scholarly journals Multiple chromatographic forms of ATP citrate lyase from rat liver

1983 ◽  
Vol 214 (2) ◽  
pp. 299-307 ◽  
Author(s):  
A P Corrigan ◽  
C C Rider

ATP citrate lyase is shown to exist as multiple forms in extracts of rat liver. DEAE-Sephadex ion-exchange chromatography of liver supernatants reveals two peaks of activity. A minor, basic, component, comprising 14% of the recovered activity, is eluted without retention, whereas the major, acidic, form is eluted by a KCl gradient. Gel filtration of similar extracts shows the presence of a high-Mr form of ATP citrate lyase (Mr around 10(7) in addition to the tetrameric enzyme (Mr 4.1 X 10(5). This associated state, which represents 10% of the total activity, is unstable, breaking down to the tetramer, and appears to be disrupted by Mg2+. The basic form changes in the partially purified state to give the acidic form. Most of the high-Mr enzyme is acidic in nature. No evidence could be found for an association of the enzyme with mitochondrial or microsomal membranes. ATP citrate lyase from rat brain also shows two peaks of activity on DEAE-Sephadex ion-exchange chromatography, but the activity is distributed between the peaks in almost equal proportions. However, only the tetrameric enzyme was observed on gel filtration.

1990 ◽  
Vol 36 (11) ◽  
pp. 1906-1910 ◽  
Author(s):  
J Osada ◽  
T Gea ◽  
C Sanz ◽  
I Millan ◽  
J Botella

Abstract A group of substances of molecular masses between 300 and 1500 Da have been found to be toxic metabolites in patients with uremia. We determined the concentration in serum of these molecules in the following groups of patients: two hemodialyzed groups (one with cuprophane and the other with polyacrylonitrile dialyzers), one group treated with continuous ambulatory peritoneal dialysis, one group of nondialyzed azotemic patients, and one control group of healthy persons. Ultrafiltrates of the subjects' sera were fractionated on Sephadex G-15 followed by ion-exchange chromatography. Eluates were monitored by absorbance at 254 and 206 nm. Partially characterized peaks P1 and P2, obtained by gel filtration, correlated with the concentration of creatinine in serum; their concentrations were significantly (P less than 0.01) larger in hemodialyzed groups than in peritoneal dialyzed or in nondialyzed azotemic patients. After ion-exchange chromatography, two peaks (P'5 and P'6) correlated with serum creatinine and also were larger in hemodialyzed patients than in the other groups. Apparently, adequate discrimination is obtained by gel-filtration analysis and further analysis by ion-exchange chromatography does not provide additional information in most of the affected patients.


1986 ◽  
Vol 239 (3) ◽  
pp. 553-558 ◽  
Author(s):  
M Nogueira ◽  
G Garcia ◽  
C Mejuto ◽  
M Freire

A cofactor of Mr 10(4), characterized as a polypeptide, was found to co-operate with GSSG to prevent the inhibition of glucose-6-phosphate dehydrogenase by NADPH, in order to ensure the operation of the oxidative phase of the pentose phosphate pathway, in rat liver [Eggleston & Krebs (1974) Biochem. J. 138, 425-435; Rodriguez-Segade, Carrion & Freire (1979) Biochem. Biophys. Res. Commun. 89, 148-154]. This cofactor has now been partially purified by ion-exchange chromatography and molecular gel filtration, and characterized as a protein of Mr 10(5). The lighter cofactor reported previously was apparently the result of proteolytic activity generated during the tissue homogenization. The heavier cofactor was unstable, and its amount increased in livers of rats fed on carbohydrate-rich diet. Since the purified cofactor contained no glutathione reductase activity, the involvement of this enzyme in the deinhibitory mechanism of glucose-6-phosphate dehydrogenase by NADPH should be ruled out.


