scholarly journals PURIFICATION AND PHYSICAL PROPERTIES OF GROUP C STREPTOCOCCAL PHAGE-ASSOCIATED LYSIN

1971 ◽  
Vol 133 (5) ◽  
pp. 1105-1117 ◽  
Author(s):  
Vincent A. Fischetti ◽  
Emil C. Gotschlich ◽  
Alan W. Bernheimer

A purification procedure for the Group C phage-associated lysin is described utilizing tetrathionate to protect the enzyme's -SH group(s) from thiol-inactivating agents. A 652-fold purification has been accomplished yielding a solution in which the enzyme activity corresponds to essentially a single band on polyacrylamide gel which accounts for 70% of the total protein in the preparation. A molecular weight of 101,000 and frictional ratio of 1.526 was determined for the lysin utilizing experimentally determined values for its Stokes radius and sedimentation coefficient.

1969 ◽  
Vol 47 (11) ◽  
pp. 1021-1025 ◽  
Author(s):  
J. A. Blakely ◽  
S. L. MacKenzie

A β-hexosidase has been isolated from Sporobolomyces singularis by conventional techniques involving ammonium sulfate precipitation and chromatography on columns of Sephadex G-200 and DEAE-Sephadex A-50. Electrophoresis on polyacrylamide gel was used as the final preparative step. The sedimentation coefficient (s°20,w) of the enzyme was 7.6 and its molecular weight was in the range 140 000–145 000. Although the β-hexosidase performed the functions of a β-D-galactoside galactohydrolase (β-galactosidase), it also catalyzed the hydrolytic function normally performed by a β-D-glucoside glucohydrolase; both these functions appear to reside in the same molecule.


1980 ◽  
Vol 58 (1) ◽  
pp. 67-72
Author(s):  
D. J. S. Arora ◽  
L. Vincent ◽  
J. Hill-Schubert

A ribonuclease activity associated with influenza virus has been purified to homogeneity. This preparation is free of DNAase, phosphodiesterase, and phosphatase activities. The purified enzyme has a pH optima of 7.0 at 37 °C, and moves as a single band on sodium dodecyl sulfate – polyacrylamide gel with an estimated molecular weight of 84 000.


1981 ◽  
Vol 97 (2) ◽  
pp. 258-269 ◽  
Author(s):  
Kalle Jääskeläinen ◽  
Hannu Rajaniemi ◽  
Leo E. Reichert

Abstract. Membrane particles of luteinized rat ovaries and immature and mature granulosa cells of rat ovarian follicles were labelled with [125I]human chorionic gonadotrophin (hCG), membranes of mature granulosa cells were also labelled with [125I]ovine follitropin (oFSH). Hormone-receptor complexes were solubilized with Triton X-100 and their physical properties were characterized by sedimentation and gel filtration. No difference in the macroscopic physical properties of the specific receptor-hCG-complex was observed between different developmental stages of granulosa cells. The Stokes radius of the specific receptor-[125I]hCG-complex was 58 Å and the sedimentation coefficient 6.7 ± 0.3 S. The physical properties of free LH/hCG-receptor of luteinized ovaries were also characterized. The Stokes radius was found to be 57–59 Å and the sedimentation coefficient 4.8–5.6 S. Both [125I]hCG and [125I]oFSH formed non-specific complexes with ovarian as well as with non-gonadal membrane components. The sedimentation coefficient of the non-specific complex was 1.3 ± 0.5 S and the Stokes radius 49 Å. These results show that the macroscopic physical properties of the receptor-hCG-complex do not change during the maturation and subsequent luteinization of the granulosa cells. The methods used were not enough discriminating to reveal the existing structural differences between receptor-oFSH-complex and receptor-hCG-complex.


1971 ◽  
Vol 49 (6) ◽  
pp. 647-657 ◽  
Author(s):  
Ronald R. Marquardt

Aldolase (fructose-1,6-diphosphate D-glyceraldehyde-3-phosphate-lyase, EC 4.1.2.13) was purified from chicken liver. The enzyme was shown to be homogeneous according to the following criteria: purification to a constant specific activity following sequential chromatography on carboxymethyl-Sephadex and Sephadex G-200, electrophoresis on cellulose acetate strips, sedimentation velocity analysis, absence of 10 other glycolytic enzymes, and immunodiffusion in agar.The sedimentation coefficient (s°20w 8.0), Stokes radius (47 Å), diffusion constant (D°20w 4.0 × 10−7 cm2/s), and molecular weight (160 000) are similar to those of rabbit liver aldolase and the muscle and brain enzymes from both chickens and rabbits.


1984 ◽  
Vol 219 (2) ◽  
pp. 583-591 ◽  
Author(s):  
M K Metsikkö

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.


