scholarly journals A cyclic AMP-independent protein kinase from Candida albicans

1986 ◽  
Vol 234 (3) ◽  
pp. 543-546 ◽  
Author(s):  
B Gupta Roy ◽  
A Datta
Keyword(s):  
Candida Albicans ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Gel Electrophoresis ◽  
Thermal Denaturation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Maximal Activity ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Independent Protein

A cyclic AMP-independent protein kinase which phosphorylates casein was purified to homogeneity from Candida albicans by affinity and ion-exchange chromatography. This protein kinase exhibits maximal activity with casein as substrate and is not stimulated by cyclic AMP or cyclic GMP. The Mr of the purified enzyme is 115,000, as determined by h.p.l.c. It migrates as a single band on gel electrophoresis and has three non-identical subunits, of Mr 44,000, 28,500 and 26,000, as determined by SDS/polyacrylamide-gel electrophoresis. This enzyme is insensitive to heparin, but is inhibited by polyamines. Furthermore, it is sensitive to thermal denaturation and to thiol reagents.

Rapid separation of bovine caseins by mass ion exchange chromatography

1989 ◽  
Vol 56 (3) ◽  
pp. 391-397 ◽  
Author(s):  
K. F. Ng-Kwai-Hang ◽  
J. P. Pélissier
Keyword(s):  
Liquid Chromatography ◽  
Ion Exchange ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Polyacrylamide Gel ◽  
Rapid Separation ◽  
Rapid Isolation ◽  
Time Required

SummaryThe rapid isolation of major bovine caseins in gram quantities was investigated. Whole casein was precipitated from individual cow's milk by adjusting the pH to 4·6 and the precipitated casein was suspended in 4·5 M urea (pH 8·0) containing 0·02 M imidazole and 0·03 M β-mercaptoethanol, and bound on a QAE Zeta Prep 250 cartridge. Stepwise elution with the urea/imidazole β-mercaptoethanol buffer and varying amounts of NaCl gave five well resolved peaks, which were identified by polyacrylamide gel electrophoresis and fast protein liquid chromatography to be pure γ-casein, κ-casein. β-casein, β-casein and αs-casein, respectively. The ion exchange cartridge was regenerated by flushing with buffer containing 0·50 Μ-NaCl followed by equilibration with starting buffer before separation of next sample. The time required to run each sample including cartridge regeneration and equilibration was 4 hours.

scholarly journals Purification of rabbit bone inhibitor of collagenase

1981 ◽  
Vol 195 (1) ◽  
pp. 159-165 ◽  
Author(s):  
T E Cawston ◽  
W A Galloway ◽  
E Mercer ◽  
G Murphy ◽  
J J Reynolds
Keyword(s):  
Tissue Culture ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Serine Proteinases ◽  
Bacterial Collagenase ◽  
Rabbit Bone

1. Rabbit bones in tissue culture synthesize an inhibitor of collagenase during the first 4 days of culture. 2. The inhibitor was purified by a combination of gel filtration, concanavalin A--Sepharose chromatography, ion-exchange chromatography and zinc-chelate affinity chromatography. 3. The purified inhibitor migrated as a single band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and had a mol.wt. of 28000. 4. The inhibitor blocked the activity of the metalloproteinases collagenase, gelatinase, neutral proteinase III (proteoglycanase), human leucocyte collagenase and gelatinase, but not thermolysin or bacterial collagenase. The serine proteinases plasmin and trypsin were not inhibited. 5. The inhibitor interacted with purified rabbit bone collagenase with 1:1 stoichiometry. 6. The inhibitory activity was lost after incubation for 1 h at 90 degrees C, after treatment with trypsin (250 micrograms/ml) at 37 degrees C for 30 min and after reduction and alkylation.

Charge Properties of Mitochondrial Matrix Proteins

1975 ◽  
Vol 53 (11) ◽  
pp. 1150-1157 ◽  
Author(s):  
P. M. Strasberg ◽  
K. B. Freeman
Keyword(s):  
Gel Electrophoresis ◽  
Matrix Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Matrix Proteins ◽  
Mitochondrial Matrix ◽  
Total Fraction ◽  
Acidic Nature

Proteins of the rat liver mitochondrial matrix have been separated into anionic (acidic), cationic (basic), and neutral groups by electrophoresis. These groups represent 69, 8, and 23% of the total matrix protein, respectively, compared to 69, 21, and 10% for the cytosol protein. The acidic nature of the mitochondrial matrix proteins has been confirmed by cellulose ion-exchange chromatography, isoelectric focusing in sucrose gradients, and amino acid analysis. The anionic, cationic, and neutral matrix proteins were separated by sodium dodecyl sulfate – polyacrylamide gel electrophoresis into 18, 6, and 5 bands, respectively, compared to 22 bands for the total fraction. The significance of the charge properties of these proteins in terms of mitochondrial biogenesis is discussed.

