Some properties of a highly thermostable α-amylase from a Thermoactinomyces sp.

1984 ◽  
Vol 30 (6) ◽  
pp. 780-785 ◽  
Author(s):  
S. K. C. Obi ◽  
F. J. C. Odibo
Keyword(s):  
Molecular Weight ◽  
Enzyme Activity ◽  
Ion Exchange ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Enzyme Activation ◽  
Cow Dung ◽  
C 30 ◽  
Hydrolysis Of

Thermostable α-amylase from Thermoactinomyces sp. No. 15, isolated from cow dung, was partially purified and characterized. The enzyme was purified (318-fold) by acetone precipitation, ion-exchange chromatography, and gel filtration techniques. The molecular weight was estimated to be 47 800. Optimum enzyme activity was recorded at pH 7 and at 80 °C. The enzyme was stable at pH 5.0–10.0 and retained 74% activity at 100 °C (30 min). Enzyme activation was observed in the presence of Mn2+, Ag+, and Fe2+, but Hg2+ and Zn2+ were inhibitory. Products of hydrolysis of native starches were mainly glucose and maltose.

A dipeptidylpeptidase secreted by Fasciola hepatica

Parasitology ◽  
1994 ◽  
Vol 109 (1) ◽  
pp. 113-118 ◽  
Author(s):  
C. Carmona ◽  
S. McGonigle ◽  
A. J. Dowd ◽  
A. M. Smith ◽  
S. Coughlan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Liver Fluke ◽  
Fasciola Hepatica ◽  
Gel Filtration ◽  
Serine Proteinase ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Substrate Preference ◽  
Proteolytic Digestion

SUMMARYA dipeptidylpeptidase (DPP) was isolated from Fasciola hepatica by gel-filtration and ion-exchange chromatography. The exoproteinase is secreted by newly excysted juveniles, immature and mature flukes. The liver fluke DPP is a serine proteinase of molecular weight > 200 kDa and differs from previously characterized mammalian DPPs in its substrate preference and susceptibility to inactivation by inhibitors. The parasite DPP may function in the latter stages of the proteolytic digestion of host macromolecules. In this manner, the enzyme may be important in providing the parasite with dipeptides that could be absorbed through the intestine as nutrient.

Comparative studies of manganese(II)-, nickel(II)-, zinc(II)-, copper(II)-, cadmium(II)-, and iron(III)-binding components in human cord and adult sera

1984 ◽  
Vol 62 (6) ◽  
pp. 449-455 ◽  
Author(s):  
Show-Jy Lau ◽  
Bibudhendra Sarkar
Keyword(s):  
Molecular Weight ◽  
Trace Metals ◽  
Ion Exchange ◽  
Comparative Studies ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Low Molecular Weight ◽  
High Molecular Weight Proteins

The binding of six trace metals, Mn(II), Ni(II), Zn(II), Cu(II), Cd(II) and Fe(III), to human cord serum has been studied by Sephadex G-100 gel filtration at physiological pH, using radioisotopes as tracers. The results are compared with those obtained from adult serum. In both cord and adult sera, extensive amounts of the metals are bound to high molecular weight proteins. Among them, Fe(III) is mostly bound to transferrin; Ni(II), Zn(II), Cu(II), and Cd(II) are bound to albumin and other macro-molecules. The binding of Mn(II) either to transferrin or albumin is not resolved. Small fractions of Zn(II), Cu(II), and Cd(II) and large fractions of Mn(II) and Ni(II) are found to be associated with low molecular weight components of both sera. The distribution varies from metal to metal. However, the low molecular weight component of the size 1500 – 10 000 is present in all the metals studied. Further purification of this component was attempted by DEAE-cellulose ion-exchange chromatography. The possible identity as well as the biological role played by this particular component of serum in the transport of metals in blood and across membranes is discussed.

