Step Purification Procedure Research Articles

Purification and biochemical characterization of pullulanase produced from Bacillus sp. modified by ethyl-methyl sulfonate for improved applications

Strain improvement via chemical mutagen could impart traits with better enzyme production or improved characteristics. The present study sought to investigate the physicochemical properties of pullulanase produced from the wild Bacillus sp and the mutant. The pullulanases produced from the wild and the mutant Bacillus sp. (obtained via induction with ethyl methyl sulfonate) were purified in a-three step purification procedure and were also characterized. The wild and mutant pullulanases, which have molecular masses of 40 and 43.23 kDa, showed yields of 2.3% with 6.0-fold purification and 2.0% with 5.0-fold purification, respectively, and were most active at 50 and 40 °C and pH 7 and 8, respectively. The highest stability of the wild and mutant was between 40 and 50 °C after 1 h, although the mutant retained greater enzymatic activity between pH 6 and 9 than the wild. The mutant had a decreased Km of 0.03 mM as opposed to the wild type of 1.6 mM. In comparison to the wild, the mutant demonstrated a better capacity for tolerating metal ions and chelating agents. These exceptional characteristics of the mutant pullulanase may have been caused by a single mutation, which could improve its utility in industrial and commercial applications.

Production of Extracellular Alkaline Serine Protease from Pediococcus acidilactici NCDC 252: Isolation, Purification, Physicochemical and Catalytic Characterization

Proteases are the most important industrial enzymes capable of hydrolyzing proteins into small peptides and amino acids and used commercially in food, textile and pharmaceutical industries. An alkaline serine protease from Pediococcus acidilactici NCDC 252 was purified using a simple two step purification procedure i.e. ammonium sulphate precipitation and gel filtration chromatography with purification fold of 5.9, a yield and specific activity of 11.8% and 23.3 U mg/ml respectively. Purified enzyme worked optimally at pH 8.5 and 37 °C. The enzyme was stable in the pH range of 6.5–9.5 and up to 50 °C. The Km for BAPNA was 38 µM and Vmax was 10.6 U/mg. Purified enzyme exhibited highest hydrolyzing activity for BAPNA. Inhibition of purified enzyme by soybean trypsin inhibitor, benzamide and β-ME suggested the enzyme to be alkaline serine protease with involvement of cysteine residues either in binding or regulation. In-silico characterization of alkaline serine protease revealed the presence of Ser, His and Asp residues at its catalytic site. This shows the resemblance of alkaline protease under study with other studied serine proteases.

Expression and one step intein-mediated purification of biologically active human G-CSF in Escherichia coli.

Recombinant form of granulocyte colony stimulating factor (G-CSF) was first approved by FDA in 1998 for chemotherapy induced neutropenia. However, despite production of its biosimilars, less expensive production of G-CSF could reduce the overall therapeutic cost. The aim of this study was to evaluate the possibility of producing biologically active recombinant G-CSF via a single step purification procedure mediated by a self-cleavable intein. G-CSF was expressed by E. coli BL21 (DE3) through IPTG induction, followed by its purification using pH optimization on a chitin column. Western blotting, ELISA, size exclusion chromatography, circular diachorism, peptide mapping, and in vitro assays were performed to compare the structural similarity and biological activity of the purified G-CSF with Neupogen™. Protein purification was confirmed by revealing a band of approximately 18.8kDa on SDS-PAGE. Bioactivity and physicochemical assays based on the US pharmacopeia showed almost identical or acceptable ranges of similarities between recombinant G-CSF and Neopogen™. this study, biologically active soluble recombinant G-CSF was successfully produced with high purity without using chaotropic solvents through a one-step procedure. This shorter and more efficient purification procedure can reduce the cost and time of G-CSF production which makes its industrial production more cost-effective and might be also applicable for production of other biopharmaceuticals.

Purification and characterization of a new thermophilic collagenase from Nocardiopsis dassonvillei NRC2aza and its application in wound healing

A thermostable metallo-collagenase enzyme (150 kDa), recently identified in a newly isolated actinomycestes strain (Nocardiopsis dassonvillei NRC2aza), has been purified from natural source, characterized to have application in wound healing. A simple 3 step purification procedure gave an increase of purity by 6.23 fold with a specific activity of 387.2 U mg−1. The enzyme activity showed stability across a range of pH (7.0–8.5) and temperature (40–55 °C) with optima at pH 8.0 and 60 °C, respectively. Activators include Mg+2, Ca+2, Zn+2, Na+, K+ and Ba+2, while Mn+2, Co+2, Ni+2and Ag+ ions gave partial inhibition. Full inhibition was given by other tested ions and metalloproteinase inhibitors. Broad substrate specificity was demonstrated including activity against a native collagen. The Km and Vmax of the enzyme using azocollagen were 5.5 mg/ml and 1280 U, respectively. The purified collagenase enhanced wound closure in vitro and in vivo and the repair process was dose dependent. Topical application of the purified collagenase (either of 25 or 50 U) to cutaneous wounds significantly accelerated the rate of wound healing and the formation of granulation tissue. Hence, the purified collagenase has a great potential as a therapeutic agent in wound care and collagen related diseases.

