scholarly journals A subunit-sized butyrylcholinesterase present in high concentrations in pooled rabbit serum

1977 ◽  
Vol 167 (2) ◽  
pp. 367-376 ◽  
Author(s):  
A. Russell Main ◽  
Susan C. McKnelly ◽  
Sybil K. Burgess-Miller
Keyword(s):  
Active Site ◽  
Horse Serum ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Rabbit Serum ◽  
Aromatic Esters ◽  
Choline Esters ◽  
A Subunit ◽  
High Concentrations ◽  
Hydrolysis Of

A butyrylcholinesterase of mol.wt. approx. 83000 was observed in pooled rabbit serum. The enzyme was named monomeric butyrylcholinesterase to distinguish it from the larger oligomeric butyrylcholinesterase of horse and human serum whose subunits are the same size as the monomeric enzyme. The active-site concentration of monomeric butyrylcholinesterase in the pooled serum was 0.18μm, which is five times the concentration of butyrylcholinesterase in pooled horse serum. This was surprising, since the horse serum is regarded as a rich source of butyrylcholinesterase, whereas rabbit serum is not generally thought to contain significant amounts of any butyrylcholinesterase. The explanation, in large part, was the relatively low kcat. of the monomeric enzyme, which was approx. 57s−1 with butyrylthiocholine as substrate and is one-thirtieth of the comparable kcat. of horse butyrylcholinesterase. The substrate specificity of monomeric butyrylcholinesterase also differed significantly from that of horse and human butyrylcholinesterase. For example, with the monomeric enzyme, the hydrolysis of 1mm-acetylthiocholine was only 4% the rate for 1mm-butyrylthiocholine, whereas human and horse butyrylcholinesterases hydrolysed 1mm-acetylthiocholine at 50% of the rate for 1mm-butyrylthiocholine. Moreover, monomeric butyrylcholinesterase generally hydrolysed aromatic esters more rapidly than choline esters, whereas the reverse is true of the butyrylcholinesterases. To facilitate the study of monomeric butyrylcholinesterase, it was separated from the larger butyrylcholinesterase and acetylcholinesterase, also present in rabbit serum, and purified 89-fold by fractionation with (NH4)2SO4 and ion-exchange chromatography.

scholarly journals A comparative study of class-D β-lactamases

1993 ◽  
Vol 292 (2) ◽  
pp. 555-562 ◽  
Author(s):  
P Ledent ◽  
X Raquet ◽  
B Joris ◽  
J Van Beeumen ◽  
J M Frère
Keyword(s):  
Active Site ◽  
Gene Sequence ◽  
Catalytic Properties ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Beta Lactamase ◽  
Serine Residue ◽  
Beta Lactamases ◽  
Class D ◽  
Burst Kinetics

Three class-D beta-lactamases (OXA2, OXA1 and PSE2) were produced and purified to protein homogeneity. 6 beta-Iodopenicillanate inactivated the OXA2 enzyme without detectable turnover. Labelling of the same beta-lactamase with 6 beta-iodo[3H]penicillanate allowed the identification of Ser-70 as the active-site serine residue. In agreement with previous reports, the apparent M(r) of the OXA2 enzyme as determined by molecular-sieve filtration, was significantly higher than that deduced from the gene sequence, but this was not due to an equilibrium between a monomer and a dimer. The heterogeneity of the OXA2 beta-lactamase on ion-exchange chromatography contrasted with the similarity of the catalytic properties of the various forms. A first overview of the enzymic properties of the three ‘oxacillinases’ is presented. With the OXA2 enzyme, ‘burst’ kinetics, implying branched pathways, seemed to prevail with many substrates.

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.

scholarly journals Confirmation of d-aspartic acid in the novel dipeptide β-aspartylglycine isolated from tissue extract of Aplysia kurodai

1989 ◽  
Vol 263 (2) ◽  
pp. 617-620 ◽  
Author(s):  
M Sato ◽  
T Yamaguchi ◽  
N Kanno ◽  
Y Sato
Keyword(s):  
Aspartic Acid ◽  
Body Wall ◽  
Optical Resolution ◽  
Paper Electrophoresis ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Optical Rotatory Dispersion ◽  
The Novel ◽  
Reactive Compound ◽  
High Concentrations

A novel o-phthalaldehyde-reactive compound was found in the h.p.l.c. chromatogram of Aplysia kurodai extract. This compound was isolated by ion-exchange chromatography and preparative high-voltage paper electrophoresis. It was shown by optical-rotatory-dispersion spectrum and optical-resolution h.p.l.c. analysis that this compound consisted of equimolar amounts of D-aspartic acid and glycine. This compound resisted cleavage in the Edman reaction. This peptide was inferred to be beta-D-aspartylglycine, and this was confirmed by synthesis. beta-D-Aspartylglycine was detected in all tissues of Aplysia kurodai, with especially high concentrations in body wall (skin and muscle) and gill.

