Properties and Regulation of Adenylate Kinase From Zea mays Leaf Operating in C4 Pathway Photosynthesis

1982 ◽  
Vol 9 (3) ◽  
pp. 287 ◽  
Author(s):  
MD Hatch
Keyword(s):  
Zea Mays ◽  
Adenylate Kinase ◽  
Kinase Activity ◽  
Mesophyll Cell ◽  
Reverse Reaction ◽  
Mesophyll Cells ◽  
Ph Optimum ◽  
Strong Inhibitor ◽  
Cell Extracts ◽  
Regulatory Properties

Adenylate kinase from the mesophyll cells of Zea mays was partially purified and its kinetic and regulatory properties determined. Fractionation of mesophyll cell extracts by (NH4)2SO4 precipitation, filtration on Sephacryl S-200 and diethylaminoethylcellulose chromatography gave a fraction purified about 90-fold. For the reaction in the direction of ADP synthesis (forward reaction), activity was influenced by a complex interaction between Mg2+, ATP and pH. Optimal activity was observed with a Mg2+ to ATP ratio of about unity and the pH optimum under these conditions was about 8.0. With an excess of Mg2+, activity was reduced and the pH optimum was shifted to lower values. Varying ATP or AMP in a lower range of concentrations gave simple Michaelis- Menten responses. However, at higher concentrations there was a complex response to increasing ATP, and AMP became inhibitory. For the reverse reaction the Km (ADP) was about 70 �M and the pH optimum was between 8.0 and 8.5. AMP was a strong inhibitor of the reverse reaction (competitive with respect to ADP), the KI being about 40 �M. Several other metabolites tested had no effect on adenylate kinase activity. Adenylate kinase extracted from washed mesophyll chloroplasts had essentially identical properties.

scholarly journals Protein Phosphorylation — Dephosphorylation in the Cytosol of Pea Mesophyll Cells

1986 ◽  
Vol 41 (9-10) ◽  
pp. 856-860 ◽  
Author(s):  
Ruth Hracky ◽  
Jürgen Soll
Keyword(s):  
Protein Phosphorylation ◽  
Protein Phosphatase ◽  
Kinase Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Alkaline Ph ◽  
Strong Decrease ◽  
Mesophyll Cells ◽  
Ph Optimum ◽  
Molecular Weights ◽  
Protein Dephosphorylation

Abstract Soluble protein kinase and protein phosphatase activities were localized in the cytosol of pea mesophyll cells using protoplasts fractionation techniques. The molecular weights of the phosphorylated cytosolic proteins, as determined by polyacrylamide gel electrophoresis, were 68, 55, 46, 38, 36, 30, 22 and 12 kDa. Histone and, to a much lesser extent, casein but not phosvitin were accepted as exogenous substrates. In every case serine served as acceptor amino acid for the phosphate residue. The protein phosphorylation activity had an alkaline pH optimum, and showed no response to varying Mg-2, Ca2+, Pi cyclo-AMP or calmodulin concentrations. The kinase activity was competitively inhibited by ADP and pyrophosphate with apparent Ki values of 0.5 and 0.17 mᴍ , respectively. High ATP concentrations (1-4 mᴍ) resulted in a strong decrease of radioactivity in the 32P labeled proteins. It is proposed that the ratio of protein phosphorylation to protein dephosphorylation is regulated by the ATP to ADP ratio in the cytosol.

scholarly journals APPARENT ADENYLATE KINASE ACTIVITY IN VIVO

1953 ◽  
Vol 204 (1) ◽  
pp. 283-288
Author(s):  
Florapearl A. Cobey ◽  
Philip Handler
Keyword(s):  
Adenylate Kinase ◽  
Kinase Activity

scholarly journals The diphosphoinositide kinase of rat brain

1968 ◽  
Vol 106 (4) ◽  
pp. 791-801 ◽  
Author(s):  
M. Kai ◽  
J. G. Salway ◽  
J. N. Hawthorne
Keyword(s):  
Rat Brain ◽  
Kinase Activity ◽  
Ion Concentration ◽  
Supernatant Fraction ◽  
Thiol Groups ◽  
Ph Optimum ◽  
Adult Rat ◽  
Phosphatidylinositol Kinase ◽  
Adult Rat Brain ◽  
Ammonium Sulphate Fractionation