An improved purification method for the lysosomal storage disease protein β-glucuronidase produced in CHO cells

Human β-glucuronidase (GUS; EC 3.2.1.31) is a lysosomal enzyme that catalyzes the hydrolysis of β-d-glucuronic acid residues from the non-reducing termini of glycosaminoglycans. Impairment in GUS function leads to the metabolic disorder mucopolysaccharidosis type VII, also known as Sly syndrome. We produced GUS from a CHO cell line grown in suspension in a 15 L perfused bioreactor and developed a three step purification procedure that yields ∼99% pure enzyme with a recovery of more than 40%. The method can be completed in two days and has the potential to be integrated into a continuous manufacturing scheme.

PROLink-Single Step Circularization and Purification Procedure for the Generation of an Improved Variant of Human Growth Hormone.

Human growth hormone (hGH) plays an important role during human development and is also an approved therapeutic for the treatment of several diseases. However, one major drawback of hGH is its short circulating half-life requiring frequent administration, which is inconvenient and painful for the patients. Recent publications indicate that circularization greatly increases the stability of proteins due to their protection from exoproteolytic attack and a higher thermal stability of the circular form. Using sortase A, a transpeptidase isolated from Staphylococcus aureus, we developed a single step solid-phase circularization and purification procedure resulting in a circular version of hGH with improved properties. We could show that circular hGH binds to the recombinant hGH receptor with binding kinetics similar to those of linear hGH and that circularization does not alter the biological activity of hGH in vitro. Besides, circular hGH showed almost complete resistance toward exoproteolytic attack and slightly increased thermal stability which could possibly translate into an extended plasma half-life. The single step solid-phase circularization and purification procedure is in principle a generic process, which could also be applied for other proteins that meet the requirements for circularization.

Engineering of Harobin for enhanced fibrinolytic activity obtained by random and site-directed mutagenesis

We have previously published a report on the cloning and characterization of Harobin, a fibrinolytic serine protease. However, the broad application of this fibrinolytic enzyme is limited by its low expression level that was achieved in Pichia pastoris. To counteract this shortcoming, random and site-directed mutagenesis have been combined in order to improve functional expression and activity of Harobin. By screening 400 clones from random mutant libraries for enhanced fibrinolytic activity, two mutants were obtained: N111R, R230G. By performing site-directed mutagenesis, a Harobin double mutant, N111R/R230G, was constructed and can be functionally expressed at higher level than the wild type enzyme. In addition, it possessed much higher fibrinolytic and amidolytic activity than the wild type enzyme and other single mutants. The N111R/R230G expressed in basal salts medium was purified by a three step purification procedure. At pH of 6.0–9.0, and the temperature range of 40–90 °C, N111R/R230G was more active and more heat resistant. The fibrinolytic activities of Harobin mutants were completely inhibited by PMSF and SBTI, but not by EDTA, EGTA, DTT, indicating that Harobin is a serine protease. N111R/R230G showed much better anti-thrombosis effect than wild type Harobin and single mutants, and could significantly increase bleeding and clotting time. Intravenous injection of N111R/R230G in spontaneous hypertensive rats (SHR) led to a significant reduction in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) (p < 0.01), while heart rate (HR) was not affected. The in vitro and in vivo results of the present study revealed that Harobin double mutant N111R/R230G is an appropriate candidate for biotechnological applications due to its high expression level and high activity in area of thrombosis and hypertension.

Antimicrobial Properties of an Oxidizer Produced by Burkholderia cenocepacia P525

A compound with both oxidizing properties and antibiotic properties was extracted and purified from broth cultures of Burkholderia cenocepacia strain P525. A four step purification procedure was used to increase its specific activity ~400-fold and to yield a HPLC-UV chromatogram containing a single major peak. Size exclusion chromatography suggests a molecular mass of ~1,150 and UV spectroscopy suggests the presence of a polyene structure consisting of as many as six conjugated double bonds. Biological studies indicate that the compound is bacteriostatic. Enterobacter soli and E. aerogenes cells incubated with the compound exhibit a longer lag phase of growth. The bacteriostatic activity is greater at pH 3 than at pH 5. Bacteria such as B. cenocepacia strain P525 may have value in the agricultural industry as biocontrol agents.

