TWO PROTEINS PURIFIED FROM LOBSTER NERVE EXTRACT

1. A protein component, fraction B, of lobster nerve extracts has been isolated and purified by differential ultracentrifugation and precipitation with zinc acetate. 2. Physicochemical data obtained from this protein and from fraction C are summarized. 3. Fraction B is present in lobster nerve extracts in higher concentration (relative to fraction A) than in blood. 4. A second component, fraction C, of sedimentation constant S20o = 13.2 has been isolated from lobster nerve extracts.

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The Immuno-Electron Microscopic Localization of the Mo-Fe Protein Component of Nitrogenase in Cells of Azotobacter Vinelandii

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100073313 ◽

1973 ◽

Vol 31 ◽

pp. 574-575

Author(s):

J. T. Stasny ◽

R. C. Burns ◽

R. W. F. Hardy

Keyword(s):

Cellular Localization ◽

Direct Evidence ◽

Azotobacter Vinelandii ◽

Intracellular Localization ◽

Protein Component ◽

Electron Microscopic ◽

Thin Sections ◽

Fe Protein ◽

Intracytoplasmic Membranes

Structure-functlon studies of biological N2-fixation have correlated the presence of the enzyme nitrogenase with increased numbers of intracytoplasmic membranes in Azotobacter. However no direct evidence has been provided for the internal cellular localization of any nitrogenase. Recent advances concerned with the crystallizatiorTand the electron microscopic characterization of the Mo-Fe protein component of Azotobacter nitrogenase, prompted the use of this purified protein to obtain antibodies (Ab) to be conjugated to electron dense markers for the intracellular localization of the protein by electron microscopy. The present study describes the use of ferritin conjugated to goat antitMo-Fe protein immunoglobulin (IgG) and the observations following its topical application to thin sections of N2-grown Azotobacter.

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Neutralization of Antithrombin VI (Fibrinogen Breakdown Products) with Platelet Antiheparin Factor (Platelet Factor 4)*

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654885 ◽

1965 ◽

Vol 14 (03/04) ◽

pp. 490-499 ◽

Cited By ~ 4

Author(s):

S Niewiarowski ◽

R Farbiszewski ◽

A Popławski

Keyword(s):

Zinc Acetate ◽

Antithrombin Iii ◽

Platelet Factor 4 ◽

Breakdown Product ◽

Platelet Factor ◽

Chromatography Column ◽

Antiheparin Activity

SummaryIt has been found that fibrinogen breakdown product – antithrombin VI – is neutralized by the purified preparation of platelet factor 4, obtained by means of zinc acetate precipitation and DEAE chromatography column. It has been suggested that antiheparin activity of platelet factor 4 and its ability to neutralize antithrombin VI may be related to the same protein.The purified preparation of platelet factor 4 does not influence the fibrinogen – fibrin conversion by thrombin. This means that platelet factor 2 and platelet factor 4 are not the same substance.Crude platelet extracts neutralize antithrombin III and V. However, the purified product did not interferes with the action of these antithrombins.

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EFFECT OF PROPYLTHIOURACIL ON THE IODINATION AND MATURATION OF RAT THYROGLOBULIN

Acta Endocrinologica ◽

10.1530/acta.0.0530271 ◽

1966 ◽

Vol 53 (2) ◽

pp. 271-285 ◽

Cited By ~ 9

Author(s):

Claude Simon ◽

Marie Roques ◽

Janine Torresani ◽

Serge Lissitzky

Keyword(s):

Single Injection ◽

Freezing And Thawing ◽

Isotopic Equilibrium ◽

Sedimentation Constant

ABSTRACT The effect of propylthiouracil on the maturation of rat thyroglobulin in vivo has been investigated. Newly iodinated thyroglobulin dimer is labile to freezing and thawing. This observation has been used to interpret the findings in the present experiments. From experiments using rats in isotopic equilibrium with 125I, and treated with propylthiouracil or propylthiouracil and tri-iodothyronine and also given a single injection of 131I, the following conclusions were formulated 1) the appearance of iodinated S12 thyroglobulin monomer is due to the dissociation of labile iodinated thyroglobulin dimer and appears more readily if the dimer is poorly iodinated, 2) uniodinated thyroglobulin dimer is the most probable substrate for iodination in vivo, 3) maturation of thyroglobulin dimer (as shown by increasing sedimentation constant from 16—17 to 19) is accompanied by increasing amounts of iodine in the molecule, 4) it is not possible to say at present if iodination and iodothyronine formation is the cause or the consequence of thyroglobulin dimer maturation, 5) propylthiouracil might inhibit thyroglobulin maturation by decreasing iodine organification.

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