Physical and chemical properties of human plasma β2-macroglobulin

Alpha2-M (alpha2-macroglobulin) was purified from human plasma by two different procedures. As well as having no detectable impurities by the usual criteria for testing the homogeneity of protein preparations, these alpha2M preparations showed a single component, after reduction in urea, of 185000 daltons by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The molecular weight of the alpha2M was found to be 718000 by sedimentation equilibrium experiments using the gravimetrically determined -v of 0.731 ml/g. The interaction of several proteinases with alpha2M was studied by using a novel discontinuous polyacrylamide-gel system, which showed clear separation of the enzyme-complexed alpha2M from the free alpha2M. These studies indicated that urokinase, as well as trypsin, chymotrypsin, plasmin and thrombin forms complexes with alphaM. The cleavage of the 185000-dalton subunit to a 85000-dalton species on interaction of trypsin with alpha2M was demonstrated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis after reduction of the alpha2M-trypsin complex in urea. The amino acid composition, carbohydrate content, absorption coefficient at 280 nm, the specific refractive increment and the sedimentation coefficient for these alpha2M preparations were measured. The stability of the trypsin-binding activity of the alpha2M preparations was also studied under several storage situations.

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Structural properties of homogeneous protein disulphide-isomerase from bovine liver purified by a rapid high-yielding procedure

Biochemical Journal ◽

10.1042/bj2130225 ◽

1983 ◽

Vol 213 (1) ◽

pp. 225-234 ◽

Cited By ~ 107

Author(s):

N Lambert ◽

R B Freedman

Keyword(s):

Amino Acid ◽

Sodium Dodecyl Sulphate ◽

Gel Electrophoresis ◽

Specific Activity ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Sedimentation Coefficient ◽

Bovine Liver ◽

Polyacrylamide Gel ◽

Protein Disulphide Isomerase

Protein disulphide-isomerase from bovine liver was purified to homogeneity as judged by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, two-dimensional electrophoresis and N-terminal amino acid analysis. The preparative procedure, a modification of that of Carmichael, Morin & Dixon [(1977) J. Biol. Chem. 252, 7163-7167], is much faster and higher-yielding than previous procedures, and the final purified material is of higher specific activity. The enzyme has Mr 57 000 as determined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, both in the presence and in the absence of thiol compounds. Gel-filtration studies on Sephadex G-200 indicate an Mr of 107 000, suggesting that the native enzyme is a homodimer with no interchain disulphide bonds. Ultracentrifugation studies give a sedimentation coefficient of 3.5S, implying that the enzyme sediments as the monomer. The isoelectric point, in the presence of 8 M-urea, is 4.2, and some microheterogeneity is detectable. The amino acid composition is comparable with previous analyses of this enzyme from bovine liver and of other preparations of thiol:protein disulphide oxidoreductases whose relation to protein disulphide-isomerase has been controversial. The enzyme contains a very high proportion of Glx + Asx residues (27%). The N-terminal residue is His. The pure enzyme has a very small carbohydrate content, determined as 0.5-1.0% by the phenol/H2SO4 assay. Unless specific steps are taken to remove it, the purified enzyme contains a small amount (5 mol/mol of enzyme) of Triton X-100 carried through the purification.

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Purification and properties of succinyl-coenzyme A-3-oxo acid coenzyme A-transferase from sheep kidney

Biochemical Journal ◽

10.1042/bj1730759 ◽

1978 ◽

Vol 173 (3) ◽

pp. 759-765 ◽

Cited By ~ 15

Author(s):

J A Sharp ◽

M R Edwards

Keyword(s):

Isoelectric Focusing ◽

Sodium Dodecyl Sulphate ◽

Gel Electrophoresis ◽

Coenzyme A ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Sedimentation Coefficient ◽

