scholarly journals The purification in high yield and characterization of rat hepatic glucokinase

1976 ◽  
Vol 153 (2) ◽  
pp. 363-373 ◽  
Author(s):  
M J Holroyde ◽  
M B Allen ◽  
A C Storer ◽  
A S Warsy ◽  
J M E Chesher ◽  
...  

A new improved procedure for the purification of rat hepatic glucokinase (ATP-d-glucose 6-phosphotransferase, EC 2.7.1.2) is given. A key step is affinity chromatography on Sepharose-N-(6-aminohexanoyl)-2-amino-2-deoxy-d-glucopyranose. A homogeneous enzyme, specific activity 150 units/mg of protein, is obtained in about 40% yield. The molecular weight of the pure enzyme was determined by several procedures. In particular, sedimentation-equilibrium studies under a variety of conditions indicate a molecular weight of 48000 and no evidence for dimerization; reports in the literature of other values are discussed in the light of this evidence on the pure enzyme. The amino acid composition suggests that hepatic glucokinase is closely related to rat brain hexokinase and also the wheat “light” hexokinases.

1976 ◽  
Vol 29 (2) ◽  
pp. 11 ◽  
Author(s):  
Robert C Marshall ◽  
JM Gillespie

The present paper continues the study of the reduced and S-carboxymethylated high-sulphur proteins from mouse hair. Fractions have been obtained in a substantially purified form by fractional precipitation with ammonium sulphate at pH 6, followed by ion exchange chromatography on cellulose phosphate at pH 2�6. Approximately 80% by weight of the high-sulphur proteins fall into the ultra-high-sulphur category (carboxymethyicysteine content greater than 26 residues per 100 residues), and they cover a molecular weight range of 17000-28000. The components show a remarkable diversity in amino acid composition; for example the contents of arginine and glycine each vary by about 3 : 1. The remainder of the proteins contain 17-20 residues per 100 residues of carboxymethyicysteine, are smaller in size (molecular weight 11 500), and also show great diversity in overall amino acid composition.


1975 ◽  
Author(s):  
W. Hornebeck ◽  
Y. Legrand ◽  
J. P. Caen ◽  
L. Robert

An elastase-like enzyme has been isolated from human platelets. Its purification using precipitations with ammonium sulphate, gel filtration and affinity chromatography on Agarose-elastin, is described. The acrylamide gel of the affinity peak reveals only one band corresponding to a molecular weight of about 25,000 daltons. The amino acid composition is similar to pancreatic elastase. Using the same kind of purification procedure an aortic elastase-like enzyme has also been isolated and characterized. These two enzymes possess comparable proteolytic activity on various synthetic and natural substrates considered as specific for elastases. The ratio of their activity on these substrates differs however from that of pancreatic elastase. The inhibitory effect of α1, antitrypsine and α2 macroglobuline were also studied and shown to differ quantitatively from those on pancreatic elastase. These elastase like enzymes may be responsible for the degradation of elastin occuring in ageing and arteriosclerosis.


1970 ◽  
Vol 48 (9) ◽  
pp. 1017-1021 ◽  
Author(s):  
C. Gilardeau ◽  
M. Chrétien

A lipolytic substance was isolated from porcine pituitary glands. It's amino acid composition, molecular weight, N-terminal amino acid, isoelectric point, and biological activities are reported. These results are compared to the corresponding values of sheep β-lipolytic hormone.


1952 ◽  
Vol 35 (4) ◽  
pp. 629-637 ◽  
Author(s):  
Choh Hao Li ◽  
Kai O. Pedersen

The physiochemical characteristics of the follicle-stimulating hormone (FSH) from whole sheep pituitary glands have been studied. The hormone behaves as a single protein in electrophoresis, diffusion, and ultracentrifugation. It has an isoelectric point at pH 4.5 and a molecular weight of 67,000 and contains 1.23 per cent hexose and 1.51 per cent hexosamine. The amino acid composition has also been determined in large part. The stability of the hormone to acid and heat has been investigated.


1975 ◽  
Vol 53 (3) ◽  
pp. 269-274 ◽  
Author(s):  
W. S. Rickert ◽  
P. A. McBride-Warren

The acid protease produced by a strain of Mucor miehei isolated in Cuba was purified by column electrofocusing and partially characterized as to amino-acid composition, molecular weight, helical content, total carbohydrate content, and approximate isoelectric point. A detailed comparison of these results with those reported previously for Mucor miehei protease (Ottesen, M. &Rickert, W. S. (1970) C.R. Trav. Lab. Carlsberg 37, 301) suggested that the two enzymes are similar but not identical. This conclusion was reinforced by an analysis of circular-dichroism spectra.


1963 ◽  
Vol 41 (3) ◽  
pp. 697-705 ◽  
Author(s):  
P. K. Datta ◽  
K. R. Hanson ◽  
D. R. Whitaker

The molecular weight of Myrothecium cellulase was estimated by the Archibald method to be approximately 49,000. No N-terminal amino acid could be detected by the Edman degradation or with fluorodinitrobenzene. Hydrazinolysis gave glycine as the C-terminal amino acid. No free sulphydryl groups could be detected in the enzyme. The amino acid composition and the fingerprint pattern after tryptic digestion were determined.


1984 ◽  
Vol 51 (2) ◽  
pp. 259-266 ◽  
Author(s):  
Jutta Cerning-Beroard ◽  
Claude Zevaco

Summaryκ-casein from porcine milk was isolated and purified by affinity chromatography on thiopropyl Sepharose followed by hydroxyapatite chromatography. The amino acid composition of this protein is similar to that of bovine κ-casein. The sugar composition was established and sow κ-casein was found to be highly glycosylated. It contains 12 N-acetylneuraminic acid, 10 N-acetylgalactosamine, 2 N-acetylglucosamine and 22 galactose residues.


1963 ◽  
Vol 41 (1) ◽  
pp. 697-705 ◽  
Author(s):  
P. K. Datta ◽  
K. R. Hanson ◽  
D. R. Whitaker

The molecular weight of Myrothecium cellulase was estimated by the Archibald method to be approximately 49,000. No N-terminal amino acid could be detected by the Edman degradation or with fluorodinitrobenzene. Hydrazinolysis gave glycine as the C-terminal amino acid. No free sulphydryl groups could be detected in the enzyme. The amino acid composition and the fingerprint pattern after tryptic digestion were determined.


1970 ◽  
Vol 24 (03/04) ◽  
pp. 325-333 ◽  
Author(s):  
G. H Tishkoff ◽  
L. C Williams ◽  
D. M Brown

SummaryAs a corollary to our previous studies with bovine prothrombin, we have initiated a study of human prothrombin complex. This product has been isolated in crystalline form as a barium glycoprotein interaction product. Product yields were reduced compared to bovine product due to the increased solubility of the barium glycoprotein interaction product. On occasion the crystalline complex exhibited good yields. The specific activity of the crystalline complex was 1851 Iowa u/mg. Further purification of human prothrombin complex was made by removal of barium and by chromatography on Sephadex G-100 gels. The final product evidenced multiple procoagulant activities (II, VII, IX and X). The monomeric molecular weight determined by sedimentation equilibrium in a solvent of 6 M guanidine-HCl and 0.5% mercaptoethanol was 70,191 ± 3,057 and was homogeneous with respect to molecular weight. This product was characterized in regard to physical constants and chemical composition. In general, the molecular properties of human prothrombin complex are very similar to the comparable bovine product. In some preparations a reversible proteolytic enzyme inhibitor (p-aminophenylarsonic acid) was employed in the ultrafiltration step of the purification scheme to inhibit protein degradation.


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