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

Author(s):  
Quynh DangThu ◽  
Thu-Thuy Nguyen ◽  
Sei-Heon Jang ◽  
ChangWoo Lee

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.

2002 ◽  
Vol 367 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Dipali SINHA ◽  
Mariola MARCINKIEWICZ ◽  
David GAILANI ◽  
Peter N. WALSH

Human factor XI, a plasma glycoprotein required for normal haemostasis, is a homodimer (160kDa) formed by a single interchain disulphide bond linking the Cys-321 of each Apple 4 domain. Bovine, porcine and murine factor XI are also disulphide-linked homodimers. Rabbit factor XI, however, is an 80kDa polypeptide on non-reducing SDS/PAGE, suggesting that rabbit factor XI exists and functions physiologically either as a monomer, as does prekallikrein, a structural homologue to factor XI, or as a non-covalent homodimer. We have investigated the structure and function of rabbit factor XI to gain insight into the relation between homodimeric structure and factor XI function. Characterization of the cDNA sequence of rabbit factor XI and its amino acid translation revealed that in the rabbit protein a His residue replaces the Cys-321 that forms the interchain disulphide linkage in human factor XI, explaining why rabbit factor XI is a monomer in non-reducing SDS/PAGE. On size-exclusion chromatography, however, purified plasma rabbit factor XI, like the human protein and unlike prekallikrein, eluted as a dimer, demonstrating that rabbit factor XI circulates as a non-covalent dimer. In functional assays rabbit factor XI and human factor XI behaved similarly. Both monomeric and dimeric factor XI were detected in extracts of cells expressing rabbit factor XI. We conclude that the failure of rabbit factor XI to form a covalent homodimer due to the replacement of Cys-321 with His does not impair its functional activity because it exists in plasma as a non-covalent homodimer and homodimerization is an intracellular process.


2007 ◽  
Vol 189 (14) ◽  
pp. 5265-5275 ◽  
Author(s):  
Dylan Dodd ◽  
Joseph G. Reese ◽  
Craig R. Louer ◽  
Jimmy D. Ballard ◽  
M. Ashley Spies ◽  
...  

ABSTRACT Glutamate racemase activity in Bacillus anthracis is of significant interest with respect to chemotherapeutic drug design, because l-glutamate stereoisomerization to d-glutamate is predicted to be closely associated with peptidoglycan and capsule biosynthesis, which are important for growth and virulence, respectively. In contrast to most bacteria, which harbor a single glutamate racemase gene, the genomic sequence of B. anthracis predicts two genes encoding glutamate racemases, racE1 and racE2. To evaluate whether racE1 and racE2 encode functional glutamate racemases, we cloned and expressed racE1 and racE2 in Escherichia coli. Size exclusion chromatography of the two purified recombinant proteins suggested differences in their quaternary structures, as RacE1 eluted primarily as a monomer, while RacE2 demonstrated characteristics of a higher-order species. Analysis of purified recombinant RacE1 and RacE2 revealed that the two proteins catalyze the reversible stereoisomerization of l-glutamate and d-glutamate with similar, but not identical, steady-state kinetic properties. Analysis of the pH dependence of l-glutamate stereoisomerization suggested that RacE1 and RacE2 both possess two titratable active site residues important for catalysis. Moreover, directed mutagenesis of predicted active site residues resulted in complete attenuation of the enzymatic activities of both RacE1 and RacE2. Homology modeling of RacE1 and RacE2 revealed potential differences within the active site pocket that might affect the design of inhibitory pharmacophores. These results suggest that racE1 and racE2 encode functional glutamate racemases with similar, but not identical, active site features.


