Two Different Chalcone Synthase Activities from Spinach

1985 ◽  
Vol 40 (3-4) ◽  
pp. 160-165 ◽  
Author(s):  
L. Beerhues ◽  
R. Wiermann
Keyword(s):  
Ion Exchange ◽  
Substrate Specificity ◽  
Chalcone Synthase ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Enzyme Preparations ◽  
Assay Mixture ◽  
Suitable Substrate ◽  
Malonyl Coa ◽  
Young Leaves

Chalcone synthase activity was found in enzyme preparations from spinach. In homogenates of young leaves two different activities of the enzyme could be separated by DEAE-ion exchange chromatography and chromatofocusing. Both activities formed naringenin with [2-14C] malonyl- CoA and 4-coumaroyl-CoA as substrates. They exhibited only slight differences in substrate specificity. For both activities 4-coumaroyl-CoA proved to be the most suitable substrate at both pH 6.8 and 8.0. Eriodictyol and homoeriodictyol formation from caffeoyl-CoA and feruloyl-CoA, respectively, only occured at pH 6.8. The formation of naringenin by the two activities was maximal at pH 7.5-8.0 and dependent upon the DTE-concentration in the assay mixture.

LINGCOD MUSCLE PHOSPHORIBOISOMERASE AND RIBULOSE 5′-PHOSPHATE 3′-EPIMERASE

1959 ◽  
Vol 37 (8) ◽  
pp. 961-973 ◽  
Author(s):  
H. L. A. Tarr
Keyword(s):  
Acid Phosphatase ◽  
Ion Exchange ◽  
Ammonium Sulphate ◽  
Simple Procedure ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Water Extraction ◽  
Enzyme Preparations

Comparatively pure phosphoriboisomerase and ribulose 5′-phosphate 3′-epimerase enzyme preparations were obtained from lingcod muscle by a simple procedure involving water extraction, saturation of the extract with ammonium sulphate, dialysis, brief heating to 55 °C, lyophilization of the solution, and final separation by ion exchange chromatography, using diethylamiuoethyl cellulose columns. Both enzymes have broad pH optima above pH 7.0, but are rapidly inactivated below this value. The following equilibria were established and compared with those obtained by other investigators: [Formula: see text], 1.35:1.0; [Formula: see text], 1: 1.5 and [Formula: see text], 1:0.58:0.66. The ketopentulose phosphate resulting from the action of phosphoriboisomerase on D-ribose 5-phosphate was isolated and identified as D-ribulose5-phosphate. Both D-ribulose and D-xylulose were demonstrated after subjecting a product of epimerase action to hydrolysis by acid phosphatase and ion exchange chromatography.

LINGCOD MUSCLE PHOSPHORIBOISOMERASE AND RIBULOSE 5′-PHOSPHATE 3′-EPIMERASE

1959 ◽  
Vol 37 (1) ◽  
pp. 961-973
Author(s):  
H. L. A. Tarr
Keyword(s):  
Acid Phosphatase ◽  
Ion Exchange ◽  
Ammonium Sulphate ◽  
Simple Procedure ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Water Extraction ◽  
Enzyme Preparations

Comparatively pure phosphoriboisomerase and ribulose 5′-phosphate 3′-epimerase enzyme preparations were obtained from lingcod muscle by a simple procedure involving water extraction, saturation of the extract with ammonium sulphate, dialysis, brief heating to 55 °C, lyophilization of the solution, and final separation by ion exchange chromatography, using diethylamiuoethyl cellulose columns. Both enzymes have broad pH optima above pH 7.0, but are rapidly inactivated below this value. The following equilibria were established and compared with those obtained by other investigators: [Formula: see text], 1.35:1.0; [Formula: see text], 1: 1.5 and [Formula: see text], 1:0.58:0.66. The ketopentulose phosphate resulting from the action of phosphoriboisomerase on D-ribose 5-phosphate was isolated and identified as D-ribulose5-phosphate. Both D-ribulose and D-xylulose were demonstrated after subjecting a product of epimerase action to hydrolysis by acid phosphatase and ion exchange chromatography.

scholarly journals Aminopeptidases in Webbing Clothes Moth Larvae. Properties and Specificities of Enzymes of Highest Electrophoretic Mobility

1975 ◽  
Vol 28 (6) ◽  
pp. 447 ◽  
Author(s):  
Colin W Ward
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Substrate Specificity ◽  
Metal Ions ◽  
Electrophoretic Mobility ◽  
Enzyme Inhibitors ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Polyacrylamide Gels ◽  
Tineola Bisselliella

The group of aminopeptidase bands from Tineola bisselliella larvae with highest electrophoretic mobility in polyacrylamide gels were purified further and partially separated by ion exchange chromatography. Three aminopeptidase bands were present in this material and were very similar with respect to their pH optima (7� 7), their molecular weight of 94000, their responses to metal ions and enzyme inhibitors and in their substrate specificity requirements.

