Purification and characterization of D-β-hydroxybutyrate dehydrogenase expressed in Escherichia coli

1993 ◽  
Vol 71 (7-8) ◽  
pp. 406-410
Author(s):  
Les Jones ◽  
Sharon Churchill ◽  
Perry Churchill
Keyword(s):  
Escherichia Coli ◽  
Kinetic Parameters ◽  
Functional Properties ◽  
Rat Liver ◽  
Specific Activity ◽  
Purification And Characterization ◽  
E Coli ◽  
Specific Activities ◽  
Viable Method

D-β-Hydroxybutyrate dehydrogenase (BDH), a lipid-requiring enzyme, has been cloned into pUC18, expressed in Escherichia coli, and purified to homogeneity. The apoenzyme, i.e., the enzyme devoid of phospholipid, has no activity, but can be activated by phospholipid to a specific activity of 129 μmol/(min∙mg). The functional properties of the enzyme expressed in E. coli were compared with the enzyme purified from rat liver. The specific activities, kinetic parameters, and phospholipid activation profiles were virtually identical. These results indicate that the expression of the enzyme in E. coli is a viable method for producing active functional BDH and should allow for the production of specifically altered BDH molecules.Key words: D-β-hydroxybutyrate dehydrogenase, cloning, expression, lipid requiring.

scholarly journals Identification and Function of the pdxY Gene, Which Encodes a Novel Pyridoxal Kinase Involved in the Salvage Pathway of Pyridoxal 5′-Phosphate Biosynthesis in Escherichia coli K-12

1998 ◽  
Vol 180 (7) ◽  
pp. 1814-1821 ◽  
Author(s):  
Yong Yang ◽  
Ho-Ching Tiffany Tsui ◽  
Tsz-Kwong Man ◽  
Malcolm E. Winkler
Keyword(s):  
Escherichia Coli ◽  
De Novo ◽  
Specific Activity ◽  
Salvage Pathway ◽  
Pyridoxal Kinase ◽  
Triple Mutant ◽  
Reading Frame ◽  
E Coli ◽  
Specific Activities ◽  
K 12

ABSTRACT pdxK encodes a pyridoxine (PN)/pyridoxal (PL)/pyridoxamine (PM) kinase thought to function in the salvage pathway of pyridoxal 5′-phosphate (PLP) coenzyme biosynthesis. The observation that pdxK null mutants still contain PL kinase activity led to the hypothesis that Escherichia coli K-12 contains at least one other B6-vitamer kinase. Here we support this hypothesis by identifying the pdxY gene (formally, open reading frame f287b) at 36.92 min, which encodes a novel PL kinase. PdxY was first identified by its homology to PdxK in searches of the complete E. coli genome. Minimal clones of pdxY + overexpressed PL kinase specific activity about 10-fold. We inserted an omega cassette intopdxY and crossed the resultingpdxY::ΩKanr mutation into the bacterial chromosome of a pdxB mutant, in which de novo PLP biosynthesis is blocked. We then determined the growth characteristics and PL and PN kinase specific activities in extracts ofpdxK and pdxY single and double mutants. Significantly, the requirement of the pdxB pdxK pdxY triple mutant for PLP was not satisfied by PL and PN, and the triple mutant had negligible PL and PN kinase specific activities. Our combined results suggest that the PL kinase PdxY and the PN/PL/PM kinase PdxK are the only physiologically important B6vitamer kinases in E. coli and that their function is confined to the PLP salvage pathway. Last, we show thatpdxY is located downstream from pdxH (encoding PNP/PMP oxidase) and essential tyrS (encoding aminoacyl-tRNATyr synthetase) in a multifunctional operon.pdxY is completely cotranscribed with tyrS, but about 92% of tyrS transcripts terminate at a putative Rho-factor-dependent attenuator located in thetyrS-pdxY intercistronic region.

scholarly journals Purification and characterization of 3-dehydroquinase from Escherichia coli

1986 ◽  
Vol 239 (3) ◽  
pp. 699-704 ◽  
Author(s):  
S Chaudhuri ◽  
J M Lambert ◽  
L A McColl ◽  
J R Coggins
Keyword(s):  
Escherichia Coli ◽  
Gel Electrophoresis ◽  
Catalytic Properties ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Permeation Chromatography ◽  
Purification And Characterization ◽  
Gel Permeation

A procedure has been developed for the purification of 3-dehydroquinase from Escherichia coli. Homogeneous enzyme with specific activity 163 units/mg of protein was obtained in 19% overall yield. The subunit Mr estimated from polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate was 29,000. The native Mr, estimated by gel permeation chromatography on Sephacryl S-200 (superfine) and on TSK G3000SW, was in the range 52,000-58,000, indicating that the enzyme is dimeric. The catalytic properties of the enzyme have been determined and shown to be very similar to those of the biosynthetic 3-dehydroquinase component of the arom multifunctional enzyme of Neurospora crassa.