2017 ◽  
Vol 51 (03) ◽  
Author(s):  
A. S. Shahjahan ◽  
Enciy R. Martin

Sorbitol Dehydrogenase (SDH) is important enzymes responsible for the protection of eggs from harsh condition as it convert fructose to sorbitol which serves as polyol and stabilize the soluble proteins and lipid bilayer. The enzyme SDH (d-Idiol NAD oxidoreductase EC 1.1.1.14) is purified from the eggs of red cotton bug, Dysdercus cingulatus exposed to low temperature. The SDH from eggs were purified by using different protein purification technique viz, ion exchange chromatography, gel filtration and SDS–PAGE. The ion exchange chromatography showed 0.185U total activity, with a purification fold of 1.48 and yield 3.36%. Gel filtration chromatography showed an increase in purification of SDH activity by 2.73 with 0.095 U total activity and yield of 1.73%. SDS-PAGE revealed that SDH molecular weight of 38 KDa. The Km value of Fructose: NADH is 0.4:0.01 and the Vmax was 0.6 and 0.03. Thus low temperature increases the activity of SDH which convert fructose to sorbitol which protects the cell during diapause condition.


2017 ◽  
Vol 51 (03) ◽  
Author(s):  
A. S. Shahjahan ◽  
Enciy R. Martin

<span>Sorbitol Dehydrogenase (SDH) is important enzymes responsible for the protection of eggs from harsh condition as it convert fructose to sorbitol which serves as polyol and stabilize the soluble proteins and lipid bilayer. The enzyme SDH (d-Idiol NAD oxidoreductase EC 1.1.1.14) is purified from the eggs of red cotton bug, Dysdercus cingulatus exposed to low temperature. The SDH from eggs were purified by using different protein purification technique viz, ion exchange chromatography, gel filtration and SDS–PAGE. The ion exchange chromatography showed 0.185U total activity, with a purification fold of 1.48 and yield 3.36%. Gel filtration chromatography showed an increase in purification of SDH activity by 2.73 with 0.095 U total activity and yield of 1.73%.  SDS-PAGE revealed that SDH molecular weight of 38 KDa. The Km value of Fructose: NADH is 0.4:0.01 and the Vmax was 0.6 and 0.03. Thus low temperature increases the activity of SDH which convert fructose to sorbitol which protects the cell during diapause condition.</span>


1973 ◽  
Vol 30 (02) ◽  
pp. 414-424 ◽  
Author(s):  
Ulla Hedner

SummaryA procedure is described for partial purification of an inhibitor of the activation of plasminogen by urokinase and streptokinase. The method involves specific adsorption of contammants, ion-exchange chromatography on DEAE-Sephadex, gel filtration on Sephadex G-200 and preparative electrophoresis. The inhibitor fraction contained no antiplasmin, no plasminogen, no α1-antitrypsin, no antithrombin-III and was shown not to be α2 M or inter-α-inhibitor. It contained traces of prothrombin and cerulo-plasmin. An antiserum against the inhibitor fraction capable of neutralising the inhibitor in serum was raised in rabbits.


1984 ◽  
Vol 51 (01) ◽  
pp. 016-021 ◽  
Author(s):  
S Birken ◽  
G Agosto ◽  
B Lahiri ◽  
R Canfield

SummaryIn order to investigate the early release of NH2-terminal plasmic fragments from the Bβ chain of fibrinogen, substantial quantities of Bβ 1-42 and Bβ 1-21 are required as immunogens, as radioimmunoassay standards and for infusion into human volunteers to determine the half-lives of these peptides. Towards this end methods that employ selective proteolytic cleavage of these fragments from fibrinogen have been developed. Both the N-DSK fragment, produced by CNBr cleavage of fibrinogen, and Bβ 1-118 were employed as substrates for plasmin with the finding of higher yields from N-DSK. Bβ 1-42 and Bβ 1-21 were purified by gel filtration and ion-exchange chromatography on SP-Sephadex using volatile buffers. When the purified preparation of Bβ 1-42 was chromatographed on reverse-phase high performance liquid chromatography, two peaks of identical amino acid composition were separated, presumably due either to pyroglutamate or to amide differences.


