in temperature stability upon substitution showed that the N-terminal region plays a role in temperature stability and activity of L2 lipase.

Highlights

Lipases have diverse applications in industrial processes that demand enzymes with high stability and tolerance towards extreme conditions
Thermostability and catalytic efficiency are favourable characteristics of enzymes, as many industrial processes occur at high temperatures to facilitate the processes and reduce the risk of biological contamination [1]
The N-terminal region of L2 lipase was defined as amino acid residues from Ala1 to

Summary

Introduction

Lipases have diverse applications in industrial processes that demand enzymes with high stability and tolerance towards extreme conditions. The thermostability of enzymes is primarily contributed by molecular interactions formed between atoms of residues within the enzyme structure [7,8,9]. Reported of such interactions are hydrogen bonds, ion pairs and hydrophobic bonds [10,11,12]. The increase in such interactions contributes to the compactness of the structure, increasing stability at high temperature [3,5,13,14,15]. Other interactions, such as aromatic interaction and disulphide bridge were discussed as contributing

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Conclusion