COMPARISON OF DIFFERENT CELL DISRUPTION METHODS AND CELL EXTRACTANT BUFFERS FOR RECOMBINANT BROMELAIN EXPRESSED IN E.COLI BL21-A1

2015 ◽  
Vol 77 (24) ◽  
Author(s):  
Zatul Iffah Mohd Arshad ◽  
Azura Amid ◽  
Muhd. Ezza Faiez Othman

The often-encountered problem such as protein degradation has driven various methods of cell lysis in obtaining recombinant protein post fermentation. In this paper, we compare methods such as homogenization, sonication, sonication with lysozyme and chemical lysis using B-PER reagent with lysozyme to extract the recombinant bromelain from E. coli BL21-AI. The sonication process is found to be the most effective in releasing recombinant bromelain without any pre-treatment. To obtain the high quality of protein from sonication method, the influence of different extractant buffer was investigated including phosphate buffer saline (PBS), PBS containing cysteine and EDTA (PBS-CE), and sodium phosphate buffer containing cysteine and EDTA (EB-CE). The highest specific enzyme activity was obtained when it was extracted with EB-CE buffer. Under sodium dodecyl sulfate polyacrylamide gel electrophoresis, the recombinant bromelain showed protein band at 55kDa. In conclusion, the sonication method with extractant buffer containing 100mM phosphate buffer pH7.0 with 15 mM cysteine and 2 mM EDTA (EB-CE) was shown to give high specific activity of recombinant bromelain.

1993 ◽  
Vol 10 (3) ◽  
pp. 345-357
Author(s):  
X Casabiell ◽  
J L Zugaza ◽  
C M Pombo ◽  
L Bokser ◽  
N Mulet ◽  
...  

ABSTRACT In order to detect putative markers of prolactin-secreting pituitary tumours, adult rats were subjected to long-term oestrogenization with oestradiol benzoate (OE2) on a monthly basis. At 6 months, anterior pituitaries were dissected and incubated either as tissue fragments or as dispersed cells with a S]methionine mix for labelling. Proteins released into the incubation medium and from tissue extracts were further analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and fluorography. Oestrogen induced the appearance in the incubation medium of a protein (OE2 band) with an Mr of 38 000 under reducing conditions, and high specific activity. Surprisingly, such a protein was not detected in tissue extracts. The OE2 band was detectable by 7 days after the first dose of oestrogen, and remained throughout 1 year of treatment. The tumour cell line GH3 showed a similar OE2 band which was further enhanced by oestrogens. The protein was observed similarly in both female and male pituitary donors, either intact or gonadectomized, and also in rats of different strains, suggesting that its appearance was independent of the strain of rat and gonadal status. Furthermore, the OE2 band was specific for pituitary cells and not produced by other oestrogenized tissues. No alteration in the rate of generation or the electrophoretic pattern of the OE2 band was observed when pituitary cells from oestrogenized rats were metabolically labelled while being incubated with tunicamycin. Furthermore, a system for glycan detection, adsorption to Concanavalin A or incubation with endoglycosidase F also failed to show a clear amount of glycosylation of the oestrogen-induced protein. Both immunoprecipitation experiments and time-limited proteolysis with V8 protease ruled out the possibility that the OE2 band could be structurally related to either GH or prolactin. In conclusion, oestrogens induce the generation of a new monocatenary protein with an apparent Mr of 38 000, which has at least one intramolecular disulphide loop and is not glycosylated. The OE2 band was detected only in incubation medium and never in tissue extracts.


1981 ◽  
Vol 195 (1) ◽  
pp. 83-92 ◽  
Author(s):  
N S Beer ◽  
W T Griffiths

A procedure for the purification of the enzyme NADPH:protochlorophyllide oxidoreductase is described. This involves fractionation of sonicated oat etioplast membranes by discontinuous-sucrose-density-gradient centrifugation, which gives membranes in which the enzyme is present at a high specific activity. The enzyme is solubilized from the membranes with Triton X-100, followed by gel filtration of the extract; enzyme activity is eluted in fractions corresponding to a mol.wt of approx. 35000. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of the enzyme-containing fractions from gel filtration shows two peptides, of mol.wts. approx. 35000 and 37000.