Purification and Characterization of Acid Phosphatase from Monocrotophos (MCP) Hydrolyzing Aspergillus niger ITCC 7782.10 Isolated from Local Agricultural Field

Objective: The present study aimed the characterization and purification of acid phosphatases from monocrotophos (MCP) hydrolyzing Aspergillus niger ITCC 7782.10 isolated from local agricultural field. Material and Methods: Intracellular phosphatases from MCP hydrolyzing Aspergillus niger ITCC 7782.10 were purified by four step purification procedure which were further characterized. Results: The study demonstrated the presence of two intracellular phosphatases of varying molecular weights of 33 and 67 kDa which were purified to 126 and 76 fold respectively by four step purification strategy. Both the phosphatases showed similar pattern for pH, temperature and metal ion however, the activity of P33 was found to be higher than that of P67. The phosphatases were found to be most active at acidic pH and were found to be stable till 80°C demonstrating them to be acid phosphatases and thermostable. Km and Vmax values of P33 was found to be 0.28 mM and 1.21 Umg-1protein respectively whereas K m of P67 was found to be 0.72 mM and Vmax value was 1.85 Umg -1 protein. This indicated that P33 had more affinity towards para nitro phenol phosphate (pNPP) as a substrate than P67. Conclusion: This is the first report indicating the presence of two different intracellularly thermostable acid phosphatases within the same MCP hydrolyzing fungal strain Aspergillus niger ITCC 7782.10. Therefore, these acid phosphatases could be effectively used for the bioremediation of MCP contaminated sites.

Identification and characterization of MIP-1α/CCL3 isoform 2 from bovine serum as a potent monocyte/dendritic cell chemoattractant

Bovine serum is a rich source of cytokines and growth factors supporting in vitro cell culture. Here, a novel bovine monocyte chemotactic factor (boMCF-1) was isolated from commercial bovine serum by a four step purification procedure including adsorption to silicic acid, heparin affinity and cation-exchange chromatography and reversed phase HPLC. Homogeneous boMCF-1 was characterized as a 7717Da protein by mass spectrometry and identified by Edman degradation as the predicted product of bovine macrophage inflammatory protein-1α gene (boMIP-1α/CCL3) isoform 2 (lacking three NH2-terminal amino acids), belonging to the MIP subfamily of CC chemokines. Monocyte chemotactic activity of boCCL3 isoform 2 was completely desensitized by human CCL3 and CCL5, partially by CCL7 and not by CCL2. Its activity was better inhibited by CCR1 than by CCR5 blockade. BoCCL3 isoform 2, present in bovine serum at about 10ng/ml, functioned as a most potent chemoattractant for immature (but not mature) dendritic cells with a minimal effective concentration of 0.03ng/ml and a maximal chemotactic index of 30 at 0.3ng/ml. Its chemotactic activity on immature dendritic cells was significantly desensitized by human CCL3, CCL5 and CCL7. Blockade of CCR5 rather than CCR1 partially prevented chemotactic activity, whereas blockade of both further enhanced this inhibition. BoCCL3 isoform 2 was not chemokinetic but, like human CCL3, synergized with CXCL12 in monocytic cell chemotaxis. Since it cannot be deduced which is the exact human homolog of boCCL3 isoform 2, further research is required to study the biology of other boCCL3 family members.

Secretory Expression and Purification of the Recombinant Duck Interleukin-2 in Pichia pastoris

Interleukin-2 (IL-2) is a vital cytokine secreted by activated T lymphocytes, and plays an important role in the regulation of cellular functions and immunity of animals. In this study, the recombinant duck IL-2 (rduIL-2) was secretory expressed in Pichia pastoris (P. pastoris). The recombinant P. pastoris strain was cultured in shake flasks and then scaled up in a 5.0-l bioreactor. The result showed that the maximal fresh-cell-weight of 594.1 g/l and the maximal OD600 of 408 were achieved in the bioreactor. The rduIL-2 was purified by two steps of purification procedures, and approximately 311 mg of rduIL-2/L fermentation supernatant was obtained. SDS-PAGE showed that the purified rduIL-2 constituted a homogeneous band of ~16 kDa or ~14 kDa corresponding to the glycosylated or non-glycosylated duIL-2 protein in size, respectively. The bioactivity of rduIL-2 was determined by lymphocyte proliferation assay. The result indicated that the rduIL-2 greatly promoted the proliferation of ConA-stimulated lymphocytes in vitro. The P. pastoris expression system described here could provide promising, inexpensive, and large-scale production of the rduIL-2, which lays the foundation for development of novel immunoadjuvants to enhance both the immunity of ducks against various infectious pathogens and vaccine efficacy.

