Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.2.13 (aldolase)
 3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An ORF designated b2245 (yfaU) in the Escherichia coli K12 genome sequence, identified as an HHED aldolase homologue, was cloned into the high-expression plasmid pT7-7 and overexpressed in E. coli B835(DE3). The enzyme was purified in three steps to 95% purity prior to crystallization. Crystals were obtained by the hanging-drop vapour-diffusion method at 277 K from a number of screening conditions. Crystals suitable for structural studies were grown from solutions containing 0.4 M ammonium dihydrogen phosphate and grew to a maximum dimension of approximately 0.5 mm. Diffraction data to 1.7 A were collected using an in-house Cu Kalpha radiation source at 100 K. The crystals belong to space group C222(1), with unit-cell parameters a = 105.1, b = 136.6, c = 123.1 A. A 90% complete data set was collected to 1.78 A from a single native crystal using in-house facilities.
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PMID:Expression, purification, crystallization and preliminary characterization of an HHED aldolase homologue from Escherichia coli K12. 1245 98

The Class II fructose 1,6-bisphosphate aldolase (fda, Rv0363c) from the pathogen Mycobacterium tuberculosis H37RV was subcloned in the Escherichia coli vector pT7-7 and purified to near homogeneity. The specific activity (35 U/mg) is approximately 9 times higher than previously reported for the enzyme partially purified from the pathogen. Attempts to express the enzyme with an N-terminal fusion tag yielded inactive, mostly insoluble protein. The native recombinant enzyme is zinc-dependent and has a catalytic efficiency for fructose 1,6-bisphosphate cleavage higher than most Class II aldolases characterized to date. The aldolase has a Km of 20 microM, a kcat of 21 s(-1), and a pH optimum of 7.8. The molecular mass of the enzyme subunits as determined by mass spectrometry is in agreement with the mass calculated on the basis of its gene sequence minus the terminal methionine, 36,413 Da. The enzyme is a homotetramer and retains only two zinc ions per tetramer when transferred to a metal-free buffer, as determined by ICP-MS and by a colorimetric assay using 4-(2-pyridylazo)-resorcinol (PAR) as a chelator. The E. coli expression system reported in this study will facilitate the further characterization of this enzyme and the screening for potential inhibitors.
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PMID:Molecular cloning, expression, purification, and characterization of fructose 1,6-bisphosphate aldolase from Mycobacterium tuberculosis--a novel Class II A tetramer. 1529 2

The Class II fructose 1,6-bisphosphate aldolase from the Rice Blast causative agent Magnaporthe grisea was subcloned in the Escherichia coli vector pT7-7. The enzyme was overexpressed using fed-batch fermentation in a small bench-top reactor. A total of 275 g of cells and 1.3 g of highly purified enzyme with a specific activity of 70 U/mg were obtained from a 1.5L culture. The purified enzyme is a homodimer of 39.6 kDa subunits with a zinc ion at the active site. Kinetic characterization indicates that the enzyme has a K(m) of 51 microM, a k(cat) of 46 s(-1), and a pH optimum of 7.8 for fructose 1,6-bisphosphate cleavage. The fermentation system procedure reported exemplifies the potential of using a lab-scale bioreactor for the large scale production of recombinant enzymes.
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PMID:High level production of the Magnaporthe grisea fructose 1,6-bisphosphate aldolase enzyme in Escherichia coli using a small volume bench-top fermentor. 1690 16

Fructose 1,6-bisphosphate (FBP) aldolase has been used as biocatalyst in the synthesis of several pharmaceutical compounds such as monosaccharides and analogs. Is has been suggested that microbial metal-dependant Class II aldolases could be better industrial catalysts than mammalian Class I enzyme because of their greater stability. The Class II aldolases from four microbes were subcloned into the Escherichia coli vector pT7-7, expressed and purified to near homogeneity. The kinetic parameters, temperature stability, pH profile, and tolerance to organic solvents of the Class II enzymes were determined, and compared with the properties of the Class I aldolase from rabbit muscle. Contrary to results obtained previously with the E. coli Class II aldolase, which was reported to be more stable than the mammalian enzyme, other recombinant Class II aldolases were found to be generally less stable than the Class I enzyme, especially in the presence of organic solvents. Class II aldolase from Bacillus cereus showed higher temperature stability than the other enzymes tested, but only the Mycobacterium tuberculosis Class II aldolase had a stability comparable to the Class I mammalian enzyme under assay conditions. The turnover number of the recombinant M. tuberculosis and Magnaporthe grisea Class II type A aldolases was comparable or higher than that of the Class I enzyme. The recombinant B. cereus and Pseudomonas aeruginosa Class II type B aldolases had very low turnover numbers and low metal content, indicating that the E. coli overexpression system may not be suitable for the Class II type B aldolases from these microorganisms.
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PMID:Evaluation of four microbial Class II fructose 1,6-bisphosphate aldolase enzymes for use as biocatalysts. 2176 25