Determination of Small Quantities of Nitrogen in Serological Precipitates and Other Biological Materials.

Lanni, Frank; Dillon, Marcus L.; Beard, J. W.

doi:10.3181/00379727-74-17791

Cited by 87 publications

(26 citation statements)

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“…The analyses of total phosphorus was done by the Allen method (14). Total nitrogen was measured by the Nessler method of Lanni et al (15). The semiquantitative determination of desoxyribose was done by the diphenylamine method of Dische (16).…”

Section: Methodsmentioning

confidence: 99%

Microsomal Nucleoprotein Particles From Pea Seedlings

Ts’o

Bonner

Vinograd

1956

The Journal of Cell Biology

131

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Ultracentrifugal analysis of an extract of pea epicotyls, previously freed of debris and larger particles by centrifugation at 40,000 g for 10 minutes, has revealed the presence of a major component which possesses a sedimentation coefficient of 74 S. This component constitutes about 25 per cent of the TCA-precipitable material in the clarified epicotyl extract and is estimated to make up 1 to 2 per cent of the dry weight of the original tissue. In size, chemical composition, and morphology, the 74 S component resembles the nucleoproteins of the microsomes from animal tissues. The 74 S component of pea epicotyl extracts has been purified by repeated cycles of differential centrifugation to yield a preparation which is 80 per cent homogeneous in the analytical ultracentrifuge. It has been found to contain 30 to 37 per cent RNA as judged by a variety of analytical techniques. Approximately 55 per cent of the weight of the material is protein and a further 4.5 per cent phospholipide. Electron micrographs of air-dried specimens of the purified preparation show the 74 S constituent to be flattened spheres with an average height of 180 A and an average diameter of approximately 280 A. The molecular weight of the 74 S particles is computed from sedimentation, viscosity, and partial specific volume data to be 4.5 million ± 10 per cent in agreement with the value estimated from electron micrographs. The 74 S or microsomal component of pea epicotyls is rapidly aggregated in the presence of low concentrations of Mg ions or by somewhat higher concentrations of Ca or K salts. ATP on the contrary causes resolution of electrolyte-induced microsomal aggregates with simultaneous degradation of the particles to an ultracentrifugally inhomogeneous mixture of lower molecular weight materials.

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Section: Methodsmentioning

confidence: 99%

Microsomal Nucleoprotein Particles From Pea Seedlings

Ts’o

Bonner

Vinograd

1956

The Journal of Cell Biology

131

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“…Tissue non-collagen nitrogen (NCN) was determined by a modification of the technique of Lanni et al, 19 based on the method of Koch and McMeekin. 20 By determining the quantity of alkalisoluble nitrogen in a muscle, this procedure provides a measurement of myofibrillar protein.…”

Section: Bliss Adolphmentioning

confidence: 99%

Effect of Experimental Congestive Heart Failure and Acetyl Strophanthidin on Myocardial Electrolyte and Water Content

Bliss

Adolph

1963

Circulation Research

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The syndrome of chronic congestive heart failure was produced in female dogs by progressive pulmonary artery constriction. A factorial experimental design, containing seven experiments of four dogs each, was employed. Each experiment was completed in one day and consisted of two groups of two dogs each, one group containing dogs with heart failure and the other, normal dogs. One animal from each group received intravenous acetyl strophanthidin, 0.015 mg/kg ascites-free weight, while the other was given an injection of inert material. The heart was quickly removed from the chest nine minutes after the injection and the right ventricle was taken for analysis. Previous work indicated that this dose of the drug produced and inotropic effect both in normal animals and in dogs with heart failure without producing digitalis toxicity. The myocardium from animals with congestive heart failure contained significantly less potassium but more sodium, chloride, and water per kilogram of dry fat-free blood-free myocardium than the myocardium from normal dogs. The concentration of sodium plus potassium in tissue water was subnormal in failing hearts. The sodium and chloride composition of the fluid gained by failing hearts differed significantly from that of interstitial fluid. Acetyl strophanthidin increased myocardial chloride and water. Although potassium in the myocardium was unchanged in treated control dogs, it increased significantly after acetyl strophanthidin in animals with heart failure. The findings are consistent with myocardial cellular swelling in congestive heart failure. The quantity of blood in each kilogram of failing myocardial tissue was severely reduced, probably because of muscle fiber hypertrophy. The possibility is considered that this alteration, together with the increased tissue water, may lead to lowered oxygen tension in failing heart muscle. It is suggested that digitalis exerts two opposing effects on ion transport through the myocardial cell membrane and that neither of these is fundamental to its inotropic action.

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“…Chemically fractionated human gamma globulin (HGG), lot 17968, obtained from Cutter Laboratories served as a standard. The H G G was prepared in a large batch at a concentration of 100 ~g nitrogen per ml as determined by the microKjeldahl method of Lanni (20) and divided into small ampoules, which were kept at --20°C. A single ampoule z Solution of B(3) was kept at a I:10 dilution to increase its stability and I0 ml instead of 1 ml was used to prepare 50 ml of solution C. was thawed and diluted for a standard curve with each set of Folin determinations.…”

Section: Separation Of Peptide-bound S 35 Activity From Free and Disumentioning

confidence: 99%

The Lack of Selective Reincorporation into Tissue Protein of the Amino Acids Derived from the Catabolism of Serum Protein

Radovich

Szentivanyi

Talmage

1963

The Journal of General Physiology

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Homologous S35-1abeled albumin, gamma globulin, and alphabeta globulin were transfused into rabbits and the specific activities of the electrophorefic fractions of the sera of the recipients were determined at various time intervals up to 12 days after injection. Detectable reincorporation into a fraction other than that transfused was found only in the gamma globulin fraction after albumin injection. This activity rose between 2 and 12 days and reached a level of 2 to 3 per cent of the extrapolated zero time activity of the albumin fraction. When homologous serum protein doubly labeled with I z31 and S 3~ was transfused into mice, marked drops in the ratios of I nl to S 35 in the serum and tissue proteins were observed between 1 and 48 hours after injection. On the basis of a determination of the absolute and relative amounts of I m and S .5 found in the various tissue and serum proteins, the amount of reincorporation of S 3~ into each protein was calculated. The relative amounts of reincorporation of S 35 among the various tissues were remarkably similar to the relative amounts of incorporation of S ~ after the injection of labeled free amino acids. It is concluded that serum protein does not form a major direct source of amino acids to the tissues but feeds them indirectly through the extracellular pool.Little support can be found today for the once popular concept that proteins or their peptide products are incorporated directly into new proteins without breakdown to the amino acid level (1-4). The DNA-RNA code for amino acids based on nucleotide triplets appears to leave little room or information for a concept involving the direct incorporation of peptides (5-7). In addition, considerable experimental evidence has accumulated for the incorporation of labeled amino acids directly into proteins without the formation of long lived intermediates. These include experiments on formation of bacterial enzymes by Rotman and Spiegelman (8) and by Monod (9, 10), on ferritin in rats by Loftfield and Harris (11,12), and on antibodies in rabbits by

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Determination of Small Quantities of Nitrogen in Serological Precipitates and Other Biological Materials.

Cited by 87 publications

References 0 publications

Microsomal Nucleoprotein Particles From Pea Seedlings

Microsomal Nucleoprotein Particles From Pea Seedlings

Effect of Experimental Congestive Heart Failure and Acetyl Strophanthidin on Myocardial Electrolyte and Water Content

The Lack of Selective Reincorporation into Tissue Protein of the Amino Acids Derived from the Catabolism of Serum Protein

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