scholarly journals Analysis of the forms of acetylcholinesterase from adult mouse brain

1975 ◽  
Vol 147 (2) ◽  
pp. 205-214 ◽  
Author(s):  
E D Adamson ◽  
S E Ayers ◽  
Z A Deussen ◽  
C F Graham
Keyword(s):  
Enzyme Activity ◽  
Mouse Brain ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Acetylcholinesterase Activity ◽  
Total Activity ◽  
Polyacrylamide Gel ◽  
Soluble Extract ◽  
Molecular Sizes

The solubilization of 80% of the acetylcholinesterase activity of mouse brain was performed by repeated 2h incubations of homogenates at 37 degrees C in an aqueous medium. Analysis of the soluble extract by gel filtration on Sephadex G-200 showed that up to 80% of the enzyme activity was eluted in a peak which was estimated to consist of molecules of about 74000mol.wt. This peak was called the monomer form of the enzyme. After 3 days at 4 degrees C, the soluble extract was re-analysed and was eluted from the column in four peaks of about 74000, 155000, 360000 and 720000 mol.wt. Since the total activity of the enzyme in these peaks was the same as that in the predominantly monomer elution profile of fresh enzyme, we concluded that the monomer had aggregated, possibly into dimers, tetramers and octomers. Extracts of the enzyme were analysed by polyacrylamide-gel electrophoresis and the resulting multiple bands of enzyme activity on gels were shown to separate according to their molecular sizes, that is by molecular sieving. All these forms had similar susceptibilities to the inhibitors eserine, tetra-isopropyl pyrophosphoramide and compound BW 284c51 [1,5-bis-(4-allyldimethylammoniumphenyl)pentan-3-one dibromide]. Thus the forms of the enzyme in mouse brain which can be detected by gel filtration and polyacrylamide-gel electrophoresis may all be related to a single low-molecular-weight form which aggregates during storage. This supports similar suggestions made for the enzyme in other locations.

scholarly journals Occurrence of an endo-1,3-β-glucanase in culture fluids of the yeast Candida utilis. Purification and characterization of the enzyme activity

1979 ◽  
Vol 177 (1) ◽  
pp. 107-114 ◽  
Author(s):  
T G Villa ◽  
V Notario ◽  
J R Villanueva
Keyword(s):  
Enzyme Activity ◽  
Gel Electrophoresis ◽  
Candida Utilis ◽  
Culture Medium ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Beta Glucanase ◽  
Hydrolysis Of

The endo-1,3-beta-glucanase (EC 3.2.1.6) secreted into the culture medium by cells of Candida utilis was isolated and purified to homogeneity on polyacrylamide-gel electrophoresis and in ultracentrifugation studies (s20,w = 1.97S). The purified enzyme represented only 0.001% of the total 1,3-beta-glucanase activity, the remainder being due to an exo-1,3-beta-glucanase enzyme, and behaved as an acidic glycoprotein (pI 3.3) in isoelectric-focusing experiments. The mol.wt. was estimated to be 21 000 by gel filtration and polyacrylamide-gel electrophoresis. Studies on the hydrolysis of different substrates showed that the enzyme was only able to break down (1 leads to 3)-beta-linkages, by an endo-splitting mechanism. Glucono-delta-lactone, D-glucoronolactone and heavy metal ions such as Hg2+ were inhibitors of the enzyme activity. The function of this endo-beta-glucanase in C. utilis is discussed.

scholarly journals Purification of an exo-β-D-glucanase from cell-free extracts of Candida utilis

1976 ◽  
Vol 159 (3) ◽  
pp. 555-562 ◽  
Author(s):  
V Notario ◽  
T G Villa ◽  
J R Villanueva
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Gel Electrophoresis ◽  
Candida Utilis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Acidic Amino Acids ◽  
Sepharose 4B ◽  
Hydrolysis Of

β-Glucanase present in cell-free extracts from Candida utilis was isolated and purified 562-fold by procedures that include adsorption on DEAE-Sephadex A-50 and filtration through columns of Sephadex G-50, G-100 and G-200, Bio-Gel P-10, and Concanavalin A-Sepharose 4B. The purified enzyme appeared homogeneous on polyacrylamide-gel electrophoresis and in ultracentrifugation studies (S20,w = 1.74S). The enzyme behaved as an acidic glycoprotein (pI4.1) with 68% carbohydrate and a high content of acidic amino acids. The mol.wt. was estimated to be 20000 from gel filtration and polyacrylamide-gel electrophoresis and 36000 from sedimentation experiments. Studies on the hydrolysis of different substrates showed that the enzyme is an unspecific β-glucanase able to break down both (1 leads to 3)-eta- and (1 leads to 6)-β-linkages by an exo-splitting mechanism. Glucono-δ-lactone, Zn2+ and Hg2+ inhibited the enzyme activity.