2003 ◽  
Vol 373 (3) ◽  
pp. 759-765 ◽  
Author(s):  
Jantana WONGSANTICHON ◽  
Thasaneeya HARNNOI ◽  
Albert J. KETTERMAN

A variant form of an Anopheles dirus glutathione S-transferase (GST), designated AdGSTD4-4, possesses a single amino acid change of leucine to arginine (Leu-103-Arg). Although residue 103 is outside of the active site, it has major effects on enzymic properties. To investigate these structural effects, site-directed mutagenesis was used to generate mutants by changing the non-polar leucine to alanine, glutamate, isoleucine, methionine, asparagine, or tyrosine. All of the recombinant GSTs showed approximately the same expression level at 25° C. Several of the mutants lacked glutathione (GSH)-binding affinity but were purified by S-hexyl-GSH-based affinity chromatography. However the protein yields (70-fold lower), as well as the GST activity (100-fold lower), of Leu-103-Tyr and Leu-103-Arg purifications were surprisingly low and precluded the performance of kinetic experiments. Size-exclusion chromatography showed that both GSTs Leu-103-Tyr and Leu-103-Arg formed dimers. Using 1-chloro-2,4-dinitrobenzene (CDNB) and GSH substrates to determine kinetic constants it was demonstrated that the other Leu-103 mutants possessed a greater Km towards GSH and a differing Km towards CDNB. The Vmax ranged from 44.7 to 87.0 μmol/min per mg (wild-type, 44.7 μmol/min per mg). Substrate-specificity studies showed different selectivity properties for each mutant. The structural residue Leu-103 affects the active site through H-bond and van-der-Waal contacts with six active-site residues in the GSH binding site. Changes in this interior core residue appear to disrupt internal packing, which affects active-site residues as well as residues at the subunit–subunit interface. Finally, the data suggest that Leu-103 is noteworthy as a sensitive residue in the GST structure that modulates enzyme activity as well as stability.


2021 ◽  
Vol 22 (18) ◽  
pp. 10068
Author(s):  
Sabrina Fasoli ◽  
Ilaria Bettin ◽  
Riccardo Montioli ◽  
Andrea Fagagnini ◽  
Daniele Peterle ◽  
...  

Human Angiogenin (hANG, or ANG, 14.1 kDa) promotes vessel formation and is also called RNase 5 because it is included in the pancreatic-type ribonuclease (pt-RNase) super-family. Although low, its ribonucleolytic activity is crucial for angiogenesis in tumor tissues but also in the physiological development of the Central Nervous System (CNS) neuronal progenitors. Nevertheless, some ANG variants are involved in both neurodegenerative Parkinson disease (PD) and Amyotrophic Lateral Sclerosis (ALS). Notably, some pt-RNases acquire new biological functions upon oligomerization. Considering neurodegenerative diseases correlation with massive protein aggregation, we analyzed the aggregation propensity of ANG and of three of its pathogenic variants, namely H13A, S28N, and R121C. We found no massive aggregation, but wt-ANG, as well as S28N and R121C variants, can form an enzymatically active dimer, which is called ANG-D. By contrast, the enzymatically inactive H13A-ANG does not dimerize. Corroborated by a specific cross-linking analysis and by the behavior of H13A-ANG that in turn lacks one of the two His active site residues necessary for pt-RNases to self-associate through the three-dimensional domain swapping (3D-DS), we demonstrate that ANG actually dimerizes through 3D-DS. Then, we deduce by size exclusion chromatography (SEC) and modeling that ANG-D forms through the swapping of ANG N-termini. In light of these novelties, we can expect future investigations to unveil other ANG determinants possibly related with the onset and/or development of neurodegenerative pathologies.


1984 ◽  
Vol 160 (3) ◽  
pp. 772-787 ◽  
Author(s):  
J A Schmidt

A protocol for the rapid, efficient purification of the major charged species of human interleukin 1 (IL-1) has been developed using high performance anion exchange and size exclusion chromatography. The isolated material is pure as determined by sodium dodecyl sulfate (SDS) gradient polyacrylamide gel electrophoresis (PAGE) and analytical isoelectric focusing (IEF). The molecular weight of the purified material is 15,000 and the isoelectric point (pI) is 6.8, values that are in good agreement with those previously reported for human IL-1. 10(-10) M concentrations of the purified material give half-maximal stimulation in the thymocyte proliferation assay. Amounts of IL-1 sufficient for receptor studies and detailed biochemical analysis can now be produced on a regular basis.


