IMPROVED PROCEDURES FOR PREPARATION AND CHARACTERIZATION OF MYROTHECIUM CELLULASE: PART 2. PURIFICATION PROCEDURES

1963 ◽  
Vol 41 (3) ◽  
pp. 671-696 ◽  
Author(s):  
D. R. Whitaker ◽  
K. R. Hanson ◽  
P. K. Datta

Two methods are described for purification of the cellulase of Myrothecium verrucaria from concentrated culture filtrates. The steps of method I are (1) fractionation with ammonium sulphate, (2) elution through Sephadex G25, (3) elution through Sephadex G75, (4) precipitation with polymethacrylic acid, and (5) elution through Amberlite CG50 with citrate buffer containing a gradient of urea concentration. The steps of method II are precipitation by saturated ammonium sulphate, (2) and (4) as above, elution through DEAE-cellulose with phosphate buffer containing 7 M urea, followed by (2) and (3) as above. The two methods gave final products with identical specific activities toward carboxymethyl cellulose; the increase in specific activity was approximately 12-fold. Starch-gel electrophoresis at pH 6.8 showed no major indications of heterogeneity. The purified enzyme was unstable but could be stored frozen in dilute salt solution.Enzyme passed through DEAE-cellulose without an inhibitor of cellulase activity was contaminated by DEAE-substituted oligoglucosides and subject to proteolysis. Urea could be replaced by cellobiose as an inhibitor but the latter gave enzyme contaminated by products of transfer reactions.Binding of urea by the resin is shown to influence significantly the resolution attainable in chromatographic fractionations on Amberlite CG-50 with buffers containing gradients of urea concentration.Procedures for dialysis and desalting of cellulases and a compact reaction vessel for pH stats are described.

1963 ◽  
Vol 41 (1) ◽  
pp. 671-696
Author(s):  
D. R. Whitaker ◽  
K. R. Hanson ◽  
P. K. Datta

Two methods are described for purification of the cellulase of Myrothecium verrucaria from concentrated culture filtrates. The steps of method I are (1) fractionation with ammonium sulphate, (2) elution through Sephadex G25, (3) elution through Sephadex G75, (4) precipitation with polymethacrylic acid, and (5) elution through Amberlite CG50 with citrate buffer containing a gradient of urea concentration. The steps of method II are precipitation by saturated ammonium sulphate, (2) and (4) as above, elution through DEAE-cellulose with phosphate buffer containing 7 M urea, followed by (2) and (3) as above. The two methods gave final products with identical specific activities toward carboxymethyl cellulose; the increase in specific activity was approximately 12-fold. Starch-gel electrophoresis at pH 6.8 showed no major indications of heterogeneity. The purified enzyme was unstable but could be stored frozen in dilute salt solution.Enzyme passed through DEAE-cellulose without an inhibitor of cellulase activity was contaminated by DEAE-substituted oligoglucosides and subject to proteolysis. Urea could be replaced by cellobiose as an inhibitor but the latter gave enzyme contaminated by products of transfer reactions.Binding of urea by the resin is shown to influence significantly the resolution attainable in chromatographic fractionations on Amberlite CG-50 with buffers containing gradients of urea concentration.Procedures for dialysis and desalting of cellulases and a compact reaction vessel for pH stats are described.


The enzyme benzylamine oxidase of pig plasma has been purified and some of the properties of the pure preparation have been studied. The purification procedure included several precipitations with ammonium sulphate and separations of proteins by column chromatography, first on DEAE-cellulose, followed by DEAE-Sephadex and lastly on a hydroxyapatite column. Crystals were prepared from solutions of the purified enzyme by adding ammonium sulphate. The crystalline preparation was homogeneous when studied by starch-gel electrophoresis and by ultracentrifugation. The molecular weight, as determined on the analytical ultracentrifuge, was 195 000. The copper content of the enzyme, as determined by radioactivation analysis, was about four atoms of Cu per molecule of enzyme. Concentrated solutions of the enzyme had a pink colour; the colour disappeared when substrate (benzylamine) was added under anaerobic conditions. The amines which were tested and found to be oxidized by the pure enzyme were: benzylamine, histamine, mescaline and 4-picolylamine. The affinity of the enzyme for benzylamine was more than one hundred times that for histamine.


1968 ◽  
Vol 46 (3) ◽  
pp. 347-350 ◽  
Author(s):  
F. C. Monkhouse ◽  
Susan Milojevic

A method for the preparation of purified plasma antithrombin and heparin-cofactor is described. The method involves adsorption by aluminium hydroxide, separation on a DEAE-cellulose column by means of a graded salt concentration, and vertical curtain electrophoresis. A 100-fold increase in the specific activity of antithrombin and a 30-fold increase in the specific activity of heparin-cofactor have been achieved. In spite of the increased purification, no separation of the two activities was achieved. When a highly purified fraction was subjected to starch-gel electrophoresis for 16–18 h and then eluted from the gel, there was significant loss of heparin-cofactor activity but not of antithrombin activity. The electrophoretic patterns of the recovered proteins were not altered.


