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T Sugo

Publications and source records attributed to T Sugo.

72 records · Page 4Linked to original sources
PubMed1981

The role of bovine high-molecular-weight (HMW) kininogen in contact-mediated activation of bovine factor XII: interaction of HMW kininogen with kaolin and plasma prekallikrein.

Previous studies from our laboratories (Sugo et al. (1980) Biochemistry 19, 3215-3220) have shown that bovine high-molecular-weight (HMW) kininogen remarkably accelerates the kaolin-mediated activation of Factor XII in the presence of prekallikrein, and that both fragment 1.2 and the light chain regions located in the COOH terminal half of the kininogen molecule are essential for the activation. In the present study, we demonstrate that the accelerating effect of HMW kininogen is mediated through its adsorption on the kaolin surface through the fragment 1.2 region and its complex formation with prekallikrein through the light chain region. The evidence is as follows: 1. HMW kininogen radio-labeled with 125I was adsorbed on kaolin and the adsorption was inhibited by the prior treatment of kaolin with fragment 1.2, fragment 1.2-light chain, kinin-free protein or HMW kininogen, but not with kinin- and fragment 1.2-free protein, light chain or low molecular-weight (LMW) kininogen. 2. The complex formation of HMW kininogen with prekallikrein in bovine plasma or in the purified system was examined by gel-filtration on a column of Sephacryl S-200 In bovine plasma, prekallikrein was eluted in the same fraction as HMW kininogen, showing an apparent molecular weight of 250,000, whereas purified prekallikrein was eluted in the fraction corresponding to an apparent molecular weight of 100,000. When purified prekallikrein was mixed with purified HMW kininogen in a mol ratio of 1 to 2, all prekallikrein was found to be associated with HMW kininogen. Furthermore, purified prekallikrein mixed with kininogen derivatives, such as kinin- and fragment 1.2-free protein, fragment 1.2-light chain or light chain, was eluted in the higher molecular weight fraction. HMW kininogen did not form a complex with prekallikrein. Using the same technique, it was shown that kinin- and fragment 1.2-free protein forms a complex not only with prekallikrein but also with kallikrein.

Adsorption↗
PubMed1981

High-molecular-weight kininogen from horse plasma. Isolation, characterization and comparison with bovine high-Mr kininogen.

High-molecular-weight (high-Mr) kininogen was purified from horse plasma by chromatography on columns of DEAE-Sephadex A-50, CM-Sephadex C-50, p-chlorobenzylamine-Sepharose and Sephadex G-150. The yield was about 150 mg from 81 of fresh plasma. The purified material gave a single band on sodium dodecylsulfate/polyacrylamide gel electrophoresis and a single precipitin line on immunodiffusion and immunoelectrophoresis. The molecular weight of horse high-Mr kininogen was estimated to be 78000 by dodecylsulfate gel electrophoresis using the Ferguson plot. Its polypeptide content was determined to be 86% by amino acid analysis and there was a total of 581 amino acid residues/molecule of protein. The kininogen contained a total of 13.9% carbohydrates, consisting of hexoses (7.8%), glucosamine (1.9%), galactosamine (0.6%) and sialic acid (3.6%). On incubation of horse high-Mr kininogen with bovine and horse plasma kallikreins, several fragments which contained extremely high levels of histidine, were liberated, in addition to kinin. After the liberation of kinin and histidine-rich fragments, a protein free of kinin and its fragments was isolated. This protein consisted of two polypeptide chains, heavy chain and light chain, which are bridged by disulfide bonds. The molecular weight and amino acid composition of the heavy chain and the light chain from horse high-Mr kininogen were very similar to those of the heavy and light chains from bovine high-Mr kininogen, respectively. From these results, it was revealed that horse high-Mr kininogen is quite similar to bovine high-Mr kininogen in terms of their physicochemical and chemical properties, although they are immunologically distinguishable.

Amino Acids↗
PubMed1979

Occurrence of Leu-Lys-bradykinin and histidine-rich peptide in high-molecular-weight kininogen isolated from horse plasma.

On incubation of purified horse plasma high-molecular-weight kininogen with purified plasma kallikrein, three new peptides, named fragment 1.2, fragment 1 and fragment 2, were released, in addition to the vasopeptide, bradykinin. Fragment 2 contained an extremely high level of histidine, in which eleven residues out of the total 48 residues were characterized. Thus the result proves the existence of the histidine-rich region in horse high-molecular-weight kininogen, which is similar to the region previously identified in bovine high-molecular-weight kininogen. Moreover, we have identified a new kinin derivative, Leu-Lys-bradykinin, in horse high-molecular-weight kininogen.