UDP-D-Glucose: Flavonol 3 -0 -and 7-O-Glucosyl Transferases from Young Leaves of Paederia scandens var. mairei

1993 ◽  
Vol 48 (7-8) ◽  
pp. 563-569 ◽  
Author(s):  
Nariyuki Ishikura ◽  
Zhi-qing Yang ◽  
Susumu Teramoto
Keyword(s):  
Ion Exchange ◽  
Ammonium Sulfate ◽  
Isoelectric Point ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
The Other ◽  
Hydroxyl Group ◽  
Ph Optimum ◽  
Young Leaves ◽  
Paederia Scandens

Two different O-glucosyl transferases (F3GT and F7GT ) catalyzing the transfer of ᴅ-glucose from UDP-ᴅ-glucose to the 3 and 7 positions of flavonol, respectively, were isolated from the young leaves of Paederia scandens var. mairei. F3GT and F7GT, which were recovered in about a 1:1 ratio in the activity, were purified by about 140- and 136-fold, respectively, by precipitation with ammonium sulfate followed by ion exchange chromatography and chromatofocusing. F3GT and F7GT both had a pH optimum of 7.5 in Tris-HCl buffer, and an Mr of 43 kDa. Neither F3GT nor F7GT had a Mg2+ requirement. Both were inhibited by each 1 mᴍ of Zn2+, Cu2+, N-ethylmaleimide and p-chloromercuribenzoate, and both were stimulated by 14 mᴍ 2-M E . F3GT and F7GT were different from each other in having an isoelectric point (pI) at pH 5.12 and 4.50, respectively. F3GT mediated the transfer of D-glucose exclusively to the 3-hydroxyl group of kaempferol and some flavonols, but neither the 7-O-glucosides nor the 3-O-glucosides of their flavonols were able to accept D-glucose. On the other hand, F7GT mediated the transfer of D-glucose exclusively to the 7-hydroxyl group of kaempferol and some flavonols, and in addition, the 3-O -glucosides of kaempferol and quercetin were able to accept D-glucose thoughn less efficiently. Consequently, the possibility of sequential steps of 3-O- and then 7-O-glucosylations of flavonols to give the 3,7-di-O-glucoside was discussed.

Studies on an Inhibitor of Plasminogen Activation in Human Serum

1973 ◽  
Vol 30 (02) ◽  
pp. 414-424 ◽  
Author(s):  
Ulla Hedner
Keyword(s):  
Ion Exchange ◽  
Human Serum ◽  
Antithrombin Iii ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Specific Adsorption ◽  
Partial Purification ◽  
Plasminogen Activation ◽  
Preparative Electrophoresis

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.

Review on the Application of Mixed-mode Chromatography for Separation of Structure Isoforms

2018 ◽  
Vol 20 (1) ◽  
pp. 56-60 ◽  
Author(s):  
Tsutomu Arakawa
Keyword(s):  
Ion Exchange ◽  
Mixed Mode ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Charged State ◽  
Partial Structure ◽  
Reverse Phase ◽  
Oligomer Formation ◽  
Structure Rearrangement ◽  
Disulfide Scrambling

Proteins often generate structure isoforms naturally or artificially due to, for example, different glycosylation, disulfide scrambling, partial structure rearrangement, oligomer formation or chemical modification. The isoform formations are normally accompanied by alterations in charged state or hydrophobicity. Thus, isoforms can be fractionated by reverse-phase, hydrophobic interaction or ion exchange chromatography. We have applied mixed-mode chromatography for fractionation of isoforms for several model proteins and observed that cation exchange Capto MMC and anion exchange Capto adhere columns are effective in separating conformational isoforms and self-associated oligomers.

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