scholarly journals Rat liver uroporphyrinogen III synthase has similar properties to the enzyme from Euglena gracilis, including absence of a requirement for a reversibly bound cofactor for activity

1988 ◽  
Vol 253 (1) ◽  
pp. 275-279 ◽  
Author(s):  
E Smythe ◽  
D C Williams
Keyword(s):  
Enzyme Activity ◽  
Rat Liver ◽  
Euglena Gracilis ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Lysine Residue ◽  
Great Similarity ◽  
Full Activity

Uroporphyrinogen III synthase purified from rat liver is a monomer of Mr 36,000 by gel filtration and 28,000 by SDS/polyacrylamide-gel electrophoresis. The enzyme exists in two interconvertible forms separable on h.p.l.c. Both forms of the enzyme could be renatured with full activity after SDS/polyacrylamide-gel electrophoresis, demonstrating the absence of a reversibly bound cofactor. The enzyme activity could be inhibited by pyridoxal 5′-phosphate in the absence and in the presence of NaBH4, consistent with (an) essential lysine residue(s). The enzyme thus shows great similarity to that from Euglena gracilis.

Photoactivated linkage of catechol O-methyltransferase and S-adenosyl-L-methionine

1984 ◽  
Vol 62 (10) ◽  
pp. 964-969 ◽  
Author(s):  
Peter H. Yu
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Ultraviolet Light ◽  
Paper Chromatography ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Comt Inhibitors ◽  
Isoelectric Focussing

The formation of a stably linked complex of tritiated S-adenosyl-L-methionine (AdoMet) and catechol O-methyltransferase (COMT) has been achieved by irradiating the enzyme and ligand in Tris–HCl buffer (pH 7.5) with ultraviolet light at 254 nm. The reaction is specific as shown by a number of criteria. COMT inhibitors such as S-adenosylhomocysteine can block this photoactivated linkage. The [3H]AdoMet–COMT adduct has been shown to be a homogeneous protein by Sephadex gel filtration, sodium dodecyl sulfate – polyacrylamide gel electrophoresis, and isoelectric focussing. After extensive proteolysis of the [3H]AdoMet–COMT adduct with pronase P, one major labelled product was released. This fragment could be separated by paper chromatography and was shown to be chromatographically identical to that released from the [3H]AdoMet – phenylethanolamine N-methyltransferase adduct.

Formation of Soluble Complexes of Fibrinogen Related Material During Ancrod Infusion

1975 ◽  
Author(s):  
Caroline McKillop ◽  
W. Edgar ◽  
C. D. Forbes ◽  
C. R. M. Prentice
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Agarose Gel ◽  
Blood Samples ◽  
Related Material ◽  
Beta Alanine ◽  
Soluble Complexes

Seven pationts undergoing therapeutic defibrination by ancrod infusion were studied. Blood samples were obtained before treatment and after 6 and 24 hours ancrod infusion. Fibrinogen and its derivatives were precipitated with beta-alanine and separated by ΰ per cent agarose gel filtration. A range of soluble complexes were demonstrated after 6 hours infusion. Polyacrylamide gel electrophoresis in SDS showed that the soluble complexes were largely composed of units with molecular weight similar to a minimally degraded early Fragment X. Polyacrylamide gel electrophoresis in SDS and mercaptoethanol showed a marked loss of intact alphachain in the soluble complexes when compared with the uncomplexed material, suggesting that the soluble complexes had undergone preferential fibrinolytic digestion. It is suggested that, during ancrod therapy, FDP may be produced directly from soluble complexes rather than insoluble micro-thrombi as has been suggested previously.

scholarly journals Purification of 2-oxoaldehyde dehydrogenase and its dependence on unusual amines