2021 ◽  
Vol 13 (2) ◽  
pp. 107-112
Author(s):  
C.F. Okechukwu ◽  
P.L. Shamsudeen ◽  
R.K. Bala ◽  
B.G. Kurfi ◽  
A.M. Abdulazeez

The most effective and acceptable therapy for snakebite victims is the immediate administration of antivenin which is limited by problems of hypersensitivity reactions in some individuals and its inability to resolve the local effects of the venom. The aim of this study was to isolate, partially purify and characterize phospholipase A2 from Naja Katiensis venom. Phospholipase A2 was partially purified via a two-step process: gel filtration on Sephadex G-75 and ion exchange chromatography using CM Sephadex, and subjected to SDS-PAGE analysis. From the results, the specific activity of the partially purified PLA2 decreased from 0.67μmol/min/mg in crude venom to 0.29μmol/min/mg after ion exchange chromatography with a yield of 5% and purification fold of 0.43. The optimum temperature of the purified PLA2 was found to be 35ºC and optimum p.H of 7. velocity studies for the determination of kinetic constants using L-a-lecithin as substrate revealed a Km  of 1.47mg/ml and Vmax  of 3.32μ moles/min/mg. The sodium dodecyl sulphate polyacrylamide gel electrophoresis of the purified PLA2 showed a distinct band with molecular weight estimated to be 14KDa. In conclusion, the present study shows that phospholipase A2 was isolated, purified and characterized. This may serve as a promising candidate for future development of a novel anti-venin drug.


1973 ◽  
Vol 58 (3) ◽  
pp. 405-419 ◽  
Author(s):  
M. JOAN REED ◽  
S. R. STITCH

SUMMARY The uptake of 65Zn and [1,2-3H]testosterone by minced tissue of human benign hypertrophic prostates and the subcellular distribution of radioactivity were examined. The nature of steroid and 65Zn binding by the cytosol (105000 g supernatant) fraction was investigated by gel filtration, ion-exchange chromatography and electrophoresis. It was found that steroid binding after incubation at 4°C was specific. One or two regions of steroid binding were observed after gel filtration of the cytosol using Sephadex G-200, depending upon incubation conditions. Binding of 65Zn was found in the low molecular weight peak after G-200 gel filtration. Equimolar CdCl2 and 65ZnCl2 were incubated with [1,2-3H]testosterone and minced tissue and the cytosol was subjected to gel filtration. Compared with control values, without CdCl2, reduction of 65Zn binding by about 50% occurred, while binding of 3H-labelled steroid was unaffected. Electrophoresis and ion-exchange chromatography showed that 65Zn and 3H-labelled steroid were bound to different proteins. A sample of the zinc-binding protein was prepared by ion-exchange chromatography and the homogeneity was checked by electrophoresis.


2016 ◽  
Vol 78 (6-5) ◽  
Author(s):  
Zainon Mohd Noor ◽  
Mohd Sidek Ahmad ◽  
Zaidah Zainal Ariffin

Three enzymes FH3, S13 and LR1 from three different sources showed fibrinolytic activities. Two were from endophytic fungal cultures and one from the sclerotium of Lignosus rhinocerus mushroom (LR1). FH3, S13 cultures and LR1, the crude extract of the sclerotium were concentrated and purified by ammonium sulphate precipitation, ion-exchange chromatography and gel-filtration. The molecular weights of the FH3, S13 and LR1 purified enzymes were estimated to be approximately 34kDa, 34kDa and 10kDa, respectively. Maximum fibrinolytic activities were observed for FH3 at pH 7 and 30°C, S13 at pH 8 and 40°C and LR1 at pH 6 and 40°C.  In our earlier paper we identified FH3 as Fusarium sp. and S13 as Penicilium citrinum. 


Sign in / Sign up

Export Citation Format

Share Document