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 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

Highly concentrated single-chain atomic crystal LiMo3Se3 solution using ion-exchange chromatography

2018 ◽  
Vol 54 (88) ◽  
pp. 12503-12506 ◽  
Author(s):  
Sudong Chae ◽  
Seungbae Oh ◽  
Akhtar J. Siddiqa ◽  
Kyung Hwan Choi ◽  
Weon-Gyu Lee ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Aqueous Solutions ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Single Chain ◽  
Stern Layer ◽  
High Concentrations ◽  
Atomic Crystal

The enlargement of the Stern layer distance caused by this ion exchange improves the dispersibility of (Mo3Se3−)∞ chains and also prevents the re-bundling and aggregation of nanowires in aqueous solutions, even at high concentrations (1 mg mL−1).

scholarly journals The Modified β-Ketoadipate Pathway in Rhodococcus rhodochrous N75: Enzymology of 3-Methylmuconolactone Metabolism

1998 ◽  
Vol 180 (24) ◽  
pp. 6668-6673 ◽  
Author(s):  
Chang-Jun Cha ◽  
Ronald B. Cain ◽  
Neil C. Bruce
Keyword(s):  
Ammonium Sulfate ◽  
Gel Filtration ◽  
Sole Source ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Rhodococcus Rhodochrous ◽  
Natural Substrate ◽  
Ph Optimum ◽  
A Subunit ◽  
Hydrolysis Of

ABSTRACT Rhodococcus rhodochrous N75 is able to metabolize 4-methylcatechol via a modified β-ketoadipate pathway. This organism has been shown to activate 3-methylmuconolactone by the addition of coenzyme A (CoA) prior to hydrolysis of the butenolide ring. A lactone-CoA synthetase is induced by growth of R. rhodochrous N75 on p-toluate as a sole source of carbon. The enzyme has been purified 221-fold by ammonium sulfate fractionation, hydrophobic chromatography, gel filtration, and anion-exchange chromatography. The enzyme, termed 3-methylmuconolactone-CoA synthetase, has a pH optimum of 8.0, a native M r of 128,000, and a subunitM r of 62,000, suggesting that the enzyme is homodimeric. The enzyme is very specific for its 3-methylmuconolactone substrate and displays little or no activity with other monoene and diene lactone analogues. Equimolar amounts of these lactone analogues brought about less than 30% (most brought about less than 15%) inhibition of the CoA synthetase reaction with its natural substrate.

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 Human liver cathepsin L

1985 ◽  
Vol 226 (1) ◽  
pp. 233-241 ◽  
Author(s):  
R W Mason ◽  
G D J Green ◽  
A J Barrett
Keyword(s):  
Active Site ◽  
Human Liver ◽  
Cathepsin L ◽  
Cysteine Residue ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Active Site Cysteine ◽  
Apparent Homogeneity ◽  
Polypeptide Chains ◽  
Active Site Cysteine Residue

Cathepsin L was purified to apparent homogeneity from human liver obtained post mortem. It was necessary to treat the homogenate at pH 4.2 and 37 degrees C to release active enzyme. The purification procedure involved ion-exchange chromatography on carboxymethyl-Sephadex and the Mono S column of a Pharmacia fast-protein-liquid-chromatography system. The enzyme was found to consist of two polypeptide chains of Mr 25 000 and 5000. The larger chain was shown to contain the active-site cysteine residue. Human cathepsin L proved to be similar to the rat and rabbit enzymes in regard to kinetic constants for the substrate benzyloxycarbonylphenylalanylarginine 7-(4-methyl)coumarylamide and rates of inactivation by the active-site-directed reagents benzyloxycarbonylphenylalanylphenylalanyldiazomethane and benzyloxycarbonylphenylalanylalanyldiazomethane. Thus clear characteristics of cathepsin L are now emerging, and these should simplify the identification of the enzyme in other tissues and species.

Sign in / Sign up

Export Citation Format

Share Document