scholarly journals The microsporidian spore invasion tube. The ultrastructure, isolation, and characterization of the protein comprising the tube.

1976 ◽  
Vol 71 (1) ◽  
pp. 23-34 ◽  
Author(s):  
E Weidner
Keyword(s):  
Molecular Weight ◽  
Sodium Dodecyl ◽  
Low Molecular Weight ◽  
Two Dimensional ◽  
Polar Tube ◽  
Isolation And Characterization ◽  
Disulfide Linkages ◽  
Microsporidian Spore ◽  
Ph Range

The extrusion apparatus of the microsporidian parasitic protozoan Nosema michaelis discharges an invasion (or polar) tube with a velocity suitalbe for piercing cells and injecting infective sporoplasm. The tube is composed of a polar tube protein (PTP) which consists of a single, low molecular weight polypeptide slightly smaller than chymotrypsinogen-A. Assembled PTP tubes resist dissociation in sodium dodecyl sulfate and brief exposures in media at extreme ends of the pH range; however, the tubes are reduced by mercaptoethanol and dithiothreitol. When acidified, mercaptoethanol-reduced PTP self-assembles into plastic, two-dimensional monolayers. Dithiothreitol-reduced PTP will not reassemble when acidified. Evidence is presented which indicates that PTP is assembled as a tube within the spore; that the ejected tube has plasticity during sporoplasm passage; and, finally, that the subunits within the tube polymer are bound together, in part, by interprotein disulfide linkages.

Isolation and Characterization of Plasminogen Activator from Pig Leucocytes

1974 ◽  
Vol 31 (01) ◽  
pp. 072-085 ◽  
Author(s):  
M Kopitar ◽  
M Stegnar ◽  
B Accetto ◽  
D Lebez
Keyword(s):  
Molecular Weight ◽  
Plasminogen Activator ◽  
Gel Electrophoresis ◽  
Gel Filtration ◽  
Ph Optimum ◽  
Isolation And Characterization ◽  
Ph Range ◽  
Inhibition Studies ◽  
Final Purification

SummaryPlasminogen activator was isolated from disrupted pig leucocytes by the aid of DEAE chromatography, gel filtration on Sephadex G-100 and final purification on CM cellulose, or by preparative gel electrophoresis.Isolated plasminogen activator corresponds No. 3 band of the starting sample of leucocyte cells (that is composed from 10 gel electrophoretic bands).pH optimum was found to be in pH range 8.0–8.5 and the highest pH stability is between pH range 5.0–8.0.Inhibition studies of isolated plasminogen activator were performed with EACA, AMCHA, PAMBA and Trasylol, using Anson and Astrup method. By Astrup method 100% inhibition was found with EACA and Trasylol and 30% with AMCHA. PAMBA gave 60% inhibition already at concentration 10–3 M/ml. Molecular weight of plasminogen activator was determined by gel filtration on Sephadex G-100. The value obtained from 4 different samples was found to be 28000–30500.

Isolation and Characterization of Human Platelet β-Thromboglobulin

1975 ◽  
Author(s):  
D. S. Pepper ◽  
S. Moore ◽  
J. D. Cash
Keyword(s):  
Molecular Weight ◽  
Plasma Proteins ◽  
Human Platelet ◽  
Weight Fraction ◽  
Human Platelets ◽  
Low Molecular Weight ◽  
Purification Procedure ◽  
Isolation And Characterization

The thrombin released products from washed human platelets were separated by filtration on 4% agarose in 0.15 M NaCl. The high molecular weight PF4 complex was dissociated and re-chromatographed in 0.75 M NaCl. The low molecular weight fraction, including β thromboglobulin and a low MW anti-heparin was freed of plasminogen anti-activator by dissociation and chromatography in pH 3.5 pyridine acetic acid. The anti-activator was irreversibly denatured and albumin was removed in the void volume of the column. A more suitable purification procedure for recovery of all activities was affinity chromatography on heparin-agarose. The anti-activator was excluded and could be obtained free of plasma proteins by Sephadex G-200 chromatography. The βTG eluted at 0.3 M NaCl and the low MW anti-heparin at 1.5 M NaCl. The pure βTG (MW 36,000) was injected into rabbits and the resulting antiserum used to produce a radioimmunoassay for the release reaction in vivo.

Isolation and characterization of a low molecular weight growth-promoting factor from human plasma

Life Sciences ◽  
1987 ◽  
Vol 41 (3) ◽  
pp. 297-304 ◽  
Author(s):  
M.H. Heulin ◽  
J. Rajoelina ◽  
M. Artur ◽  
C. Geschier ◽  
J. Straczek ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Human Plasma ◽  
Low Molecular Weight ◽  
Weight Growth ◽  
Isolation And Characterization ◽  
Growth Promoting

Isolation and characterization of cotiaractivase, a novel low molecular weight prothrombin activator from the venom of Bothrops cotiara

2006 ◽  
Vol 1764 (5) ◽  
pp. 863-871 ◽  
Author(s):  
Yotis A. Senis ◽  
Paul Y. Kim ◽  
Gemma L.J. Fuller ◽  
Ángel García ◽  
Sripadi Prabhakar ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Isolation And Characterization

The Isolation and Characterization of the ATPase Inhibitory Protein (TN-I) from Bovine Cardiac Muscle

1975 ◽  
Vol 53 (11) ◽  
pp. 1207-1213 ◽  
Author(s):  
L. D. Burtnick ◽  
W. D. McCubbin ◽  
C. M. Kay
Keyword(s):  
Molecular Weight ◽  
Cardiac Muscle ◽  
Calcium Binding ◽  
Sodium Dodecyl ◽  
Basic Amino Acid ◽  
Sedimentation Equilibrium ◽  
Amino Acid Residues ◽  
Inhibitory Protein ◽  
Isolation And Characterization

The inhibitory component of the troponin complex (TN-I) was purified from bovine cardiac muscle, using a combination of ion exchange and molecular exclusion chromatographies in the presence of urea. It has the ability to inhibit the Mg2+-activated ATPase (EC 3.6.1.3) of a synthetic cardiac actomyosin preparation and this inhibition is reversed by the addition of cardiac calcium binding component of troponin (TN-C). Conventional sedimentation equilibrium experiments suggest a molecular weight for cardiac TN-I of 22 900 ± 500. However, sodium dodecyl sulfate (SDS) gels indicate a molecular weight of 27 000 ± 1000. The mobility of TN-I on SDS gels may be anomalous due to the high proportion of basic amino acid residues in the protein. Cardiac TN-I and TN-C interact to form a tight complex, even in the presence of 6 M urea. The results of this study invite direct comparison with results published for rabbit skeletal TN-I.

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