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Comparative studies on the properties of tryptophanase and tyrosine phenol-lyase immobilized directly on Sepharose or by use of Sepharose-bound pyridoxal 5'-phosphate.

Tryptophanase from Escherichia coli B/qt 7-A and tyrosine phenol-lyase (beta-tyrosinase) from Escherichia intermedia were immobilized on Sepharose 4B by several direct coupling reactions or through pyridoxal 5'-phosphate previously bound to Sepharose. The most active preparation of immobilized tryptophanase was obtained by coupling tetrameric apoenzyme to pyridoxal-P bound on Sepharose at the 6-position through a diazo linkage. This immobilization procedure involves the formation to Schiff base linkage between 4-formyl group of Sepharose-bound pyridoxal-P and the epsilon-amino group of the lysine residue at the active center of one subunit of tetrameric apo-tryptophanase, followed by the fixation of the Schiff base linkage by reduction with NaBH4. In the case of beta-tyrosinase having two catalytic centers, however, this method was not so suitable as the case of tryptophanase. Direct coupling of the apoenzyme to CNBr-activated Sepharose or to a bromoacetyl derivative of Sepharose gave better results. In each case, the affinity for substrate or coenzyme was scarcely influenced by the immobilization. When used repeatedly in a batch system or continuously in a flow system in the absence of added pyridoxal-P, immobilized holo-tryptophanase of holo-beta-tyrosinase gradually lost its original activity; however, supplement of pyridoxal-P to the reaction system restored its initial activity. From the kinetic analyses of these phenomena, the rate constants of coenzyme dissociation from immobilized tryptophanase and beta-tyrosinase were calculated. Upon immobilization, the pH optima of both enzymes shifted 0.5 to 1.0 pH unit to the alkaline side. Both immobilized enzymes showed higher thermal stability and resistance to a denaturing agent such as guinidine-HCl than their free counterpart. Furthermore, the reactivity of sulfhydryl group of beta-tyrosinase, in connection with its coenzyme-binding property, was conveniently studied by use of the immobilized enzyme.

Apoenzymes

The relevance of the structure of lysine bound to Sepharose for the affinity of rabbit plasminogen;.

The features of the structure of lysine, linked to Sepharose by the alpha-amino group, which are important for affinity chromatography of rabbit plasminogem were studied. Nine lysine and lysine-like conjugates, including epsilon-aminohexanoic acid DL-norleucine, DL-alpha-aminoadipic acid, DL-alpha-epsilon-diaminopimelic acid, cadaverine L-ornithine, L-arginine and D-lysine, were prepared; Using labelled rabbit plasminogen added to plasma, the ability of each conjugate to absorb plasminogen and separate the allomeric forms, type I and type II, during epsilon-aminohexanoic acid gradient elution was compared to Sepharose-L-lysine. Plasminogen had no affinity for Sepharose-epsilon-aminohexanoic acid, and was only weakly attracted by Sepharose-norleucine, Sepharose-cadaverine and others. Sepharose-ornithine held a greater attraction to the protein but the strongest binding was obtained with Sepharose-arginine. The affinity of plasminogen type I was always less than type II for the Sepharose-lysine analogues and the recovery of type II greater than type I from Sepharose-ornithine and Sepharose-arginine. Plasminogen affinity was in the order of Sepharose-arginine greater than Sepharose-lysine greater than Sepharose-ornithine. However, because of the present difficulty in recovering plasminogen from Sepharose-arginine the use of Sepharose-lysine in the affinity chromatography of rabbit plasminogen remains unchallenged. It is concluded that binding of rabbit plasminogen to conjugates of lysine and its analogues is determined by the presence of both a free carboxyl and a free amino group and that the distance between these groups is critical.

Animals

Interaction of lipoprotein lipase with heparin-Sepharose. Evaluation of conditions for affinity binding.