1990 ◽  
Vol 268 (3) ◽  
pp. 759-764 ◽  
Author(s):  
R Hobkirk ◽  
M A Glasier ◽  
L Y Brown

An oestrogen sulphotransferase, active towards both oestrone and oestradiol, and of high specific activity, is present in cytosol prepared from adrenal glands of both sexes of English Shorthair and Hartley guinea pigs. The ovarian and testicular cytosolic activities of this enzyme are markedly low in comparison with the adrenal activity. The adrenal enzyme is distinct from an accompanying pregnenolone sulphotransferase as judged by f.p.l.c. gel filtration, chromatofocusing, and differences in activation brought about by the addition of thiol groups. The oestrogen sulphotransferase behaved as a 67 kDa protein on a Sephadex G100 column and as a 48 kDa protein on f.p.l.c. gel-filtration columns. Two forms of the enzyme with apparent pI values of 6.1 and 5.5 were eluted during f.p.l.c. chromatofocusing. Sequential salt fractionation, f.p.l.c. gel filtration and elution from an agarose-hexane-adenosine-3′,5′-diphosphate affinity gel has resulted in a preparation which, when resubmitted to f.p.l.c. gel filtration, yields a considerably purified oestrogen sulphotransferase. When submitted to SDS/polyacrylamide-gel electrophoresis under reducing conditions, a main protein band of 34-36 kDa is observed. It is suggested that the enzyme may exist as a dimer in the cytosol.


1981 ◽  
Vol 193 (3) ◽  
pp. 861-867 ◽  
Author(s):  
R H Jackson ◽  
A Cornish-Bowden ◽  
J A Cole

A substantially improved purification of Escherichia coli NADH-dependent nitrite reductase was obtained by purifying it in presence of 1 mM-NO2- and 10 microM-FAD. The enzyme was obtained in 20% yield with a maximum specific activity of 1.04 kat . kg-1: more than 95% of this sample subjected to sodium dodecyl sulphate/polyacrylamide-gel electrophoresis migrated as a single band of protein. This highly active enzyme contained one non-covalently bound FAD molecule, and, probably, 5 Fe atoms and 4 acid-labile S atoms per subunit. No FMN, covalently bound flavin or Mo was detected. The spectrum of the enzyme shows absorption maxima at 386, 455, 530 and about 575 nm with a shoulder at 480–490 nm. The Soret-band/alpha-band absorbance ratio is about 4:1. These spectral features are characteristic of sirohaem, apart from the maximum at 455nm, which is attributed to flavin. The enzyme also catalyses the NADH-dependent reduction of horse heart cytochrome c, 2,6-dichlorophenol-indophenol and K3Fe(CN)6. The presence of sirohaem in E. coli nitrite reductase explains the apparent identity of the cysG and nirB gene of E. coli and inability of hemA mutants to reduce nitrite.


2001 ◽  
Vol 183 (19) ◽  
pp. 5491-5495 ◽  
Author(s):  
Sepideh Afshar ◽  
Eric Johnson ◽  
Simon de Vries ◽  
Imke Schröder

ABSTRACT The nitrate reductase of the hyperthermophilic archaeonPyrobaculum aerophilum was purified 137-fold from the cytoplasmic membrane. Based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, the enzyme complex consists of three subunits with apparent molecular weights of 130,000, 52,000, and 32,000. The enzyme contained molybdenum (0.8-mol/mol complex), iron (15.4-mol/mol complex) and cytochrome b (0.49-mol/mol complex) as cofactors. The P. aerophilum nitrate reductase distinguishes itself from nitrate reductases of mesophilic bacteria and archaea by its very high specific activity using reduced benzyl viologen as the electron donor (V max with nitrate, 1,162 s−1 (326 U/mg);V max with chlorate, 1,348 s−1 (378 U/mg) [assayed at 75°C]). The Km values for nitrate and chlorate were 58 and 140 μM, respectively. Azide was a competitive inhibitor and cyanide was a noncompetitive inhibitor of the nitrate reductase activity. The temperature optimum for activity was >95°C. When incubated at 100°C, the purified nitrate reductase had a half-life of 1.5 h. This study constitutes the first description of a nitrate reductase from a hyperthermophilic archaeon.


1985 ◽  
Vol 226 (1) ◽  
pp. 217-223 ◽  
Author(s):  
S Chaudhuri ◽  
J R Coggins

A procedure was developed for the purification of shikimate dehydrogenase from Escherichia coli. Homogeneous enzyme with specific activity 1100 units/mg of protein was obtained in 21% overall yield. The subunit Mr estimated by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate was 32 000. The native Mr, estimated by gel-permeation chromatography on a TSK G2000SW column, was also 32 000. E. coli shikimate dehydrogenase is therefore a monomeric NADP-linked dehydrogenase.


2011 ◽  
Vol 17 (4) ◽  
pp. 395-402 ◽  
Author(s):  
S. Ketnawa ◽  
P. Chaiwut ◽  
S. Rawdkuen

Large amount of pineapple peels (by-products) is left over after processing and they are a potential source for bromelain extraction. Distilled water (DI), DI containing cysteine and ethylenediaminetetraacetic acid (EDTA) (DI-CE), sodium phosphate buffer pH 7.0 (PB) and PB containing cysteine and EDTA (PB-CE) were used as extractants for bromelain from the pineapple peels. The highest bromelain activity was obtained when it was extracted with PB-CE (867 and 1032 units for Nang Lae and Phu Lae cultv, respectively). The PB could maintain the pH of the extract (pH 5.1—5.7) when compared with others. Under sodium dodecyl sulfate polyacrylamide gel electrophoresis, the extract showed protein bands in the range 24—28 kDa. The protein band with a molecular weight of ∼28 kDa exposed the clear zone on blue background under the casein-substrate gel electrophoresis. The effects of the bromelain extract on the protein patterns of beef, chicken and squid muscles were also determined. Trichloroacetic acid soluble peptide content of all the treated muscles increased when the amount of bromelain extract increased. Decrease in myosin heavy chains and actin was observed in all the muscle types when bromelain extract was used. The best extractant for bromelain from pineapple peels was PB-CE. Moreover, bromelain extract could be used as a muscle food tenderizing agent in food industries.