Purification and properties of an exocellular β-glucosidase of Candida molischiana (Zikes) Meyer and Yarrow capable of hydrolyzing soluble cellodextrins

1985 ◽  
Vol 63 (11) ◽  
pp. 1160-1166 ◽  
Author(s):  
Pierre Gondé ◽  
Robert Ratomahenina ◽  
Alain Arnaud ◽  
Pierre Galzy
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Optimum Temperature ◽  
Purification And Properties ◽  
Optimum Ph

The exocellular enzyme β-glucosidase of Candida molischiana was studied. This strain is able to ferment soluble cellodextrins. The enzyme was partially purified by ion-exchange chromatography and gel filtration. The molecular weight of this enzyme was 120 000; its optimum pH was between 4 and 4.5 and its optimum temperature was 60 °C. This enzyme was active against different soluble glucosides and was inhibited by p-chloromercuribenzoate, gluconolactone, and glucose. A "glucosyltransferase" activity appeared in the presence of ethanol. The biosynthesis of the enzyme was constitutive but repressed by glucose.

Purification of extracellular amylolytic enzymes from the thermophilic fungus Thermomyces lanuginosus

1988 ◽  
Vol 34 (3) ◽  
pp. 218-223 ◽  
Author(s):  
Bo Jensen ◽  
Jorgen Olsen ◽  
Knud Allermann
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Soluble Starch ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Thermomyces Lanuginosus ◽  
Amylolytic Enzymes ◽  
Molecular Weights ◽  
Isoelectric Points ◽  
Hydrolysis Of

When grown in static culture it appears as if Thermomyces lanuginosus has a biphasic secretion of the extracellular starch-degrading activity. This could be due to the presence of at least two different amylases. By ion-exchange chromatography on DEAE-Trisacryl an α-amylase (EC 3.2.1.1) and a glucoamylase (EC 3.2.1.3) were separated and purified from the extracellular protein from 14-day-old static cultures grown on soluble starch. The hydrolysis of soluble starch by the purified glucoamylase resulted in only glucose as the end product, whereas the α-amylase gave maltose as the smallest end product. The molecular weights and isoelectric points of the enzymes were for glucoamylase 70 000 – 76 000 and pH 4.0, and for α-amylase 54 000 – 57 000 and pH 3.4. An α-glucosidase (EC 3.2.1.20) with a molecular weight of 44 000 – 48 000 and an isoelectric point at pH 3.8 was eluted close to the α-amylase fraction on the DEAE-Trisacryl column.

Separation and Characterization of Two Fibrinolytic Inhibitors from Human Placenta

1971 ◽  
Vol 25 (03) ◽  
pp. 580-589 ◽  
Author(s):  
M Uszynski ◽  
U Abildgaard
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Isoelectric Focusing ◽  
Basic Protein ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Coagulation Inhibitor ◽  
Tissue Thromboplastin

SummaryProcedures for the separation of two inhibitors of the activation of plasminogen to plasmin by urokinase are described. Tissue thromboplastin was removed by adsorption to Al(0H)3 gel followed by ultracentrifugation. Plasminogen, plasminogen activator, a coagulation inhibitor and hemoglobin were removed by ion exchange chromatography (CM- or DEAE-Sephadex with NaCl gradients). The minor UK inhibitor is a relative basic protein with a pI of about 5.8. The major inhibitor was purified further by isoelectric focusing, preparative electrophoresis in polyacrylamide gel, and gel filtration. This inhibitor has α1-motility, the pI is about 5.2, and the molecular weight about 100,000. It inactivates urokinase progressively, but does not inhibit streptokinase, plasmin or thrombin.

In Vitro Anticoagulant Activity of Esters of Heparin.

