Purification of jack bean meal beta-D-galactosidase by a new affinity adsorbent.

A simple procedure has been developed for the purification of jack bean beta-D-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) by affinity chromatography employing a new affinity adsorbent. The ligand 6-N-beta-(4-aminophenyl)-ethylamino-3-O-beta-D-galactopyranosyl-6-deoxy-L-gulitol was prepared by the reaction between lactose and beta-(4-aminophenyl)-ethylamine and was coupled to cyanogen bromide activated Sepharose 4B via the amino groups of the 4-aminophenyl moiety. This affinity gel resulted in a 111-fold purification of beta-D-galactosidase with a 64% recovery of the enzyme. With p-nitrophenyl-beta-D-galactopyranoside as the substrate the apparent Km and V values were 0.59 mM and 1.87 mumol/min per mg, respectively. The method for purification of beta-D-galactosidase may be applicable to other glycosidases depending upon the choice of specific di- or oligosaccharides of known structures to be used in the preparation of ligands.     

Characteristics of a beta-galactosidase substance obtained by an ultrafiltration method

The ultrafiltration method with application of Vladipor membranes YAM-300 has been used to obtain 8.9 times purified preparation of beta-D-galactosidase (EC 3.2.1.23) from the Escherichia coli lysate. The preparation activity is 43,400 u/g, specific activity--167.57 u/mg of protein. The preparation includes 25.9% of protein and does not possess the collateral proteolytic activity. The results of the ultraconcentrate isofocusing in the borate-polyol system within the pH range of 4.5-9.5 and electrophoresis in polyacrylamide gel testify to the presence of five basic protein fractions, one of which includes 57 +/- 2% of protein with the beta-galactosidase activity. This fraction is homogeneous, its isoelectric point corresponds to pH 7.8.     

Trial of purifying tumor degenerating factor of human fibroblasts

Tumor-degenerating factor (TDF) with the specific activity of 2.9 units/mg of protein was produced and purified by several chromatographies. The specific activity was increased to 302 units/mg of protein by DEAE-Sephadex A-50 chromatography, repeated twice. Then, this preparation was purified to the specific activity of 2,040 units/mg of protein with recovery rate of 16.6% by Con A-Sepharose and CM-Sephadex C-50 chromatographies. Finally, the specific activity was increased to 9,010 units/mg of protein with the final recovery rate of 14.6% by Blue Sepharose CL-6B chromatography.     

Preparation of a monomeric 2,4-dinitrophenyl Fab'-beta-D-galactosidase conjugate for immunoenzymometric assay

A method is described for the preparation of a monomeric Fab'-beta-D-galactosidase conjugate, which is required for the development of a sensitive immunoenzymometric assay. Anti-human IgG F(ab')2 was labeled with 2,4-dinitrophenyl groups, split into Fab' by reduction and reacted with excess maleimide groups which had been introduced into beta-D-galactosidase through thiol groups using N,N'-o-phenylenedimaleimide. The monomeric 2,4-dinitrophenyl Fab'-beta-D-galactosidase conjugate was subsequently separated from unconjugated beta-D-galactosidase by affinity chromatography on a column of (anti-2,4-dinitrophenyl) IgG-Sepharose 4B. In the monomeric conjugate preparation, 98% of beta-D-galactosidase activity was associated with Fab' and 90% was associated with specific (anti-human IgG) Fab'. This conjugate allowed the measurement of 0.1 fmol of human IgG by an immunoenzymometric assay technique.     

Purification of glycogen phosphorylase by affinity chromatography on 5'-AMP Sepharose.

Glycogen phosphorylase from human polymorphonuclear leukocytes was purified by a factor of 2500 using differential centrifugations and affinity chromatography on 5′-AMP bound to agarose. The preparation had a specific activity of 95 units per mg protein and the recovery was 26%.     

Chromatin-associated ornithine decarboxylase at early stages of growth and differentiation of etiolated mono- and dicotyledonous plants

Ornithine decarboxylase (ODC) of barley, corn, bean and pea plants was associated with chromatin at early stages of growth. In corn, bean and pea plants the chromatin of roots possessed ODC with the highest specific activity of 30–65 units per mg protein. After 200 h of growth ODC activity of chromatin declined, while ODC activity of cytosol increased linearly to 4–19 units per mg protein. ODC activity of either chromatin or cytosol of shoots in the above mentioned plants was usually low, 1–2 units per mg protein and only at the beginning of shoot growth (96 h) did pea chromatin have high ODC activity (14 units per mg protein). In these plants ODC was tightly bound to chromatin and could not be extracted with different concentrations of NaCl (0.1–1.0 M) or non-ionic detergent (Triton X100, Tween 20) but could be extracted by freezing and thawing with satisfactory recovery.     