1982 ◽  
Vol 47 (01) ◽  
pp. 014-018 ◽  
Author(s):  
H Sumi ◽  
N Toki ◽  
S Takasugi ◽  
S Maehara ◽  
M Maruyama ◽  
...  

SummaryPapain treatment of human urinary trypsin inhibitor (UTI67; mol. wt. 43,000 by SDS-polyacrylamide gel electrophoresis, specific activity 1,897 U/mg protein) produced four new protease inhibitors, which were highly purified by gel chromatography on Sephadex G-100 and isoelectric focusing. The purified inhibitors (UTI26, UTI9-I, UTI9-II, and UTI9-III) were shown to be homogeneous by polyacrylamide disc gel electrophoresis, and had apparent molecular weights of 26,000, 9,000, 9,000, and 9,800, respectively, by sodium dodecyl sulfate gel electrophoresis. During enzymatic degradation of UTI67, the amino acid compositions changed to more basic, and the isoelectric point increased from pH 2.0 (UTI67) to pHs 4.4, 5.2, 6.6, and 8.3 (UTI26, UTI9-I, UTI9-II, and UTI9-III), respectively. Both the parent and degraded inhibitors had anti-plasmin activity as well as antitrypsin and anti-chymotrypsin activities. Much higher anti-plasmin/anti-trypsin and anti-plasmin/anti-chymotrypsin activities were observed in the degraded inhibitors than in the parent UTI67. They competitively inhibited human plasmin with Ki values of 1.13 X 10-7 - 2.12 X 10-6 M (H-D-Val-Leu-Lys-pNA substrate). The reactions were very fast and the active site of the inhibitors to plasmin was thought to be different from that to trypsin or chymotrypsin.


1990 ◽  
Vol 258 (2) ◽  
pp. C344-C351 ◽  
Author(s):  
H. Schmidt ◽  
G. Wegener

White skeletal muscle of crucian carp contains a single isoenzyme of glycogen phosphorylase, which was purified approximately 300-fold to a specific activity of approximately 13 mumol.min-1.mg protein-1 (assayed in the direction of glycogen breakdown at 25 degrees C). Tissue extracts of crucian muscle produced three distinct peaks of phosphorylase activity when separated on DEAE-Sephacel. Peaks 1 and 3 were identified, in terms of kinetic properties and by interconversion experiments, as phosphorylase b and a, respectively. Peak 2 was shown to be a phospho-dephospho hybrid. The three interconvertible forms of phosphorylase were purified and shown to be dimeric molecules at 20 degrees C. At 5 degrees C, a and the hybrid tended to form tetramers. The Mr of the subunit was estimated to be 96,400 from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The hybrid is kinetically homogeneous, and its kinetic properties are intermediate between those of b and a forms. The b, hybrid, and a forms of phosphorylase can be isolated from rapidly frozen muscle of crucian but in different proportions, depending on whether fish were anesthetized or forced to muscular activity for 20 s. Muscle of anesthetized crucian had 36, 36, and 28% of phosphorylase b, hybrid, and a forms, respectively, whereas the corresponding values for exercised fish were 12, 37, and 51%. Results suggest that three interconvertible forms of phosphorylase exist simultaneously in crucian muscle and that hybrid phosphorylase is active in contracting muscle in vivo.


1986 ◽  
Vol 64 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Malcolm B. Perry ◽  
Leann MacLean ◽  
Douglas W. Griffith

The phenol-phase soluble lipopolysaccharide isolated from Escherichia coli 0:157 by the hot phenol–water extraction procedure was shown by sodium dodecyl sulfate–polyacrylamide gel electrophoresis, periodate oxidation, methylation, and 13C and 1H nuclear magnetic resonance studies to be an unbranched linear polysaccharide with a tetrasaccharide repeating unit having the structure:[Formula: see text]The serological cross-reactivity of E. coli 0:157 with Brucella abortus, Yersinia enterocolitica (serotype 0:9), group N Salmonella, and some other E. coli species can be related immunochemically to the presence of 1,2-glycosylated N-acylated 4-amino-4,6-dideoxy-α-D-mannopyranosyl residues in the O-chains of their respective lipopolysaccharides.


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