Lipoprotein lipases from a variety of sources have been shown previously to bind to heparin and some related polysaccharides. For the present studies lipoprotein lipase purified from bovine milk was used. 1. In batch experiments binding of the enzyme activity to heparin-Sepharose occurred relatively slowly, so that 30min was required for the system to come to near-equilibrium. In contrast, release of the enzyme activity from heparin-Sepharose by addition of salt to the liquid phase occurred rapidly. 2. Some binding was observed also with unsubstituted Sepharose, but this binding had a low capacity compared with that observed with heparin-Sepharose. High salt concentrations, heparin or deoxycholate decreased the binding to unsubstituted Sepharose. These factors also increase the solubility of the enzyme, which is low. 3. Addition of heparin to the liquid phase caused a concentration-dependent release of enzyme activity from the gel. These results suggested that the binding of the enzyme to heparin-Sepharose was mainly through interaction with heparin. 4. The enzyme activity was also quantitatively displaced to the liquid phase at increased concentrations of salt. Among the positive ions tested the following order of effectiveness was noted: Cs(+) approximately K(+)>Na(+)>Li(+); and among the negative the following: SCN(-)>I(-)> NO(3) (-)>Br(-) approximately Cl(-). The differences were quite large. Thus addition of 0.16m-KSCN (in addition to the 0.32m-NaCl originally present) displaced one-half of the enzyme activity to the supernatant, whereas 0.8m-LiCl only displaced one-quarter. 5. The distribution of heparin in the gel also profoundly influenced the binding. Two series of gels were studied. One series was made by mixing heparin-Sepharose with unsubstituted Sepharose. Results obtained with these gels were those expected from a series of decreasing volumes of heparin-Sepharose. In contrast, a series of heparin-Sepharoses made with different degrees of substitution gave quite different results. With these gels the amount of enzyme activity bound per amount of heparin increased markedly, whereas the salt concentration needed to displace the enzyme activity from the gel decreased markedly with decreased concentration of heparin in the gel. 6. On stepwise elution of small columns of heparin-Sepharose the enzyme activity was eluted over a remarkably wide range of salt concentrations. When enzyme eluted at one salt concentration was re-applied, it gave the same elution profile as enzyme previously eluted at other salt concentrations or the entire enzyme preparation. These and other results suggested that, whereas the enzyme preparation was rather homogeneous in its binding to heparin, the heparin preparation was polydisperse in binding of lipoprotein lipase.

Animals

Protein chromatography on adsorbents with hydrophobic and ionic groups. Some properties of N-(3-carboxypropionyl)aminodecyl-sepharose and its interaction with wheat-germ aspartate transcarbamoylase.

1. The charge state of two derivatives of Sepharose prepared by the CNBr activation method were studied by acid-base titration and by ion-exchange chromatography. Dodecyl-Sepharose exhibited cationic groups (21mumol/ml of settled gel; pKa=9.6) that were tentatively assigned to the coupling isourea group. 2. CPAD-Sepharose [N-(3-carboxypropionyl)aminodecyl-Sepharose] has anionic (carboxyl) groups (pKa=4.5) and cationic groups (pKa=9.6) in roughly equal concentrations (e coupling group. CPAD-Sepharose is slightly negatively charged at pH 7.0 and substantially negatively charged at pH 8.5. 3. The pKa values of dodecyl-Sepharose and CPAD-Sepharose are unaffected by a 100-fold increase in the concentration of KCl. 4. CPAD-Sepharose has considerable affinity for wheat-germ aspartate transcarbamoylase at pH 8.5 when the adsorbent and enzyme are both negatively charged. The interaction involves the C10 chain but is relatively moderate compared with C10 chains associated only with positive charge. 5. Desorption of the enzyme adsorbed to CPAD-Sepharose can be achieved by raising the pH to increase the electrostatic repulsion, or by introducing the detergent sodium deoxycholate. Acetone and butan-1-ol also weaken the adsorption at pH 8.5. 6. High concentrations of sodium acetate or sodium phosphate induced the enzyme to bind more tightly to CPAD-Sepharose. 7. These results are discussed in terms of a 'repulsion-controlled' model or hydrophobic chromatography.

Adsorption

Flurbiprofen-sepharose chromatography of the prostaglandin synthetase from bovine seminal vesicles.

