13 Holland, J. J., these PROCEEDINGS, 50, 436 (1963). 14 Frederiksen, S., and H. Klenow, Biochem. Biophys. Res. Commun., 17, 165 (1964). 15 "Deoxyribonuclease I, free of ribonuc lease, obtained from Worthington Biochemicals, Freehold, N. J. 16 Britten, R. J., and R. B. Roberts, Science, 131, 32 (1960). 17 Bray, G. A., Anal. Biochem., 1, 279 (1960). 18 S values for components sedimenting in sucr...

Polyoma and Shope papilloma viruses were purified and analyzed by chemical and physical methods. Disc electrophoresis of degraded virions indicated the presence, in both cases, of only one major species of polypeptide subunit. The weight of the peptide chain of polyoma virus was estimated in 8 m urea to be about 45,000 avograms, based on the sedimentation rate in a sucrose-urea gradient and the...

,Our experiments suggest that when the blood sedimentation rate is raised, there is no alteration in the chemical structure of the proteins. A possible exception to this is the Bence-Jones protein [Devine, 1941]. Geottsch [1936] found that nephritic total globulin was immunologically different from the normal, and Alving [1936] found changes in the cystine content of total albumin in nephrosis....

In recent times sedimentation data have become increasingly relevant in modeling sedimentation operations such as filtration, fluidization, two-phase flow operations and in environmental engineering. In this study, the effects of reactants concentrations and size of settling vesselson the sedimentation rates of strontium and barium carbonates, in aqueous medium, were studied by a modified appro...

A protein was isolated from bovine thymus that was shown to accelerate the appearance of hemolysin to sheep erythrocytes in neonatal mice. The isolation procedure consisted of saline homogenization, ammonium sulfate precipitation, and methanol precipitation, followed by chromatography on diethylaminoethyl-cellulose and two chromatographies on Sephadex G-150. The protein was shown to be homogene...

(b) Sedimentation equilibrium: an experiment performed at a lower speed so that the sedimentation and backdiffirsion forces are of comparable magnitudes and therefore give rise to an equilibrium distribution of solute concentration. Because there is no net transport at equilibrium, shape effects do not come into play and the distribution becomes an absolute function of molecular mass for a sing...

Type 5 adenovirus fiber protein was purified and subjected to chemical characterization. Equilibrium sedimentation ultracentrifugation analysis indicated that the intact fiber has a molecular weight of approximately 183,000. Denaturation and chemical analyses implied that the fiber consists of three polypeptide chains, each of about 61,000 mol wt. Mapping of tryptic peptides and electrophoretic...

Estimation of the influence of the degree of esterification on the hydrodynamic properties of citrus pectins provides a simple demonstration of how chemical variation can influence structural properties of polysaccharides. Five citrus pectins with average degree of esterification 77.8, 65.0, 53.9, 37.8 and 27.9%, respectively were studied using capillary viscometry, sedimentation velocity, sedi...

The molecular weight of native vaccinia deoxyribonucleic acid (DNA) is 1 to 1.17 times that of native T4 DNA. Sedimentation of denatured vaccinia DNA through alkaline sucrose gradients yields an apparent molecular weight greater than twice that of denatured T4 DNA, implying that the complementary strands of vaccinia DNA do not separate upon denaturation. When alkali-denatured vaccinia DNA is ne...

A method is presented for determining the relative degree of sedimentation of proteins and other small particles, either in pure form or in a mixture, utilizing the concentration centrifuge of Bauer and Pickels. Chemical analysis or biological assay of material obtained at different fluid levels by means of a special sampling device is used to measure the degree of sedimentation. The results ar...