scholarly journals Extraction, purification, identification and metabolism of 3′,5′-cyclic UMP, 3′,5′-cyclic IMP and 3′,5′-cyclic dTMP from rat tissues

1986 ◽  
Vol 236 (2) ◽  
pp. 431-439 ◽  
Author(s):  
R P Newton ◽  
E E Kingston ◽  
N A Hakeem ◽  
S G Salih ◽  
J H Beynon ◽  
...  

The large-scale extraction and partial purification of endogenous 3′,5′-cyclic UMP, 3′,5′-cyclic IMP and 3′,5′-cyclic dTMP are described. Rat liver, kidney, heart, spleen and lung tissues were subjected to a sequential purification procedure involving freeze-clamping, perchlorate extraction, alumina and Sephadex ion-exchange chromatography and preparative electrophoresis. The samples thus obtained co-chromatographed with authentic cyclic UMP, cyclic IMP and cyclic dTMP on t.l.c. and h.p.l.c. and the u.v. spectra of the extracted samples were identical with those of the standards. Fast atom bombardment of the three cyclic nucleotide standards yielded mass spectra containing a molecular protonated ion in each case; mass-analysed ion kinetic-energy spectrometry (‘m.i.k.e.s’) of these ions produced a spectrum unique to the parent cyclic nucleotide. The extracted putative cyclic UMP, cyclic IMP and cyclic dTMP each produced a m.i.k.e.s. identical with that obtained with the corresponding cyclic nucleotide standard. Rat liver, heart, kidney, brain, intestine, spleen, testis and lung protein preparations were each found capable of the synthesis of cyclic UMP, cyclic IMP and cyclic dTMP from the corresponding nucleoside triphosphate, of the hydrolysis of these cyclic nucleotides and of their binding, with the exception that cyclic dTMP was not synthesized by the kidney preparation.

1982 ◽  
Vol 47 (4) ◽  
pp. 1139-1148 ◽  
Author(s):  
Karel Hauzer ◽  
Linda Servítová ◽  
Tomislav Barth ◽  
Karel Jošt

Post-proline endopeptidase was isolated from pig kidneys and partially purified. The procedure consisted of fractionation with ammonium sulphate, ion exchange chromatography on DEAE-Sephadex A-50, gel filtration on Sephadex G-200 and rechromatography on DEAE-Sephadex A-50. The preparation had 55 times higher specific activity than the crude extract and did not contain any contaminating enzymic activities. The enzyme cleaved a number of proline-containing peptides and was strictly specific in catalyzing the hydrolysis of the peptide bond on the carboxyl side of the proline residue. The optimum pH for the hydrolysis of the synthetic peptides benzyl-oxycarbonylglycyl-prolyl-leucyl-glycinamide and benzyloxycarbonyl-glycyl-proline β-naphtylamide was 7.8-8.0 and, in the case of benzyloxycarbonylglycyl-proline p-nitroanilide, 7.2 to 7.5. For the hydrolysis of the tetrapeptide benzyloxycarbonylglycyl-prolyl-leucyl-glycinamide, the Km value of 75 μ mol l-1 was obtained.


2017 ◽  
Vol 37 (1) ◽  
pp. 31
Author(s):  
Fitria Fitria ◽  
Nanik Rahmani ◽  
Sri Pujiyanto ◽  
Budi Raharjo ◽  
Yopi Yopi