Polyacrylamide Gel ◽

Transferase Activity ◽

Coa Transferase

CoA-transferase (succinyl-CoA-3-oxo acid CoA-transferase, EC 2.8.3.5) isolated from sheep kidney was purified to homogeneity. The purified enzyme has a specific activity of approx. 200 units/mg. A mol.wt. of 110000 was obtained by gel filtration on Sephadex G-200, and a lower mol.wt. of 102000 was determined by analytical ultracentrifugation. A sedimentation coefficient of 5.6S was also determined. A subunit mol.wt. of 56000 was obtained by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Isoelectric focusing of sheep kidney extracts indicated the presence of a single band of CoA-transferase activity with pI9.0. However, isoelectric focusing of purified CoA-transferase showed the presence of two peaks of CoA-transferase activity with pI values of 8.7 and 8.4, suggesting the presence of proteolytic activity during purification. Evidence for sheep kidney CoA-transferase being a dimer of two identical subunits has been obtained from sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, the amino acid composition, peptide ‘mapping’ and N-terminal analysis.

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The exocellular dd-carboxypeptidase-endopeptidase from Streptomyces albus G. Purification and chemical properties

Biochemical Journal ◽

10.1042/bj1750793 ◽

1978 ◽

Vol 175 (3) ◽

pp. 793-800 ◽

Cited By ~ 22

Author(s):

C Duez ◽

J M Frère ◽

F Geurts ◽

J M Ghuysen ◽

L Dierickx ◽

...

Keyword(s):

Sodium Dodecyl Sulphate ◽

Gel Electrophoresis ◽

Molecular Sieve ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Chemical Properties ◽

Polyacrylamide Gel ◽

Streptomyces Albus ◽

Enzyme I ◽

And Chemical Properties

The exocellular DD-carboxypeptidase-endopeptidase of Streptomyces albus G was purified to protein homogeneity and compared with the exocellular DD-carboxypeptidases-transpeptidases of Streptomyces R61 and Actinomadura R39. The S. albus G enzyme, as it is isolated, occurs in two forms. Enzyme I (30% of the total amount) and enzyme II (70% of the total amount) are identical in all respects, except that, by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate, enzyme I has an apparent mol. wt. (9000) that is half of that found by molecular-sieve filtration under non-denaturing conditions. Irrespective of the technique used, enzyme II has an apparent mol. wt. of about 18500.

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Covalent labelling of the lutropin binding site. Evidence for a single Mr 90000 sialoglycopolypeptide

Biochemical Journal ◽

10.1042/bj2190583 ◽

1984 ◽

Vol 219 (2) ◽

pp. 583-591 ◽

Cited By ~ 10

Author(s):

M K Metsikkö

Keyword(s):

