scholarly journals Purification of phosphatidylinositol kinase from bovine brain myelin

1987 ◽  
Vol 241 (3) ◽  
pp. 759-763 ◽  
Author(s):  
A R Saltiel ◽  
J A Fox ◽  
P Sherline ◽  
N Sahyoun ◽  
P Cuatrecasas
Keyword(s):  
Enzyme Activity ◽  
Affinity Chromatography ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Bovine Brain ◽  
Anion Exchange Column ◽  
Ionic Detergent ◽  
Membrane Bound ◽  
Phosphatidylinositol 4 ◽  
Pi Kinase

A membrane-bound phosphatidylinositol (PI) kinase (EC 2.7.1.67) was purified by affinity chromatography from bovine brain myelin. This enzyme activity was solubilized with non-ionic detergent and chromatographed on an anion-exchange column. Further purification was achieved by affinity chromatography on PI covalently coupled to epoxy-activated Sepharose, which was eluted with a combination of PI and detergent. The final step in the purification was by gel filtration on an Ultrogel AcA44 column. This procedure afforded greater than 5500-fold purification of the enzyme from whole brain myelin. The resulting activity exhibited a major silver-stained band on SDS/polyacrylamide-gel electrophoresis with an apparent Mr 45,000. The identity of this band as PI kinase was corroborated by demonstration of enzyme activity in the gel region corresponding to that of the stained protein. The purified enzyme exhibited a non-linear dependence on PI as substrate, with two apparent kinetic components. The lower-affinity component exhibited a Km similar to that observed for the phosphorylation of phosphatidylinositol 4-phosphate by the enzyme.

scholarly journals Biochemical characterization including amino acid and carbohydrate compositions of canine and human brain Thy-1 antigen

1981 ◽  
Vol 197 (3) ◽  
pp. 629-636 ◽  
Author(s):  
J L McKenzie ◽  
A K Allen ◽  
J W Fabre
Keyword(s):  
Monoclonal Antibody ◽  
Amino Acid ◽  
Human Brain ◽  
Affinity Chromatography ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Antibody Affinity ◽  
Lentil Lectin

Human and canine brain Thy-1 antigens were solubilized in deoxycholate and antigen activity was followed both by conventional absorbed anti-brain xenosera of proven specificity and by mouse monoclonal antibodies to canine and human Thy-1. It is shown that greater than 80% of Thy-1 activity in the dog and man binds to lentil lectin, that the mobility on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of canine and human Thy-1 is identical with that of rat Thy-1 and that the Stokes radius in deoxycholate of canine and human brain Thy-1 is 3.0 nm and 3.25 nm respectively. Both lentil lectin affinity chromatography followed by gel-filtration chromatography on the one hand and monoclonal antibody affinity chromatography on the other gave high degrees of purification of the brain Thy-1 molecule in the dog and man, resulting in single bands staining for both protein and carbohydrate on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis (except for a slight contaminant of higher molecular weight staining for protein but not carbohydrate with human Thy-1 purified by lentil lectin and gel-filtration chromatography). Analysis of canine and human brain Thy-1 purified by monoclonal antibody affinity chromatography with additional gel filtration through Sephadex G-200 showed that these molecules had respectively 38% and 36% carbohydrate. The amino acid and carbohydrate compositions were similar to those previously reported for Thy-1 of the rat and mouse, the main point of interest being the presence in canine and human brain Thy-1 of N-acetylgalactosamine, which has been reported in rat and mouse brain Thy-1 but not in Thy-1 from other tissues.

scholarly journals Analysis of the forms of acetylcholinesterase from adult mouse brain

1975 ◽  
Vol 147 (2) ◽  
pp. 205-214 ◽  
Author(s):  
E D Adamson ◽  
S E Ayers ◽  
Z A Deussen ◽  
C F Graham
Keyword(s):  
Enzyme Activity ◽  
Mouse Brain ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Acetylcholinesterase Activity ◽  
Total Activity ◽  
Polyacrylamide Gel ◽  
Soluble Extract ◽  
Molecular Sizes

