Skip to main content
NCBI home page
Biochemical Journal logoLink to Biochemical Journal
. 1972 Nov;130(1):95–101. doi: 10.1042/bj1300095

α1-Acute-phase globulins of rats. Microheterogeneity after isoelectric focusing

A H Gordon 1, P J Dykes 1
PMCID: PMC1174304  PMID: 4120436

Abstract

1. Improved resolution of mixtures of α1-globulins was obtained by the use of isoelectric focusing. 2. Because material recovered after isoelectric focusing in polyacrylamide gels behaved in a manner which suggested interaction with components derived from the gel, isoelectric focusing when used for preparative purposes was done in a matrix of Sephadex G-75. 3. By this means material from the individual bands formed by isoelectric focusing in 6m-urea could be isolated. The stability of these substances was examined by further isoelectric focusing. 4. Analysis of material that had been shown to be homogenous by isoelectric focusing in the absence of urea and of that from several individual bands derived from the same sample by isoelectric focusing in 6m-urea showed different proportions of sialic acid but no change in amino acid composition. 5. In the presence of 6m-urea the isoelectric points found were increased by 0.14–0.25 pH unit. After removal of most of the sialic acid with neuraminidase the increase was 0.36–0.72 pH unit. After treatment with 0.025m-H2SO4 at 80°C for 1h, which removed all the sialic acid, the increase was 0.40–0.87 pH unit. 6. Because removal of all the sialic acid did not decrease the number of bands formed by isoelectric focusing the observed heterogeneity could not be caused entirely by the presence of various proportions of sialic acid.

Full text

PDF
95

Images in this article

96-2PLATE 2
on p.96-2
96-3PLATE 3
on p.96-3
96-4PLATE 4
on p.96-4
96-5PLATE 5
on p.96-5
96-6PLATE 6
on p.96-6
96-1PLATE 1
on p.96-1

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. AMINOFF D. Methods for the quantitative estimation of N-acetylneuraminic acid and their application to hydrolysates of sialomucoids. Biochem J. 1961 Nov;81:384–392. doi: 10.1042/bj0810384. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Awdeh Z. L., Williamson A. R., Askonas B. A. Isoelectric focusing in polyacrylamide gel and its application to immunoglobulins. Nature. 1968 Jul 6;219(5149):66–67. doi: 10.1038/219066a0. [DOI] [PubMed] [Google Scholar]
  3. Beeley J. G. Ovomucoid heterogeneity examined by flat bed isoelectric focussing. Biochim Biophys Acta. 1971;230(3):595–598. doi: 10.1016/0304-4165(71)90192-9. [DOI] [PubMed] [Google Scholar]
  4. Billingham M. E., Gordon A. H., Robinson B. V. Role of the liver in inflammation. Nat New Biol. 1971 May 5;231(18):26–27. doi: 10.1038/newbio231026a0. [DOI] [PubMed] [Google Scholar]
  5. Delincée H., Radola B. J. Thin-layer isoelectric focusing on Sephadex layers of horseradish peroxidase. Biochim Biophys Acta. 1970 Feb 17;200(2):404–407. doi: 10.1016/0005-2795(70)90183-2. [DOI] [PubMed] [Google Scholar]
  6. ELLMAN G. L. Tissue sulfhydryl groups. Arch Biochem Biophys. 1959 May;82(1):70–77. doi: 10.1016/0003-9861(59)90090-6. [DOI] [PubMed] [Google Scholar]
  7. Gordon A. H., Louis L. N. Alpha-1 acute-phase globulins of rats. Isolation and some properties. Biochem J. 1969 Jul;113(3):481–488. doi: 10.1042/bj1130481. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Hayes M. B., Wellner D. Microheterogeneity of L-amino acid oxidase. Separation of multiple components by polyacrylamide gel electrofucusing. J Biol Chem. 1969 Dec 25;244(24):6636–6644. [PubMed] [Google Scholar]
  9. Kaplan L. J., Foster J. F. Isoelectric focusing behavior of bovine plasma albumin, mercaptalbumin, and beta-lactoglobulins A and B. Biochemistry. 1971 Feb 16;10(4):630–636. doi: 10.1021/bi00780a014. [DOI] [PubMed] [Google Scholar]
  10. Nimberg R., Motoyama T., Schmid K. The amino acid substitutions found in the genetic variants of 1 -acid glycoprotein. J Biol Chem. 1971 Sep 25;246(18):5817–5821. [PubMed] [Google Scholar]
  11. Oshiro Y., Eylar E. H. Physical and chemical studies on glycoproteins. 3. The microheterogeneity of fetuin, a fetal calf serum glycoprotein. Arch Biochem Biophys. 1968 Sep 20;127(1):476–489. doi: 10.1016/0003-9861(68)90252-x. [DOI] [PubMed] [Google Scholar]
  12. Salaman M. R., Williamson A. R. Isoelectric focusing of proteins in the native and denatured states. Anomalous behaviour of plasma albumin. Biochem J. 1971 Mar;122(1):93–99. doi: 10.1042/bj1220093. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Schmid K., Polis A., Hunziker K., Fricke R., Yayoshi M. Partial characterization of the sialic acid-free forms of alpha-1-acid glycoprotein from human plasma. Biochem J. 1967 Aug;104(2):361–368. doi: 10.1042/bj1040361. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Biochemical Journal are provided here courtesy of The Biochemical Society

RESOURCES