A systematic comparative analysis of 21 psychrophilic enzymes belonging to different structural families from prokaryotic and eukaryotic organisms is reported. The sequences of these enzymes were multiply aligned to 427 homologous proteins from mesophiles and thermophiles. The net flux of amino acid exchanges from meso/thermophilic to psychrophilic enzymes was measured. To assign the observed preferred exchanges to different structural environments, such as secondary structure, solvent accessibility and subunit interfaces, homology modeling was utilized to predict the secondary structure and accessibility of amino acid residues for the psychrophilic enzymes for which no experimental three-dimensional structure is available. Our results show a clear tendency for the charged residues Arg and Glu to be replaced at exposed sites on alpha-helices by Lys and Ala, respectively, in the direction from 'hot' to 'cold' enzymes. Val is replaced by Ala at buried regions in alpha-helices. Compositional analysis of psychrophilic enzymes shows a significant increase in Ala and Asn and a decrease in Arg at exposed sites. Buried sites in beta-strands tend to be depleted of VAL: Possible implications of the observed structural variations for protein stability and engineering are discussed.
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http://dx.doi.org/10.1093/protein/14.3.141 | DOI Listing |
Food Res Int
February 2025
College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong 266109, China; Qingdao Special Food Research Institute, Qingdao, Shandong 266109, China; Shandong Technology Innovation Center of Special Food, Shandong 266109, China. Electronic address:
Psychrophilic Pseudomonas fluorescens can secrete extracellular enzymes, biofilms, and other substances even under refrigeration conditions, which have a negative impact on the quality of dairy products, aquatic products, meat products, produce, and other foods, causing food spoilage and huge economic losses. Therefore, strengthening the prevention and control of psychrophilic P. fluorescens in food is of great significance.
View Article and Find Full Text PDFACS Omega
January 2025
School of Biology, University of St Andrews, North Haugh, St Andrews KY16 9ST, U.K.
The synthesis of nucleosides is crucial for pharmaceutical and biotechnological applications, acting as drugs and as essential building blocks for numerous therapeutic agents. However, most enzymes employed in nucleoside biocatalysis are not recycled, possess limited stability, and have strict substrate selection for ribonucleosides or 2'deoxyribonucleosides. We employed 2'-deoxyribonucleoside transferase (NDT) enzymes from thermophilic and psychrophilic bacteria to demonstrate they can be immobilized to enhance specific activity, stability, and recyclability.
View Article and Find Full Text PDFFood Sci Nutr
January 2025
Modern-day consumers are interested in highly nutritious and safe foods with corresponding organoleptic qualities. Such foods are increasingly subjected to various processing techniques which include the use of enzymes. These enzymes like amylases, lipases, proteases, xylanases, laccases, pullulanase, chitinases, pectinases, esterases, isomerases, and dehydrogenases could be derived from extremophilic organisms such as thermophiles, psychrophiles, acidophiles, alkaliphiles, and halophiles.
View Article and Find Full Text PDFCrit Rev Biotechnol
January 2025
Department of Animal Biotechnology, Faculty of Biotechnology, College of Applied Life Sciences, Jeju National University, Jeju Special Self-Governing Province, Republic of Korea.
Exploring the untapped potential of deep-sea microorganisms, particularly their cold-active enzymes, or psychrozymes, offers exciting possibilities for revolutionizing various aspects of the food processing industry. This review focuses on these enzymes, derived from the largely unexplored depths of the deep ocean, where microorganisms have developed unique adaptations to extreme conditions. Psychrozymes, as bioactive molecules, hold significant promise for food industry applications.
View Article and Find Full Text PDFAMB Express
January 2025
Botany and Microbiology Department, Faculty of Science, Cairo University, Giza, 12613, Egypt.
A Novel cold-active chitin deacetylase from Shewanella psychrophila WP2 (SpsCDA) was overexpressed in Escherichia coli BL21 and employed for deacetylation of chitin to chitosan. The produced chitosan was characterized, and its antifungal activity was investigated against Fusarium oxysporum. The purified recombinant SpsCDA appeared as a single band on SDS-PAGE at approximately 60 kDa, and its specific activity was 92 U/mg.
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