Structure-based Mechanism of CMP-2-keto-3-deoxymanno-octulonic Acid Synthetase

The enzyme CMP-Kdo synthetase (KdsB) catalyzes the addition of 2-keto-3-deoxymanno-octulonic acid (Kdo) to CTP to form CMP-Kdo, a key reaction in the biosynthesis of lipopolysaccharide. The reaction catalyzed by KdsB and the related CMP-acylneuraminate synthase is unique among the sugar-activating enzymes in that the respective sugars are directly coupled to a cytosine monophosphate. Using inhibition studies, in combination with isothermal calorimetry, we show the substrate analogue 2beta-deoxy-Kdo to be a potent competitive inhibitor. The ligand-free Escherichia coli KdsB and ternary complex KdsB-CTP-2beta-deoxy-Kdo crystal structures reveal that Kdo binding leads to active site closure and repositioning of the CTP phosphates and associated Mg(2+) ion (Mg-B). Both ligands occupy conformations compatible with an S(n)2-type attack on the alpha-phosphate by the Kdo 2-hydroxyl group. Based on strong similarity with DNA/RNA polymerases, both in terms of overall chemistry catalyzed as well as active site configuration, we postulate a second Mg(2+) ion (Mg-A) is bound by the catalytically competent KdsB-CTP-Kdo ternary complex. Modeling of this complex reveals the Mg-A coordinated to the conserved Asp(100) and Asp(235) in addition to the CTP alpha-phosphate and both the Kdo carboxylic and 2-hydroxyl groups. EPR measurements on the Mn(2+)-substituted ternary complex support this model. We propose the KdsB/CNS sugar-activating enzymes catalyze the formation of activated sugars, such as the abundant CMP-5-N-acetylneuraminic acid, by recruitment of two Mg(2+) to the active site. Although each metal ion assists in correct positioning of the substrates and activation of the alpha-phosphate, Mg-A is responsible for activation of the sugar-hydroxyl group.

Expression, Purification, and Characterization of Hepatitis B Virus Surface Antigens (HBsAg) in Yeast Pichia Pastoris

Prevention of the prevalence of HB depends upon the development of efficient diagnostic reagent and preventive vaccine. Pichia pastoris offers many advantages over the other expression systems in the production of recombinant HBsAg. In this study, we reported that the recombinant P. pastoris strains were cultured in shake flasks and then scaled up in a 5.0-l bioreactor: approximately 27 mg/l of the protein and the maximal cell OD at 600 nm of 310 were achieved in the bioreactor. The recombinant HBsAg was purified by three steps of purification procedures. SDS-PAGE showed that the purified recombinant HBsAg constituted only one homogeneous band of approximately 24 kDa. CsCl density gradient ultracentrifugation assay indicated that the density of the HBsAg was 1.2 mg/ml, which was in agreement with the natural HBsAg, the HBsAg expressed in Saccharomyces cerevisiae and in mammalian cells. Electron microscope observation revealed that the purified recombinant HBsAg was homogeneous 22-nm particles, suggesting the HBsAg expressed in P. pastoris was self-assembled to virus-like structures. Competitive ELISA indicated that P. pastoris-derived HBsAg possessed the excellent immunoreaction with anti-HBsAg. Animal immunization showed that the immunogenicity of P. pastoris-derived HBsAg was superior to that of S. cerevisiae-derived HBsAg. Together, our results demonstrated that the recombinant HBsAg expressed in P. pastoris could provide promising, inexpensive, and large-scale materials for the diagnostic reagent and vaccine to prevent HBV infection.