Biomolecules ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 57
Author(s):  
Konstantin M. Boyko ◽  
Mariya V. Kryukova ◽  
Lada E. Petrovskaya ◽  
Elena A. Kryukova ◽  
Alena Y. Nikolaeva ◽  
...  

The gene coding for a novel cold-active esterase PMGL3 was previously obtained from a Siberian permafrost metagenomic DNA library and expressed in Escherichia coli. We elucidated the 3D structure of the enzyme which belongs to the hormone-sensitive lipase (HSL) family. Similar to other bacterial HSLs, PMGL3 shares a canonical α/β hydrolase fold and is presumably a dimer in solution but, in addition to the dimer, it forms a tetrameric structure in a crystal and upon prolonged incubation at 4 °C. Detailed analysis demonstrated that the crystal tetramer of PMGL3 has a unique architecture compared to other known tetramers of the bacterial HSLs. To study the role of the specific residues comprising the tetramerization interface of PMGL3, several mutant variants were constructed. Size exclusion chromatography (SEC) analysis of D7N, E47Q, and K67A mutants demonstrated that they still contained a portion of tetrameric form after heat treatment, although its amount was significantly lower in D7N and K67A compared to the wild type. Moreover, the D7N and K67A mutants demonstrated a 40 and 60% increase in the half-life at 40 °C in comparison with the wild type protein. Km values of these mutants were similar to that of the wt PMGL3. However, the catalytic constants of the E47Q and K67A mutants were reduced by ~40%.


2020 ◽  
Author(s):  
Chihiro Inoue ◽  
Yoshitaka Abe ◽  
Nobutaka Fujieda

<p>Recently, the functional expression of group-5 hydroxylase component (MimA and MimC) in <i>Escherichia coli </i>along with its related chaperonin-like component (MimG) was reported by Furuya and Kino. In this study, we report the purification via a heterologous expression system and the biochemical characterization of MimAC, the complex of MimA and MimC and MimG to understand their exact roles. MimAC and MimG were fused with His-tags and purified using affinity chromatography in a homogenous state on SDS-PAGE. Blue native PAGE demonstrated that the quaternary structure of MimG was almost identical to that of chaperonin GroEL, indicating that its function was also similar to GroEL. Size-exclusion chromatography and ICP-AES analysis demonstrated that MimAC was assembled in the dimer of two sort of subunits and exhibited two iron atoms and at least one zinc atom per two subunits. This result indicated that MimAC possessed a dinuclear iron center, similar to other soluble diiron monooxygenase hydroxylases.</p>


1986 ◽  
Vol 240 (1) ◽  
pp. 155-161 ◽  
Author(s):  
J J Calvete ◽  
J González-Rodríguez

The alpha- and beta-subunits of glycoprotein IIb (GPIIb) of human platelet plasma membrane were isolated in fully reduced, partially reduced and alkylated, and fully alkylated forms, by size-exclusion chromatography after reduction of pure GPIIb. The sugar moiety of GPIIb alpha accounts for 16.4% of its total weight, whereas that of GPIIb beta accounts for only 10.2%. The molar percentages (per 100 mol of total amino acids) of neuraminic acid and galactose in the alpha-subunit more than double those in the beta-subunit, whereas galactosamine is present only in GPIIb alpha. From the amino acid and sugar compositions the acidic nature of both subunits was confirmed. The Mr values obtained, 114,000 for GPIIb alpha and 22,200 for GPIIb beta, are in very good agreement with those obtained by physical methods. We found by stepwise reduction of pure GPIIb with dithioerythritol that GPIIb alpha and GPIIb beta are joined by a single interchain disulphide bridge, while the remaining half-cystine residues participate in intrachain bonds, six in GPIIb alpha and one in GPIIb beta, the intersubunit disulphide bond being that reduced first. Neither of the two subunits is liberated from isolated plasma membranes when this GPIIb interchain bond is reduced in isolated membranes.


