scholarly journals Persistence of methylated bases in ribonucleic acid of syrian golden hamster liver after administration of dimethylnitrosamine

1979 ◽  
Vol 177 (3) ◽  
pp. 967-973 ◽  
Author(s):  
G P Margison ◽  
J M Margison ◽  
R Montesano
Keyword(s):  
Ribosomal Rna ◽  
Golden Hamster ◽  
Excision Repair ◽  
Experimental System ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Syrian Golden Hamster ◽  
Low Doses ◽  
Enzymic Hydrolysis ◽  
Hydrolysis Of

1. Syrian golden hamster liver ribosomal RNA was isolated up to 96 h after administration of [14C]dimethylnitrosamine at 25 mg/kg or 2.5 mg/kg body weight. 2. The chemical alkyation products, 7-methylguanine, 3-methylcytosine, O6-methylguanosine and 1-methyladenosine, were measured after acidic or enzymic hydrolysis of the RNA to bases or mononucleosides followed by ion-exchange chromatography. 3. Between 7 and 96 h, the relative amounts of alkylation products did not change with time even though the absolute amounts fell by approx. 80% and 51% after the high and low doses respectively. 4. The results suggest that base specific excision repair does not exist for RNA alkylation products in this experimental system.

Intestinal Absorption of Dipeptides Containing Glycine, Phenylalanine, Proline, β-Alanine or Histidine in the Rat

1973 ◽  
Vol 45 (6) ◽  
pp. 849-858 ◽  
Author(s):  
D. J. Boullin ◽  
R. F. Crampton ◽  
Christine E. Heading ◽  
D. Pelling
Keyword(s):  
Intestinal Absorption ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Peptide Absorption ◽  
Physiological Conditions ◽  
Anaesthetized Rats ◽  
Tissue Homogenates ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

1. The intestinal absorption of carnosine, glycylglycine, glycyl-d-phenylalanine, glycyl-l-phenylalanine, glycyl-l-proline and l-prolylglycine were investigated after intraluminal injection of dipeptide into anaesthetized rats. 2. With all six dipeptides, the intact substance was detected by ion-exchange chromatography in blood samples taken from the superior mesenteric vein. 3. The rate of hydrolysis of the dipeptides in tissue homogenates was measured in vitro. 4. The relative rates of hydrolysis varied by a factor of 300; there was an apparent inverse relationship between rate of hydrolysis and detection of intact peptide. 5. Peptide absorption was accompanied by increases in venous concentrations of the component amino acids, which appeared in proportions appropriate to the view that peptide absorption preceded hydrolysis. 6. It is suggested that slowly hydrolysed dipeptides may pass intact through the intestine wall under physiological conditions.

scholarly journals The synthesis and purification of 2′-carboxy-d-arabinitol 1-phosphate, a natural inhibitor of ribulose 1,5-bisphosphate carboxylase, investigated by31P n.m.r

1989 ◽  
Vol 260 (3) ◽  
pp. 711-716 ◽  
Author(s):  
S Gutteridge ◽  
G S Reddy ◽  
G Lorimer
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Ion Exchange ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Enzymic Hydrolysis ◽  
Bisphosphate Carboxylase ◽  
Natural Inhibitor

2′-Carboxy-D-arabinitol 1-phosphate (2CA1P), a natural inhibitor of ribulose 1,5-bisphosphate carboxylase was synthesized from 2′-carboxy-D-arabinitol 1,5-bisphosphate (2CABP). The selective dephosphorylation of 2CABP with either acid phosphatase or alkaline phosphatase was investigated by using 31P n.m.r. The n.m.r. spectra of the progress of the reactions indicated that both phosphatases preferentially removed the 5-phosphate from the bisphosphate. After the consumption of all of the bisphosphate, alkaline phosphatase generated a mixture of 2′-carboxy-D-arabinitol 1- and 5-monophosphates in the ratio of about 4:1, along with Pi. The enzyme also hydrolysed the monophosphates to 2′-carboxyarabinitol, thus decreasing the yield of 2CA1P further. In contrast, acid phosphatase catalysed almost quantitative conversion of 2CABP into 2CA1P, preferring to hydrolyse only the 5-phosphate. In either case, separation of the 2CA1P from Pi or other products of enzymic hydrolysis was readily accomplished by conventional ion-exchange chromatography or h.p.l.c.