Purification, characterization, and antifungal activity of chitinase from Fusarium chlamydosporum, a mycoparasiteto groundnut rust, Puccinia arachidis

1998 ◽  
Vol 44 (7) ◽  
pp. 646-651 ◽  
Author(s):  
N Mathivanan ◽  
V Kabilan ◽  
K Murugesan
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Puccinia Arachidis ◽  
Fusarium Chlamydosporum ◽  
Groundnut Rust ◽  
Germ Tubes

Chitinase (EC 3.2.1.14) was isolated from the culture filtrate of Fusarium chlamydosporum and purified by ion-exchange chromatography and gel filtration. The molecular mass of purified chitinase was 40 kDa as estimated by sodium dodecyl sulfate – polyacrylamide gel electrophoresis. Chitinase was optimally active at a pH of 5 and stable from pH 4 to 6 and up to 40°C. Among the metals and inhibitors tested, mercuric chloride completely inhibited the enzyme activity. The activity of chitinase was high on colloidal and pure chitin. The purified chitinase inhibited the germination of uredospores of Puccinia arachidis and also lysed the walls of uredospores and germ tubes. The results from these experiments indicated that chitinase of F. chlamydosporum plays an important role in the biocontrol of groundnut rust. Key words: Fusarium chlamydosporum, chitinase, purification, Puccinia arachidis, uredospores.

Enhanced phosphorylation of myocardial sarcoplasmic reticulum in experimental hyperthyroidism

1978 ◽  
Vol 234 (4) ◽  
pp. H426-H431
Author(s):  
C. J. Limas
Keyword(s):  
Protein Kinase ◽  
Sarcoplasmic Reticulum ◽  
Cyclic Amp ◽  
Gel Electrophoresis ◽  
Calcium Transport ◽  
Polyacrylamide Gel Electrophoresis ◽  
Dependent Protein Kinase ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Phosphoprotein Phosphatase ◽  
Dependent Protein

Calcium transport by cardiac sarcoplasmic reticulum (SR) was compared in hyperthyroid (HT) and euthyroid (ET) rats. Both Ca2+ uptake (97 +/- 3.1 nmol/mg per min in HT vs. 63 +/- 2.9 nmol/mg per min in ET, P less than 0.01) and CA2+ -stimulated ATPase activity (61 +/- 4.1 vs. 37 +/- 1.6 nmol Pi/mg per min, P less than 0.01) were higher in the thyroxine-treated animals. These changes were accompanied by enhanced cyclic AMP-dependent phosphorylation of cardiac SR in hyperthyroid rats (180 +/- 4.3 pmol Pi/mg per min vs. 117 +/- 4.2 pmol Pi/mg per min, P less than 0.01). SDS-polyacrylamide gel electrophoresis of cardiac SR showed that phosphorylation of a 22,000-dalton protein (phospholamban) primarily accounted for the differences between the two groups. There was no difference in the rate of SR dephosphorylation by endogenous phosphoprotein phosphatase between HT and ET rats. Differences in cyclic AMP-dependent phosphorylation between the two groups were blunted in the presence of excess exogenous cyclic AMP-dependent protein kinase. These results suggest that increased levels or activity of endogenous cyclic AMP-dependent protein kinases may partially explain enhanced calcium transport by the cardiac SR of hyperthyroid animals.

Biosynthèse "In Vitro" de l'Hormone Béta-Lipotropique de Boeuf

1974 ◽  
Vol 52 (5) ◽  
pp. 349-358 ◽  
Author(s):  
X. Bertagna ◽  
M. Lis ◽  
C. Gilardeau ◽  
M. Chrétien
Keyword(s):  
Amino Acids ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Usual Method ◽  
Pituitary Hormone ◽  
Melanocyte Stimulating Hormone

Sheep beta-lipotropic hormone (β-LPH) is a pituitary hormone made of 90 amino acids and having a portion of its sequence (41–58) identical with the structure of beta-melanocyte-stimulating hormone (β-MSH). We hypothetized that β-LPH could be the biological precursor of β-MSH. We studied the biosynthesis of these two molecules by monitoring the incorporation of radioactive amino acids in beef pituitary slices. We separated β-LPH from the other radioactive proteins with the usual method of purification described previously and we characterized the proteins by ion-exchange chromatography, gel filtration, and polyacrylamide gel electrophoresis. Our results show that the pituitary slices synthesized a radioactive β-LPH which has all the characteristics of non-radioactive β-LPH. However, in the conditions used, we could not demonstrate any biosynthesis of β-MSH after 4 h incubation. These results suggest that the conversion of β-LPH into β-MSH, if it exists, is a slow process and should be studied in more prolonged incubations.

scholarly journals Cyclic AMP-dependent histone-specific nucleoplasmic protein kinase from rat liver