Purification and comparison of phosphoenolpyruvate carboxykinase from the liver and kidney of the Arabian camel (Camelus dromedarius)

1. Phosphoenolpyruvate carboxykinase was partially purified from camel liver and kidney by ammonium sulphate fractionation, gel filtration and ion-exchange chromatography. 2. The specific activity of the purified preparation from liver was 39.2 mumol/min per mg protein. 3. When isolated from the kidney the specific activity of the enzyme was very much higher 155.5 mumol/min per mg protein. 4. The enzyme from the two sources were similar in their pH optimum which was approx. 7.2 and their relative stability to thermal inactivation at 60 degrees C. 5. The mol. wt of the enzyme from both organs was estimated at 80,000 +/- 5000.     

Purification of pancreatic phospholipase A2 from human duodenal juice

Phospholipase A2 (EC 3.1.1.4) was purified from delipidated human duodenal juice by hydrophobic and cation exchange chromatography, followed by molecular sieving on an HPLC column. The resulting enzyme preparation of phospholipase A2 had a molecular weight of 14 kDa, a specific activity of 2000 U/mg protein, and an N-terminal amino acid sequence which was characteristic for human pancreatic phospholipase A2.     

Purification and properties of hyaluronidase from bull sperm.

Hyaluronidase from bull sperm was fractionated by ammonium sulfate and further purified by DEAE-cellulose and Sephadex chromatography. The highly purified hyaluronidase preparation showed 2,370 units per mg of protein (68,730 N.F. units per mg of protein), i.e. 182-fold purification. Disc gel electrophoresis showed one major component. The molecular weight of bull sperm hyaluronidase was 62,000 by sodium dodecyl sulfate gel electrophoresis. Hyaluronidase from bull sperm has optimum activity at pH 3.8 and an absolute requirement for cations. Kplus and Naplus have a greater effect than Ca2plus, Mg2plus, and Mn2plus, whereas Co2plus, Cu2plus, and Zn2plus do not affect the enzyme activity. Purified preparations are less stable than crude extracts stored frozen at minus 15 degrees. Km of hyaluronidase with hyaluronic acid as substrate is 3.7 mg per ml and Vmax is 2.4 mumol per min by Hofstee plot.     

Human tissue kallikrein. I. Isolation and characterization of human pancreatic kallikrein from duodenal juice

Human pancreatic kallikrein was purified from duodenal juice by ion exchange chromatography on DEAE-Sepharose and immunoaffinity chromatography. Thus, an enzyme preparation with a specific activity (using Ac-Phe-Arg-OEt as substrate) of 1 000 U/mg protein was obtained. A specific biological activity of 1310 KE/mg protein was measured in the dog blood pressure assay and of 0.361 HMW kininogen-U/mg, corresponding to the liberation of 383 micrograms bradykinin-equivalents per mg enzyme per min from HMW kininogen in the rat uterus assay. In dodecyl sulfate gel electrophoresis one protein band corresponding to a molecular mass of 27 kDa was obtained. Using gel filtration on Ultrogel AcA-44 a molecular mass of 40 kDa was measured. The amino-acid composition was determined and isoleucine and alanine were identified as the only N-terminal amino-acid residues. On isoelectric focusing four protein bands with isoelectric points of 5.60, 5.65, 5.70 and 5.85 were separated. The bimolecular velocity constant for the inhibition by diisopropyl fluoro phosphate was determined as 10.5 l x mol-1 x min-1. The dissociation constant Ki of the human pancreatic kallikrein-aprotinin complex was calculated to be 1.5 x 10(-10)M. The kinetic constants for the kallikrein-catalysed hydrolysis of Ac-Phe-Arg-OEt and D Val-Leu-Arg-Nan were determined. Immunological studies showed a close relationship between the human pancreatic kallikrein and other human tissue kallikreins, especially with human urinary kallikrein. Detergents such as Triton X-100, Tween 20 and lysolecithin, as well as human serum albumin, activated the human pancreatic kallikrein preparation.     

Thermostable Pyrococcus woesei beta-D-galactosidase--high level expression, purification and biochemical properties

The gene encoding beta-D-galactosidase from Pyrococcus woesei was PCR amplified, cloned, expressed in Escherichia coli under the control of an inducible T7 promoter, purified and characterized. The expression system was developed by the construction of recombinant plasmid, based on the high copy number pUET1 vector, giving four times more efficient expression of P. woesei beta-D-galactosidase (20 mg of enzyme from 1 liter of culture) than that obtained from a previously constructed one. The recombinant enzymes were purified in a two-step procedure: double heat-denaturation of E. coli cell proteins and affinity chromatography on p-aminobenzyl 1-thio-beta-D-galactopyranoside-agarose. To achieve efficient purification of P. woesei beta-D-galactosidase by immobilized metal-ion affinity chromatography (IMAC), a His-tag was placed either at the N- or the C-terminal of the coding sequence. The obtained fusion proteins revealed the same specific activity of approximately 5400 U/mg, which was 10 times lower than the wild-type beta-D-galactosidase (51100 U/mg). The activity of P. woesei beta-D-galactosidase was enhanced by thiol compounds, Mg(2+) ions and D-galactose, and was inhibited by heavy metal ions and D-glucose, while Ca(2+) ions had no effect.     

