Skip to main content
NCBI home page
The Journal of Biophysical and Biochemical Cytology logoLink to The Journal of Biophysical and Biochemical Cytology
. 1959 Jan 25;5(1):59–68. doi: 10.1083/jcb.5.1.59

The Incorporation of Leucine-C14 into Microsomal Particles and other Subcellular Components of the Pea Epicotyl

Paul O P Ts'o 1, Clifford S Sato 1
PMCID: PMC2224622  PMID: 13630935

Abstract

Incorporation of leucine-C14 into subcellular fractions of the apical section of pea seedlings has been studied as a function of the length of incubation. The specific activity of the microsomes was higher than that of the supernatant for short but not for long incubations, in agreement with observations on other systems. In this developing tissue the nuclei and especially the mitochondria appear to incorporate amino acid very rapidly. An insoluble fraction of the microsome pellet, which is presumably a liponucleoprotein complex, was found to possess, after 1 hour of incubation, a specific activity much greater than that of the purified microsomal particles or the supernatant fraction. Ninety-eight per cent of the leucine-C14 in the purified microsomal particles has been shown to possess bound amino groups, presumably in peptide linkages, by the DNP-end group method. These particles liberate but little peptide or protein of very high specific activity when they are destroyed by removal of Mg or by hydrolysis of RNA. Microsomal particles were fractionated into an RNA fraction and five protein fractions by means of density gradient centrifugation. By this method 95 per cent of the RNA can be separated from 90 per cent of the protein of the particle. Furthermore, the RNA fraction has been shown to contain very little protein of high specific activity. A particular protein fraction which contains the remaining 5 per cent of the RNA, possessed after 1 hour of incubation a specific activity 2 to 9 times higher than the protein of the other fractions.

Full Text

The Full Text of this article is available as a PDF (766.3 KB).

Selected References

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

  1. AKAZAWA T., BEEVERS H. Mitochondria in the endosperm of the germinating castor bean; a developmental study. Biochem J. 1957 Sep;67(1):115–118. doi: 10.1042/bj0670115. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. ALLFREY V. G., MIRSKY A. E., OSAWA S. Protein synthesis in isolated cell nuclei. J Gen Physiol. 1957 Jan 20;40(3):451–490. doi: 10.1085/jgp.40.3.451. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Allen R. J. The estimation of phosphorus. Biochem J. 1940 Jun;34(6):858–865. doi: 10.1042/bj0340858. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. CAMPBELL P. N., GREENGARD O., JONES H. E. The intracellular distribution of amino acid incorporation by slices of liver and liver tumours and by ascites cells. Exp Cell Res. 1957 Jun;12(3):689–692. doi: 10.1016/0014-4827(57)90192-1. [DOI] [PubMed] [Google Scholar]
  5. COHN P., BUTLER J. A. Fractionation of microsomal proteins by a non-inoic detergent. Biochim Biophys Acta. 1957 Jul;25(1):222–223. doi: 10.1016/0006-3002(57)90458-4. [DOI] [PubMed] [Google Scholar]
  6. GORNALL A. G., BARDAWILL C. J., DAVID M. M. Determination of serum proteins by means of the biuret reaction. J Biol Chem. 1949 Feb;177(2):751–766. [PubMed] [Google Scholar]
  7. LITTLEFIELD J. W., KELLER E. B., GROSS J., ZAMECNIK P. C. Studies on cytoplasmic ribonucleoprotein particles from the liver of the rat. J Biol Chem. 1955 Nov;217(1):111–123. [PubMed] [Google Scholar]
  8. LUND H. A., VATTER A. E., HANSON J. B. Biochemical and cytological changes accompanying growth and differentiation in the roots of Zea mays. J Biophys Biochem Cytol. 1958 Jan 25;4(1):87–98. doi: 10.1083/jcb.4.1.87. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Meselson M., Stahl F. W., Vinograd J. EQUILIBRIUM SEDIMENTATION OF MACROMOLECULES IN DENSITY GRADIENTS. Proc Natl Acad Sci U S A. 1957 Jul 15;43(7):581–588. doi: 10.1073/pnas.43.7.581. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. SANGER F. The terminal peptides of insulin. Biochem J. 1949;45(5):563–574. doi: 10.1042/bj0450563. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. SIMKIN J. L., WORK T. S. Incorporation of radioactive amino acids into proteins of the microsome fraction of guinea-pig liver in a cell-free system. Biochem J. 1957 Dec;67(4):617–624. doi: 10.1042/bj0670617. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. SIMKIN J. L., WORK T. S. Protein synthesis in guinea-pig liver; incorporation of radioactive amino acids into proteins of the microsome fraction in vivo. Biochem J. 1957 Feb;65(2):307–315. doi: 10.1042/bj0650307. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. SIMPSON M. V., MCLEAN J. R. The incorporation of labeled amino acids into the cytoplasmic particles of rat muscle. Biochim Biophys Acta. 1955 Dec;18(4):573–575. doi: 10.1016/0006-3002(55)90156-6. [DOI] [PubMed] [Google Scholar]
  14. TS'O P. O., BONNER J., DINTZIS H. On the similarity of amino acid composition of microsomal nucleoprotein particles. Arch Biochem Biophys. 1958 Jul;76(1):225–227. doi: 10.1016/0003-9861(58)90137-1. [DOI] [PubMed] [Google Scholar]
  15. TS'O P. O., BONNER J., VINOGRAD J. Structure and properties of microsomal nucleoprotein particles from pea seedlings. Biochim Biophys Acta. 1958 Dec;30(3):570–582. doi: 10.1016/0006-3002(58)90104-5. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Biophysical and Biochemical Cytology are provided here courtesy of The Rockefeller University Press

RESOURCES