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. 1974 Nov 1;63(2):456–465. doi: 10.1083/jcb.63.2.456

PROTEINS OF THE POSTSYNAPTIC DENSITY

G Banker 1, L Churchill 1, C W Cotman 1
PMCID: PMC2110954  PMID: 4419608

Abstract

An analysis was made of the protein composition of a fraction of postsynaptic densities (PSDs) prepared from rat brain. Protein makes up 90% of the material in the PSD fraction. Two major polypeptide fractions are present, based on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The major polypeptide fraction has a molecular weight of 53,000, makes up about 45% of the PSD protein, and comigrates on gels with a major polypeptide of the synaptic plasma membrane. The other polypeptide band has a molecular weight of 97,000, accounts for 17% of the PSD protein, and is not a prominent constituent of other fractions. Six other polypeptides of higher molecular weight (100,000–180,000) are consistently present in small amounts (3–9% each). The PSD fraction contains slightly greater amounts of polar amino acids and proline than the synaptic plasma membrane fraction, but no amino acid is usually prominent. The PSD apparently consists of a structural matrix formed primarily by a single polypeptide or class of polypeptides of 53,000 molecular weight. Small amounts of other specialized proteins are contained within this matrix.

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Selected References

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  1. BLIGH E. G., DYER W. J. A rapid method of total lipid extraction and purification. Can J Biochem Physiol. 1959 Aug;37(8):911–917. doi: 10.1139/o59-099. [DOI] [PubMed] [Google Scholar]
  2. Banker G. A., Cotman C. W. Measurement of free electrophoretic mobility and retardation coefficient of protein-sodium dodecyl sulfate complexes by gel electrophoresis. A method to validate molecular weight estimates. J Biol Chem. 1972 Sep 25;247(18):5856–5861. [PubMed] [Google Scholar]
  3. Banker G., Crain B., Cotman C. W. Molecular weights of the polypeptide chains of synaptic plasma membranes. Brain Res. 1972 Jul 20;42(2):508–513. doi: 10.1016/0006-8993(72)90551-3. [DOI] [PubMed] [Google Scholar]
  4. Bloom F. E., Aghajanian G. K. Cytochemistry of synapses: selective staining for electron microscopy. Science. 1966 Dec 23;154(3756):1575–1577. doi: 10.1126/science.154.3756.1575. [DOI] [PubMed] [Google Scholar]
  5. Bloom F. E., Aghajanian G. K. Fine structural and cytochemical analysis of the staining of synaptic junctions with phosphotungstic acid. J Ultrastruct Res. 1968 Mar;22(5):361–375. doi: 10.1016/s0022-5320(68)90027-0. [DOI] [PubMed] [Google Scholar]
  6. Cohen L. A. Group-specific reagents in protein chemistry. Annu Rev Biochem. 1968;37:695–726. doi: 10.1146/annurev.bi.37.070168.003403. [DOI] [PubMed] [Google Scholar]
  7. Cotman C. W., Banker G., Churchill L., Taylor D. Isolation of postsynaptic densities from rat brain. J Cell Biol. 1974 Nov;63(2 Pt 1):441–455. doi: 10.1083/jcb.63.2.441. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Cotman C. W., Mahler H. R., Hugli T. E. Isolation and characterization of insoluble proteins of the synaptic plasma membrane. Arch Biochem Biophys. 1968 Sep 10;126(3):821–837. doi: 10.1016/0003-9861(68)90476-1. [DOI] [PubMed] [Google Scholar]
  9. Cotman C. W., Taylor D. Isolation and structural studies on synaptic complexes from rat brain. J Cell Biol. 1972 Dec;55(3):696–711. doi: 10.1083/jcb.55.3.696. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Cotman C. W., Taylor D. Localization and characterization of concanavalin A receptors in the synaptic cleft. J Cell Biol. 1974 Jul;62(1):236–242. doi: 10.1083/jcb.62.1.236. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Fairbanks G., Steck T. L., Wallach D. F. Electrophoretic analysis of the major polypeptides of the human erythrocyte membrane. Biochemistry. 1971 Jun 22;10(13):2606–2617. doi: 10.1021/bi00789a030. [DOI] [PubMed] [Google Scholar]
  12. Feit H., Slusarek L., Shelanski M. L. Heterogeneity of tubulin subunits. Proc Natl Acad Sci U S A. 1971 Sep;68(9):2028–2031. doi: 10.1073/pnas.68.9.2028. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Florendo N. T., Barrnett R. J., Greengard P. Cyclic 3',5'-nucleotide phosphodiesterase: cytochemical localization in cerebral cortex. Science. 1971 Aug 20;173(3998):745–747. doi: 10.1126/science.173.3998.745. [DOI] [PubMed] [Google Scholar]