scholarly journals Purification and characterization of the class-II D-fructose 1,6-bisphosphate aldolase from Escherichia coli (Crookes' strain)

1978 ◽  
Vol 169 (3) ◽  
pp. 633-641 ◽  
Author(s):  
S A Baldwin ◽  
R N Perham ◽  
D Stribling
Keyword(s):  
Escherichia Coli ◽  
Common Ancestor ◽  
Class Ii ◽  
Purification And Characterization ◽  
Thiol Compounds ◽  
E Coli ◽  
Optimum Ph ◽  
Class Ii Aldolase ◽  
Fructose 1,6 Bisphosphate

A new form of the class-II D-fructose 1,6-bisphosphate aldolase (EC 4.1.2.13) of Escherichia coli (Crookes' strain) was isolated from an extract of glycerol-grown bacteria. It has a higher molecular weight (approx. 80000)than previous preparations of the enzyme and closely resembles the typical class-II aldolase from yeast in size and amino acid composition. On the other hand, its kinetic behaviour is not typical of a class-II aldolase. The enzyme has no requirement for thiol compounds either for stability or activity, added K+ ions have no effect, and the optimum pH for the cleavage activity is unusually high. The class-II enzymes from the prokaryote E. coli and the eukaryote yeast show no immunological identity. However, the similarity of their structures suggests that they have evolved from a common ancestor.

scholarly journals Purification and Characterization of the Folate Catabolic Enzyme p-Aminobenzoyl-Glutamate Hydrolase from Escherichia coli

2010 ◽  
Vol 192 (9) ◽  
pp. 2407-2413 ◽  
Author(s):  
Jacalyn M. Green ◽  
Ryan Hollandsworth ◽  
Lenore Pitstick ◽  
Eric L. Carter
Keyword(s):  
Escherichia Coli ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Minor Component ◽  
Size Exclusion ◽  
Breakdown Product ◽  
Purification And Characterization ◽  
Sds Page

ABSTRACT The abg locus of the Escherichia coli chromosome includes three genes encoding proteins (AbgA, AbgB, and AbgT) that enable uptake and utilization of the folate breakdown product, p-aminobenzoyl-glutamate (PABA-GLU). We report on the purification and characterization of the p-aminobenzoyl-glutamate hydrolase (PGH) holoenzyme encoded by abgA and abgB. One-step purification was accomplished using a plasmid carrying abgAB with a hexahistidine tag on the carboxyl terminus of AbgB and subsequent metal affinity chromatography (MAC). Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed two subunits (∼53-kDa and ∼47-kDa proteins) of the expected masses of AbgB and AbgA; N-terminal sequencing confirmed the subunit identification, and amino acid analysis yielded a 1:1 ratio of the subunits. Size exclusion chromatography coupled with light-scattering analysis of purified PGH revealed a predominant molecular mass of 206 kDa and a minor component of 400 to 500 kDa. Both peaks contained PGH activity, and SDS-PAGE revealed that fractions containing activity were composed of both AbgA and AbgB. MAC-purified PGH was highly stimulated by manganese chloride. Kinetic analysis of MAC-purified PGH revealed a Km value for PABA-GLU of 60 ± 0.08 μM and a specific activity of 63,300 ± 600 nmol min−1 mg−1. Folic acid and a variety of dipeptides served as poor substrates of PGH. This locus of the E. coli chromosome may encode a portion of a folate catabolism pathway.

scholarly journals Purification and characterization of a diptericin homologue from Sarcophaga peregrina (flesh fly)

1992 ◽  
Vol 287 (2) ◽  
pp. 573-578 ◽  
Author(s):  
M Ishikawa ◽  
T Kubo ◽  
S Natori
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Bactericidal Activity ◽  
Fat Body ◽  
Amino Acid Sequencing ◽  
Purification And Characterization ◽  
E Coli ◽  
Escherichia Coli Cells

A protein with a molecular mass of 8 kDa was found to be synthesized specifically when the fat-body from injured Sarcophaga peregrina larvae was cultured in vitro. This protein was purified from the haemolymph of the injured larvae to near-homogeneity. Partial amino acid sequencing revealed that this protein is a diptericin homologue. It showed bactericidal activity on growing, but not resting Escherichia coli cells. E. coli cells become elongated on treatment with this protein.

scholarly journals Kinetic Properties of Four Plasmid-Mediated AmpC β-Lactamases

2005 ◽  
Vol 49 (10) ◽  
pp. 4240-4246 ◽  
Author(s):  
Cédric Bauvois ◽  
Akiko Shimizu Ibuka ◽  
Almeida Celso ◽  
Jimena Alba ◽  
Yoshikazu Ishii ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Kinetic Parameters ◽  
Kinetic Properties ◽  
Kinetic Characterization ◽  
Heterologous Production ◽  
Periplasmic Space ◽  
E Coli ◽  
Class C ◽  
Susceptibility Patterns