1967 ◽  
Vol 105 (1) ◽  
pp. 409-416 ◽  
Author(s):  
P. C. L. John ◽  
P. J. Syrett

1. Isocitrate lyase (threo-ds-isocitrate glyoxylate-lyase, EC 4.1.3.1) has been purified from acetate-adapted cells of Chlorella pyrenoidosa. 2. The final preparation was homogeneous by the criteria of sedimentation, diffusion and polyacrylamide-gel electrophoresis. 3. The sedimentation coefficient (S20,w) was 9·04×10−13sec. and the diffusion coefficient (D20,w) 4·62×10−7cm.2/sec.; from these values the molecular weight of the enzyme was calculated to be 170000 and its Stokes radius to be 4·63×10−7cm. 4. The elution of the enzyme from Sephadex G-100 was studied and estimates of molecular weight and Stokes radius were obtained from the elution data. 5. The turnover number of the enzyme was 5950moles of glyoxylate formed/min./mole of enzyme at 30°. 6. With threo-ds(+)-isocitrate as substrate, the Km of the enzyme was 0·023mm.


1978 ◽  
Vol 175 (2) ◽  
pp. 449-454 ◽  
Author(s):  
J Berüter ◽  
J P Colombo ◽  
C Bachmann

Arginase was isolated from human liver and erythrocytes. The purification procedure used acetone precipitation, heat-treatment, (NH4)2SO4 precipitation, DEAE-cellulose chromatography and gel filtration on Sephadex G-200 in the presence of 2-mercaptoethanol. Both enzymes migrated to the anode at pH8.3 on polyacrylamide-gel electrophoresis. After incubation at pH8.0 and 37 degrees C the purified anionic liver arginase migrated to the cathode on polyacrylamide-gel electrophoresis. It is assumed that the multiple forms of the enzyme reported in the literature are partly artifacts of the purification procedure. The liver arginase showed a mol.wt. of 107000 determined by gel filtration and a sedimentation coefficient of 5.9S. Treatment of the liver enzyme with 0.25% sodium dodecyl sulphate at pH10 demonstrated an oligomeric structure of the enzyme with a mol.wt. of the subunit of 35000. The kinetic properties determined for the purified liver arginase showed an optimum pH of 9.3 and an optimal MnCl2 concentration of 2mM. The Km for L-arginine was 10.5 mM and for L-canavanine 50mM, and L-lysine exhibited a competitive type of inhibition with a Ki of 4.4mM. L-Homoarginine was not a substrate for liver arginase.


1981 ◽  
Author(s):  
G C Russell ◽  
G Kemble ◽  
E G D Tuddenham

Human factors IX and X have been purified to homogeneity from clinical factor IX concentrate that had been rejected for therapeutic use due to particulate contamination. (It was necessary to start with this material since in the UK, plasma is not commercially available). The procedure involved barium citrate adsorption followed by ammonium sulphate elution, DEAE- cellulose chromatography, gel filtration on Sephacryl S-200 and affinity chromatography on heparin sepharose gel. The preparation of factor IX at this stage showed a single band on SDS-polyacrylamide gel electrophoresis, of molecular weight 58,000. No change in molecular weight was observed in the presence of 2-mercaptoethanol. A further affinity chromatography column - poly (homoarginine) Sepharose or dextran sulphate sepharose - was necessary to obtain homogeneous factor X. The preparation obtained showed a single band on SDS-polyacrylamide gel electrophoresis of molecular weight 67,000. In the presence of 2-mercaptoethanol, two bands were obtained of molecular weights 49000 and 17000 representing the heavy and light chains respectively of factor X. The purified coagulation proteins contained no activated species detectable by nonactivated partial thromboplastin time or by chromogenic substrate (S2222) assay. Prothrombin protein Sand protein C are by-products of this purification procedure.


1976 ◽  
Vol 157 (2) ◽  
pp. 409-413 ◽  
Author(s):  
R K Airas ◽  
E A Hietanen ◽  
V T Nurmikko

Pantothenase (EC 3.5.1.22) from Pseudomonas fluorescens UK-1 was purified to homogeneity as judged by disc-gel electrophoresis and isoelectric focusing. The purification procedure consisted of four steps: DEAE-Sephadex chromatography, (NH4)2SO4 precipitation, hydroxyapatite chromatography and preparative polyacrylamide-gel electrophoresis. Gel filtration on Ultrogel AcA 34 was used to determine the molecular weight, and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis to study the subunit molecular weight. The enzyme appeared to be composed of two subunits with mol.wts. of approx. 50000 each. The total mol.wt. of the enzyme was thus about 100000. The isoelectric point was 4.7 at 10 degrees C.


2015 ◽  
Vol 63 (2) ◽  
Author(s):  
Yingyin Xu ◽  
Yuxiao Lu ◽  
Rui Zhang ◽  
Hexiang Wang ◽  
Qinghong Liu

A novel laccase was purified from the white rot fungus, Hohenbuehelia serotina, to investigate the applications of this laccase in the decoloration of various dyes. SDS-PAGE revealed a single band of this laccase corresponding to a molecular weight of approximately 57.8 kDa. The enzyme showed activity towards several substrates, the most sensitive of which was 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS). The highest enzymatic activity using ABTS as a substrate was observed at pH 6.8 and 30°C. The enzyme activity was found to be significantly enhanced in the presence of Zn(2+) ions and inhibited by Fe(2+) ions. Moreover, SDS and β-mercaptoethanol were inhibitory, and inhibition by L-cysteine was observed while EDTA and DMSO had almost no inhibitory effect. The laccase could effectively decolorize seven different dyes within 30 minutes at 40°C.


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