  14. Furthmayr H., Timpl R. Characterization of collagen peptides by sodium dodecylsulfate-polyacrylamide electrophoresis. Anal Biochem. 1971 Jun;41(2):510–516. doi: 10.1016/0003-2697(71)90173-4. [DOI] [PubMed] [Google Scholar]
  15. Habeeb A. J., Hiramoto R. Reaction of proteins with glutaraldehyde. Arch Biochem Biophys. 1968 Jul;126(1):16–26. doi: 10.1016/0003-9861(68)90554-7. [DOI] [PubMed] [Google Scholar]
  16. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  17. Landis D. M., Reese T. S. Differences in membrane structure between excitatory and inhibitory synapses in the cerebellar cortex. J Comp Neurol. 1974 May 1;155(1):93–125. doi: 10.1002/cne.901550107. [DOI] [PubMed] [Google Scholar]
  18. Marchesi V. T., Andrews E. P. Glycoproteins: isolation from cellmembranes with lithium diiodosalicylate. Science. 1971 Dec 17;174(4015):1247–1248. doi: 10.1126/science.174.4015.1247. [DOI] [PubMed] [Google Scholar]
  19. Nicolson G. L., Painter R. G. Anionic sites of human erythrocyte membranes. II. Antispectrin-induced transmembrane aggregation of the binding sites for positively charged colloidal particles. J Cell Biol. 1973 Nov;59(2 Pt 1):395–406. doi: 10.1083/jcb.59.2.395. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Olmsted J. B., Witman G. B., Carlson K., Rosenbaum J. L. Comparison of the microtubule proteins of neuroblastoma cells, brain, and Chlamydomonas flagella. Proc Natl Acad Sci U S A. 1971 Sep;68(9):2273–2277. doi: 10.1073/pnas.68.9.2273. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Pfenninger K. H. The cytochemistry of synaptic densities. I. An analysis of the bismuth lodide impregnation method. J Ultrastruct Res. 1971 Jan;34(1):103–122. doi: 10.1016/s0022-5320(71)90007-4. [DOI] [PubMed] [Google Scholar]
  22. Rodbard D., Chrambach A. Estimation of molecular radius, free mobility, and valence using polyacylamide gel electrophoresis. Anal Biochem. 1971 Mar;40(1):95–134. doi: 10.1016/0003-2697(71)90086-8. [DOI] [PubMed] [Google Scholar]
  23. Rodbard D., Chrambach A. Unified theory for gel electrophoresis and gel filtration. Proc Natl Acad Sci U S A. 1970 Apr;65(4):970–977. doi: 10.1073/pnas.65.4.970. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Segrest J. P., Jackson R. L., Andrews E. P., Marchesi V. T. Human erythrocyte membrane glycoprotein: a re-evaluation of the molecular weight as determined by SDS polyacrylamide gel electrophoresis. Biochem Biophys Res Commun. 1971 Jul 16;44(2):390–395. doi: 10.1016/0006-291x(71)90612-7. [DOI] [PubMed] [Google Scholar]
  25. Shapiro A. L., Viñuela E., Maizel J. V., Jr Molecular weight estimation of polypeptide chains by electrophoresis in SDS-polyacrylamide gels. Biochem Biophys Res Commun. 1967 Sep 7;28(5):815–820. doi: 10.1016/0006-291x(67)90391-9. [DOI] [PubMed] [Google Scholar]
  26. Stark G. R. Recent developments in chemical modification and sequential degradation of proteins. Adv Protein Chem. 1970;24:261–308. doi: 10.1016/s0065-3233(08)60243-0. [DOI] [PubMed] [Google Scholar]
  27. Trayer H. R., Nozaki Y., Reynolds J. A., Tanford C. Polypeptide chains from human red blood cell membranes. J Biol Chem. 1971 Jul 25;246(14):4485–4488. [PubMed] [Google Scholar]
  28. Tung J. S., Knight C. A. Effect of charge on the determination of molecular weight of proteins by gel electrophoresis in SDS. Biochem Biophys Res Commun. 1971 Mar 19;42(6):1117–1121. doi: 10.1016/0006-291x(71)90020-9. [DOI] [PubMed] [Google Scholar]
  29. Weber K., Osborn M. The reliability of molecular weight determinations by dodecyl sulfate-polyacrylamide gel electrophoresis. J Biol Chem. 1969 Aug 25;244(16):4406–4412. [PubMed] [Google Scholar]
  30. Weber K., Pringle J. R., Osborn M. Measurement of molecular weights by electrophoresis on SDS-acrylamide gel. Methods Enzymol. 1972;26:3–27. doi: 10.1016/s0076-6879(72)26003-7. [DOI] [PubMed] [Google Scholar]
  31. Weisenberg R. C., Borisy G. G., Taylor E. W. The colchicine-binding protein of mammalian brain and its relation to microtubules. Biochemistry. 1968 Dec;7(12):4466–4479. doi: 10.1021/bi00852a043. [DOI] [PubMed] [Google Scholar]
  32. Zahler P. H., Wallach D. F. Isolation of lipid-free plasma membrane proteins by gel filtration on Sephadex LH-20 using 2-chloroethanol-water as solvent. Biochim Biophys Acta. 1967 May 2;135(2):371–374. doi: 10.1016/0005-2736(67)90135-6. [DOI] [PubMed] [Google Scholar]

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