2004 ◽  
Vol 383 (3) ◽  
pp. 589-597 ◽  
Author(s):  
Michael J. HUBBARD ◽  
Jonathan E. MANGUM ◽  
Nicola J. McHUGH

ERp29 is a recently characterized resident of the ER (endoplasmic reticulum) lumen that has broad biological significance, being expressed ubiquitously and abundantly in animal cells. As an apparent housekeeper, ERp29 is thought to be a general folding assistant for secretory proteins and to probably function as a PDI (protein disulphide isomerase)-like molecular chaperone. In the present paper, we report the first purification to homogeneity and direct functional analysis of native ERp29, which has led to the unexpected finding that ERp29 lacks PDI-like folding activities. ERp29 was purified 4800-fold in non-denaturing conditions exploiting an unusual affinity for heparin. Two additional biochemical hallmarks that will assist the classification of ERp29 homologues were identified, namely the idiosyncratic behaviours of ERp29 on size-exclusion chromatography (Mr<globular homodimer) and SDS/PAGE (Mr>monomeric mass). In contrast with PDI and parallel-purified co-residents (calreticulin, ERp60), native ERp29 lacked classical chaperone, disulphide reductase and isomerase, and calcium-binding activities. In the chaperone assays, ERp29 neither protected substrate proteins against thermal aggregation nor interacted stably with chemically denatured proteins as detected by cross-linking. ERp29 also did not exhibit helper activity toward calreticulin (chaperone) or PDI and ERp60 (disulphide reductase). By refuting long-standing predictions about chaperone activity, these results expose ERp29 as a functionally distinct member of the ER machinery and prompt a revised hypothesis that ERp29 acts as a non-classical folding assistant. The native preparation and biochemical hallmarks established here provide a useful foundation for ongoing efforts to resolve the functional orphan status of ERp29.


2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Jong Eun Park ◽  
Geum Seok Jeong ◽  
Hyun Woo Lee ◽  
Hoon Kim

AbstractA novel family IV esterase (hormone-sensitive lipase, HSL) gene, est15L, was isolated from a compost metagenomic library. Encoded Est15L comprised 328 amino acids with a molecular weight of 34,770 kDa and was an intracellular esterase without a signal peptide. The multiple sequence alignment (MSA) of Est15L with other family IV esterases showed conserved regions such as HGG, DYR, GXSXG, DPL, and GXIH. Native Est15L was a dimeric form from the results of size exclusion chromatography. It was optimally active at 50 ℃ and pH 9.0, indicating alkaline esterase. However, it showed a low thermostability with half-lives of 30.3 at 30 ℃ and 2.7 min at 40 ℃. It preferred p-nitrophenyl butyrate (C4) with Km and Vmax values of 0.28 mM and 270.8 U/mg, respectively. Est15L was inhibited by organic solvents such as 30% methanol, isopropanol, and acetonitrile with residual activities of 12.5, 0.9, and 0.3%, respectively. It was also inhibited by 1% SDS and 1% PMSF; however, Est15L maintained its activity at 1% Triton X-100 and EDTA. Est15L was inhibited by Cu2+, Zn2+, Mn2+, Co2+, Fe2+, and Na+. In addition, Est15L hydrolyzed glyceryl tributyrate with a residual substrate amount of 43.7% at 60 min but could not hydrolyze the oils (fish and olive) and glyceryl trioleate. Interestingly, Est15L showed significant enantioselectivity toward the R-form with a residual substrate amount of 44.6%, lower than that of the S-form (83.5%). Considering its properties, Est15L can be a potential candidate for chemical reactions, such as the synthesis of pharmaceutical compounds.


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