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At least 271 records · Page 15Linked to original sources
PubMed1955

Two proteins purified from lobster nerve extract; isolation and physicochemical characterization.

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 S(20) (o) = 13.2 has been isolated from lobster nerve extracts.

Animals↗
PubMed1954

Immunochemical studies of antitoxin produced in normal and allergic individuals hyperimmunized with diphtheria toxoid. V. Peculiar electrophoretic configuration of serum proteins and protein-bound polysaccharides in certain antitoxic sera; demonstration of serum changes in certain severe manifestations of allergy.

The method of filter paper electrophoresis was used to study proteins and protein-bound polysaccharides in sera obtained from subjects before and after a single booster dose of diphtheria toxoid, and in sera from allergic subjects. The electrophoretic patterns of precipitating antitoxic sera resembled those found in normal non-immune sera. However, skin-sensitizing antitoxic sera were distinguished by a relatively large beta globulin component and a small or indistinct alpha(2) globulin. Fusion of both components was present in some sera containing this variety of antitoxin. Considerable amounts of serum-bound polysaccharides in these sera migrated relatively slowly in contrast to the behavior of polysaccharides of precipitating antitoxic sera which migrated faster when tested under similar conditions. Alterations in proteins and carbohydrates were most readily observed in specimens containing high titers of antitoxin. There were no demonstrable differences between the electrophoretic behavior of sera obtained from subjects before or after immunization with toxoid. Electrophoretic patterns of serum from allergic subjects who developed marked eosinophilia showed attenuation of the alphas globulin associated with a relative preponderance of slow migrating protein-bound polysaccharides. These alterations were not present in sera obtained from the same persons before and after the development of eosinophilia. Changes in the proteins and polysaccharides could not be demonstrated with consistency in subjects with mild to moderate hay-fever symptoms. One person who developed severe acute hay-fever symptoms showed alterations in the beta and alpha(2) globulins. Rheumatic fever subjects showed no unusual changes in the distribution of serum components. However, transition from the acute process to convalescence is graphically demonstrated by the marked decreases in gamma and alpha globulins and in protein-bound carbohydrates.

Antitoxins↗
PubMed1951

Electrophoresis of proteins on filter paper.

A simplified procedure for filter paper electrophoresis is described in which disturbing factors such as evaporation, heating, buffer concentration gradients, and pH changes in the electrode vessels were reduced to a minimum. Artificial mixtures of highly purified proteins could be separated and the components isolated. The application of the method to a variety of studies on serum proteins is demonstrated. Protein concentration in paper segments was determined by two different methods of protein estimation. Curves were obtained showing the same five major peaks for normal serum as found by the classical methods of free electrophoresis. Comparisons were made of the areas of the various components under the curves obtained with the different methods. Two dimensional electrophoresis was applied to serum and serum components. It proved of value in demonstrating the heterogeneity of fractions such as the gamma-globulin of serum. The polysaccharide dextran was used as an index of the extent of electro-osmotic flow during the course of the various experiments. The ratio of the distance of electroosmotic flow and the distance of protein migration was shown to be constant for a given type of paper. For serum albumin on Munktell 20 paper this ratio was 0.35. A formula for mobilities applicable to liquid in a highly porous supporting medium is presented. Mobility values for human serum albumin at various pH levels on paper showed approximate agreement with those obtained in free solution giving a similar isoelectric point.

Buffers↗
PubMed1955

Chromatography of blood-clotting factors and serum proteins on columns of diatomaceous earth.

1. In batch adsorptions with prothrombin solutions, hyflo was the weakest adsorbent, standard super-cel intermediate, and filter-cel strongest. Of these three grades of diatomaceous earth, hyflo has the smallest surface area per gram and filter-cel the largest. In parallel breakthrough experiments, a column of standard super-cel had a capacity almost six times that of a hyflo column. 2. After partial removal of impurities by diatomaceous earth, prothrombin preparations contained less thrombokinase, were more stable, and displayed less tendency to form thrombin "spontaneously." Thrombokinase (or its precursor) was removed from a preparation of prothrombin by passage through a filter cake of standard super-cel. The specific activity of the prothrombin was increased; and 62 per cent of the activity was recovered. 3. Prothrombin was adsorbed from an ammonium sulfate solution at pH 5.26 by columns of hyflo or standard super-cel. When eluted by phosphate solutions, the protein moved down the columns more readily at higher pH and higher concentration of phosphate salts, within the pH range 5.0 to 6.6, and within the phosphate range 0.1 to 1.0 M. 4. Thrombin was adsorbed on a column of standard super-cel at pH 5.11. As successive eluents passed through the column, the thrombin emerged between two bands of impurities. The specific activity of the thrombin was raised; and 83 per cent of the activity was recovered. 5. With a column of standard super-cel, and with a series of eluents within the pH range 5.1 to 6.3, total serum proteins were separated into four major bands. About 94 per cent of the protein was recovered.

Blood Coagulation↗
PubMed1959

Protein concentration in normal mouse lymphocytes, thymocytes, and mouse and human leukemic cells as measured by interference microscopy.

The apparent protein content of a single spherical lymphocyte or a similar cell, as well as its diameter, can be measured by a modified and stabilized AO-Baker interference microscope which is either fitted with an AO half-shade eyepiece or connected to a photomultiplier. This paper gives results for the apparent protein content and the diameter of normal mouse lymphocytes and thymocytes; these do not differ significantly from each other. It also gives values for the apparent protein concentration and the diameter of the lymphocytes of mice of the same strain which have developed leukemia or lymphoma; these values are significantly different from those of normal mice. Related data are given for the apparent protein content and for the diameter of normal human lymphocytes and the white cells found in myeloblastic leukemia and in stem cell leukemia in man; here the values differ significantly from those of the normal human lymphocyte. The rule seems to be that the abnormal white cells become more watery and larger as the disease advances.

Animals↗