Flurbiprofen-Sepharose and Acetyl-Sepharose have been prepared by coupling dl-2-(2-fluoro-4-biphenylyl)propionic acid [Flurbiprofen] and acetic acid, respectively, to 3-(N-[3-aminopropyl)aminopropyl Sepharose 4B using a water soluble carbodiimide. The arachidonic acid oxygenase activity of solubilized bovine seminal vesicle microsomes is retarded during chromatography on Flurbiprofen-Sepharose but not Acetyl-Sepharose. Thus binding of the oxygenase to Flurbiprofen-Sepharose results from interaction with the immobilized inhibitor. However, the impure oxygenase is either not bound and/or not eluted in a biospecific manner since the abilities of flufenamic acid, R(+) and S(-)-5-cyclohexylindan-1-carboxylic acid, and R and S-Naproxen to remove the enzyme from Flurbiprofen-Sepharose do not parallel the relative efficacies of these compounds as prostaglandin synthesis inhibitors. Nevertheless, gradient elution of arachidonic acid oxygenase activity from Flurbiprofen-Sepharose with flufenamic acid provides a 15 fold enrichment of the enzyme from solubilized bovine seminal vesicle microsomes in 80% yield indicating that this chromatographic reagent can be a powerful tool for use in purification of the prostaglandin synthetase.

Animals

Affinity chromatography of galactose containing biopolymers using covalently coupled Ricinus communis lectin to Sepharose 4B.

A galactose-specific lectin isolated from Ricinus communis beans has been covalently coupled to Sepharose 4B activated with cyanogen bromide. The immobilized lectin retains its polysaccharide-binding property. The Sepharose-lectin can be used for the purification of polysaccharides containing terminal nonreducing galactose. Only a small fraction of 'native fetuin' and 'native ceruloplasmin' are retarded on Sepharose-lectin. On analysis it was observed that they had a lower content of sialic acids as compared to the native and unbound glycoproteins (sialated fractions). However, on desialation, fetuin and ceruloplasmin were completely adsorbed to Sepharose-lectin. The asialoglycoproteins interact strongly with Sepharose-lectin as compared to 'partially sialated glycoproteins'. This has been attributed to the exposure of galactose residues of these glycoproteins on enzymatic desialation. These experiments demonstrated that Sepharose-lectin interacts with glycoproteins through their terminal, non-reducing galactose. On the basis of these experiments it is suggested that Sepharose-lectin can be used as an analytical tool for separation of 'fully sialated glycoproteins' from the 'partially sialated glycoproteins'.

Ceruloplasmin

Purification of several proteolytic enzymes by tosyl- and carbobenzoxy-triethylene-tetramine-sepharoses.

Tosyl-triethylenetetramine-Sepharose (Tos-T-Sepharose) and carbenzoxytriethylenetetramine-Sepharose (Z-T-Sepharose) were found to be adsorbents utilizable in the purification of several microbial and animal proteases. The former Sepharose derivative adsorbed alpha-chymotrypsin, trypsin, subtilisin, thermolysin and neutral subtilopeptidase at neutral pH range, and acid proteases such as pepsin and Rhizopus niveus protease at pH 3.5-6.5. alpha-Chymotrypsin and trypsin were eluted with 0.1 N acetic acid and Rhizopus protease with 0.5 N acetic acid, thermolysin with 1 M guanidine-HCl or 33% ethyleneglycol, whilst pepsin was recovered by elution with 2 M guanidine-HCl at pH 3.5. The binding of neutral subtilopeptidase and subtilisin to this adsorbent was comparatively weak and both the enzymes were recovered by elution with 0.5 M NaCl at neutral pH. On the other hand, Z-T-Sepharose was found to bind tightly to these proteolytic enzymes except neutral subtilopeptidase. Trypsin and alpha-chymotrypsin were released from the adsorbent column with 1 M p-toluenesulfonate, and subtilisin with 1 M guanidine-HCl or 33% ethyleneglycol at neutral pH region. By these chromatographic procedures, the specific activities of these proteolytic enzymes increased effectively. Comparison of the binding abilities of acetyl-, benzoyl-, tosyl- and carbobenzoxy-T-Sepharoses to these enzymes suggests that hydrophobicity of tosyl and carbobenzoxy groups plays an important role in the enzyme-adsorbent interaction.

