scholarly journals Purification and characterization of acid phosphatase from a germinating black gram (Vigna mungo L.) seedling

2011 ◽  
Vol 63 (3) ◽  
pp. 747-756 ◽  
Author(s):  
A.K.M. Asaduzzaman ◽  
Habibur Rahman ◽  
Tanzima Yeasmin

An acid phosphatase has been isolated and purified from an extract of a germinating black gram seedling. The method was accomplished by gel filtration of a germinating black gram seedling crude extract on sephadex G-75 followed by ion exchange chromatography on DEAE cellulose. The acid phosphatase gave a single band on SDS-polyacrylamide slab gel electrophoresis. The molecular weight of the acid phosphatase determined by SDS-polyacrylamide slab gel electrophoresis was estimated to be 25 kDa. The purified enzyme showed maximum activity at pH 5 and at temperature of 55?C. Mg2+, Zn2+ and EDTA had an inhibitory effect on the activity of the acid phosphatase. Black gram seedling acid phosphatase was activated by K+, Cu2+ and Ba2+. The Km value of the enzyme was found to be 0.49 mM for pNPP as substrate.

2017 ◽  
Vol 18 (2) ◽  
pp. 1-10 ◽  
Author(s):  
Dzun Noraini Jimat ◽  
Intan Baizura Firda Mohamed ◽  
Azlin Suhaida Azmi ◽  
Parveen Jamal

A newly bacterial producing L-asparaginase was successful isolated from Sungai Klah Hot Spring, Perak, Malaysia and identified as Bacillus sp. It was the best L-asparaginase producer as compared to other isolates. Production of L-asparaginase from the microbial strain was carried out under liquid fermentation. The crude enzyme was then centrifuged and precipitated with ammonium sulfate before further purified with chromatographic method. The ion exchange chromatography HiTrap DEAE-Sepharose Fast Flow column followed by separation on Superose 12 gel filtration were used to obtain pure enzyme. The purified enzyme showed 10.11 U/mg of specific activity, 50.07% yield with 2.21 fold purification. The purified enzyme was found to be dimer in form, with a molecular weight of 65 kDa as estimated by SDS-PAGE. The maximum activity of the purified L-asparaginase was observed at pH 9 and temperature of 60°C.


2005 ◽  
Vol 37 (6) ◽  
pp. 363-370 ◽  
Author(s):  
Ye-Yun Li ◽  
Chang-Jun Jiang ◽  
Xiao-Chun Wan ◽  
Zheng-Zhu Zhang ◽  
Da-Xiang Li

Abstractβ-Glucosidases are important in the formation of floral tea aroma and the development of resistance to pathogens and herbivores in tea plants. A novel β-glucosidase was purified 117-fold to homogeneity, with a yield of 1.26%, from tea leaves by chilled acetone and ammonium sulfate precipitation, ion exchange chromatography (CM-Sephadex C-50) and fast protein liquid chromatography (FPLC; Superdex 75, Resource S). The enzyme was a monomeric protein with specific activity of 2.57 U/mg. The molecular mass of the enzyme was estimated to be about 41 kDa and 34 kDa by SDS-PAGE and FPLC gel filtration on Superdex 200, respectively. The enzyme showed optimum activity at 50 °C and was stable at temperatures lower than 40 °C. It was active between pH 4.0 and pH 7.0, with an optimum activity at pH 5.5, and was fairly stable from pH 4.5 to pH 8.0. The enzyme showed maximum activity towards pNPG, low activity towards pNP-Galacto, and no activity towards pNP-Xylo.


1989 ◽  
Vol 263 (2) ◽  
pp. 439-444 ◽  
Author(s):  
M V Laycock ◽  
T Hirama ◽  
S Hasnain ◽  
D Watson ◽  
A C Storer

A new cysteine proteinase was isolated from the digestive juice of the American lobster (Homarus americanus). The enzyme was purified by a combination of affinity and ion-exchange chromatography and gel filtration. The cysteine proteinase accounted for 80% of the proteolytic activity in the lumen of the hepatopancreas. The most potent heavy-metal inhibitors were Hg, Cu, and Ag ions. Inhibition by organic proteinase inhibitors, including E-64 [L-trans-epoxysuccinyl-leucylamido-(4-guanidino)butane] and activation of the enzyme by 2-mercaptoethanol and dithiothreitol are characteristic of cysteine proteinases. Several similarities to papain are noted and include the N-terminal sequence, of which 22 of the first 28 amino acids are identical. Some notable differences are the higher Mr of 28,000 compared with 23,350 for papain, and the low isoelectric point (pI 4.5) of the lobster enzyme. The effects of pH and temperature on catalytic activity of the lobster proteinase were studied with benzyloxycarbonylalanine p-nitrophenyl ester as the substrate. The kcat./Km value was effectively temperature-independent between 10 and 60 degrees C. The pH-activity profile for the lobster enzyme revealed four apparent protonation states, of which only two are active.