Expression, purification and characterization of murine Dkk1 protein

Dickkopf-1 (Dkk1) protein is a secreted inhibitor of canonical Wnt signaling and modulates that pathway during embryonic development. It is also implicated in several diseases and hence Dkk1 is a potential target for therapeutic intervention. In the present study 6His-tagged Dkk1 expression and secretion was assessed in five mammalian cell types. Only FreeStyle 293-F cells showed significant Dkk1 protein expression in culture medium. High and stable expression of the Dkk1 protein was obtained from a selected stable FreeStyle 293-F clone 3F8, that grows in suspension in serum-free medium. The 3F8 clone showed a high Dkk1 production level (10 mg/L) for up to 2 months of culture. A one step purification procedure resulting in large amounts of highly pure and active Dkk1 protein was developed. Purified Dkk1 binds its receptors LRP5 and LRP6, and is able to dose dependently inhibit canonical Wnt signaling. Recombinant Dkk1 is glycosylated, but this modification is not essential for its biological activity. In summary, an abundant source of pure and functionally active Dkk1 protein is developed that will support the identification of inhibitors such as neutralizing antibodies that could find therapeutic use.

Characterization of purified xylanase from finger millet (Eleusine coracana-Indaf 15) malt

Xylanase (E.C. 3.2.1.8) was purified to apparent homogeneity from 96 h finger millet (Eleusine coracana, Indaf-15) malt by a three step purification procedure via ammonium sulphate fractionation, DEAE-cellulose ion exchange and Sephadex G-75 gel permeation chromatographies with a recovery of 4.0% and fold purification of 60. Xylanase, having a molecular weight of 29 ± 2 kDa was found to be monomeric on SDS-PAGE. pH optimum of the enzyme was found to be in the range of 5.0–5.5. The activation energy was 25 kJmol−1. Xylanase showed maximum stability at 35 °C in a pH range of 5.0–6.0. Km and Vmax of purified xylanase were found to be 0.2% and 4.5 μmol min−1, respectively. Metal ions such as Ca2+, Mg2+, Mn2+, Cu2+, Fe2+, Ag2+ and Ni2+ enhanced xylanase activity at 5 mM concentration. p-chloromercuribenzoate, citric, oxalic and boric acids inhibited the enzyme in concentration dependent manner. The mode of action of xylanase was found to be “endo” as determined by the analysis of products liberated from larchwood xylan by ESI-MS and H1NMR. In vitro studies using Bifidobacterium and Lactobacillus sp. confirmed the prebiotic activity of the xylo-oligosaccharides.

Exceptional overproduction of a functional human membrane protein

Eukaryotic—especially human—membrane protein overproduction remains a major challenge in biochemistry. Heterologously overproduced and purified proteins provide a starting point for further biochemical, biophysical and structural studies, and the lack of sufficient quantities of functional membrane proteins is frequently a bottleneck hindering this. Here, we report exceptionally high production levels of a correctly folded and crystallisable recombinant human integral membrane protein in its active form; human aquaporin 1 (hAQP1) has been heterologously produced in the membranes of the methylotrophic yeast Pichia pastoris. After solubilisation and a two step purification procedure, at least 90 mg hAQP1 per liter of culture is obtained. Water channel activity of this purified hAQP1 was verified by reconstitution into proteoliposomes and performing stopped-flow vesicle shrinkage measurements. Mass spectrometry confirmed the identity of hAQP1 in crude membrane preparations, and also from purified protein reconstituted into proteoliposomes. Furthermore, crystallisation screens yielded diffraction quality crystals of untagged recombinant hAQP1. This study illustrates the power of the yeast P. pastoris as a host to produce exceptionally high yields of a functionally active, human integral membrane protein for subsequent functional and structural characterization.

A three-step purification method of large quantities of human recombinant α endothelial cellular growth factor for clinical use

The endothelial cellular growth factor alpha-ECGF is a candidate drug for the induction of therapeutic neoangiogenesis. Its use in extensive experimental and clinical trials is hampered by the fact that currently published purification procedures allow only small yields, and the absence of pyrogenic impurities is not demonstrated. The rh alpha-ECGF was expressed in E. coli. Isolation of rh alpha-ECGF from E. coli lysates to apparent homogenicity was achieved by a three step purification procedure involving ionic exchange, heparin-sepharose and polymyxin B chromatography. By this method, 200 mg of rh alpha-ECGF was purified from 15 g wet weight E. coli bacteria. The isolated protein of 18 kDa appeared as a single band after SDS gel electrophoresis and subsequent silver-staining. The biological activity was expressed in the chorion-allantois-membrane assay and in the 3H-thymidine proliferation in baby hamster kidney cells. Drug trials with rabbits revealed no increase in body temperature after intravenous injections with 1 mg rh-ECGF.