Acetylation

Use and abuse of sepharose-conjugated antibodies for the isolation of lymphocyte-surface immunoglobulins.

Immunoadsorbents of Sepharose-4B-conjugated antibodies were shown to be suitable for the characterization, by subsequent SDS-polyacrylamide gel electrophoresis, of splenocyte-membrane Immunoglobulin (Ig) solubilized by detergent lysis of surface 125I-labelled cells. However, high non-specific binding of 125I-labelled lymphocyte-membrane components to Sepharose-4B prevented accurate quantition of Ig in such lysates. 125I-labelled lymphocyte-membrane components solubilized by metabolic release also showed high non-specific binding to Sepharose-4B, and this interfered with both quantitative and qualitative analysis of Ig solubilized in this manner. Initial attempts to overcome the nonspecific binding of 125I-labelled lymphocyte-membrane components to Sepharose-4B were unsuccessful, and attention is drawn to the technical problems of using Sepharose-4B as a matrix for solid-phase immunoadsorbent studies of lymphocyte-membrane Ig.

Animals

Immunoadsorbents: non-specific binding of proteins to albumin-sepharose.

Human serum albumin-Sepharose was prepared by coupling human serum albumin to cyanogen bromide activated Sepharose 4B. This immunoadsorbent showed considerable non-specific protein adsorption. The adsorbed proteins were mainly immunoglobulins which could not be separated from required antibody. It is suggested that basic groups formed in the preparation of the albumin-Sepharose are responsible for this non-specific protein adsorption. Non-specific protein adsorption could be completely eliminated by neutralizing the basic groups of the albumin-Sepharose with the anionic dye blue dextran. The resultant blue dextran-albumin-Sepharose allowed purification of anti-albumin-antibody with high yield. It is shown that the isolated antibody is pure and retains its native properties.

Adsorption

Purification of SV-40 messenger RNA by hybridization to SV-40 DNA covalently bound to Sepharose.

SV-40 DNA sheared form was coupled in a stable covalent bond to cyanogen bromide activated Sepharose. Under the conditions used at least 80% of the DNA was bound to Sepharose. The T 1/2 of hybridization of 0.5 mug/ml of SV-40 cRNA to SV-40 DNA-Sepharose was 1 hr. This rate of hybridization is sufficiently rapid to purify SV-40 sequences from solutions containing as little as 0.05-0.1 mug/ml. Nonspecific hybridization of RNA is in the range of 0.1-0.2% of the total input RNA. The DNA-Sepharose is fairly stable and can be reused several times to purify RNA. The SV-40 DNA-Sepharose was used to select large quantities of virus specific RNA from SV-40 infected BS-C-1 cells. The virus specific RNA when added to cell-free extracts from wheat germ was shown to direct the synthesis of the major viral structural protein VP-1.

Cells, Cultured

Purification of the hexokinases by affinity chromatography on sepharose-N-aminoacylglucosamine derivates. Design of affinity matrices from free solution kinetics.

The purification is described of rat hepatic hexokinase type III and kidney hexokinase type I on a large scale by using a combination of conventional and affinity techniques similar to those previously used for the purification of rat hepatic glucokinase [Holroyde, Allen, Storer, Warsy, Chesher, Trayer, Cornish-Bowden & Walker (1976) Biochem. J. 153, 363-373] and muscle hexokinase type II [Holroyde & Trayer (1976) FEBS Lett. 62, 215-219]. The key to each purification was the use of a Sepharose-N-aminoacylglucosamine affinity matrix in which a high degree of specificity for a particular hexokinase isoenzyme could be introduced by either varying the length of the aminoacyl spacer and/or varying the ligand concentration coupled to the gel. This was predicted from a study of the free solution kinetic properties of the various N-aminoacylglucosamine derivatives used (N-aminopropionyl, N-aminobutyryl, N-aminohexanoyl and N-aminooctanoyl), synthesized as described by Holroyde, Chesher, Trayer & Walker [(1976) Biochem. J. 153, 351-361]. All derivatives were competitive inhibitors, with respect to glucose, of the hexokinase reaction, and there was a direct correlation between the Ki for a particular derivative and its ability to act as an affinity matrix when immobilized to CNBr-activated Sepharose 4B. Muscle hexokinase type II could be chromatographed on the Sepharose conjugates of all four N-aminoacylglucosamine derivatives, although the N-aminohexanoylglucosamine derivative proved best. This same derivative was readily able to bind hepatic glucokinase and hexokinase type III, but Sepharose-N-amino-octanoyl-glucosamine was better for these enzymes and was the only derivative capable of binding kidney hexokinase type I efficiently. Separate studies with yeast hexokinase showed that again only the Sepharose-N-amino-octanoylglucosamine was capable of acting as an efficient affinity matrix for this enzyme. Implications of these studies in our understanding of affinity-chromatography operation are discussed.

