scholarly journals Partial purification and properties of the two common inherited forms of human erythrocyte adenylate kinase

1972 ◽  
Vol 130 (3) ◽  
pp. 797-803 ◽  
Author(s):  
C. Brownson ◽  
N. Spencer
Keyword(s):  
Adenylate Kinase ◽  
Effect Of Temperature ◽  
Partial Purification ◽  
Heat Denaturation ◽  
Gel Chromatography ◽  
Molecular Weights ◽  
Purification And Properties ◽  
Increasing Temperature

1. The partial purification of adenylate kinase, types 1 and 2, from human erythrocytes is described. 2. Gel chromatography of both forms of the enzyme gave estimates of the molecular weights in the range 20000–23000. 3. Studies on crude haemolysates at various pH values indicated that the type 2 enzyme was less stable than the type 1. Heat denaturation studies on the partially purified enzymes confirmed these findings. 4. Measurements of rates of inhibition by iodoacetate and iodoacetamide showed that the type 2 enzyme reacts more readily than the type 1 enzyme with both reagents. 5. The effect of temperature on the initial velocity of ADP formation was measured at a single concentration of both AMP and MgATP2-. The two forms of the enzyme responded differently to increasing temperature.

scholarly journals Partial purification and properties of the common inherited forms of adenosine deaminase from human erythrocytes

1973 ◽  
Vol 133 (1) ◽  
pp. 117-123 ◽  
Author(s):  
W. R. A. Osborne ◽  
N. Spencer
Keyword(s):  
Ionic Strength ◽  
Adenosine Deaminase ◽  
Reaction Rates ◽  
Competitive Inhibitor ◽  
Human Erythrocytes ◽  
Partial Purification ◽  
Heat Inactivation ◽  
Gel Chromatography

1. The partial purification of adenosine deaminase, types 1, 2 and 2–1, from human erythrocytes is described. 2. The isoenzyme components characteristic of the three forms of the enzyme were partially resolved by chromatography on DEAE-Sephadex. 3. Gel chromatography of the various forms of the enzyme gave estimates of the molecular weights in the range 30000–35000. 4. Electrophoresis in starch gels containing increasing percentages of starch did not reveal any differences in molecular weight between the genetic variants or their isoenzyme components. 5. Analytical isoelectric-focusing experiments in polyacrylamide gels gave the following pI values for the four isoenzyme components present in type 2–1 erythrocytes: 4.70, 4.83, 4.94 and 5.06. 6. All forms of the enzyme gave Km values for adenosine of about 30μm and Ki values of about 8μm for the competitive inhibitor purine riboside. 7. Reaction rates of the type 1 and 2 enzymes were measured at different temperatures. Both enzymes gave values for the energy of activation for hydrolysis of adenosine of about 33.4kJ/mol (8kcal/mol). 8. Heat inactivation of all forms of the enzyme was markedly dependent on ionic strength, the rate of inactivation increasing with increasing ionic strength. The type 1 and type 2 forms of the enzyme differed significantly in their susceptibility to heat inactivation. From the variation of rates of inactivation with temperature, values were obtained for the energies of activation for the heat inactivation of both enzymes as follows: type 1 enzyme 275.5kJ/mol (65.9kcal/mol) and type 2 enzyme 241.6kJ/mol (57.8kcal/mol.).

scholarly journals Purification and properties of bovine caeruloplasmin

1981 ◽  
Vol 199 (3) ◽  
pp. 667-673 ◽  
Author(s):  
L Calabrese ◽  
F Malatesta ◽  
D Barra
Keyword(s):  
Copper Content ◽  
General Structure ◽  
Molecular Weight Determination ◽  
Copper Determination ◽  
Purification And Properties ◽  
Different Types ◽  
Novel Method ◽  
Fresh Preparation