Binding Site ◽

Sodium Dodecyl Sulphate ◽

Gel Electrophoresis ◽

Sodium Dodecyl ◽

Sedimentation Coefficient ◽

Binding Activity ◽

Polyacrylamide Gel ◽

Receptor Complex ◽

Stokes Radius ◽

Triton X

Membrane-associated sialoglycopolypeptides of rat ovaries were oxidized with NaIO4, reduced with NaB3H4 and solubilized with Triton X-100. The solubilized proteins carrying the 3H label were subjected to affinity chromatography on human choriogonadotropin coupled to agarose. Polyacrylamide-gel electrophoresis in sodium dodecyl sulphate followed by fluorography revealed a single component of apparent Mr 90000. This component was abolished when ovaries saturated with choriogonadotropin were used as starting material. The above result is identical to that obtained previously by conventional detection methods [Metsikk ö & Rajaniemi (1982) Biochem. J. 208, 309-316] and indicates that the 3H-labelled lutropin/choriogonadotropin sialoglycopolypeptide was observed. The affinity-purified 3H-labelled protein co-eluted with the choriogonadotropin-binding activity solubilized with Triton X-100 from rat ovarian particles, showed a Stokes' radius of 6.2 nm and sedimented as a single band with a sedimentation coefficient of 5.1 S. The sedimentation coefficient of this 3H-labelled protein was not significantly altered when boiled in 1% sodium dodecyl sulphate, indicating that non-covalently associated subunits were not present. The 3H-labelled protein cosedimented with the choriogonadotropin-binding activity solubilized with Triton X-100 from rat ovary. When 125I-choriogonadotropin-receptor complex was covalently crosslinked with glutaraldehyde, an Mr 130000 component was produced as detected by sodium dodecyl sulphate gel electrophoresis. This component was extracted from the polyacrylamide gel and subjected to sucrose-density-gradient centrifugation in 0.1% Triton X-100. A single band sedimenting at the position of the 125I-choriogonadotropin-receptor complex solubilized from a prelabelled ovary was observed, exhibiting a sedimentation coefficient of 6.5S. These data suggest that the lutropin-binding site is a single sialoglycopolypeptide of Mr 90000, which binds one molecule of hormone resulting in an apparent Mr 130000 complex. The large Stokes' radius (6.2 nm) of the binding site is accounted for by bound detergent.

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The deoxyribonucleic acid modification enzyme of bacteriophage P1. Subunit structure

Biochemical Journal ◽

10.1042/bj1330629 ◽

1973 ◽

Vol 133 (4) ◽

pp. 629-633 ◽

Cited By ~ 13

Author(s):

Jeremy P. Brockes

Keyword(s):

Sodium Dodecyl Sulphate ◽

Gel Electrophoresis ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Sedimentation Coefficient ◽

Polyacrylamide Gel ◽

Subunit Structure ◽

Acid Modification ◽

Bacteriophage P1 ◽

Modification Enzyme

The bacteriophage P1 modification enzyme was purified 1400-fold from induced lysogens of a thermoinducible mutant of bacteriophage P1. The most purified fraction, when analysed by polyacrylamide-gel electrophoresis in sodium dodecyl sulphate, showed two principal stained bands. The two bands co-sedimented in a glycerol gradient with the modification activity, at a rate which, when compared with the rate of sedimentation of marker proteins, corresponds to a sedimentation coefficient in water of 6S. The mobilities of the bands on sodium dodecyl sulphate–polyacrylamide-gel electrophoresis corresponded to polypeptides of molecular weight 70000 and 45000 and they were present in equimolar amounts. It was concluded that the 6S species of the enzyme is a dimer of unlike subunits.

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Identifikasi Daging Tikus Pada Produk Baso Dengan Metode Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE)

YARSI Medical Journal ◽

10.33476/jky.v26i2.394 ◽

2018 ◽

Vol 26 (2) ◽

pp. 058

Author(s):

Anna P. Roswiem ◽

Triayu Septiani

Keyword(s):

Sodium Dodecyl Sulphate ◽

Gel Electrophoresis ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Polyacrylamide Gel ◽

Sds Page

Bahan baku untuk membuat baso adalah daging hewan, pada umumnya dari daging sapi, ayam, ikan dan babi. Di beberapa daerah di Indonesia terjadi kasus baso tikus. Tujuan penelitian ini adalah menguji ada tidaknya kandungan daging tikus pada produk baso yang dijual di pasar Cempaka Putih-Kecamatan Kramat Jakarta Pusat dan di pedagang baso atau mie baso di sekitar kampus Universitas YARSI Jakarta. Daging adalah protein salah satu metode untuk mengidentifikasi protein adalah metode Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE). Hasil penelitian menunjukkan bahwa dari 6 sampel baso terindikasi ada 2 sampel baso dengan nomor 1 dan 5 yang dibuat dari campuran daging sapi dan tikus; ada 1 sampel baso dengan nomor 6 yang terbuat dari daging tikus; dan 2 sampel baso dengan nomor 2 dan 3 yang terbuat dari campuran sapi dan babi, dan hanya 1 sampel baso dengan nomor sampel 4 yang benar-benar terbuat dari daging sapi.

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