1979 ◽  
Author(s):  
J. Mardiguian ◽  
M. Trillou ◽  
J. Marin
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Chemical Modification ◽  
Anticoagulant Activity ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Hydroxyl Groups ◽  
Oh Groups

Chemical modification of Heparin by esterification of its hydroxyl groups has been carried out in order to study its influence on the in vitro anticoagulant activity. Beef and pig mucosal Heparins have been fractionated by gel filtration and by ion-exchange chromatography to yield fractions which have been esterified.Two types of esters have been prepared : 4-chlorophenoxy-acetic and 4-chlorophenoxy-isobutyric.The anticoagulant activity of the these esters has been evaluated in vitro (using U.S.P. method, anti-Xa and anti-thrombin assays) and correlated with their chlorine content and U.V. absorption.This study shows that the in vitro anticoagulant activity of heparin is decreased by esterification of its OH groups, to an extent depending upon the type of ester, the molecular weight and the degree of substitution.The results of these experiments will be reported and discussed in detail.

scholarly journals Multiple Haemoglobins of the Bivalve Mollusc Anadara Trapezia

1980 ◽  
Vol 33 (6) ◽  
pp. 643 ◽  
Author(s):  
PF Como ◽  
EOP Thompson
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Bivalve Mollusc ◽  
Marine Mollusc ◽  
Respiratory Proteins

The respiratory proteins of the invertebrate marine mollusc A. trapezia have been separated by a combination of gel filtration and ion-exchange chromatography. There is a major tetrameric haemoglobin, HbI, of molecular weight approximately 67000 and two minor polymorphic haemoglobins HbIIa and HbIIb that are dimeric with molecular weight approximately 31000, in agreement with previous reports in the literature.

scholarly journals Interaction between S-Type Pyocins and Microcin-II-Like Bacteriocins in Pseudomonas aeruginosa

2021 ◽  
Vol 83 (3) ◽  
pp. 72-80
Author(s):  
O.B. Balko ◽  
Keyword(s):  
Molecular Weight ◽  
Pseudomonas Aeruginosa ◽  
Ion Exchange ◽  
Protein Concentration ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Activity Increase ◽  
Activity Indices

According to our previous results, S-type bacteriocins of Pseudomonas aeruginosa are characterized by high activity against phytopathogenic Pseudomonas syringae strains. In addition to these pyocins producing strains are able to synthesize microcin-II-like bacteriocins. Presence of interaction between these two killer factors can determine methods of their use and activity increase of bacteriocins with antiphytopathogenic properties. The aim of the work was to test possibility of interaction between S-type pyocins and microcin-II-like bacteriocins of P. aeruginosa. Methods. The objects of the study were pyocins produced by 6 P. aeruginosa strains. Killer factors in composition of induced lysates were concentrated by 70% ammonium sulphate precipitation, dialyzed through dialysis membrane with molecular weight cut-off (MWCO) 3.5 kDa. Then ion-exchange chromatography with DEAE-cellulose, gel filtration with Sephadex G-75 and ultracentrifugation at 215.000 g for 1 and 4 hours were used for their separation. Protein concentration and antimicrobial activity were determined in obtained fractions. Visualization of proteins in active fraction composition was conducted by electrophoresis according to the Laemmli method. Results. Under ion-exchange chromatography with DEAE-cellulose application elution of bacteriocins available in lysate composition occurs simultaneously. The highest indices of activity and protein concentration were in the 4th fraction, containing two protein bands with molecular weight near 58 and 9 kDa, which are typical for S5 pyocin and microcin-II-like bacteriocins of P. aeruginosa. Further gel filtration of sampled fractions through Sephadex G-75 allowed to separate noted killer factors and obtaine purified fraction containing microcin-II-like pyocins only. Application of ultracentrifugation during 1 hour didn’t precipitate studied bacteriocins, whereas during 4 hours – lead to their separation. At the same time a twofold increase of activity indices for S-type pyocins in precipitates and for microcin-IIlike killer factors – in supernatants were observed. However achieved concentration was characterized by short-term effect, since in 14 days activity of supernatants decreased by 4–16 times, and for precipitates – by 80–640 times. Then revealed tendency for activity decrease continued. Conclusions. S-type pyocins and microcin-II-like bacteriocins of P. aeruginosa interact with each other, that ensures their stabilization and protects again destruction. Application of methods that cause separation of these killer factors is inexpedient, since it results into considerable decrease of bacteriocin activity indices.