2016 ◽  
Vol 47 (4) ◽  
Author(s):  
Abood & Hakeem

Amylase inhibitors were purified by many sequential steps included concentration by gradual addition of ammonium sulfate at  saturation ratios. ranged from 0 to 90% . The best ratio of saturation was found to be 70% as the specific activity and inhibition activity toward Human alpha-amylase(HAS)  were the highest ( 8 U/mg and 6 U/ml respectively as compared to those of the rest ratios, the ratio of saturation with ammonium sulfate 60 % and then 50%, (5.8 ,5.5  )U/ml and( 7.7 ،7 )U/mg respectively for inhibition activity and specific activity and for  40% ,30%20%  saturation  the inhibition activity and specific activity were(5 ،4.8 ،4 ) u/ml (6.6 ،6 ،5.8) u/mg respectively .The precepitation step was followed by ionic exchange chromatography technique by DEAE-cellulose column( 3×11 )cm and the results showed that there was one peak with inhibition activity toward (HAS). Further  purification steps were conducted using gel filtration on Sephacryl S-200 column    (1.5  ×  60)cm; the purification folds was5.59 times with outcome of 46.5%.The results of alpha-amylase inhibitors characterization showed that the molecular weight was about 23.44 and 22.9  kDa  as determined by electrophoresis and gel filteration respectively.                                         


1974 ◽  
Vol 77 (3) ◽  
pp. 485-497 ◽  
Author(s):  
P. A. Torjesen ◽  
T. Sand ◽  
N. Norman ◽  
O. Trygstad ◽  
I. Foss

ABSTRACT Highly purified human LH, FSH and TSH were isolated from batches of 300 frozen pituitary glands (200 g) by pH, acetone and ethanol fractionation, Sephadex gel filtration, ion-exchange chromatography on DEAE-cellulose and CM-Sephadex, and preparative polyacrylamide-gel electrophoresis. Sodium dodecyl-sulphate (SDS) polyacrylamide gel electrophoresis was used in order to check the purity, the identity and the molecular weight of the purified LH, FSH and TSH. This procedure showed that the hormone preparations consisted of two subunits with molecular weights of: LH: 21 300 and 17 900, FSH: 22 100 and 18 300 and TSH: 20 800 and 16 400. The purity of the hormone preparations was also evaluated by analytical disc electrophoresis at pH 8.9. The purified hormone preparations had radioimmunological activity as follows: LH: 20 000 IU/mg, FSH: 16 500 IU/mg and TSH: 5 IU/mg. All preparations had high biological potency.


1981 ◽  
Vol 195 (1) ◽  
pp. 71-81 ◽  
Author(s):  
G McKay ◽  
P D Shargool

N-Acetylglutamate 5-phosphotransferase (acetylglutamate kinase, EC 2.7.2.8) has been isolated from pea (Pisum sativum) cotyledons and purified 312-fold by using heat treatment, (NH4)2SO4 fractionation, affinity chromatography on ATP--Sepharose and ion-exchange chromatography on DEAE-cellulose. This preparation was shown on polyacrylamide-gel electrophoresis to yield one band staining with Coomassie Blue. The enzyme was shown by a variety of techniques to be composed of two different kinds of subunits, of mol.wts. 43000 and 53000 respectively. These subunits are arranged to give either a dimeric or tetrameric enzyme composed of equal numbers of each type of subunit. The dimeric and tetrameric enzyme forms are thought to be interconvertible, the equilibrium between these forms being influenced by the type of ligand bound to the subunits. Kinetic studies performed on the purified enzyme, indicated a random Bi Bi type of mechanism. The enzyme displayed apparent negative co-operativity with respect to one of its substrates, N-acetylglutamate; as a result, two Km values were found for this substrate, one at 1.9 X 10(-3) M and the other at 6.2 X 10(-3) M. A single Km value for ATP was found to be 1.7 X 10(-3) M. Allosteric regulation by arginine was also shown. A model, based on the Koshland, Némethy & Filmer [(1966) Biochemistry 5, 365-385] Sequential model, which adequately describes the kinetic and structural properties of N-acetylglutamate 5-phosphotransferase, is presented.


