Molecular cloning and biochemical characterization of a NAD-dependent sorbitol dehydrogenase from cold-adaptedPseudomonas mandelii

Abstract

Sugar alcohols (polyols) have important roles as nutrients, anti-freezing agents, and scavengers of free radicals in cold-adapted bacteria, but the characteristics of polyol dehydrogenases in cold-adapted bacteria remain largely unknown. In this study, based on the observation that a cold-adapted bacterium Pseudomonas mandelii JR-1 predominantly utilized D-sorbitol as its carbon source, among the four polyols examined (D-galactitol, D-mannitol, D-sorbitol, or D-xylitol), we cloned and characterized a sorbitol dehydrogenase (SDH, EC 1.1.1.14) belonging to the short-chain dehydrogenase/reductase family from this bacterium (the SDH hereafter referred to as PmSDH). PmSDH contained Asn111, Ser140, Tyr153, and Lys157 as catalytic active site residues and existed as a ∼67 kDa dimer in size-exclusion chromatography. PmSDH converted D-sorbitol to D-fructose using NAD+ as a coenzyme and, vice versa, D-fructose to D-sorbitol using NADH as a coenzyme. PmSDH maintained its conformational flexibility, secondary and tertiary structures, and thermal stability at 4–25°C. At 40°C, PmSDH was rapidly denatured. These results indicate that PmSDH, which has a flexible structure and a high catalytic activity at colder temperatures, is well-suited to sorbitol utilization in the cold-adapted bacterium P. mandelii JR-1.

D-Allulose (D-Psicose) Biotransformation From Allitol by a Newly Found NAD(P)-Dependent Alcohol Dehydrogenase From Gluconobacter frateurii NBRC 3264 and the Enzyme Characterization

“…The enzyme activity was slightly decreased by 2.6 and 3.3% when the enzyme was incubated with Ca 2+ and Mg 2+ , respectively, while the enzyme activity was decreased to 83.1, 69.4, 52.4, 50.3, and 30.3% when the enzyme was incubated with Ba 2+ , Fe 3+ , Mn 2+ , Fe 2+ , and Cu 2+ , respectively. About the activity of NAD-dependent sorbitol dehydrogenase from cold-adapted Pseudomonas mandelii , the metal ions of Zn 2+ , Mn 2+ , and Ca 2+ had slight activation effects while Ni 2+ had an inhibition effect ( DangThu et al, 2021 ). Ni 2+ , Mn 2+ , Mg 2+ , and Ca 2+ can increase the ADH activity which was from Bartonella apis , while Zn 2+ , Li + , and Mo 2+ decrease the ADH activity ( Zhu et al, 2019a ).…”

Molecular cloning, characterization, and homology modeling of serine hydroxymethyltransferase from psychrophilic bacterium Psychrobacter sp.

“…To survive in cold environments, the cold‐adapted enzymes, produced by psychrophilic organisms, are endowed with high specific activity at low temperatures. The structures of these enzymes are usually flexible [14], which have made the Antarctic sea‐ice microorganisms become a new source of cold‐adapted enzymes with multiple applications. Accordingly, a certain amount of the properties and functions of some enzymes from Antarctic microbes were studied, including glutathione reductase [15], 2‐Cys Peroxiredoxin [16].…”