Animals

The application of the sepharose bead immunofluorescence test for the detection of allergen-specific IgE and IgG antibodies in pollinosis.

A new application of the Sepharose bead immunofluorescence test for detection of allergen-specific IgE and IgG antibodies is described. Allergen extracts of four different grass pollens were coupled to CNBr-activated Sepharose 4B. Twenty normal and allergic sera were incubated with the allergen-coupled beads, washed and incubated with fluorescence-conjugated anti-gamma E and G globulins. After washing and staining with 0.5% trypan blue, the percentage of fluorescent beads was detected by fluorescence microscopy. In the IgG/anti IgG system, the smallest amount of IgG demonstrated was 20ng/ml; in the IgE/anti-IgE system it was 40ng/ml. Independent examination of tests gave a mean difference between observations of 4.1%. Reproducibility was also very good (var. coeff = 18%). The number of beads stained with IgE correlated well with intensity of skin reactions to the same extracts (r = 0.64; p = 5 x 10-7), the percentage of IgG stained beads being independent of skin reactivity. The Sepharose-IgE test allowed clear distinction between allergic and normal sera (p = 4 x 10-7), while the Sepharose IgG test did not distinguish between them at the time of diagnosis. However, the number of beads stained with IgG significantly increased in patients undergoing immunotherapy (p = 3.8 x 10-3). The Sepharose bead immunofluorescence test requires a very small amount of materials, is highly sensitive and easy to handle. It may be valuable in the "in vitro" diagnosis of grass pollen allergy and useful in evaluating immunotherapy.

Allergens

[Biospecific chromatography of poly(A)-containing RNA on poly(U)-Sepharose].

It is shown that in addition to specific binding of polyadenylic sequence with poly(U), the chromatography of poly(A)-containing RNAs on poly(U)-Sepharose is accompanied by nonspecific irreversible adsorption of polynucleotides on Sepharose gel. This disadvantage may be overcome by establishing optimal BrCN/Sepharose rations during Sepharose activation and by many-fold treatment of poly(U)-Sepharose with ethanolamine immediately before chromatography of RNAs. It was also found that the efficient separation of poly(A+)-RNA preparations from poly(A-)-RNAs is achieved only after double chromatography of RNA on poly(U)-Sepharose. The amount of poly(A+)-RNA in total RNA preparations isolated from bound polyribosomes of 10-day-old chick embryos is equal to 1%. Data from PAAG gel electrophoresis are indicative of the lack of degradation and high heterogeneity of the preparations under study.

Chemical Phenomena

Blue Sepharose chromatography of human alcohol dehydrogenase: evidence for interlocus and interallelic differences in affinity characteristics.

1. The various isozymes of human alcohol dehydrogenase have been examined by Blue Sepharose column chromatography. 2. The products (alpha, beta1 and gamma1) of the common alleles at the three ADH loci (ADH1 ADH2 and ADH3 respectively) were found to show slight, but significant differences in their affinities for Blue Sepharose. The order of affinity of the homodimeric isozymes was: alphaalpha less than gamma1gamma1 less than beta1beta1. The heterodimeric isozymes showed intermediate affinities. 3. The products (gamma1 and gamma2) of the common alleles (ADH31 and ADH32 respectively) at the ADH3 locus showed a pronounced difference in their affinities: the gamma1gamma1 isozyme was firmly adsorbed by Blue Sepharose, whereas the gamma2gamma2 isozyme was not adsorbed. The heterodimeric gamma1gamma2 isozyme was intermediate in its behaviour. 4. The 'usual' and 'atypical' forms of ADH were indistinguishable by Blue Sepharose column chromatography. 6. The 'anodal' form of ADH showed no affinity for Blue Sepharose.