1978 ◽  
Vol 171 (1) ◽  
pp. 123-135 ◽  
Author(s):  
J R Neumann ◽  
A R O'Meara ◽  
R L Herrmann
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Kinase Inhibitor ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Maximal Activity ◽  
Nuclear Extract ◽  
Type I ◽  
Adult Rats ◽  
Bivalent Cation

A nucleoplasmic histone kinase activity was isolated from livers of adult rats and purified 39-fold compared with whole nuclei by ultracentrifugation of the nuclear extract and Sephadex G-200 gel filtration in the presence of cyclic AMP. Analysis by polyacrylamide-gel electrophoresis as well as by gel filtration indicates a mol.wt. of approx. 60,000 for the catalytic subunit and 130000-150000 for the cyclic AMP-binding activity. The purified enzyme displays a 20-fold greater preference for histone fractions 1 and 2b than for any non-histone substrate, including alpha-casein. Endogenous protein in the preparation is not appreciably phosphorylated. The unfractioned enzyme is stimulated significantly by cyclic GMP, cyclic IMP and dibutyryl cyclic AMP as well as by cyclic AMP. The catalytic reaction requires Mg2+ (Km 1.9mM) and ATP (Km 15.4 micron). Half-maximal activity of the enzyme is observed with histone 2b at 12micron and histone 1 at a higher substrate concentration. The pH optima are 6.1 and 6.5 with histones 2b and 1 respectively. This nuclear protein kinase appears to be distinct from other nuclear enzymes that have been reported, on the basis of histone specificity, univalent-salt-sensitivity, pH optima and nuclear location. However, the enzyme possesses many properties similar to those of the cytoplasmic kinases, including cyclic AMP-dependence, Mg2+ and ATP affinities and pH optima. It differs from cytoplasmic protein kinase type I, the major form in the liver, with respect to bivalent-cation effects and response to the heat-stable protein kinase inhibitor protein isolated from ox heart.

scholarly journals Phosphorylation of partially purified 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine:acetyl-CoA acetyltransferase from rat spleen

1987 ◽  
Vol 245 (3) ◽  
pp. 893-897 ◽  
Author(s):  
J Gomez-Cambronero ◽  
J M Mato ◽  
F Vivanco ◽  
M Sanchez-Crespo
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein Band ◽  
Improved Method ◽  
Serine Residue ◽  
Dependent Protein Kinase ◽  
Single Protein ◽  
Dependent Protein

A new improved method for purification of the enzyme 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine: acetyl-CoA acetyltransferase (EC 2.3.1.67) from rat spleen is described. The catalytic subunit of cyclic AMP-dependent protein kinase in the presence of MgATP stimulated about 3-fold the activity of this partially purified enzyme activity. When [gamma-32P]ATP was included in the assay mixture, the analysis of phosphoprotein products by SDS/polyacrylamide-gel electrophoresis and autoradiography showed the incorporation of [32P]phosphate into a single protein band of about 30 kDa. Analysis of the phosphorylated amino acids indicated that the phosphate was incorporated into a serine residue. Activation of the acetylation reaction by the protein kinase was reversible. The reversal of the activation was coincident with the loss of the [32P]phosphate incorporated into the 30 kDa protein band, which suggests that the acetyltransferase is regulated by a phosphorylation-dephosphorylation mechanism dependent on cyclic AMP.

scholarly journals Purification of phospholipid methyltransferase from rat liver microsomal fraction

1986 ◽  
Vol 237 (3) ◽  
pp. 699-705 ◽  
Author(s):  
M A Pajares ◽  
M Villalba ◽  
J M Mato
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Molecular Mass ◽  
Rat Liver ◽  
Gel Electrophoresis ◽  
Microsomal Fraction ◽  
Polyacrylamide Gel Electrophoresis ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Liver Microsomal Fraction

Phospholipid methyltransferase, the enzyme that converts phosphatidylethanolamine into phosphatidylcholine with S-adenosyl-L-methionine as the methyl donor, was purified to apparent homogeneity from rat liver microsomal fraction. When analysed by SDS/polyacrylamide-gel electrophoresis only one protein, with molecular mass about 50 kDa, is detected. This protein could be phosphorylated at a single site by incubation with [alpha-32P]ATP and the catalytic subunit of cyclic AMP-dependent protein kinase. A less-purified preparation of the enzyme is mainly composed of two proteins, with molecular masses about 50 kDa and 25 kDa, the 50 kDa form being phosphorylated at the same site as the homogeneous enzyme. After purification of both proteins by electro-elution, the 25 kDa protein forms a dimer and migrates on SDS/polyacrylamide-gel electrophoresis with molecular mass about 50 kDa. Peptide maps of purified 25 kDa and 50 kDa proteins are identical, indicating that both proteins are formed by the same polypeptide chain(s). It is concluded that rat liver phospholipid methyltransferase can exist in two forms, as a monomer of 25 kDa and as a dimer of 50 kDa. The dimer can be phosphorylated by cyclic AMP-dependent protein kinase.

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