scholarly journals The presence of ribonucleic acid in the cell walls of higher plants

1968 ◽  
Vol 108 (1) ◽  
pp. 25-31 ◽  
Author(s):  
P. D. Phethean ◽  
L. Jervis ◽  
Mary Hallaway
Keyword(s):  
Cell Wall ◽  
Ion Exchange ◽  
Ribosomal Rna ◽  
Cell Walls ◽  
Potassium Hydroxide ◽  
Base Composition ◽  
Higher Plants ◽  
Nuclear Material ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography

A method for isolating extensively purified cell walls from higher plants is described; the preparations contain no detectable chloroplast or nuclear material and the protein content (2–5% of the dry wt. of walls) indicates that there is little contamination with cytoplasm. Incubation of purified cell walls with 0·3n-potassium hydroxide for 17hr. at 37° liberates ribonucleotides, which can be purified by adsorption on charcoal and by ion-exchange chromatography. Ribonucleotides are also liberated by incubating the walls with ribonuclease, but not with deoxyribonuclease. The RNA content varies from 0·5 to 6mg./g. dry wt. of walls, depending on the nature and age of the tissue, and at 3mg./g. dry wt. of walls accounts for about 7% of the total RNA of the tissue. Less than 0·2% of the RNA of the walls is due to the presence of bacteria in the preparation. The base composition of the cell-wall RNA is identical with that of ribosomal RNA.

scholarly journals PEMISAHAN ASAM AMINO DARI LIMBAH CAIR PABRIK KELAPA SAWIT DENGAN KROMATOGRAFI PENUKAR ION

2018 ◽  
Vol 6 (2) ◽  
pp. 69
Author(s):  
Indah Rahmi Sari ◽  
Ade Ayu Oksari ◽  
Irma Kresnawaty
Keyword(s):  
Amino Acid ◽  
Ion Exchange ◽  
Liquid Waste ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Enzyme Hydrolysis ◽  
Protease Enzyme ◽  
Absorbance Reading ◽  
Amino Acid Levels ◽  
Hydrolysis Of

Separation of Amino acid from Liquid waste of Oil palm Factory with Ion Exchange Chromatography Research on Separation of Amino Acid Liquid Waste mills with Ion Exchange Chromatography was carried out from October to November 2015. The results of  hydrolysis of 6 N HCl results showed  that the highest absorbance reading was obtained at a concentration of eluent of 0,2 and 0,6 M NaCl, while the results of the protease enzyme hydrolysis the highest absorbance reading at NaCl eluent 0,2 and 1 M. There was no significant difference in the results of separation by ion exchange chromatography, showed that the concentration of NaCl eluent is not very influential, so for subsequent analysis used only one concentration of the eluent. Results of linear regression obtained was equal to 0,9946, these results indicate that the series standard amino acid lysine has a value that is linear as it approaches 1. The amino acid levels obtained on the sample results LCPKS hydrolysis with 6 N HCl which was about 0 to 8.82 ppm and samples of the protease enzyme hydrolysis of about 0 to 4.31 ppm. Amino acid levels obtained were still far from the expected.Keywords: Amino Acid, Oil Palm, Liquid Waste, Ion Exchange Chromatography ABSTRAKPenelitian mengenai Pemisahan Asam Amino dari Limbah Cair Pabrik Kelapa Sawit dengan Kromatografi Penukar Ion telah dilaksanakan dari bulan Oktober sampai November 2015. Hasil hidrolisis HCl 6 N menunjukkan bahwa pembacaan absorbansi tertinggi diperoleh pada konsentrasi eluen NaCl 0,2 dan 0,6 M, sedangkan hasil hidrolisis enzim protease pembacaan absorbansi tertinggi pada eluen NaCl 0,2 dan 1 M. Tidak ada perbedaan yang signifikan pada hasil pemisahan dengan kromatografi penukar ion ini, menunjukkan bahwa konsentrasi eluen NaCl tidak terlalu berpengaruh, sehingga untuk analisis selanjutnya digunakan hanya satu konsentrasi eluen. Hasil regresi linear yang diperoleh yaitu sebesar 0,9946, hasil tersebut menunjukkan bahwa deret standar asam amino lisin mempunyai nilai yang linear karena mendekati 1. Kadar asam amino yang diperoleh pada sampel hasil hidrolisis LCPKS dengan HCl 6N yaitu sekitar 0 – 8,82 ppm dan sampel hasil hidrolisis enzim protease sekitar 0 – 4,31 ppm. Kadar asam amino yang diperoleh masih jauh dari yang diharapkan.Kata Kunci: Asam Amino, Minyak Kelapa Sawit, Limbah Cair, Kromatografi Penukar Ion