The solubilization of 80% of the acetylcholinesterase activity of mouse brain was performed by repeated 2h incubations of homogenates at 37 degrees C in an aqueous medium. Analysis of the soluble extract by gel filtration on Sephadex G-200 showed that up to 80% of the enzyme activity was eluted in a peak which was estimated to consist of molecules of about 74000mol.wt. This peak was called the monomer form of the enzyme. After 3 days at 4 degrees C, the soluble extract was re-analysed and was eluted from the column in four peaks of about 74000, 155000, 360000 and 720000 mol.wt. Since the total activity of the enzyme in these peaks was the same as that in the predominantly monomer elution profile of fresh enzyme, we concluded that the monomer had aggregated, possibly into dimers, tetramers and octomers. Extracts of the enzyme were analysed by polyacrylamide-gel electrophoresis and the resulting multiple bands of enzyme activity on gels were shown to separate according to their molecular sizes, that is by molecular sieving. All these forms had similar susceptibilities to the inhibitors eserine, tetra-isopropyl pyrophosphoramide and compound BW 284c51 [1,5-bis-(4-allyldimethylammoniumphenyl)pentan-3-one dibromide]. Thus the forms of the enzyme in mouse brain which can be detected by gel filtration and polyacrylamide-gel electrophoresis may all be related to a single low-molecular-weight form which aggregates during storage. This supports similar suggestions made for the enzyme in other locations.

A three step purification procedure for human liver ferritin

1980 ◽  
Vol 58 (6) ◽  
pp. 494-498 ◽  
Author(s):  
M. Pagé ◽  
J. Lagueux ◽  
C. Gauthier
Keyword(s):  
Affinity Chromatography ◽  
Gel Electrophoresis ◽  
Human Liver ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Purification Procedure ◽  
Human Liver Ferritin ◽  
Normal Human Liver ◽  
Normal Human ◽  
Liver Ferritin

We describe a method for the purification of normal human liver ferritin by ultrafiltration, gel filtration on Sephacryl S-300, and affinity chromatography on DEAE-Affi Gel Blue. The purity of the ferritin obtained was verified by immunoelectrophoresis, Ouchterlony immunodiffusion, polyacrylamide gel electrophoresis, and electrofocusing. This rapid method yields 32% of the original ferritin.

scholarly journals Mouse Uterine Alkaline Phosphatase: Improved Purification by Affinity Chromatography and Further Characterization of the Enzyme

1980 ◽  
Vol 33 (3) ◽  
pp. 279 ◽  
Author(s):  
RN Murdoch ◽  
Louise E Buxton ◽  
DJ Kay
Keyword(s):  
Alkaline Phosphatase ◽  
Affinity Chromatography ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Apparent Molecular Weight ◽  
Anion Exchange Chromatography ◽  
Pregnant Mouse ◽  
Exchange Chromatography ◽  
Enzyme Preparations

An improved procedure for the purification of alkaline phosphatase from about 10 g of day 7 pregnant mouse uterine tissue is described. Following homogenization, the procedure involved solubilization and extraction with 0�8% (v/v) Triton X-lOO and 20% (v/v) n-butanol, ammonium sulfate precipitation, concanavalin A-Sepharose 4B affinity chromatography, DEAE-cellulose anion-exchange chromatography and Sephacryl S200 gel filtration. On subjecting 2162-fold purified enzyme preparations to polyacrylamide-gel electrophoresis, a single band of protein coincident with the zone of enzyme activity and having an apparent molecular weight of 205 OOO� lOOOO was identified. Affinity chromatography yielded the largest increase in purity of any step in the procedure and established the glycoprotein nature of the uterine enzyme.

scholarly journals Occurrence of an endo-1,3-β-glucanase in culture fluids of the yeast Candida utilis. Purification and characterization of the enzyme activity

1979 ◽  
Vol 177 (1) ◽  
pp. 107-114 ◽  
Author(s):  
T G Villa ◽  
V Notario ◽  
J R Villanueva
Keyword(s):  
Enzyme Activity ◽  
Gel Electrophoresis ◽  
Candida Utilis ◽  
Culture Medium ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Beta Glucanase ◽  
Hydrolysis Of