Enzyme xylanase (EC 3.2.1.8) is widely used in various industrial  fields for the hydrolysis of xylan (hemicellulose) into xylooligosaccharide and xylose. The aims of this study were to  conduct partial purification and characterization of xylanase from marine Bacillus safencis strain LBF P20 and to obtain the  xylooligosaccharide types from xylan hydrolysis by this enzyme.  Based on this research, the optimum time for enzyme production  occurred at 96 hours with the enzyme activity of 6.275 U/mL and  enzyme specific activity of 5.093 U/mg. The specific activities were  obtained from precipitation by amicon® ultra-15 centrifugal filter devices, gel filtration chromatography and anion exchange chromatography that were increased by 15.07, 34.7, and 96.0  U/mg. The results showed that the highest activity at pH 7, temperature of 60 °C, and stable at 4 °C. Type of  xylooligosaccharide produced by this study were xylohexoses, xylotriose, and xylobiose. SDS-PAGE analysis and zimogram  showed that the molecular weight of xylanase protein were about  25 kDa. ABSTRAKEnzim xilanase (EC 3.2.1.8) digunakan dalam hidrolisis xilan  (hemiselulosa) menjadi xilooligosakarida dan xilosa. Penelitian  ini bertujuan untuk melakukan purifikasi parsial dan karakterisasi xilanase dari bakteri laut Bacillus safencis strain LBF P20 serta uji  hidrolisis untuk mengetahui jenis xilooligosakarida yang  dihasilkan oleh enzim tersebut. Berdasarkan hasil penelitian, waktu optimum untuk produksi enzim terjadi pada jam ke 96  dengan aktivitas enzim sebesar 6,275 U/mL dan aktivitas spesifik enzim sebesar 5,093 (U/mg). Aktivitas spesifik enzim hasil  pemekatan dengan amicon® ultra-15 centrifugal filter devices,  kromatografi filtrasi gel dan kromatografi penukar anion  mengalami peningkatan berturut-turut sebesar 15,1; 34,7 dan96,0 U/mg. Hasil karakterisasi menunjukkan aktivitas  tertinggi pada pH 7, suhu 60 °C dan stabil pada suhu 4 °C. Analisis SDS-PAGE dan zimogram menunjukkan berat molekul protein xilanase berkisar 25 kDa. Jenis gula reduksi yang  dihasilkan yaitu xiloheksosa, xilotriosa, dan xilobiosa.


1984 ◽  
Vol 221 (3) ◽  
pp. 665-673 ◽  
Author(s):  
R P Newton ◽  
S G Salih ◽  
B J Salvage ◽  
E E Kingston

The large-scale extraction and purification to homogeneity of cyclic CMP and its unequivocal identification are described. Rat liver, kidney, heart, spleen and lung tissues were subjected to a sequential purification procedure involving freeze-clamping, perchlorate extraction, alumina and boronate column chromatography, polyacrylamide-gel column electrophoresis and high-voltage paper electrophoresis. The purified sample co-chromatographed with authentic cyclic CMP on t.l.c. and high-pressure liquid chromatography and was positive in a cyclic CMP radio-immunoassay. The u.v., i.r. and p.m.r. spectra were each essentially identical with those of authentic cyclic CMP. Fast-atom bombardment of authentic cyclic CMP yielded a mass spectrum containing a molecular protonated ion: mass-ion-kinetic-energy scanning of this ion produced a spectrum unique to 3′,5′-cyclic CMP. The extracted nucleotide produced an identical mass-ion-kinetic-energy spectrum.


1980 ◽  
Vol 84 (2) ◽  
pp. 189-197 ◽  
Author(s):  
A. F. BRISTOW ◽  
D. MONTAGUE ◽  
D. SYNETOS ◽  
G. JENKINS ◽  
D. COCKAYNE ◽  
...  

In most previous reports material with corticotrophin releasing factor (CRF) activity has been obtained from hypothalami after extraction with dilute aqueous acid. Such conditions allow substantial proteolytic degradation. By adopting conditions designed to precipitate proteases and by using information on the nature of CRF gained from earlier studies, rapid large scale extraction and partial purification of porcine hypothalamic CRF in high yield was achieved. After extraction with 0·2 m-HCl: acetone (1: 1, v/v), centrifugation and ultrafiltration, considerable preliminary purification of the CRF activity was achieved by adsorption onto carboxymethylcellulose and subsequent elution at increased salt concentration. Following ion-exchange chromatography of the extract on carboxymethylcellulose, CRF activity was obtained in good yield (minimal effective dose of about 1–2 μg/ml) for ACTH release in an in-vitro CRF bioassay utilizing a coupled isolated pituitary cell–adrenal cell system. The data indicated that the previously reported heterogeneous corticotrophin releasing factors of low activity may be a consequence of proteolytic degradation.


