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.

scholarly journals Isolation, in the intact state, of the pterin molybdenum cofactor from xanthine oxidase

1989 ◽  
Vol 263 (2) ◽  
pp. 477-483 ◽  
Author(s):  
J Deistung ◽  
R C Bray
Keyword(s):  
Aqueous Solution ◽  
Ion Exchange ◽  
Xanthine Oxidase ◽  
Specific Activity ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Molybdenum Cofactor ◽  
Anaerobic Conditions ◽  
Intact State

A procedure is described for isolation of the pterin molybdenum cofactor, in the active molybdenum-containing state, starting from purified milk xanthine oxidase. The method depends on the use of anaerobic-glove-cabinet techniques and on working in aqueous solution, in the presence of 1 mM-Na2S2O4. SDS was used to denature the protein, followed by ion-exchange chromatography and gel filtration. The cofactor, obtained at concentrations up to 0.5-1.0 mM, was fully active in the nit-1 assay [Hawkes & Bray (1984) Biochem. J. 214, 481-493], with a specific activity of 22 nmol of NO2-/min per pg-atom of Mo (with 15% molybdate-dependence). The Mr, determined by gel filtration, was about 610, consistent with the structure proposed by Kramer, Johnson, Ribeiro, Millington & Rajagopalan [(1987) J. Biol. Chem. 262, 16357-16363]. At pH 5.9, under anaerobic conditions, the cofactor was stable for at least 300 h at 20-25 degrees C.

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

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.

Enzymatic Digestion of DNA γ-irradiated in Aqueous Solution Separation of the Digests by Ion-exchange Chromatography

1978 ◽  
Vol 33 (6) ◽  
pp. 563-569 ◽  
Author(s):  
Miral Dizdaroglu ◽  
Wolfgang Hermes ◽  
Dietrich Schulte-Frohlinde ◽  
Clemens von Sonntag
Keyword(s):  
Aqueous Solution ◽  
Ion Exchange ◽  
Enzymatic Digestion ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography

Purification and Properties of an Antiactivator Fraction from Bovine Serum

1979 ◽  
Vol 42 (03) ◽  
pp. 855-863 ◽  
Author(s):  
L B Nanninga ◽  
M M Guest
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Dissociation Constant ◽  
Bovine Serum ◽  
Gamma Globulin ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Low Concentrations ◽  
Purification And Properties ◽  
Free Serum

SummaryA method is described for the purification of antiactivator from bovine euglobulin-free serum by means of gelfiltration and ion exchange chromatography. The purified antiactivator has no antifibrinolytic activity. It has a molecular weight of about 115,000 and it appears to be a gamma globulin. The dissociation constant of its complex with urokinase is 1.6 X 10-9 M and the maximum urokinase binding is close to 2000 CTA units per mg. Its concentration in bovine serum is 0.37%. Flufenamate displaces urokinase from the antiactivator at very low concentrations, about 10-4 M. Cysteine restores its activity if lost by standing. Also an antifibrinolysin fraction is obtained free of antiactivator activity.

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