Affinity chromatography of angiotensin I-converting enzyme from rabbit lung using hippurylhistidylleucyl-OH.

Approximately 50-fold purification of angiotensin I-converting enzyme (Peptidyldipeptide hydrolase, EC 3.4.15.1) from rabbit lung was achieved by affinity chromatography using the synthetic substrate Hippuryl-His-Leu-OH. The specific activity of the enzyme was increased from 0.044 units/mg protein to 1.911 units/mg protein for Hippuryl-His-Leu-OH and from 0.33 nmol/min per mg protein to 13.8 nmol/min per mg protein for angiotensin I.     

Purification and properties of NADP-dependent isocitrate dehydrogenase from the bovine adrenal cortex

NADP-dependent isocitrate dehydrogenase (EC 1.1.42) was isolated and 430 times purified from the hyaloplasm fraction of bull adrenal cortex using fractionation by ammonium sulphate and acetone, heat treatment, chromatography on DEAE-Sephadex A-50, gel-filtration on Sephadex G-200 and affinity chromatography on 2',5'-ADP-sepharose 4B. The specific activity of homogeneous enzyme is 60 units per 1 mg of protein at 30 degrees C, yield--34%, pH optimum--8.0, molecular weight, determined by gel filtration on Sephadex G-200, is 96 kDa. The preparation electrophoresis in PAAG in the presence of DS-Na reveals one protein fraction with the mobility corresponding to that of protein having molecular weight of 46 kDa. The data obtained evidence for a dimer structure of the isocitrate dehydrogenase molecule from bull adrenals.     

Isolation of a highly active preparation of beta-D-galactosidase

Methods for isolation and purification of beta-galactosidase from Bacillus subtilis, st. IBP-101 are described. The bacterial cells were disrupted by different procedures such as freezing and thawing with subsequent autolysis at 37 degrees C, disrupting in a French press DKM-3 or in ultrasonic disintegrators UZDN-1 (USSR) and Soniprep-150. It is shown that the specific activity and yield of the enzyme depends to a great extent on the disrupting procedure used. The best results were obtained in case of sonication. The preparation was purified by precipitation with ammonium sulphate (25-75% saturated) and chromatography on DEAE-cellulose and DEAE-Sephadex. The purified enzyme had a specific activity of 3155 units per mg protein. The molecular weight of the homogeneous according to gel polyacrylamide electrophoresis preparation was 215,000, as estimated by gel filtration, and 105,000, as estimated by SDS gel electrophoresis. The enzyme retains the activity in the presence of Na+, Mn2+ or Mg2+ ions or the thiolic reagents, dithiothreitol or 2-mercaptoethanol. The pH optimum of the enzyme activity is 6.3 and it is stable in water solutions at pH from 6 to 9 and can be lyophilized. The given preparation of beta-galactosidase has a high affinity for synthetic substrates such as o- and p-nitrophenyl-beta-D-galactopyranosides and 4-methylumbelliferyl-beta-D-galactopyranoside.     

Generation of catalytic protein particles in <Emphasis Type="Italic">Escherichia coli</Emphasis> cells using the cellulose-binding domain from <Emphasis Type="Italic">Cellulomonas fimi</Emphasis> as a fusion partner

The cellulose-binding domain (CBD) of a Cellulomonas fimi exo-glucanase was translationally fused with β-glucuronidase (GusA) from Escherichia coli and β-glycosidase (BglA) from Thermus caldophilus, respectively. Two fusion proteins (GusA-CBD and BglA-CBD) were expressed as insoluble aggregates in cells and isolated by centrifugation of the cell lysates. Interestingly, activity assays revealed that > 90% of the catalytic activity of both proteins was localized in the insoluble fractions. For example, the GusA-CBD particles exhibited 21 units per mg protein, which corresponded to 19% specific activity of the highly purified soluble GusA. The specific activity increased further up to 42 units per mg protein when treated with either sonication or chaotropic L-arginine. These results demonstrate that fusion with CBD family II may activate catalytic protein particles in E. coli cells, and that internal proteins of the particles are also active. Finally, the protein particles were tested in repeated batch operations after being cross-linked with chemicals, indicating that they have potential as a new preparation for immobilized biocatalysts.     

Angiotensin I converting enzyme from human plasma.