Novel immunotoxin: A fusion protein consisting of gelonin and an acetylcholine receptor fragment as a potential immunotherapeutic agent for the treatment of Myasthenia gravis

In continuation of our attempts for antigen-specific suppression of the immune system [I.L. Urbatsch, R.K.M. Sterz, K. Peper, W.E. Trommer, Eur. J. Immunol. 23(1993) 776–779] a novel fusion protein composed of amino acids 4–181 of the extracellular domain of the α-subunit of the human muscle acetylcholine receptor and the plant toxin gelonin was expressed in Escherichia coli. The fusion protein formed inclusion bodies but could be solubilized in the presence of guanidinium hydrochloride. After a simple two step purification and refolding procedure, it exhibited a native structure at least in the main immunogenic region as shown by antibodies recognizing a conformational epitope. Half maximal inhibition of translation was achieved at 46 ng/ml as compared to 4.6 ng/ml for native and 2.4 for recombinant gelonin. Its use as therapeutic agent for the treatment of Myasthenia gravis was investigated in an animal model. Female Lewis rats were immunized with complete acetylcholine receptor from the electric ray Torpedo californica and developed thereafter experimental autoimmune M. gravis. Quantitative assessment of the disease was achieved by repetitive stimulation of the Nervus tibialis. Rats showed no symptoms of M. gravis, neither visually nor electrophysiologically after treatment with the fusion protein as determined one and seven weeks after the second application. This approach may also be useful for the therapy of further autoimmune diseases by substituting other autoantigens for the AchR fragment in the fusion protein.

Purification and partial amino acid sequences of the enzyme vinorine synthase involved in a crucial step of ajmaline biosynthesis

The acetyl-CoA-dependent enzyme vinorine synthase was isolated from hybrid cell suspension cultures of Rauvolfia serpentina and Rhazya stricta. The sarpagan-type alkaloid gardneral was used as a substrate of the enzyme leading to the ajmalan-type 10-methoxyvinorine. An HPLC-based assay was developed to monitor vinorine synthase activity, which allowed establishing a five step purification procedure combining anion exchange, hydrophobic interaction, hydroxyapatite and gel filtration. Purification resulted in a yield of 0.2% and an approximately 991-fold enrichment of the acetyltransfer activity. SDS-PAGE analysis showed a M r for the enzyme of ∼50 kDa. The four peptide fragments generated by proteolysis of the pure enzyme with endoproteinase LysC and the N-terminal part of the enzyme were sequenced. The enzyme preparation (>875-fold enrichment) delivering the N-terminal sequence was isolated from R. serpentina cell suspensions. Sequence alignment of the five peptides showed highest homologies in a range of 30–71% to acetyltransferases from other higher plants involved in natural plant product biosynthesis. Based on the partial sequences vinorine synthase is probably a novel member of the BAHD enzyme super family.

Expression, purification, and characterization of 3-deoxy- d- arabino-heptulosonate 7-phosphate synthase from Pyrococcus furiosus

The enzyme 3-deoxy- d- arabino-heptulosonate 7-phosphate synthase (DAH7PS) catalyzes the condensation reaction between phosphoenolpyruvate (PEP) and erythrose 4-phosphate (E4P). DAH7PS from the hyperthermophile Pyrococcus furiosus has been expressed in Escherichia coli. The expressed protein was insoluble but was partially solubilized as a dimer by the inclusion of 200 mM KCl in the cell lysis buffer. An effective two step purification procedure has been developed. The first step resulted in a high degree of purification and involved lysis by sonication at approximately 40 °C followed by a heat treatment at 70 °C. A continuous assay measuring the loss of PEP at 232 nm at elevated temperatures was also developed. Temperature, pH, and divalent metal ions all had an effect on the extinction coefficient of PEP. Purified recombinant P. furiosus DAH7PS is a dimer with a subunit M r of 29,226 (determined by ESMS), shows resistance to denaturation by SDS, has activity over a broad pH range, and has an activation energy of 88 kJ mol −1. The kinetic parameters are K m (PEP) 120 μM, K m (E4P) 28 μM, and k cat 1.5 s −1, at 60 °C and pH 6.8. DAH7PS is not inhibited by phenylalanine, tyrosine, or tryptophan. EDTA inactivates the enzyme and enzyme activity is restored by a wide range of divalent metal ions including (in order of decreasing effectiveness): Zn 2+, Cd 2+, Mn 2+, Co 2+, Ni 2+, Ca 2+, Hg 2+, and Cu 2+. This detailed characterization of the DAH7PS from P. furiosus raises the possibility that the subfamily Iβ DAH7PS enzymes are metal ion dependent, contrary to previous predictions.