1965 ◽  
Vol 13 (2) ◽  
pp. 117-124 ◽  
Author(s):  
V. K. HOPSU ◽  
R. S. SANTTI ◽  
G. G. GLENNER

Enzymes in guinea pig homogenates hydrolyzing a variety of halogenated and nonhalogenated acyl α- and β-naphthylamide substrates can be separated into two major groups on the basis of substrate hydrolysis rates, solubility and affector characteristics. Both groups of enzymes, those acting on the non-, mono- and dihalogenated acyl naphthylamides and those acting on trihalogen derivatives, have characteristics like those of arylesterases and are inseparable from enzymes hydrolyzing naphthol AS acetate. These enzymes are, However, separable on fractionation by starch gel electrophoresis and DEAE-cellulose chromatography from several enzymes catalyzing the hydrolysis of N-acyl amino acids (acylase I and II) and several amino acid β-naphthylamides. Species differences exist in the characteristics of enzymic hydrolysis of these acylarylamides.


1972 ◽  
Vol 29 (8) ◽  
pp. 1169-1172 ◽  
Author(s):  
J. W. Clayton ◽  
D. N. Tretiak

Amine-citrate buffer systems for pH control in starch gel electrophoresis gave good resolution of some dehydrogenase isozymes. The pK's of three new amine buffers, N-(3-aminopropyl)-morpholine, pK2 25 C, 6.12; N-(3-aminopropyl)-diethanolamine, pK2 25 C, 6.90; and 1,3-bis(dimethylamino)-2-propanol, pK2 25 C, 7.55, were determined at 5 C intervals in the range 10–40 C. These compounds, together with N, N-bis(2-hydroxyethyl)iminotris(hydroxymethyl)methane (bis-Tris) and tris-(hydroxymethyl)-methylamine(Tris), provide a series of amine buffers with pK's at 0.5 unit intervals in the pH range 6.1–8.1.


1966 ◽  
Vol 100 (3) ◽  
pp. 593-600 ◽  
Author(s):  
M Wallis ◽  
HBF Dixon

1. A method is described for the chromatographic preparation of ox growth hormone. It involves chromatography of an extract of anterior pituitary lobes on DEAE-cellulose, followed by rechromatography on a dextran gel of low cross-linkage (Sephadex G-100). 2. The product is highly active in growth-hormone assays, and is obtained in good yield. It was homogeneous by several criteria, but showed some heterogeneity on starch-gel electrophoresis. 3. The molecular weight of the hormone was estimated from its behaviour on gel-filtration columns under various conditions. Evidence that the hormone may dissociate into sub-units under some conditions is presented.


2014 ◽  
Vol 30 (3) ◽  
pp. 377-390 ◽  
Author(s):  
S.S.A. Egena ◽  
R.O. Alao

Biochemical diversity or polymorphism is the occurrence of varieties attributed to biochemical differences which are under genetic control. It has created a leeway for the genetic improvement of farm animals. This is because it can be used as a useful tool for the characterization of livestock breeds and population. This way, the degree of similarity or differences within and between breeds can be ascertained and this differences or similarity are important raw materials for genetic improvement of animals. Data obtained on gene frequencies and genotypes through polymorphism study makes it not only possible to compare the gene stocks of animals, the possible effects of the genes on reproductive and performance traits, but also study genetic variability under different environmental conditions of selection. This study was carried out to review haemoglobin (Hb) polymorphism in selected farm animals with the view of finding out the type of polymorphism observed by starch gel electrophoresis due to variation in the amino acid sequence in the polypeptide chains of Hb. The review showed clearly that there is a gene-controlled diversity in the different farm animals considered. This could serve as a reference point for future studies earmarked for the improvement of the animals possibly via marker-assisted selection.


1986 ◽  
Vol 32 (6) ◽  
pp. 481-486 ◽  
Author(s):  
C. Osothsilp ◽  
R. E. Subden

To obtain NAD-dependent malic enzyme mutants of Schizosaccharomyces pombe, a colony color indicator screening system was developed. Mutants defective for malic acid utilization (mau mutants) are yellow, while wild-type colonies are blue on the defined bromcresol green based indicator medium. NAD-dependent malic enzyme mutants were distinguished from other mau mutants by subsequent, starch gel electrophoresis, spectrophotometry, complementation tests, and intermediate pool analysis with cell-free extracts.


1990 ◽  
Vol 269 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Y Homma ◽  
Y Emori ◽  
F Shibasaki ◽  
K Suzuki ◽  
T Takenawa

A novel bovine spleen phosphoinositide-specific phospholipase C (PLC) has been identified with respect to immunoreactivity with four independent antibodies against each of the PLC isoenzymes, and purified to near homogeneity by sequential column chromatography. Spleen contains three of the isoenzymes: two different gamma-types [gamma 1 and gamma 2, originally named as PLC-gamma [Rhee, Suh, Ryu & Lee (1989) Science 244, 546-550] and PLC-IV [Emori, Homma, Sorimachi, Kawasaki, Nakanishi, Suzuki & Takenawa (1989) J. Biol. Chem. 264, 21885-21890] respectively] and delta-type of the enzyme, but PLC-gamma 1 is separated from the PLC-gamma 2 pool by the first DEAE-cellulose column chromatography. Subsequently, PLC-delta is dissociated on the third heparin-Sepharose column chromatography. The purified enzyme has a molecular mass of 145 kDa on SDS/polyacrylamide-gel electrophoresis and a specific activity of 12.8 mumol/min per mg with phosphatidylinositol 4,5-bisphosphate as substrate. This enzyme activity is dependent on Ca2+ for hydrolysis of all these phosphoinositides. None of the other phospholipids examined could be its substrate at any concentration of Ca2+. The optimal pH of the enzyme is slightly acidic (pH 5.0-6.5).


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