Adult

Demonstration of two molecular variants of carcinoembryonic antigen by concanavalin A sepharose affinity chromatography.

The carcinoembryonic antigen (CEA) active glycoproteins from perchloric acid extract of liver-metastasized primary colon tumor have been separated by concanavalin A Sepharose (Con A Sepharose) chromatography. The CEA activities separated by Con A Sepharose chromatography were designated as loosely bound and tightly bound which, respectively, eluted on the Con A Sepharose column between 0.12 and 0.15 M and 0.3 M alpha-methylmannose in a linear gradient of alpha-methylmannose. Further purification of these activities by Sephadex G-200, Bio-Gels A-1.5m and P-300 yielded two variants of glycoproteins (B1 and C2) with CEA activity. Both purified preparations of CEA had similar immunochemical properties. Their A280/A260 ratios were 1.30 and 1.56, respectively. The purified loosely bound CEA (B1) had immunological, chromatographic, and electrophoretic properties similar to those of 125I-CEA, whereas the tightly bound CEA (C2) had a lower molecular weight (120,000 to 140,000). Further, specificity to these two CEA's was established by their reactions in immunoelectrophoresis with preparations of specific goat anti-CEA anti-serum obtained from other investigators. The results indicate the practical use of Con A Sepharose affinity chromatography for the separation and characterization of glycoprotein tumor antigens.

Carcinoembryonic Antigen

Fractionation of plant aminoacyl-tRNA synthetases on tRNA-Sepharose columns.

It has been shown that tRNA-Sepharose, a chromatographic adsorbent containing unfractionated tRNA bound to a Sepharose matrix, is a useful, group-specific adsorbent for fractionation of the plant aminoacyl-tRNA synthetases. Conditions are described in which Val-, Trp-, Phe-, Leu- and Ile-tRNA synthetases from yellow lupin seeds can be separated from each other on the tRNA-Sepharose columns. Factors affecting affinity chromatography on the t-RNA-Sepharose columns are discussed. The affinity chromatography procedure for the purification of lupin Ser-tRNA synthetase to homogenity is described.

Amino Acyl-tRNA Synthetases

The affinity of human, rabbit and bovine thrombins for sepharose-lysine and other conjugates.

Human, rabbit and bovine thrombins are shown to possess marked affinities for Sepharose-lysine. Using either Xa-activated crude prothrombins (human, rabbit) or a commercial thrombin sample (bovine), the enzyme was isolated in a single chromatographic step by the affinity medium and preparations of high specific activity were obtained. The relevance of bound-lysine for the affinity of the thrombins was studied using other Sepharose conjugates with structures related to Sepharose-lysine. Using freshly activated prothrombins it was found that human and rabbit thrombin uptake required a conjugate with a spacer chain containing a minimum of four carbon atoms in length which supported a terminal amino group. As the thrombin activity aged, affinity for the terminal amino group decreased but the hydrophobic spacer chain became essential for enzyme binding. The active centre of thrombin was not involved in binding to Sepharose-lysine.

Animals

Resolution of ribonucleic acids by Sepharose 4B column chromatography.

Ribonucleic acids were resolved by molecular sieve chromatography on columns of Sepharose 4B. The elution positions of messenger ribonucleic acids were determined by detection of polyadenosine tracts and by support of protein synthesis in a messenger-dependent cell-free system. The elution position of other ribonucleic acid species from the Sepharose 4B was determined by formamide-sucrose density gradient centrifugation. Resolution of ribonucleic acids by this column was not dependent on molecular weight but rather on other properties such as secondary structure or the presence of poly(adenylic acid). The elution profiles of ribonucleic acids on cross-linked Sepharose 4B differed markely from those on conventional Sepharose and appeared to depend on molecular size alone. There was diminished resolution of high molecular weight ribonucleic acids on such columns.

Animals