A novel method is reported for isolation of bovine caeruloplasmin from plasma; it involves a rapid and mild procedure, namely two column chromatographies with stepwise elution and one (NH4)2SO4 precipitation, and results in a proteolytically undegraded homogeneous protein. The general structure of the protein, as evaluated by molecular-weight determination and amino acid composition, is very similar to that established for human and rat caeruloplasmin. Copper determination and e.p.r. spectral analysis on the native and NO-treated protein gave a metal-to-protein stoichiometry of six atoms of copper per molecule. Three copper atoms were detectable by e.p.r., with Type 2/Type 1 ratio = 1 : 3 in most samples. The protein is very sensitive to storage and/or handling. A component was isolated from aged samples, which was found to contain approximately four copper atoms per 125000 daltons, two of which were detectable by e.p.r. with the characters of Type 2 copper. However, the same component was found to be present, although to a lesser extent, in the fresh preparation and does not seem to be related to proteolytic degradation. This component has no oxidase activity. On the basis of these results it is suggested that caeruloplasmin molecules are intrinsically heterogeneous with respect to both copper content and copper type, and this can explain the intriguing stoichiometry regarding the different types of copper centres.

Partial purification and properties of an invertase from Pseudomonas fluorescens

1984 ◽  
Vol 30 (11) ◽  
pp. 1326-1329 ◽  
Author(s):  
W. M. Bugbee
Keyword(s):  
Pseudomonas Fluorescens ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Partial Purification ◽  
Anion Exchange Column ◽  
Molecular Weights ◽  
Beet Root ◽  
Purification And Properties ◽  
Optimum Ph ◽  
Sugar Beet Root

An intracellular β-fructofuranosidase was extracted from a sugar beet root isolate of Pseudomonas fluorescens. The enzyme was partially purified using Sephacryl 200 gel and anion-exchange column chromatography. The enzyme's molecular weight was estimated at 35 400 on a calibrated column of Sephacryl 200 gel. Two protein bands with molecular weights of 19 000 and 21 000 were evident after polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The isoelectric point was pH 4.18. The Km of the enzyme was estimated at 90 mM for sucrose. The optimum pH for activity was 6.5 when measured in a phosphate buffer.

scholarly journals Identification and Partial Characterization of Endogenous Double-stranded Ribonucleic Acid in Mulberry

1994 ◽  
Vol 119 (4) ◽  
pp. 859-861
Author(s):  
S.T. Nameth ◽  
S.L. Cheng
Keyword(s):  
Ribonucleic Acid ◽  
Rnase A ◽  
Deciduous Tree ◽  
Virus Particles ◽  
Molecular Weights ◽  
Low Salt ◽  
Type 3

Double-stranded ribonucleic acid (dsRNA) analysis of apparently healthy red mulberry (Morus rubra L.) yielded four distinct dsRNA banding profiles. dsRNA type 1 contained three dsRNA bands with approximate molecular weights (MWs) of 12.0, 1.0, and 0.9 × 106, respectively. dsRNA type 2 contained two dsRNA bands with MWs of 1.0 and 0.9 × 106. dsRNA type 3 contained four dsRNA bands with MWs of 1.0, 0.9, 0.89, and 0.88 × 106. dsRNA type 4 contained three dsRNA bands with MWs of 1.0, 0.88, and 0.87 × 106. No virus particles were associated with any of the samples analyzed. All four types of dsRNA were resistant to DNase I and RNase A in high salt and susceptible to RNase A in low salt. Mulberry dsRNAs were somewhat similar to endogenous dsRNAs (edsRNA) associated with other hosts. This is the first report of edsRNA associated with a deciduous tree.

Partial purification and properties of an endo-xylanase from cucumber seeds

1991 ◽  
Vol 81 (3) ◽  
pp. 327-334 ◽  
Author(s):  
Cesar V. Mujer ◽  
Dale W. Kretchman ◽  
A. Raymond Miller
Keyword(s):  
Partial Purification ◽  
Purification And Properties

Partial purification and properties of a 36-kDa 1-aminocyclopropane-l-carboxylate N-malonyltransferase from mung bean

1995 ◽  
Vol 94 (4) ◽  
pp. 629-634 ◽  
Author(s):  
Mohamed Benichou ◽  
Gracia Martinez-Reina ◽  
Felix Romojaro ◽  
Jean-Claude Pech ◽  
Alain Latche
Keyword(s):  
Mung Bean ◽  
Partial Purification ◽  
Purification And Properties

Type 2 Diabetes Overtakes Type 1 in Hispanic Girls

2008 ◽  
Vol 38 (15) ◽  
pp. 18
Author(s):  
SHERRY BOSCHERT
Keyword(s):  
Type 2 Diabetes
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