The purification of porcine haptoglobin by affinity chromatography with concanavalin A – Sepharose

1976 ◽  
Vol 54 (11) ◽  
pp. 999-1001 ◽  
Author(s):  
Frank A. Terpstra ◽  
David B. Smith

Methods designed for the isolation of human haptoglobin (Hp) were found insufficient when applied to pig plasma due to the formation of a material tentatively identified as albumin dimer. Small scale separation is possible by preparative polyacrylamide gel electrophoresis. Larger scale purification from nonglycoprotein contaminants such as albumin dimer is achieved by affinity chromatography using immobilized concanavalin A. Porcine haptoglobin is microheterogeneous. More than 14 components, partially resolveable by gel filtration, were detected.

1979 ◽  
Author(s):  
P Wallen ◽  
M Rånby ◽  
N Bergsdorf ◽  
P Kok

Tissue activator from pig heart: A highly purified activator preparation from pig heart has been prepared, essentially using two affinity adsorbtion steps. 1) Affinity adsorbtion to fibrin and elution with potassium thiocyanate. 2) Affinity chromatography on Sepharose-arginine. The final product, which is obtained by gel filtration on Sephacryl S-200 contains according to SDS-polyacrylamide gel electrophoresis one main band with Mw 64000. Reduced samples still appear as one component but with Mw 31000. The specific activity is about 500000 IU/mg (WHO Reference Preparation for Urokinase) and the yield 15-25 %. Tissue activator from human uterus: A highly purified preparation of human tissue activator has been prepared from uterus by an immunosorbent technique using antibodies produced in goats against the porcine tissue activator and coupled to Sepharose. A crude preparation from 1 kg uterus tissue and containing about 100000 IU tissue activator was adsorbed on 30 g of the immunosorbent. The activity was eluted with a KSCN-gradient. Further purification was obtained by affinity chromatography on Sepharose-arginine. The yield in the active fraction was 30-35 % and the specific activity 200000 to 300000 IU/mg. SDS-polyacrylamide gel electrophoresis showed one main band and 1-2 additional trace components.


1981 ◽  
Vol 197 (3) ◽  
pp. 629-636 ◽  
Author(s):  
J L McKenzie ◽  
A K Allen ◽  
J W Fabre

Human and canine brain Thy-1 antigens were solubilized in deoxycholate and antigen activity was followed both by conventional absorbed anti-brain xenosera of proven specificity and by mouse monoclonal antibodies to canine and human Thy-1. It is shown that greater than 80% of Thy-1 activity in the dog and man binds to lentil lectin, that the mobility on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of canine and human Thy-1 is identical with that of rat Thy-1 and that the Stokes radius in deoxycholate of canine and human brain Thy-1 is 3.0 nm and 3.25 nm respectively. Both lentil lectin affinity chromatography followed by gel-filtration chromatography on the one hand and monoclonal antibody affinity chromatography on the other gave high degrees of purification of the brain Thy-1 molecule in the dog and man, resulting in single bands staining for both protein and carbohydrate on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis (except for a slight contaminant of higher molecular weight staining for protein but not carbohydrate with human Thy-1 purified by lentil lectin and gel-filtration chromatography). Analysis of canine and human brain Thy-1 purified by monoclonal antibody affinity chromatography with additional gel filtration through Sephadex G-200 showed that these molecules had respectively 38% and 36% carbohydrate. The amino acid and carbohydrate compositions were similar to those previously reported for Thy-1 of the rat and mouse, the main point of interest being the presence in canine and human brain Thy-1 of N-acetylgalactosamine, which has been reported in rat and mouse brain Thy-1 but not in Thy-1 from other tissues.


1980 ◽  
Vol 191 (3) ◽  
pp. 799-809 ◽  
Author(s):  
R G Sutcliffe ◽  
B M Kukulska-Langlands ◽  
J R Coggins ◽  
J B Hunter ◽  
C H Gore

Pregnancy-associated plasma protein-A (PAPP-A) has been purified by a combination of methods including antibody-affinity chromatography. The resultant protein, obtained in 16% yield from maternal serum, appeared as a single major component on non-denaturing polyacrylamide and SDS/polyacrylamide gel electrophoresis. The protein showed a single component when analysed by isoelectric focusing under denaturing conditions in the presence and absence of reduction and had a pI of 4.34 and 4.42 respectively. These pI values were indistinguishable from those of alpha 2-macroglobulin (alpha 2M). The molecular weight of the PAPP-A polypeptide as shown by SDS/polyacrylamide-gel electrophoresis was 187000, with a minor component of mol.wt. 82500 that was attributed to proteolysis. Since native PAPP-A had a molecular weight on gel chromatography very similar to that of alpha 2M (620000–820000), it was concluded that PAPP-A was a homotetramer. In the absence of reduction, a high-molecular-weight (420000) protomer of PAPP-A was found. It was deduced that PAPP-A, like alpha 2M, is a dinner, whose protomers are composed of disulphide-linked polypeptide chains. It was found that the molecular weight of the PAPP-A polypeptide exceeded that of alpha 2M by 3.3%, but that the total carbohydrate content of PAPP-A exceeded that of alpha 2M by 10% and that its neutral carbohydrate content exceeded that of alpha 2M by between 7.4 and 9.0%. The significance of the estimated molecular weights of alpha 2M (181000) and its major tryptic fragments is discussed in the light of published values. A tryptic fragment alpha 2M (82500 mol.wt.) was apparently the same size as the major tryptic fragment of PAPP-A.


1975 ◽  
Vol 147 (2) ◽  
pp. 205-214 ◽  
Author(s):  
E D Adamson ◽  
S E Ayers ◽  
Z A Deussen ◽  
C F Graham

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.


1984 ◽  
Vol 62 (10) ◽  
pp. 964-969 ◽  
Author(s):  
Peter H. Yu

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.


1980 ◽  
Vol 58 (6) ◽  
pp. 494-498 ◽  
Author(s):  
M. Pagé ◽  
J. Lagueux ◽  
C. Gauthier

We describe a method for the purification of normal human liver ferritin by ultrafiltration, gel filtration on Sephacryl S-300, and affinity chromatography on DEAE-Affi Gel Blue. The purity of the ferritin obtained was verified by immunoelectrophoresis, Ouchterlony immunodiffusion, polyacrylamide gel electrophoresis, and electrofocusing. This rapid method yields 32% of the original ferritin.


1975 ◽  
Author(s):  
Caroline McKillop ◽  
W. Edgar ◽  
C. D. Forbes ◽  
C. R. M. Prentice

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.


1979 ◽  
Vol 177 (1) ◽  
pp. 107-114 ◽  
Author(s):  
T G Villa ◽  
V Notario ◽  
J R Villanueva

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.


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