1. The supernatant fraction of adult rat brain contains a diphosphoinositide kinase. 2. Formation of triphosphoinositide by the enzyme in the presence of ATP and Mg2+ ions was shown with labelled ATP or labelled diphosphoinositide. 3. The kinase was also activated by Ca2+, Mn2+ and Co2+ ions, but to a smaller extent than by Mg2+ ions. 4. In the presence of optimum Mg2+ ion concentration the enzyme was inhibited by Ca2+ ions. 5. Activity did not depend on thiol groups and the pH optimum was 7·3. 6. The dialysed supernatant fraction had no diglyceride kinase activity and negligible phosphatidylinositol kinase activity. 7. Triphosphoinositide phosphomonoesterase was present but showed little activity under the conditions used to assay the kinase. 8. Diphosphoinositide kinase was purified by ammonium sulphate fractionation, ethanol treatment and chromatography on Sephadex G-200. 9. This purification removed much of the triphosphoinositide phosphomonoesterase.

Identification, purification, and characterization of phosphotyrosine-specific protein phosphatases from cultured chicken embryo fibroblasts

1984 ◽  
Vol 4 (6) ◽  
pp. 1003-1012
Author(s):  
R L Nelson ◽  
P E Branton
Keyword(s):  
Chicken Embryo ◽  
Protein Phosphatases ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Soluble Form ◽  
Ph Optimum ◽  
Cell Extracts ◽  
Phosphoprotein Phosphatases ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

Tyrosine phosphorylation catalyzed by a unique class of protein kinases is an important process in both normal cell proliferation and oncogenic transformation. In this study, phosphoprotein phosphatases specific for the dephosphorylation of phosphotyrosine residues were partially purified from secondary chicken embryo fibroblasts, using 32P-labeled immunoglobulin G phosphorylated by pp60src as substrate. Crude cell extracts contained ca. 70% of the activity in the soluble form and ca. 30% associated with a crude membrane fraction. The soluble activity was purified by using DEAE-cellulose and carboxymethyl cellulose column chromatography and gel filtration, and at least three enzyme species of apparent Mr 55,000 (pTPI), 50,000 (pTPII), and 95,000 (pTPIII)--comprising ca. 20, 45, and 35%, respectively, of the total activity--were resolved. All three enzymes possessed somewhat similar properties. They had a pH optimum of about 7.4, they were inhibited by Zn2+, vanadate, ATP, and ADP, and they were unaffected by divalent metal cations, EDTA, and F- under standard assay conditions employing a physiological ionic strength. These properties suggest that they represent a class of enzymes distinct from well-known phosphoseryl-phosphothreonyl-protein phosphatases and that dephosphorylation of phosphotyrosine-containing proteins may be carried out by a unique family of phosphoprotein phosphatases. Transformation by Rous sarcoma virus resulted in a small increase in phosphotyrosyl-protein phosphatase activity.

STUDIES ON SOLUBILIZED ADENYLATE KINASE FROM MITOCHONDRIA

1966 ◽  
Vol 44 (11) ◽  
pp. 1469-1475 ◽  
Author(s):  
Marjorie A. Brewster ◽  
Ezzat S. Younathan
Keyword(s):  
Activation Energy ◽  
Rat Liver ◽  
Adenylate Kinase ◽  
Divalent Cations ◽  
Metabolic Function ◽  
Kcal Mole ◽  
Temperature Optimum ◽  
Ph Optimum ◽  
Sensitive Method

Adenylate kinase from mitochondria of rat liver was made soluble by sonication. The enzyme had a pH optimum of 8.0, temperature optimum of 30°, and activation energy of 12.2 kcal/mole. It was activated by several divalent cations in the following order of efficiency: Mg++ > Co++ > Mn++ > Ca++, with an optimal Mg++: ADP ratio of 1. The apparent Km value (ADP as substrate) was found to be 1.3 mM at pH 7.4 and 30°. The activity was sensitive to phloretin and mildly activated by aurovertin. Oligomycin, 2,4-dinitrophenol, p-chloromercuribenzoate, alloxan, and phlorizin had no effect on the activity. The metabolic function and a comparison of the properties of this solubilized mitochondrial adenylate kinase with those of similar preparations from other sources are discussed in the light of these findings. During this study, a sensitive method adaptable for a large number of assays of adenylate kinase was developed, and is described in detail.

scholarly journals The lipopolysaccharide transporter complex LptB2FG also displays adenylate kinase activity in vitro dependent on binding partners LptC/LptA

