2001/03/01 by Claire Vieille, G. Zeikus · 1 citation
Biochemistry, Genetics and Molecular Biology · #Archaea #Bacteria #Biochemical and Molecular Research #Biochemistry #Biology #Enzyme #Enzyme Catalysis and Immobilization #Enzyme function and inhibition #Gene #Genetics #Hyperthermophile #Mesophile #Pyrococcus furiosus #Thermophile #Thermostability
paper · doi:10.1128/mmbr.65.1.1-43.2001
openalex publication_date 2001/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Enzymes synthesized by hyperthermophiles (bacteria and archaea with optimal growth temperatures of > 80 degrees C), also called hyperthermophilic enzymes, are typically thermostable (i.e., resistant to irreversible inactivation at high temperatures) and are optimally active at high temperatures. These enzymes share the same catalytic mechanisms with their mesophilic counterparts. When cloned and expressed in mesophilic hosts, hyperthermophilic enzymes usually retain their thermal properties, indicating that these properties are genetically encoded. Sequence alignments, amino acid content comparisons, crystal structure comparisons, and mutagenesis experiments indicate that hyperthermophilic enzymes are, indeed, very similar to their mesophilic homologues. No single mechanism is responsible for the remarkable stability of hyperthermophilic enzymes. Increased thermostability must be found, instead, in a small number of highly specific alterations that often do not obey any obvious traffic rules. After briefly discussing the diversity of hyperthermophilic organisms, this review concentrates on the remarkable thermostability of their enzymes. The biochemical and molecular properties of hyperthermophilic enzymes are described. Mechanisms responsible for protein inactivation are reviewed. The molecular mechanisms involved in protein thermostabilization are discussed, including ion pairs, hydrogen bonds, hydrophobic interactions, disulfide bridges, packing, decrease of the entropy of unfolding, and intersubunit interactions. Finally, current uses and potential applications of thermophilic and hyperthermophilic enzymes as research reagents and as catalysts for industrial processes are described.