1975 ◽  
Vol 149 (3) ◽  
pp. 609-617 ◽  
Author(s):  
J Dunkerton ◽  
S P James
Keyword(s):  
Enzyme Activity ◽  
Gel Electrophoresis ◽  
General Structure ◽  
Polyacrylamide Gel Electrophoresis ◽  
Maximum Activity ◽  
Polyacrylamide Gel ◽  
Ph Optimum ◽  
Ph Values ◽  
Sheep Liver ◽  
Living Tissues

1. 2-Oxoaldehyde dehydrogenase was purified from sheep liver and gave one band on polyacrylamide-gel electrophoresis. 2. The enzyme was completely dependent for its activity on the presence of Tris or one of a number of related amines, all of general structure: (See article). When more than one R group was hydrogen no enzyme activity was observed. 3. Only one of these amines is known to exist in living tissues and large concentrations of all amines were required for maximum activity. L-2-Aminopropan-1-ol was the most effective amine on the basis of substrate Km and Vmax. values and the amine Km values. 4. The enzyme was activated by phosphate which lowered the Km values for methylglyoxal, amine and NAD+. 5. The pH optimum of the enzyme was 9.3 and there was no activity at pH values below 7.8. A search for activators that might produce activity at pH 7.4 proved unsuccessful. 6. The enzyme was inhibited by rather large concentrations of barbiturates (6-46 mM) and nitro-alcohol analogues of the activating amines (66-139 mM).

scholarly journals Cadmium-binding proteins of rat testes. Characterization of a low-molecular-mass protein that lacks identity with metallothionein

1984 ◽  
Vol 220 (3) ◽  
pp. 811-818 ◽  
Author(s):  
M P Waalkes ◽  
S B Chernoff ◽  
C D Klaassen
Keyword(s):  
Metal Binding ◽  
Gel Electrophoresis ◽  
Binding Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Polyacrylamide Gel ◽  
Or Groups

Cadmium-binding proteins in the cytosol of testes from untreated rats were separated by Sephadex G-75 gel filtration. Three major testicular metal-binding proteins (TMBP), or groups of proteins, with relative elution volumes of approx. 1.0 (TMBP-1), 1.7 (TMBP-2) and 2.4 (TMBP-3) were separated. Elution of Zn-binding proteins exhibited a similar pattern. TMBP-3 has previously been thought to be metallothionein (MT), and hence this protein was further characterized and compared with hepatic MT isolated from Cd-treated rats. Estimation of Mr by gel filtration indicated a slight difference between MT (Mr 10000) and TMBP-3 (Mr 8000). Two major forms of MT (MT-I and MT-II) and TMBP-3 (TMBP-3 form I and TMBP-3 form II) were obtained after DEAE-Sephadex A-25 anion-exchange chromatography, with the corresponding subfractions being eluted at similar conductances. Non-denaturing polyacrylamide-gel electrophoresis on 7% acrylamide gels indicated that the subfractions of TMBP-3 had similar mobilities to those of the corresponding subfractions of MT. However, SDS (sodium dodecyl sulphate)/12% (w/v)-polyacrylamide-gel electrophoresis resulted in marked differences in migration of the two corresponding forms of MT and TMBP-3. Co-electrophoresis of MT-II and TMBP-3 form II by SDS/polyacrylamide-gel electrophoresis revealed two distinct proteins. Amino acid analysis indicated much lower content of cysteine in the testicular than in the hepatic proteins. TMBP-3 also contained significant amounts of tyrosine, phenylalanine and histidine, whereas MT did not. U.v.-spectral analysis of TMBP-3 showed a much lower A250/A280 ratio than for MT. Thus this major metal-binding protein in testes, which has been assumed to be MT is, in fact, a quite different protein.

The reaction between hemoglobin α-subunit and haptoglobin

1976 ◽  
Vol 54 (11) ◽  
pp. 1011-1015 ◽  
Author(s):  
Frank A. Terpstra ◽  
David B. Smith
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Human Hemoglobin ◽  
Gel Filtration Chromatography ◽  
Separation Techniques ◽  
Α Subunit ◽  
Α Subunits

The interaction between human hemoglobin α-subunit and porcine haptoglobin was investigated by polyacrylamide gel electrophoresis, gel filtration chromatography, sedimentation through excess α-subunit and gel filtration in an α-subunit-containing medium. No interaction was detected by the first two methods indicating dissociation of the complex during the application of these separation techniques. The latter two methods, in which the complex is studied in a medium of excess subunits, showed that haptoglobin became saturated with the binding of two α-subunits.

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