scholarly journals Isolation and characterization of C1q, a subcomponent of the first component of complement, from human and rabbit sera

1972 ◽  
Vol 130 (3) ◽  
pp. 749-763 ◽  
Author(s):  
K. B. M. Reid ◽  
D. M. Lowe ◽  
R. R. Porter
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Sedimentation Equilibrium ◽  
Soluble Form ◽  
Equilibrium Studies ◽  
Preparative Scale ◽  
Isolation And Characterization

1. C1q, a subcomponent of the first component of complement, has been isolated, in a haemolytically active and soluble form, by ion-exchange chromatography and gel filtration, from human and rabbit sera. Yields ranged from 10 to 25mg/litre of serum and the activity of final preparations was consistently in the range 5×103-15×103 C1qH50 units/mg. 2. The molecular weights of human and rabbit subcomponent C1q were 409600 and 417600, as determined by sedimentation equilibrium studies. 3. Subcomponent C1q from both species was shown to be composed of non-covalently linked subunits of approximately 57000 molecular weight as determined by gel-filtration or sedimentation equilibrium studies in 5.3m-guanidinium chloride. Reduction or oxidation of human and rabbit subcomponent C1q yielded three chains each having a molecular weight of approximately 23000 and which differed slightly in amino acid composition but markedly in carbohydrate content. The oxidized chains were separated, on a preparative scale, by ion-exchange chromatography in 8m-urea on DEAE-cellulose. 4. Both human and rabbit subcomponent C1q contained hydroxyproline, hydroxylysine, a high percentage of glycine and approximately 8% carbohydrate. Glutamic acid and aspartic acid were the free N-terminal amino acids of human subcomponent C1q whereas only serine was found in rabbit subcomponent C1q. 5. Collagenase digestion of human or rabbit subcomponent C1q caused a rapid loss of haemolytic activity which correlated with the breakdown of collagenous regions in the molecule.

scholarly journals Rat small-intestinal β-galactosidases. Studies on the fractionation of ‘acid’ β-galactosidase with isoelectric focusing, gel filtration and ion-exchange chromatography

1970 ◽  
Vol 117 (2) ◽  
pp. 369-375 ◽  
Author(s):  
Nils-Georg Asp
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
High Molecular Weight ◽  
Isoelectric Focusing ◽  
Gel Filtration ◽  
Ion Exchange Resin ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Isoelectric Points ◽  
Small Intestinal

1. Different forms of the rat small-intestinal ‘acid’ β-galactosidase were separated by using the isoelectric-focusing technique. The isoelectric points of the different forms were at pH4.2, 4.6, 5.4, 6.1 and approx. 8. 2. The two forms of ‘acid’ β-galactosidase isoelectric at pH4.2 and 4.6 were completely excluded from the Sephadex G-200 gel, whereas the form isoelectric at pH8 had Kav. 0.4. The concentration and pH of the elution buffer influenced the distribution of enzyme activity between different forms. Thus, under certain conditions of ionic strength and pH, the enzyme seems to form high-molecular-weight aggregates with low isoelectric points. These may be homopolymeric aggregates or the result of binding of enzyme to, for example, membrane fragments. The forms isoelectric at pH5.4 and 6.1 are probably aggregates of intermediate size. 3. During ion-exchange chromatography at pH6.0 one fraction of ‘acid’ β-galactosidase was not retained on the column and was isoelectric at pH8 and another fraction was eluted when the buffer concentration in the eluate had increased to about 50mm. The main part of enzyme eluted in this second fraction was also isoelectric at pH8, indicating that the elution of this fraction is not a simple ion-exchange procedure but probably also involves a splitting of high-molecular-weight aggregates, originally retained because of their low isoelectric points. The enzyme subunits have a higher isoelectric point, and are therefore no longer bound to the ion-exchange resin.

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