scholarly journals Characterization of three kinetically distinct forms of glutamate decarboxylase from pig brain

1985 ◽  
Vol 231 (3) ◽  
pp. 695-703 ◽  
Author(s):  
D C Spink ◽  
T G Porter ◽  
S J Wu ◽  
D L Martin
Keyword(s):  
Sodium Dodecyl Sulphate ◽  
Glutamate Decarboxylase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Kinetic Properties ◽  
First Order ◽  
Pig Brain ◽  
A Subunit ◽  
Activation Cycle

Pig brain contains three forms of glutamate decarboxylase with pI values of 5.3, 5.5 and 5.8, referred to as the α-, β- and γ-forms respectively. These forms were purified and kinetically characterized. The major synaptic form of glutamate decarboxylase (the β-form) migrated as a single band on electrophoresis in sodium dodecyl sulphate/polyacrylamide gels with an apparent Mr of 60 000. Sodium dodecyl sulphate/polyacrylamide gel electrophoresis followed by immunoblotting with an affinity-purified antibody to the enzyme indicated a subunit Mr of 60 000 for the α- and γ-forms as well. An extensive kinetic analysis, aided by an integrated equation that describes the inactivation and re-activation cycle of the enzyme, revealed that the three forms of the enzyme differ markedly in kinetic properties. The Km values for L-glutamate were 0.17, 0.45 and 1.24 mM respectively for the α-, β- and γ-forms. The Ki for 4-aminobutyrate, the first-order rate constants for inactivation by L-glutamate and 4-aminobutyrate, the rate constant for re-activation of the apoenzyme by pyridoxal 5′-phosphate and the dissociation constant for pyridoxal 5′-phosphate also differed in a similar way among the three forms; the values were in the order α-form less than β-form less than γ-form.

scholarly journals The identification and characterization of two separate carboxylesterases in guinea-pig serum

1983 ◽  
Vol 215 (1) ◽  
pp. 91-99 ◽  
Author(s):  
K Cain ◽  
E Reiner ◽  
D G Williams
Keyword(s):  
Guinea Pig ◽  
Sodium Dodecyl Sulphate ◽  
Enzyme Preparation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Selective Inhibitor ◽  
Nitrophenyl Phosphate ◽  
Phosphate Treatment ◽  
Pig Serum

The esterase activity of guinea-pig serum was investigated. A 3-fold purification was achieved by removing the serum albumin by Blue Sepharose CL-6B affinity chromatography. The partially purified enzyme preparation had carboxylesterase and cholinesterase activities of 1.0 and 0.22 mumol of substrate/min per mg of protein respectively. The esterases were labelled with [3H]di-isopropyl phosphorofluoridate (DiPF) and separated electrophoretically on sodium dodecyl sulphate/polyacrylamide gels. Two main labelled bands were detected: band I had Mr 80 000 and bound 18-19 pmol of [3H]DiPF/mg of protein, and band II had Mr 58 000 and bound 7 pmol of [3H]DiPF/mg of protein. Bis-p-nitrophenyl phosphate (a selective inhibitor of carboxylesterase) inhibited most of the labelling of bands I and II. The residual labelling (8%) of band I but not band II (4%) was removed by preincubation of partially purified enzyme preparation with neostigmine (a selective inhibitor of cholinesterase). Paraoxon totally prevented the [3H]DiPF labelling of the partially purified enzyme preparation. Isoelectrofocusing of [3H]DiPF-labelled and uninhibited partially purified enzyme preparation revealed that there were at least two separate carboxylesterases, which had pI3.9 and pI6.2, a cholinesterase enzyme (pI4.3) and an unidentified protein that reacts with [3H]DiPF and has a pI5.0. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of these enzymes showed that the carboxylesterase enzymes at pI3.9 and pI6.2 corresponded to the 80 000-Mr subunit (band I) and 58 000-Mr subunit (band II). The cholinesterase enzyme was also composed of 80 000-Mr subunits (i.e. the residual labelling in band I after bis-p-nitrophenyl phosphate treatment). The unidentified protein at pI5.0 corresponded to the residual labelling in band II (Mr 58 000), which was insensitive to neostigmine and bis-p-nitrophenyl phosphate. These studies show that the carboxylesterase activity of guinea-pig serum is the result of at least two separate and distinct enzymes.