1968 ◽  
Vol 110 (4) ◽  
pp. 783-788 ◽  
Author(s):  
A. W. Pronczuk ◽  
B. S. Baliga ◽  
H. N. Munro

The effects of different concentrations of ATP, GTP, UTP and CTP on polysome stability and function in a cell-free protein-synthesizing system prepared from rat liver were studied. Increasing the concentration of ATP in the incubation medium to 15mm resulted in progressive disaggregation of the polysomes; at ATP concentrations above 2mm their capacity to incorporate amino acids into peptide chains diminished. The same disaggregation phenomenon could be produced by incubating polysomes in a buffered medium containing 5mm-Mg2+ and increasing concentrations of ATP. Although the disaggregating action of ATP could be prevented by increasing Mg2+ concentration, the amino acid incorporation in the cell-free protein-synthesizing system remained impaired. The effects of different concentrations of GTP, UTP and CTP on polysome stability were similar to those of ATP. Increasing the concentrations of each nucleoside triphosphate also inhibited the hydrolysis of GTP in the cell-free protein-synthesizing system.


1978 ◽  
Vol 171 (3) ◽  
pp. 817-820 ◽  
Author(s):  
H Flodgaard ◽  
C Torp-Pedersen

An ATP pyrophosphohydrolase in a rat liver plasma-membrane subfraction was studied with respect to specific Ca2+ activation of the beta-phosphate bond hydrolysis. ATP and, in addition, adenosine 5′-[betagamma-imido]triphosphate and adenosine 5′-[betagamma-methlylene]triphosphate were substrates for Ca2+-stimulated enzymic hydrolysis of the beta-phosphate bond. A 15-fold activation was observed by raising the free Ca2+ concentration from 10(-7) to 10(-5) M. Mg2+ had little effect. Solubilization in 1% deoxycholate and partial purification on a sucrose density gradient resulted in a 5-fold increase in specific activity with unaltered Ca2+-stimulation pattern. The possible importance of the enzyme in Ca2+ transport is discussed.


2010 ◽  
Vol 34 (1) ◽  
pp. 122-129
Author(s):  
Rajiha I. Al-Nuaimy

A total of (25) stool samples were collected from children and adults (2- 4) years oldsuffering from diarrhea to isolate E. coli strains that produce heat-stable enterotoxin a (STa),and after performing microscopic examination, cultural characterization and biochemicalidentification only (11) isolates showed positive E. coli. STa activity was estimated by usingsuckling mouse assay (SMA) and from these (11) isolates only (5) showed STa activity andthe one with the highest STa activity was selected for large scale production of STa, whichwas followed by partial purification using ion-exchange chromatography (normal phase)using DEAE sephadex A-50 column. After purification and determination of proteinconcentration by using the standard curve of bovine serum albumin, the concentration oftoxin-protein was estimated as (1.08) mg/ml. The specific activity varied from (350) U/mgprotein at the first step of purification to (2366.6) U/mg protein at the final step, while thefinal purification of the toxin was about (6.76) fold and with a yield of (18.25) %.


1970 ◽  
Vol 48 (7) ◽  
pp. 799-804 ◽  
Author(s):  
C. Hétu ◽  
R. Gianetto

The hydrolysis of 1-thio-β-D-glucosiduronic acids by rat liver was studied using synthetic phenyl 1-thio-β-D-glucosiduronic acid, sodium (2-benzothiazolyl 1-thio-β- D-glucosid)uronate, and sodium (p-nitrophenyl 1-thio-β-D-glucosid)uronate. It was found that rat liver preparations can hydrolyze the β-D-glucuronides of 2-benzothiazolethiol and p-nitrothiophenol but not the β-D-glucuronide of thiophenol.Partial purification of the enzyme from a lysosomal preparation using ammonium sulfate fractionation, gel filtration on a molecular sieve, and anion-exchange chromatography showed that β-glucuronidase (EC 3.2.1.31) is the enzyme responsible for the hydrolysis of these thioglucuronides. The pH optimum and Michaelis–Menten constant (Km) were determined for both substrates using an enzyme preparation obtained after the gel filtration step. The glucuronide of 2-benzothiazolethiol was found to be almost as good a substrate as that of phenolphthalein for rat-liver β-glucuronidase, while the glucuronide of p-nitrothiophenol is hydrolyzed at a much slower rate. Possible explanations of the fact that β-glucuronidase hydrolyzes only certain thioglucuronides are suggested.


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