Amino Acid Sequence↗
PubMedDate not supplied

Multilayer binding of proteins to polymer chains grafted onto porous hollow-fiber membranes containing different anion-exchange groups.

Various anion-exchange groups were introduced into the polymer chains grafted onto a porous hollow-fiber membrane for protein recovery by radiation-induced graft polymerization and subsequent functionalization of a monomer containing an epoxy group. The graft chains extended from the pore surface toward the pore interior, resulting in the multilayer binding of proteins to the graft chains. Combinations of three anion-exchange groups, namely, amino (AM), ethylamino (EA), and diethylamino (DEA) groups, and three proteins, namely, beta-lactoglobulin, bovine serum albumin, and urease, were examined to evaluate the degree of multilayer binding of protein to the graft chains in the permeation mode. Multilayer binding was observed for hollow-fiber membranes containing EA and DEA groups, with conversions of epoxy groups to EA or DEA groups of higher than 80%. The amount of adsorbed protein remained constant irrespective of the conversion for the hollow-fiber membrane containing an AM group. The dependence of the flux on the conversion was consistent with that of the degree of multilayer binding to the graft chains.

Anion Exchange Resins↗
PubMedDate not supplied

Adsorption characteristics of an immobilized metal affinity membrane.

An immobilized metal affinity (IMA) hollow-fiber membrane was prepared by radiation-induced graft polymerization of glycidyl methacrylate (GMA) onto a porous polyethylene hollow fiber, followed by chemical conversion of the produced epoxide group into an iminodiacetate (IDA) group and its chelation with copper(II) ion. The IDA hollow fiber, whose degree of GMA grafting was 120%, was found to retain 0.42 mol of Cu ion/kg of dry weight of the resulting IMA hollow fiber. The pure water flux of the affinity membrane was 0.90 m/h at a filtration pressure of 1 x 10(5) Pa. The 0.1 g/L L-histidyl-L-leucine (His-Leu) solution permeated across the IMA hollow fiber, whose inner diameter and thickness were 0.78 and 0.365 mm, respectively, at a prescribed filtration pressure ranging from 0.2 x 10(5) to 1.0 x 10(5) Pa. The adsorption of His-Leu during permeation of the solution showed that the overall adsorption rate was independent of the filtration pressure, i.e., the residence time, because of the negligible diffusional resistance of His-Leu to the pseudobioaffinity ligand located on the pore surface of the membrane. No deterioration in the adsorption capacity was observed after five cycles of His-Leu adsorption, its elution, and reimmobilization of copper. The adsorption isotherm of bovine serum albumin (BSA) on the IMA hollow fiber was measured and compared with that for the conventional agarose-based bead containing the IDA-Cu ligand.(ABSTRACT TRUNCATED AT 250 WORDS)

Adsorption↗
PubMedDate not supplied

Ion exchange of lysozyme during permeation across a microporous sulfopropyl-group-containing hollow fiber.

A microporous hollow fiber containing a sulfopropyl (SP) group as a strongly acidic cation-exchange group was prepared by radiation-induced graft polymerization of glycidyl methacrylate, followed by hydrolysis of the resulting epoxide group into a diol, and then conversion of the diol into the SP group. The SP group density of the resulting hollow fiber ranged from 0.21 to 0.84 mol/kg of dry fiber with a pure water flux of 2.7 m/h at a filtration pressure of 0.1 MPa. Lysozyme adsorption was examined during permeation of the lysozyme solution (pH 6) through the pores across a microporous cation-exchange hollow fiber. The lysozyme concentration of the effluent penetrating the outside of the hollow fiber did not change irrespective of the residence time of the solution across the hollow fiber, which was indicative of the negligible diffusional resistance of lysozyme to the SP group. The binding capacity of lysozyme to the fiber was constant in this range of SP group density. For comparison, the adsorption characteristics of a cupric chloride solution during permeation were also determined. The binding capacity of Cu to the fiber increased linearly with increasing SP group density, because cupric ions of a smaller size than lysozyme can invade the depths of the grafted polymer branches formed in the amorphous domain of the polymer matrix.

Adsorption↗
PubMedDate not supplied

Binding of lysozyme onto a cation-exchange microporous membrane containing tentacle-type grafted polymer branches.