Acid and alkaline phosphatases of Capnocytophaga species. II. Isolation, purification, and characterization of the enzymes from Capnocytophaga ochracea

1983 ◽  
Vol 29 (10) ◽  
pp. 1361-1368 ◽  
Author(s):  
Thomas P. Poirier ◽  
Stanley C. Holt
Keyword(s):  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Alkaline Phosphatases ◽  
Purification And Characterization ◽  
Molecular Weights ◽  
Sds Page ◽  
Kinetics Of

Capnocytophaga ochracea acid (AcP; EC 3.1.3.2) and alkaline (AlP; EC 3.1.3.1) phosphatase was isolated by Ribi cell disruption and purified by sodium dodecyl sulphate – polyacrylamide gel electrophoresis (SDS–PAGE.) Both phosphatases eluted from Sephadex G-150 consistent with molecular weights (migration) of 140 000 and 110 000. SDS–PAGE demonstrated a 72 000 and 55 000 subunit molecular migration for AcP and AlP, respectively. The kinetics of activity of purified AcP and AIP on p-nitrophenol phosphate and phosphoseryl residues of the phosphoproteins are presented.

scholarly journals Purification and characterization of a plasminogen activator secreted by a pig kidney cell line

1984 ◽  
Vol 219 (3) ◽  
pp. 971-978 ◽  
Author(s):  
M Sudol ◽  
E Reich
Keyword(s):  
Plasminogen Activator ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Pig Kidney ◽  
Reducing Conditions ◽  
Pig Kidney Cells

The plasminogen activator secreted by calcitonin-treated pig kidney cells was purified, characterized and compared with human urinary urokinase. The purification procedure was based on the following steps: sulphopropyl-Sephadex chromatography, p-aminobenzamidine-Sepharose chromatography, preparative sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and isoelectrofocusing. The purified enzyme was obtained from the conditioned medium with a yield of 13% and a purification factor of 390-fold. Analysis by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis under non-reducing conditions showed one closely spaced doublet with an Mr of 50 000; in the presence of reducing agents, two additional bands of Mr 30 000 and 20 000 appeared. The purified enzyme resembles the 53 000-Mr components of human urinary urokinase in amino acid composition and two-dimensional tryptic peptide maps and in its catalytic properties, and the two enzymes cross-react immunologically with rabbit antibodies raised against either. The enzyme appears to be different from tissue plasminogen activator secreted by HeLa cells.

scholarly journals Degradation of Chloroaromatics: Purification and Characterization of a Novel Type of Chlorocatechol 2,3-Dioxygenase of Pseudomonas putida GJ31

1998 ◽  
Vol 180 (2) ◽  
pp. 296-302 ◽  
Author(s):  
Stefan R. Kaschabek ◽  
Thomas Kasberg ◽  
Dagmar Müller ◽  
Astrid E. Mars ◽  
Dick B. Janssen ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
Molecular Mass ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Great Sensitivity ◽  
Kinetic Properties ◽  
Extradiol Dioxygenase ◽  
A Subunit ◽  
Extradiol Dioxygenases

ABSTRACT A purification procedure for a new kind of extradiol dioxygenase, termed chlorocatechol 2,3-dioxygenase, that converts 3-chlorocatechol productively was developed. Structural and kinetic properties of the enzyme, which is part of the degradative pathway used for growth ofPseudomonas putida GJ31 with chlorobenzene, were investigated. The enzyme has a subunit molecular mass of 33.4 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Estimation of the native M r value under nondenaturating conditions by gel filtration gave a molecular mass of 135 ± 10 kDa, indicating a homotetrameric enzyme structure (4 × 33.4 kDa). The pI of the enzyme was estimated to be 7.1 ± 0.1. The N-terminal amino acid sequence (43 residues) of the enzyme was determined and exhibits 70 to 42% identity with other extradiol dioxygenases. Fe(II) seems to be a cofactor of the enzyme, as it is for other catechol 2,3-dioxygenases. In contrast to other extradiol dioxygenases, the enzyme exhibited great sensitivity to temperatures above 40°C. The reactivity of this enzyme toward various substituted catechols, especially 3-chlorocatechol, was different from that observed for other catechol 2,3-dioxygenases. Stoichiometric displacement of chloride occurred from 3-chlorocatechol, leading to the production of 2-hydroxymuconate.

