Structural and functional adaptation in extremophilic microbial α-amylases

Abstract

Maintaining stable native conformation of a protein under a given ecological condition is the prerequisite for survival of organisms. Extremophilic bacteria and archaea have evolved to adapt under extreme conditions of temperature, pH, salt, and pressure. Molecular adaptations of proteins under these conditions are essential for their survival. These organisms have the capability to maintain stable, native conformations of proteins under extreme conditions. The enzymes produced by the extremophiles are also known as extremozyme, which are used in several industries. Stability and functionality of extremozymes under varying temperature, pH, and solvent conditions are the most desirable requirement of industry. α-Amylase is one of the most important enzymes used in food, pharmaceutical, textile, and detergent industries. This enzyme is produced by diverse microorganisms including various extremophiles. Therefore, understanding its stability is important from fundamental as well as an applied point of view. Each class of extremophiles has a distinctive set of dominant non-covalent interactions which are important for their stability. Static information obtained by comparative analysis of amino acid sequence and atomic resolution structure provides information on the prevalence of particular amino acids or a group of non-covalent interactions. Protein folding studies give the information about thermodynamic and kinetic stability in order to understand dynamic aspect of molecular adaptations. In this review, we have summarized information on amino acid sequence, structure, stability, and adaptability of α-amylases from different classes of extremophiles.

Biochemical characterization of an acid‐thermostable glucoamylase from Aspergillus japonicus with potential application in the paper bio‐deinking

“…At pH 9.5, 40% of activity was still maintained and at pH 10.0 there was a sudden drop, reaching denaturation of the enzyme (Figure 3c). These results are consistent with those found in the literature since amylases are stable in the acid range up to pH 7.0 25 . This stability represents a very attractive mechanism in glucoamylases since these enzymes are widely used in several starch‐based manufacturing, such as paper industries, 26 and high stability in a large pH range represents a safe advantage for industries that requires pH adjustments between sequential treatments of the recycling paper process.…”

“…These results are consistent with those found in the literature since amylases are stable in the acid range up to pH 7.0. 25 This stability represents a very attractive mechanism in glucoamylases since these enzymes are widely used in several F I G U R E 1 Effect of temperature on amylase activity produced by Aspergillus japonicus. The 100% enzyme activity was 38.97 U/mL.…”

Biophysical Reviews: Turning the page from 2022 to 2023

“…The regular Issue presented the first in the Editors' Roundup series (Shearwin et al 2022) a journal commentary feature in which members of various biophysical journals' editorial boards provide a short personal recommendation of up to five articles appearing within their journal. The regular Issue also carried a 'Meet the Editors' piece, introducing new editorial board member Sabrina Leslie (Leslie 2022) and five diverse review articles that included among them an interesting description of the structural differences observed between α-amylases obtained from various types of extremophilic bacteria (Ahmad and Mishra 2022). The Issue Focus on Costa Rican biophysics did an excellent job of highlighting the research strengths of that country by presenting a series of articles from scientists both working at home and abroad (Pinto et al 2022;Brenes 2022;Céspedes-Camacho and Matysik 2022).…”