Ion-exchange adsorption of lysozyme to the sulfonic acid (SO3H) group on polymer chains grafted onto microporous polyethylene hollow-fiber membranes was examined. The lysozyme solution was forced to permeate across the hollow fiber. Diversely anchored SO3H groups, i.e., SP and SS groups, were introduced into the membrane by reaction of the glycidyl methacrylate-grafted membrane with propanesultone and sodium sulfite, respectively. The resulting SP and SS group-containing membranes, designated as SP-T and SS-T fibers, respectively, had 95 and 77% water flux of the original membrane, respectively. The binding capacity of lysozyme as a function of the SO3H group density was compared between the SP-T and SS-T fibers from measurement of the ion-exchange breakthrough curves during the permeation of lysozyme solution across the SP-T and SS-T fibers. The binding capacity of lysozyme to the SP-T fiber remained constant, independent of the SP group density, whereas that to the SS-T fiber increased linearly with increasing SS group density. This difference was explained by means of a model whereby lysozyme adheres onto the SP group-containing grafted polymer branches, while the SS group-containing grafted polymer branches hold lysozyme in a tentacle-like manner.

Cation Exchange Resins↗
PubMedDate not supplied

Reduction of nonselective adsorption of proteins by hydrophilization of microfiltration membranes by radiation-induced grafting.

Alcoholic hydroxyl groups were introduced into a polyethylene microfiltration (MF) membrane by radiation-induced graft polymerization of 2-hydroxyethyl methacrylate (HEMA), vinyl acetate (VAc), and glycidyl methacrylate (GMA). Subsequently, the VAc- and GMA-grafted membranes were quantitatively hydrolyzed into monool (single hydroxyl) and diol groups, respectively. The pure water flux of the modified membrane and the saturation capacity of bovine gamma-globulin onto the membrane were determined as a function of alcoholic hydroxyl group density. The threshold value for hydrophilization ranged between 5 and 7 mol of alcoholic hydroxyl group per kilogram of original MF membrane. Masking of the polyethylene surface with grafted polymer branches containing the diol groups was effective because approximately 70% of the pure water flux of the original MF membrane was maintained. Irrespective of the pore diameter of the original MF membrane, saturation capacities on the modified membrane correlated well with the diol group density. Saturation capacities of bovine gamma-globulin and bovine serum albumin were reduced to 1 mg/m2 of the membrane. In addition, the binding interaction changed from irreversible to reversible.

Adsorption↗
PubMedDate not supplied

High conversion in asymmetric hydrolysis during permeation through enzyme-multilayered porous hollow-fiber membranes.

We describe a novel porous hollow-fiber support for immobilizing aminoacylase in multilayers. Epoxy-group-containing polymer chains were grafted onto a porous hollow-fiber membrane by radiation-induced graft polymerization of glycidyl methacrylate, and subsequently a diethylamino group as an anion-exchange group was introduced into the graft chain. Aminoacylase was adsorbed in multilayers by allowing the amioacylase buffer solution to permeate through the pores across the hollow fiber; the graft chains provided three-dimensional space for the enzymes because of their electrostatic repulsion. The adsorbed enzyme at a degree of multilayer binding of 15 was cross-linked with glutaraldehyde to prevent leakage. An acetyl-DL-methionine solution was allowed to permeate through the pores surrounded by the aminoacylase-immobilized graft chain. Production of L-methionine was observed at a 4.1 mol/h per L of the fiber for a space velocity of 200 h(-1), defined as the flow rate of the effluent penetrating the outside surface of the hollow fiber divided by the membrane volume including the lumen.

Amidohydrolases↗
PubMedDate not supplied

Purification of docosahexaenoic acid ethyl ester using a silver-ion-immobilized porous hollow-fiber membrane module.

Docosahexaenoic acid ethyl ester (DHA-Et) was purified by adsorption on Ag-ion-immobilized membranes via selective interaction between silver ion and carbon-carbon double bonds of DHA-Et. Silver ions were immobilized onto sulfonic-acid-group-containing porous hollow-fiber membranes at an Ag ion density of 1.4 mol/kg of membrane, and 30 membranes were housed in one module (inner diameter = 18 mm and effective length = 80 mm). The adsorption isotherms of DHA-Et in various organic solvents revealed that DHA-Et was adsorbed on the immobilized Ag ions with a DHA-Et/Ag ion molar binding ratio of 1/5 in methanol, and that acetonitrile was the solvent of choice for the elution of the adsorbed DHA-Et. Permeation of bonito oil ethyl ester solution in methanol through the Ag-ion-immobilized hollow-fiber membrane module demonstrated that the displacement adsorption of other lower unsaturated fatty-acid ethyl esters by DHA-Et proceeded along the membrane thickness. The purity of DHA-Et was improved to 99 wt % by permeating first bonito oil ethyl ester containing 95 wt % DHA-Et and then acetonitrile through the module.

Adsorption↗