2021 ◽  
pp. 101313
Author(s):  
Tiago Baeta ◽  
Karine Giandoreggio-Barranco ◽  
Isabel Ayala ◽  
Elisabete C.C. M. Moura ◽  
Paola Sperandeo ◽  
...  
Keyword(s):  
Adenylate Kinase ◽  
Kinase Activity ◽  
Binding Partners

Properties of acetate kinase activity inClostridium thermocellum cell extracts

1998 ◽  
Vol 69 (2) ◽  
pp. 137-145 ◽  
Author(s):  
Wenglong R. Lin ◽  
Claudia C. Lee ◽  
Janet J. Hsu ◽  
Jean-Francois Hamel ◽  
Arnold L. Demain
Keyword(s):  
Kinase Activity ◽  
Acetate Kinase ◽  
Cell Extracts

Evaluation of adenosine 5'-monophosphate and fluoride as adenylate kinase inhibitors in the creatine kinase assay.

1976 ◽  
Vol 22 (7) ◽  
pp. 1078-1083 ◽  
Author(s):  
T G Rosano ◽  
K J Clayson ◽  
P E Strandjord
Keyword(s):  
Creatine Kinase ◽  
Adenylate Kinase ◽  
Kinase Activity ◽  
Kinase Inhibitors ◽  
Creatine Kinase Activity ◽  
Serum Creatine Kinase ◽  
Assay System ◽  
Kinase Assay ◽  
Rabbit Muscle ◽  
Atp Production

Abstract Adenylate kinase (EC 2.7.4.3) interferes positively in the serum creatine kinase (EC 2.7.3.2) assay when the rate of ATP production is monitored by a coupled enzyme system. A dual assay, measuring creatine kinase and adenylate kinase activity, was used to evaluate AMP and other possible adenylate kinase inhibitors that would permit specific measurement of creatine kinase activity in the presence of adenylate kinase. We found that AMP, routinely included in the creatine kinase assay system to inhibit adenylate kinase, partially inhibits both human serum creatine kinase and purified creatine kinase from rabbit muscle. The amount of creatine kinase inhibition is related directly to the AMP concentration and inversely to the substrate (ADP) concentration. We found that 25 mmol/liter of fluoride inhibits adenylate kinase without measurable effect on creatine kinase activity. We developed a serum creatine kinase assay including fluoride, and compared it with the dual assay system and with two commercial assay kits. Other halides or adenosine 2'-monophosphate did not selectively inhibit adenylate kinase.

Immunoinhibition and automated column chromatography compared for assay of creatine kinase isoenzyme MB in serum.

1982 ◽  
Vol 28 (1) ◽  
pp. 166-169 ◽  
Author(s):  
P M Bayer ◽  
M Boehm ◽  
P Hajdusich ◽  
H Hotschek ◽  
H Koehn ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Skeletal Muscle ◽  
Adenylate Kinase ◽  
Kinase Activity ◽  
High Ratio ◽  
Creatine Kinase Isoenzyme ◽  
Fourth Group ◽  
The Third ◽  
Altered Surface ◽  
Creatine Kinase Isoenzyme Mb

Abstract We examined sera from six different groups of patients for CK-MB activity by means of two commercially available tests, an immunoinhibition method (E. Merck) and the CK-MB test as used with the aca (Du Pont). In the first group of patients (suspicion of myocardial infarction) the correlation between the two methods was good: r = 0.9191, y = 1.068x -- 0.888, x = 18.7 U/L, y = 19.0 U/L. In the second group, patients with high adenylate kinase activity, no interference was detectable on the aca, whereas the immunoinhibition method yielded falsely high CK-MB values. The third group consisted of persons with macro-CK-BB in their serum. In the immunoinhibition test these patients usually showed a high CK-MB:total CK ratio, whereas such results were rarely found for the aca. The fourth group, patients with a different electrophoretic mobility of their CK-isoenzymes (migration of an active band towards the cathode), were detected by the immunoinhibition method (high ratio of CK-MB to total CK), but not with the aca. In the presence of free CK-BB (group five) the immunoinhibition test resulted in "falsely" high CK-MB values, whereas CK-BB was retained on the column of the aca. In skeletal muscle diseases (group six) results by the two methods differed, values for CK-MB on the aca being much higher. It was demonstrated experimentally that this was due to CK-MM with altered surface charge.

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