The endo-1,3-beta-glucanase (EC 3.2.1.6) secreted into the culture medium by cells of Candida utilis was isolated and purified to homogeneity on polyacrylamide-gel electrophoresis and in ultracentrifugation studies (s20,w = 1.97S). The purified enzyme represented only 0.001% of the total 1,3-beta-glucanase activity, the remainder being due to an exo-1,3-beta-glucanase enzyme, and behaved as an acidic glycoprotein (pI 3.3) in isoelectric-focusing experiments. The mol.wt. was estimated to be 21 000 by gel filtration and polyacrylamide-gel electrophoresis. Studies on the hydrolysis of different substrates showed that the enzyme was only able to break down (1 leads to 3)-beta-linkages, by an endo-splitting mechanism. Glucono-delta-lactone, D-glucoronolactone and heavy metal ions such as Hg2+ were inhibitors of the enzyme activity. The function of this endo-beta-glucanase in C. utilis is discussed.

Phosphorylation of liver plasma membrane-bound calmodulin

1988 ◽  
Vol 66 (8) ◽  
pp. 922-927 ◽  
Author(s):  
Shobha Ghosh ◽  
Jon G. Church ◽  
Basil D. Roufogalis ◽  
Antonio Villalobo
Keyword(s):  
Plasma Membrane ◽  
Calcium Ion ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein Band ◽  
Bovine Brain ◽  
Antibody Treatment ◽  
Liver Plasma Membrane ◽  
Phosphate Donor ◽  
Membrane Bound ◽  
Stimulation Of

In highly purified rat liver plasma membrane preparations, membrane-bound calmodulin was phosphorylated by a membrane-bound protein kinase using [γ-32P] ATP as phosphate donor. Maximum phosphorylation of calmodulin occurred in the absence of calcium ion, but was significantly decreased in its presence. Plasma membrane-bound calmodulin was identified by the following criteria: (i) extraction from the membrane by EGTA, (ii) stimulation of the activity of the Ca2+-calmodulin-dependent enzyme, (3′:5′ AMP)-phosphodiesterase, by the EGTA extract, and (iii) electrophoretic comigration of EGTA-extracted protein with standard bovine brain calmodulin, both in the presence and the absence of Ca2+. Phosphorylation of the plasma membrane-bound calmodulin was shown by electrophoretic comigration of the 32P-labelled molecule with bovine brain calmodulin, the absence of phosphorylation of this protein band in calmodulin-depleted membranes, and a Western blot of the phosphorylated band using a calmodulin antibody. Treatment of plasma membrane preparations with sheep anticalmodulin serum prevented the phosphorylation of the calmodulin band. Phosphocalmodulin, which could be partially extracted from the membrane by EGTA, comigrated with bovine brain calmodulin in polyacrylamide gel electrophoresis.

Purification and some properties of the extracellular α-amylase from Aspergillus awamori

1985 ◽  
Vol 31 (2) ◽  
pp. 149-153 ◽  
Author(s):  
Resham S. Bhella ◽  
Illimar Altosaar
Keyword(s):  
Enzyme Activity ◽  
Gel Electrophoresis ◽  
Culture Medium ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Aspergillus Awamori ◽  
Original Activity

Alpha-amylase was purified from the extracellular culture medium of Aspergillus awamori by means of ethanol precipitation. Sephacryl-200 gel filtration and anion-exchange chromatography on Dowex (AG1-X4) resin. The enzyme preparation was found to be homogeneous by means of sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The purified enzyme had a molecular weight of 54 000 ± 2 500 and its isoelectric point was pH 4.2. The enzyme was found to be most active between pH 4.8 and 5.0 and was stable between pH 3.5 and 6.5. The optimal temperature for the enzyme activity was around 50 °C and the enzyme was stable for at least 1 h up to 45 °C retaining more than 80% of its original activity. The Km (37 °C, pH 5.3) for starch hydrolysis was 1.0 g∙L−1 and maltose inhibited the enzyme activity uncompetitively with a K1 value of 20.05 g∙L−1

scholarly journals Characterization of a Thermostable d-Stereospecific Alanine Amidase from Brevibacillus borstelensis BCS-1

2003 ◽  
Vol 69 (2) ◽  
pp. 980-986 ◽  
Author(s):  
Dae Heoun Baek ◽  
Seok-Joon Kwon ◽  
Seung-Pyo Hong ◽  
Mi-Sun Kwak ◽  
Mi-Hwa Lee ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Amino Acid ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Optimum Temperature ◽  
Gene Encoding ◽  
Ph Range