The angiotensin I converting enzyme was purified 101 000-fold to homogeneity from human plasma by a combination of chromatographic and electrophoretic techniques. The enzyme is similar to other angiotensin I converting enzymes. It is an acidic glycoprotein consisting of a single polypeptide chain of molecular weight 140 000 with an isoelectric point of 4.6. The enzyme requires chloride ion for activity and is inhibited by ethylenediaminetetraacetic acid, angiotensin II, bradykinin, bradykinin potentiating factor nonapeptide, and 3-mercapto-2-D-methylpropanoyl-L-proline (SQ-14,225). The purified preparation cleaves bradykinin as well as angiotensin II and hippuryl-L-histidyl-L-leucine. Its specific activity with angiotensin I is 2.4 units per mg and with hippuryl-L-histidyl-L-leucine is 31.4 units per mg.     

Biochemical Properties of a Cephalosporin β-Lactamase from Pseudomonas aeruginosa

The cephalosporin β-lactamase from Pseudomonas aeruginosa GN918 was purified using CM-Sepha-dex column chromatography. The resulting preparation gave a single protein peak on electrofocusing column chromatography and a single protein band on polyacrylamide-gel electrophoresis. The specific enzyme activity was 22 950 units per mg of the purified enzyme protein. The optimal pH was 7.5 and the optimal temperature was 40 C for the hydrolysis of cephaloridine. Isoelectric point was 8.7 and the approximate molecular weight of the enzyme was found to be 34 000±2000. The enzyme activity was inhibited by iodine, p-chloromercuribenzoate and semi-synthetic penicillins. The enzymological properties of the isolated preparation have been compared with β-lactamases derived from other gram-negative enteric bacteria.     

Increase in Viscosity and Gel Formation of Fruit Juice by Purified Pectinesterase

The pectinesterase produced by Sclerotinia libertiana was purified by the column chromatography employing cation exchange resin Amberlite CG 50 and CM cellulose. The specific activity per mg protein was increased 266-fold. The homogeneity of the enzyme preparation was confirmed by ultracentrifugal analysis and starch zone electrophoresis. The purified pectinestrase was found to remarkably increase the viscosity of pectin solution and fruit juice, and, in a pectin solution of appropriate concentration (about 0.5~1 %) and some fruit juices, it finally formed the cosity thus increased and gel formed by the enzyme action did not change for a long time.     

Phospholipase C from Clostridium novyi type A. I.

1. Phospholipase C (EC 3.1.4.3) from Clostridium novyi (oedematiens) type A was purified 2000-fold by (NH4)2SO4 precipitation, DEAE-Sephadex treatment in a batchwise system and Sephadex G-100 column chromatography. 2. The purified preparation had a specific activity of 95 mumol per min per mg protein toward phosphatidylcholine. This preparation was free from protease, lipase and oxygen-labile delta-hemolysin. 3. Phosphatidylcholine was hydrolyzed at the highest rate, while sphingomyelin and lysophosphatidylcholine were hydrolyzed at much lower rates. 4. Sodium deoxycholate and divalent cations such as Mg2+ and Ca2+ were extremely effective in stimulating phosphatidylcholine-hydrolyzing activity of this enzyme. 5. This enzyme hemolyzed horse red cells by hydrolyzing phosphatidylcholine, spingomyelin and phosphatidylethanolamine.     

Binding of platelet factor 4 to heparin oligosaccharides.

Heparin fractions of differing Mr (7800-18 800) prepared from commercial heparin by gel filtration and affinity chromatography on immobilized anti-thrombin III had specific activities when determined by anti-Factor Xa and anti-thrombin assays that ranged from 228 to 448 units/mg. The anti-Factor Xa activity of these fractions could be readily and totally neutralized by increasing concentrations of platelet factor 4 (PF4). That these fractions bound to immobilized PF4 was indicated by the complete binding under near physiological conditions of 3H-labelled unfractionated commercial heparin. An anti-thrombin III-binding oligosaccharide preparation (containing predominantly eight to ten saccharide units), prepared by degradation of heparin with HNO2 had high (800 units/mg) anti-Factor Xa, but negligible anti-thrombin, specific activity. The anti-Factor Xa activity of this material could not be readily neutralized by PF4, and the 3H-labelled oligosaccharides did not completely bind to immobilized PF4. A heterogeneous anti-thrombin III-binding preparation containing upwards of 16 saccharides had anti-thrombin specific activity of just less than one-half the anti-Factor Xa specific activity. This material was completely bound to immobilized PF4 and was eluted with similar concentrations of NaCl to those that were required to elute unfractionated heparins from these columns. Furthermore, increasing concentrations of PF4 neutralized the anti-Factor Xa activity of this material in a manner similar to that of unfractionated heparin. It is concluded that heparin oligosaccharides require saccharide units in addition to the anti-thrombin III-binding sequence in order to fully interact with PF4.