Physical Characterization Studies Research Articles

Polymerization of vinylpyridinium salts. III. Further studies on the interfacial and isotropic polymerization of 4‐vinyl‐N‐methylpyridinium methylsulfate

AbstractIn the present study the polymerization of 4‐vinyl‐N‐methylpyridinium methylsulfate at liquid–liquid interfaces is investigated. Various experimental procedures that may favor the interfacial mode of polymerization over the isotropic one are discussed. The effectiveness of the methods was evaluated by physical characterization studies and particularly polymer tacticity. This last property is directly associated with the achieved organization of the monomers at interfaces. 13C‐NMR technique was used for tacticity determination. According to tacticity, random polymers are primarily obtained that result from an isotropic polymerization in the aqueous phase, where the monomer is extremely soluble. The small predominance of the syndiotactic triad over the isotactic one is explained by the occurrence of an interfacial polymerization induced by the orientation of the monomers. A polymerization model is proposed that justifies the stereospecificity modification of polymerization.

Thymic hormone-like restoration by human prealbumin of azathioprine sensitivity of spleen cells from thymectomized mice.

Gel filtration of fresh human serum revealed that over 95% of the thymic-hormone-like activity was present in the fraction representing the total albumin and prealbumin. Further studies demonstrated that the activity resided in the prealbumin fraction; albumin was inactive. Prealbumin was isolated from Cohn fraction IV-1 of pooled human plasma by extraction with aqueous buffer, fractionation with (NH4)2SO4, gel filtration on Sephadex G-150, and preparative disc gel electrophoresis. The final product was homogeneous by analytical gel electrophoresis was 40,000 times more active than the starting material in an azathioprine-sensitive rosette assay. Physical and chemical characterization studies showed that the isolated product was identical to authentic human plasma prealbumin. Isolation of the prealbumin fraction from sera of adult thymectomized mice revealed that the rosette activity was substantially lower than that isolated from sera of normal mice, suggesting a thymic dependence of the prealbumin activity. In vitro and in vivo bioassays of the fraction obtained prior to the final step of the purification procedure support the conclusion that prealbumin exhibits thymic hormone-like activity.

A circular dichroism study of the interactions among the components of the bovine cardiac muscle regulatory system

FEBS LettersVolume 65, Issue 2 p. 234-237 Full-length articleFree Access A circular dichroism study of the interactions among the components of the bovine cardiac muscle regulatory system Correction(s) for this article Erratum Volume 67Issue 2FEBS Letters pages: 241-241 First Published online: October 19, 2001 L.D. Burtnick, L.D. Burtnick Medical Research Council Group on Protein Structure and Function and the Department of Biochemistry, University of Alberta, Edmonton Alberta, Canada National Research Council of Canada 1967 Science Scholar Search for more papers by this authorC.M. Kay, C.M. Kay Medical Research Council Group on Protein Structure and Function and the Department of Biochemistry, University of Alberta, Edmonton Alberta, CanadaSearch for more papers by this author L.D. Burtnick, L.D. Burtnick Medical Research Council Group on Protein Structure and Function and the Department of Biochemistry, University of Alberta, Edmonton Alberta, Canada National Research Council of Canada 1967 Science Scholar Search for more papers by this authorC.M. Kay, C.M. Kay Medical Research Council Group on Protein Structure and Function and the Department of Biochemistry, University of Alberta, Edmonton Alberta, CanadaSearch for more papers by this author First published: June 01, 1976 https://doi.org/10.1016/0014-5793(76)80487-5Citations: 7 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat References 1 S. Ebashi, M. Endo, Progr. Biophys. Mol. Biol., 18, (1968), 123– 183. 2 S. Ebashi, T. Wakabayashi, F. Ebashi, J. Biochem., 69, (1971), 441– 445. 3 M.L. Greaser, J. Gergely, J. Biol. Chem., 246, (1971), 4226– 4233. 4 A.C. Murray, C.M. Kay, Biochem. Biophys. Res. Commun., 44, (1971), 237– 244. 5 J.M. Wilkinson, S.V. Perry, H.A. Cole, I.P. Trayer, Biochem. J., 127, (1972), 215– 228. 6 D.J. Hartshorne, P. Dreizen, Cold Spring Harbor Symp. Quant. Biol., 37, (1972), 225– 234. 7 W. Drabikowski, R. Dabrowska, B. Barylko, Acta Biochim. Polon., 20, (1973), 181– 199. 8 L.D. Burtnick, W.D. McCubbin, C.M. Kay, Can. J. Biochem., 53, (1975), 15– 20. 9 L.D. Burtnick, W.D. McCubbin, C.M. Kay, Can. J. Biochem., 53, (1975), 1207– 1213. 10 L.D. Burtnick, W.D. McCubbin, C.M. Kay, Can. J. Biochem., 54, (1976), in press 11 S.E. Hitchcock, H.E. Huxley, A.G. Szent-Györgi, J. Mol. Biol., 80, (1973), 825– 836. 12 S.S. Margossian, C. Cohen, J. Mol. Biol., 81, (1973), 409– 413. 13 J.D. Potter, J. Gergely, Biochemistry, 13, (1974), 2697– 2703. 14 R. Tsukui, S. Ebashi, J. Biochem., 73, (1973), 1119– 1121. 15 K. Weber, M. Osborn, J. Biol. Chem., 244, (1969), 4406– 4412. 16 W.D. McCubbin, R.F. Kouba, C.M. Kay, Biochemistry, 6, (1967), 2417– 2425. 17 K. Oikawa, C.M. Kay, W.D. McCubbin, Biochim. Biophys. Acta, 168, (1968), 164– 167. 18 W.D. McCubbin, R.S. Mani, C.M. Kay, Biochemistry, 13, (1974), 2689– 2694. 19 R.S. Mani, W.D. McCubbin, C.M. Kay, Biochemistry, 13, (1974), 5003– 5007. 20 R.S. Mani, W.D. McCubbin, C.M. Kay, FEBS Lett., 52, (1975), 127– 131. Citing Literature Volume65, Issue2June 01, 1976Pages 234-237 ReferencesRelatedInformation

Properties of High Boiling Petroleum Products. Physical and Chemical Characterization Studies with Relation to Polynuclear Aromatic Components

Properties of High Boiling Petroleum Products. Physical and Chemical Characterization Studies with Relation to Polynuclear Aromatic Components