1986 ◽  
Vol 234 (1) ◽  
pp. 157-162 ◽  
Author(s):  
N N Dewji ◽  
D R De-Keyzer ◽  
J L Stirling

beta-N-Acetylhexosaminidase I2 was purified from human liver by a combination of concanavalin A chromatography, DEAE-cellulose chromatography, gel filtration and affinity chromatography on 2-acetamido-N-(6-aminohexanoyl)-2-deoxy-beta-D-glucopyranosylamine coupled to CNBr-activated Sepharose 4B. Its specific activity was 130 mumol/min per mg of protein compared with values of 150 and 320 mumol/min/mg of protein for beta-N-acetylhexosaminidases A and B purified from the same tissue. Km values for I2, A and B were 1.0 mM, 0.8 mM and 0.74 mM respectively. On gradient gel electrophoresis under non-denaturing conditions, hexosaminidase I2 behaved similarly to A and appeared to have an Mr between 100 000 and 110 000. beta-N-Acetylhexosaminidase I2 was resolved into two major polypeptides, of Mr 56 000 and 29 000, on SDS/polyacrylamide-gel electrophoresis under denaturing conditions. Immunoblotting with anti-(hexosaminidase alpha-subunit) serum confirmed that the 56 000-Mr component was the alpha-subunit and anti-(hexosaminidase B) serum reacted with the 29 000 Mr component. beta-N-Acetylhexosaminidase I2 more closely resembles form A than B, but the features of its structure that allow it to be separated from A on the basis of net charge have not yet been found.


1986 ◽  
Vol 237 (2) ◽  
pp. 415-420 ◽  
Author(s):  
C R Goward ◽  
R Hartwell ◽  
T Atkinson ◽  
M D Scawen

Homogeneous glucokinase (EC 2.7.1.2) from the thermophile Bacillus stearothermophilus was isolated on the large scale by using four major steps: precipitation of extraneous material at pH 5.5, ion-exchange chromatography on DEAE-Sepharose, pseudo-affinity chromatography on Procion Brown H-3R-Sepharose 4B and gel filtration on Ultrogel AcA 34. The purified enzyme had a specific activity of about 330 units/mg of protein and was shown to exist as a dimer of subunit Mr 33,000. Kinetic parameters for the enzyme were determined with a variety of substrates. The glucokinase was highly specific for alpha-D-glucose, and the only other sugar substrate utilized was N-acetyl-alpha-D-glucosamine. The enzyme shows Michaelis-Menten kinetics, with a Km value of 150 microM for alpha-D-glucose. The glucokinase was maximally active at pH 9.0.


1984 ◽  
Vol 62 (2) ◽  
pp. 385-391 ◽  
Author(s):  
Sheikh Mehboob Basha

An acid phosphatase (EC 3.1.3.2) from peanut (Arachis hypogaea L.) seed has been purified 433-fold by ammonium sulfate fractionation, gel filtration, and ion-exchange chromatography. The purified preparation was found to be homogeneous by electrophoresis and gel filtration. The molecular weight of the enzyme was estimated to be approximately 240 000 and it was found to be composed of six identical subunits, each with an apparent molecular weight of 42 500. Following isoelectric focusing, the isolectric point (pI) of the enzyme was found to be around pH 5.6. The apparent Km value with p-nitrophenyl phosphate as substrate was 2 ? 10−1 μM. The enzyme was inhibited by Hg2+, Fe2+, Cu2+, Zn2+, Pb2+, and F−. Higher concentrations (2–50 μM) and long incubation periods (60–90 min) with Ca2+ and Mg2+ ions were shown to activate the enzyme. This enzyme showed no effect toward phosphorylated sugars but appear to hydrolyze ATP, ADP, AMP, and β-glycerophosphate.


1984 ◽  
Vol 223 (3) ◽  
pp. 871-877 ◽  
Author(s):  
C L Lee ◽  
S S L Li ◽  
T M Chu

Three peptide fragments (designated II, III and IV) of human prostatic acid phosphatase (PAP) were isolated to homogeneity from a limited tryptic hydrolysate of PAP by gel filtration on Sephadex G-100, followed by chromatography on DEAE-cellulose and Sephadex G-75. The homogeneity was confirmed by disc poly-acrylamide-gel electrophoresis. The Mr values were 32 500, 25 000 and 11 000 as estimated by gel filtration and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Immunoprecipitation study revealed that only fragment II formed an immune precipitate with anti-PAP antibodies. Fragment II exhibited 45% of maximum inhibitory activity on the reaction between PAP and goat anti-PAP IgG (immunoglobulin G) antibodies (or rabbit anti-PAP antibodies), whereas fragments III and IV demonstrated 24% (or 23%) and 29% (or 27%) inhibition respectively. A mixture of these three tryptic fragments of PAP result in 96% (for goat anti-PAP antibodies) and 94% (for rabbit anti-PAP antibodies) inhibitory activities, which were equivalent to the sum of maximum inhibitory activity of the three fragments individually. The results demonstrated that these three tryptic peptide fragments carried all the antigenic active sites of the native PAP, and suggested that the entire molecule of human PAP comprised a minimum of four distinguishable, nonoverlapping antigenic determinants. These three fragments also were shown to retain all the disulphide bonds of the native PAP, and thus were useful reagents for the elucidation of PAP molecular structure.


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