Alpha-Carbonic Anhydrases from Hydrothermal Vent Sources as Potential Carbon Dioxide Sequestration Agents: In Silico Sequence, Structure and Dynamics Analyses.

Colleen Manyumwa,Reza Emameh,Özlem Tastan Bishop

doi:10.3390/ijms21218066

Abstract

With the increase in CO2 emissions worldwide and its dire effects, there is a need to reduce CO2 concentrations in the atmosphere. Alpha-carbonic anhydrases (α-CAs) have been identified as suitable sequestration agents. This study reports the sequence and structural analysis of 15 α-CAs from bacteria, originating from hydrothermal vent systems. Structural analysis of the multimers enabled the identification of hotspot and interface residues. Molecular dynamics simulations of the homo-multimers were performed at 300 K, 363 K, 393 K and 423 K to unearth potentially thermostable α-CAs. Average betweenness centrality (BC) calculations confirmed the relevance of some hotspot and interface residues. The key residues responsible for dimer thermostability were identified by comparing fluctuating interfaces with stable ones, and were part of conserved motifs. Crucial long-lived hydrogen bond networks were observed around residues with high BC values. Dynamic cross correlation fortified the relevance of oligomerization of these proteins, thus the importance of simulating them in their multimeric forms. A consensus of the simulation analyses used in this study suggested high thermostability for the α-CA from Nitratiruptor tergarcus. Overall, our novel findings enhance the potential of biotechnology applications through the discovery of alternative thermostable CO2 sequestration agents and their potential protein design.

Highlights

The accumulating concentrations of greenhouse gases (GHGs) over the years have led to the warming of the earth’s atmosphere [1,2,3]
We report here computationally solved dimeric structures and the analysis of 12 α-CAs, including Caminibacter mediatlanticus (CmCA), from various bacteria coming from hydrothermal vent systems
The organisms were previously isolated in or around hydrothermal vents, and were mainly Gram-negative [51,52,53,54,55,56,57]. They are classified under four groups (Table 1): Aquificacea, Campylobacteria, Deltaproteobacteria

Summary

Introduction

The accumulating concentrations of greenhouse gases (GHGs) over the years have led to the warming of the earth’s atmosphere [1,2,3]. CO2 is considered to be one of the GHGs contributing to a significant amount of global warming, with the major source of these gases being the combustion of fossil fuels, rice paddies, and livestock fields [3,4,5,6]. The discovery and implementation of mitigation strategies is crucial. Sequestration of CO2 via biomineralization, which involves the aqueous precipitation of minerals in the presence of CO2 to form mineral carbonates, is a storage strategy currently being explored [8,9]. Some of the reactions that take place during biomineralization, require conditions, Int. J.

Methods

Results

Conclusion