ABSTRACT The heterologous production in Escherichia coli, the purification, and the kinetic characterization of four plasmid-encoded class C β-lactamases (ACT-1, MIR-1, CMY-2, and CMY-1) were performed. Except for their instability, these enzymes are very similar to the known chromosomally encoded AmpC β-lactamases. Their kinetic parameters did not show major differences from those obtained for the corresponding chromosomal enzymes. However, the Km values of CMY-2 for cefuroxime, cefotaxime, and oxacillin were significantly decreased compared to those of the chromosomal AmpC enzymes. Finally, the susceptibility patterns of different E. coli hosts producing a plasmid- or a chromosome-encoded class C enzyme toward β-lactam antibiotics are mainly due to the overproduction of the β-lactamase in the periplasmic space of the bacteria rather than to a specific catalytic profile of the plasmid-encoded β-lactamases.

scholarly journals Purification and characterization of hemocyte phenoloxidases in Chilo suppressalis walker (Lepidoptera: Crambidae)

2015 ◽  
Vol 67 (4) ◽  
pp. 1119-1125 ◽  
Author(s):  
Seyyedeh Mirhaghparast ◽  
Arash Zibaee ◽  
Hassan Hoda ◽  
Mahmoud Fazeli-Dinan
Keyword(s):  
Kinetic Parameters ◽  
Column Chromatography ◽  
Deae Cellulose ◽  
Chilo Suppressalis ◽  
Purification And Characterization ◽  
Molecular Weights ◽  
Specific Activities ◽  
Fast Flow ◽  
Statistical Effects

In the current study, two phenoloxidases (POs) from the larvae of Chilo suppressalis Walker were extracted and purified by column chromatography using Sepharyl G-100 and DEAE-Cellulose fast flow column. Two proteins possessing PO activity, named as POI and POII, were extracted by purification, 5.08- and 5.62-fold, respectively, with 8.94% and 7.31% recoveries, respectively. Also, the specific activities of POI and POII were 0.478 and 0.529 U/mg protein, respectively. Finally, the molecular weights of POI and POII were calculated as 94.6 and 95.7 kDa, respectively. Kinetic parameters of the purified phenoloxidases by Lineweaver-Burk analysis were Vmax of 2.27 and 1.11 U/mg protein and Km of 15.51 and 17.31 mM for POI and POII, respectively. Mg2+ and Cu2+ significantly increased the PO activities. Ca2+ decreased the activity of POI and showed no statistical effects on POII activity. EDTA and DTC significantly inhibited the activities of the purified enzymes, while triethylenetetramine hexaacetic acid (TTHA) and RGTA showed no significant effects on enzymatic activities.

scholarly journals Purification and characterization of a lysosomal form and a variant form of β-glucuronidase from the rat basophil leukaemia tumour

1981 ◽  
Vol 193 (3) ◽  
pp. 663-670 ◽  
Author(s):  
L B Schwartz ◽  
K F Austen
Keyword(s):  
Rat Liver ◽  
Specific Activity ◽  
Deae Cellulose ◽  
Rat Tissues ◽  
Variant Form ◽  
Polyacrylamide Gels ◽  
Purification And Characterization ◽  
Normal Rat ◽  
Single Subunit

Two isoenzyme of beta-glucuronidase from a rat basophil leukaemia tumour were co-purified 4067-fold by (NH4)2SO4 precipitation and sequential chromatography on concanavalin A–Sepharose, Sephadex G-200, DEAE-cellulose, CM-cellulose and phosphocellulose. The purity of the mixture was established by the coincidence of the peaks of enzyme activity and protein at a molecular weight of 300 000 on Bio-Gel P-300, the presence of only two protein bands, both of them enzymically active, in polyacrylamide gels after electrophoresis under non-denaturing conditions, and the presence of a single subunit species, of mol.wt. 75 000, after electrophoresis in polyacrylamide gels under a denaturing conditioning. The major isoenzyme co-migrated with the L form from rat liver during electrophoresis in alkaline polyacrylamide gels, whereas the minor isoenzyme migrated more rapidly than either the lysosomal form or the rat liver microsomal form and was designated the tumour (T) isoenzyme. A mixture of the purified isoenzymes from two preparations had an average specific activity of 1389 units/mg for phenolphthalein beta-D-glycopyranosiduronic acid. The L and T isoenzymes, which had pI5.9 and 5.7 respectively, could be obtained free of cross-contamination by isoelectric focusing and had similar specific activities. Although the T isoenzyme could be a catabolic product of the M or the L form, it could also be a unique tumour product, because it was not detected in extracts of normal rat tissues.

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