ABSTRACT A gene encoding a new thermostable d-stereospecific alanine amidase from the thermophile Brevibacillus borstelensis BCS-1 was cloned and sequenced. The molecular mass of the purified enzyme was estimated to be 199 kDa after gel filtration chromatography and about 30 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that the enzyme could be composed of a hexamer with identical subunits. The purified enzyme exhibited strong amidase activity towards d-amino acid-containing aromatic, aliphatic, and branched amino acid amides yet exhibited no enzyme activity towards l-amino acid amides, d-amino acid-containing peptides, and NH2-terminally protected amino acid amides. The optimum temperature and pH for the enzyme activity were 85°C and 9.0, respectively. The enzyme remained stable within a broad pH range from 7.0 to 10.0. The enzyme was inhibited by dithiothreitol, 2-mercaptoethanol, and EDTA yet was strongly activated by Co2+ and Mn2+. The k cat/Km for d-alaninamide was measured as 544.4 ± 5.5 mM−1 min−1 at 50°C with 1 mM Co2+.

Centrifugal analyzer used for enzyme immunoassay of progesterone and choriomammotropin.

1983 ◽  
Vol 29 (2) ◽  
pp. 302-304 ◽  
Author(s):  
B Terouanne ◽  
J Marchand ◽  
C Calzolari ◽  
J Monnier ◽  
J C Nicolas ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Affinity Chromatography ◽  
Enzyme Immunoassay ◽  
Gel Filtration ◽  
Placental Lactogen ◽  
Human Placental Lactogen ◽  
Rapid Separation ◽  
Enzyme Conjugate ◽  
Enzyme Label ◽  
Free Antigen

Abstract Recently we developed an enzyme immunoassay involving the use of steroid delta-isomerase (EC 5.3.3.1) as enzyme label and exclusion-affinity chromatography for rapid separation of free antigen-enzyme conjugate that bound to antibodies (J. Immunol. Methods 35: 267-284, 1980). Here we describe an automated version of this procedure, for immunoassay of progesterone and choriomammotropin (human placental lactogen) in serum with the use of a centrifugal analyzer. After incubation, suitable dilutions of sera or extract plus antiserum, conjugate, and double antibody were filtered on an estradiol affinity gel-filtration column; the enzyme activity of the filtrates was determined with the centrifugal analyzer. Results correlate well with those obtained by radioimmunoassay: r (progesterone) = 0.980, r (choriomammotropin) = 0.940. The within-run and between-run precision, specificity, sensitivity, accuracy, and speed of this system make it a useful tool for immunoassay.

scholarly journals Preliminary characterization of two thymus-dependent xenoantigens from mouse lymphocytes

1977 ◽  
Vol 163 (2) ◽  
pp. 211-217 ◽  
Author(s):  
I S Trowbridge ◽  
M Nilsen-Hamilton ◽  
R T Hamilton ◽  
M J Bevan
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Membrane Vesicles ◽  
Sodium Deoxycholate ◽  
Pea Lectin ◽  
Preliminary Characterization ◽  
Low Concentrations ◽  
Membrane Bound

Preliminary characterization of two mouse thymus-dependent (T) lymphocyte xenoantigens, T25 and T200, which are selectively labelled by lactoperoxidase-catalysed iodination of T-cells, is described. Both molecules are membrane-bound glycoproteins. Fractionation of membrane vesicles prepared from BW5147 lymphoma cells by sedimentation through sucrose density gradients show that antigens T25 and T200 are in fractions enriched with plasma membrane. Moreover antigen T200 is partially degraded when viable cells are treated briefly with low concentrations of trypsin. Both molecules are efficiently solubilized in buffers containing sodium deoxycholate or Nonidet P-40, as measured by failure to sediment at 100000g for 60min. However, gel filtration on Sepharose 6B showed the presence of aggregated material in Nonidet P-40 extracts which was not found in deoxycholate-solubilized membranes. After solubilization in detergent, antigens T25 and T200 bind to, and may be specifically eluted from, columns of pea lectin--Sepharose or concanavalin A--Sepharose. Both molecules are heterogeneous when examined by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. As judged by its binding to columns of pea lectin, at least part of the heterogeneity of mouse thymocyte antigen T25 resides in its carbohydrate moiety.

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