scholarly journals Studies on an antineoplastic fraction from human urine. Characterization of the major protein in this fraction

1986 ◽  
Vol 234 (2) ◽  
pp. 355-362 ◽  
Author(s):  
N H Sloane ◽  
W R Lynn ◽  
R M Macleod ◽  
E P K Hade ◽  
R Pottathil ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Lines ◽  
Human Urine ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Diploid Cell ◽  
Sedimentation Equilibrium ◽  
Major Protein ◽  
A Subunit

A fraction has been isolated from human urine which exhibits antiproliferative activity against human tumour cell lines without affecting the growth of several normal diploid cell lines or tumour cells of mouse or hamster origin. The major protein present in this fraction has been characterized and tentatively designated antineoplastic urinary protein (ANUP). An S020,W value of 3.69 S was obtained by sedimentation velocity analysis, and a subunit molecular mass of 16 300 Da was obtained by sedimentation equilibrium and by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Centrifugation data also indicated that the protein self-associates. The amino acid analysis of ANUP was consistent with its low pI (4.2) as determined by chromatofocusing analysis. Furthermore, the amino acid composition exhibited some features similar to collagen, as shown by high levels of proline and glycine, the absence of cysteine, and the presence of low levels of hydroxyproline.

Characterization of coccidial proteins by two-dimensional sodium dodecyl sulphate–polyacrylamide gel electrophoresis

Parasitology ◽  
1989 ◽  
Vol 99 (2) ◽  
pp. 175-187 ◽  
Author(s):  
C. A. Sutton ◽  
M. W. Shirley ◽  
M. H. Wisher
Keyword(s):  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Two Dimensional ◽  
Sds Page

SummaryTwo dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (2D SDS–PAGE) has been used to produce ‘fingerprint’ maps of the proteins from each of the 7 species of Eimeria which infect the chicken. All 7 species could be identified from their array of polypeptides but few differences were detected between strains of the same species. Alterations to the polypeptide array associated with the stage of sporulation of the oocysts were observed. lodination of sporozoites, 2D SDS–PAGE, autoradiography and immunoblotting techniques were combined to identify polypeptides with a surface moiety and those which were antigenic.

scholarly journals Isolation and characterization of a mannose/N-acetylglucosamine/fucose-binding protein from rat liver

1981 ◽  
Vol 194 (1) ◽  
pp. 209-214 ◽  
Author(s):  
R Townsend ◽  
P Stahl
Keyword(s):  
Affinity Chromatography ◽  
Rat Liver ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Binding Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Calcium Dependent ◽  
Isolation And Characterization

A rat liver mannan-binding protein was isolated by affinity chromatography on invertase–Sepharose by a modification of the method of Kawasaki, Etoh & Yamashina [(1978) Biochem. Biophys. Res. Commun. 81, 1018-1024] and by a new method involving chromatography on mannose-Sepharose. The binding protein appears as a single band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis with an apparent mol.wt. of approx. 30000. Binding of 125I-labelled mannan is saturable and inhibited by mannose, N-acetylglucosamine, or L-fucose but not by galactose or mannose 6-phosphate. Neoglycoproteins containing mannose, N-acetylglucosamine, or L-fucose, but not galactose, are inhibitory. The neoglycoproteins are 10000-fold more effective (based on moles of sugar) than are free monosaccharides as inhibitors. 125I-labelled mannan binding to the binding protein is calcium-dependent.

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