Synthesis of phosphonylmethyl analogues of diribonucleoside monophosphates containing modified internucleotide bond

1987 ◽  
Vol 52 (10) ◽  
pp. 2572-2588 ◽  
Author(s):  
Ivan Rosenberg ◽  
Antonín Holý
Keyword(s):  
Methyl Esters ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Oligonucleotide Synthesis ◽  
Amino Groups ◽  
Methyl Group ◽  
Hydrolysis Of ◽  
Derivatives Of ◽  
Methylene Group ◽  
Phosphotriester Method

Two types of (2'-5')- and (3'-5')-isomers of analogues of diribonucleoside monophosphates derived from O-phosphonylmethyl derivatives of ribonucleosides, differing in the position of the methylene group in the internucleotide bond (type A, B, C, and D) have been synthesized. The compounds were prepared from methyl esters of O-phosphonylmethylribonucleosides I and XVII by a procedure analogous to the phosphotriester method of oligonucleotide synthesis. The phosphonate moiety was protected with the methyl group. After protection of the hydroxyl or amino groups, the compounds I or XVII were condensed with protected ribonucleosides VIII, XI, XIV, XXIII to afford the neutral diesters IX, XII, XV, XXIV, XXVI, and XXVIII which were isolated by short column chromatography on silica gel. Deprotection, ion-exchange chromatography, and semipreparative HPLC gave (2'-5')- and (3'-5')-isomers of both types of O-phosphonylmethyl analogues of diribonucleoside monophosphates (X, XIII and XXV, XXVII). All these compounds are resistant towards cleavage with ribonucleases A and T2 and with snake venom exonuclease. Under conditions of alkaline hydrolysis of RNA, the analogues of the type A and B are completely stable whereas compounds of the type C and D are degraded to form 2'- or 3'-O-phosphonylmethylribonucleosides and 3'-terminal ribonucleosides.

scholarly journals Preparation, purification and analyses of thirteen alkali-stable dinucleotides from ribonucleic acid

1970 ◽  
Vol 116 (4) ◽  
pp. 589-598 ◽  
Author(s):  
A. R. Trim ◽  
Janet E. Parker
Keyword(s):  
Nucleotide Sequence ◽  
Ion Exchange ◽  
Ribonucleic Acid ◽  
Deae Cellulose ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Spectroscopic Constants ◽  
Commercial Yeast ◽  
High Degree ◽  
Hydrolysis Of

Of the 16 alkali-stable dinucleotides known to be obtained by hydrolysis of commercial yeast RNA with alkali, 13 were prepared in quantities of the order of 10mg or more. The samples, with only one exception, contain at least 90% of dinucleotide, and spectroscopic constants and nucleotide-sequence determinations, although not conclusive, indicate a high degree of purity of these products. The small dinucleotide fraction in 150g of RNA hydrolysed with alkali (1–2% of the total nucleotides) was separated from the mononucleotides by stepwise ion-exchange chromatography on DEAE-cellulose columns and resolved into seven fractions containing from one to four different dinucleotides by electrophoresis on paper at pH3.0. These fractions were resolved into their constituent dinucleotides by chromatography in ammonium sulphate. Contamination of the products by impurities from the paper was minimized by washing it before using it for chromatography or electrophoresis and, by using a thick grade of paper (Whatman no. 17), it was possible to handle and purify relatively large quantities of nucleotides.

scholarly journals Liberation of tryptic fragments from caseinomacropeptide of bovine κ-casein involved in platelet function. Kinetic study

1990 ◽  
Vol 271 (1) ◽  
pp. 247-252 ◽  
Author(s):  
J Léonil ◽  
D Mollé
Keyword(s):  
Platelet Function ◽  
Acid Precipitation ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Reverse Phase ◽  
Rate Of Hydrolysis ◽  
The Difference ◽  
Cationic Exchange ◽  
Hydrolysis Of ◽  
Similar Kinetic

Carbohydrate-free caseinomacropeptide (CMP) was purified from rennet-hydrolysed caseinate by trichloroacetic acid precipitation and DEAE-TSK Fractogel-650 ion-exchange chromatography. To study the liberation of 106-112, 106-116 and 113-116 fragments from carbohydrate-free CMP involved in platelet function, a quantitative study was made on the rate of hydrolysis of the three peptidic bonds that are susceptible to the action of trypsin. Data were obtained from reverse-phase (Ultrabase column) and cationic-exchange (Mono S column) h.p.l.c. On the basis of the disappearance of substrate, kcat. and Km were respectively 3.95 s-1 and 0.2 mM. The two 111-112 and 112-113 bonds were split according to similar kinetic parameters (kcat. = 1.97 s-1, Km = 0.2 mM) and much faster than the 116-117 bond. The difference in susceptibility of the bonds can probably be attributed to the nature of residues flanking the primary proteolytic sites rather than to their accessibility to the proteinase. On the basis of our results the 106-116 fragment cannot be formed.

Early Stages of the Hydrolysis of Chromium(III) in Aqueous Solution. V. Measurement of the Equilibrium Between Singly and Doubly Bridged Dimer

1989 ◽  
Vol 42 (9) ◽  
pp. 1579 ◽  
Author(s):  
T Merakis ◽  
L Spiccia
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Ion Exchange ◽  
Dissociation Constant ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Thermodynamic Constants ◽  
Hydrolysis Of

Ion-exchange chromatography has been used to measure the equilibrium between singly bridged (SBD) and doubly bridged (DBD) forms of the hydrolytic dimer of chromium(III), at variable [H+] (0.008-0.97 M) and T (288.2-318.2 K) and constant I (1.0 M). From these measurements, the acid dissociation constant, Kal , for SBD, and the equilibrium constant, K, for interconversion between monodeprotonated SBD and DBD have been determined together with their corresponding thermodynamic constants. The results at 298.2K were as follows: K = 10.1( �0.6) [ΔH� = -10( �3) kJ mol-1 and ΔS�=-15( �9) J K-1 mol-1]; KKal = 1 .83(�0.04) mol dm-3 [ΔS� = 30(�1) kJ mol-1 and ΔS�= 104(�4) J K-1 mol-1]; Kal = 0.18( �0.2) mol dm-3 [ΔS�= 43(�4) kJ mol-l and ΔS�= 128(�13) J K-1 mol-1]. The high Kalis attributed to the participation of monodeprotonated SBD in hydrogen bonding. As the temperature increases, the overall equilibrium (given by KKal ) is driven towards DBD by a dramatic increase in the acidity ( Kal ) of SBD, an increase which more than offsets a concurrent decrease in K.

Some properties of a highly thermostable α-amylase from a Thermoactinomyces sp.

1984 ◽  
Vol 30 (6) ◽  
pp. 780-785 ◽  
Author(s):  
S. K. C. Obi ◽  
F. J. C. Odibo
Keyword(s):  
Molecular Weight ◽  
Enzyme Activity ◽  
Ion Exchange ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Enzyme Activation ◽  
Cow Dung ◽  
C 30 ◽  
Hydrolysis Of

Thermostable α-amylase from Thermoactinomyces sp. No. 15, isolated from cow dung, was partially purified and characterized. The enzyme was purified (318-fold) by acetone precipitation, ion-exchange chromatography, and gel filtration techniques. The molecular weight was estimated to be 47 800. Optimum enzyme activity was recorded at pH 7 and at 80 °C. The enzyme was stable at pH 5.0–10.0 and retained 74% activity at 100 °C (30 min). Enzyme activation was observed in the presence of Mn2+, Ag+, and Fe2+, but Hg2+ and Zn2+ were inhibitory. Products of hydrolysis of native starches were mainly glucose and maltose.

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