Concanavalin A-agarose treatment of rat liver post-mitochondrial supernatant removes a fraction rich in cholesterol and 5'-nucleotidase activity but low in glucose-6-phosphatase. At the same time, radiolabel associated with the cell surface is removed. We interpret these findings as evidence that concanavalin A binds to, and under these circumstances will remove, fragments of plasma membrane present in the microsomal fraction and believe that this may be of use in the gentle, and rapid subfractionation of microsomal membranes.

The integrity of polyribosome-membrane complexes in microsomal preparations is dependent on the centrifugal conditions used for their preparation. This paper describes techniques based on gel filtration that enable the rapid and gentle separation of microsomal membranes from both free polyribosomes and soluble protein.

The chemical-carcinogen-induced detachment of ribosomes from rat liver endoplasmic reticulum was studied in vitro. Incubation of postmitochondrial supernatant with 0.2 mM-diethylnitrosamine or N-2-acetylaminofluorene removed approx. 16% of membrane-bound ribosomes, measured as differences in RNA/protein values of membrane separated from unbound ribosomes by flotation. These ribosomes are also detached by exposure to high centrifugal forces (160000g) and are among those removed by NADPH-catalysed lipid peroxidation. Extensive lipid peroxidation prohibits any measurement. The ribosomes (polyribosomes) removed are not those detached from the membrane by exposure to high KC1 concentrations (loosely bound) or high KC1 concentrations in the presence of puromycin (tightly bound). It is concluded then that centrifugally labile and carcinogen-sensitive represent a previously unreported sub-population of membrane-bound ribosomes.

Ribosome topography was examined on the surface of isolated lamellar rough endoplasmic reticulum. Groups of ribosomes, presumably corresponding to polysomes, were observed as circular, spiral, or parabolic structures. These were distributed fairly randomly on the membrane surface. When samples were incubated at 37°C with pancreatic ribonuclease, conditions that lead to spontaneous aggregation of free ribosomes, clustering of ribosomes to form large aggregates in the plane of the membrane was observed. Prior treatment with glutaraldehyde (5%) prevented this aggregation. It is suggested that ribosome binding components are potentially mobile, but are stabilized in native membranes forming ordered polysome conformations.

FEBS LettersVolume 67, Issue 2 p. 123-129 Review letterFree Access Ligand partitioning into membranes: Its significance in determining K M and K S values for cytochrome P-450 and other membrane bound receptors and enzymes Gordon Parry, Gordon Parry Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, England Department of Microbiology, Guy's Hospital Medical School, London Bridge, SE1 9RT, England. Search for more papers by this authorDavid N. Palmer, David N. Palmer Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, EnglandSearch for more papers by this authorDavid J. Williams, David J. Williams Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, EnglandSearch for more papers by this author Gordon Parry, Gordon Parry Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, England Department of Microbiology, Guy's Hospital Medical School, London Bridge, SE1 9RT, England. Search for more papers by this authorDavid N. Palmer, David N. Palmer Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, EnglandSearch for more papers by this authorDavid J. Williams, David J. Williams Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, EnglandSearch for more papers by this author First published: August 15, 1976 https://doi.org/10.1016/0014-5793(76)80348-1Citations: 82 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 M.R. Waterman, V. Ullrich, R.W. Estabrook, Arch. Biochem. Biophys., 155, (1973), 355– 360. 2 A.P. Alvares, G.R. Schilling, A. Garbut, R. Kuntzman, Biochem. Pharmacol., 19, (1970), 1449– 1455. 3 J.R. Gillette, Prog. Drug. Res., 6, (1963), 22– 23. J.R. Gillette, Prog. Drug. Res., 6, (1963), 55– 57. 4 I. Schuster, C. Fleschurz, I. Helm, Eur. J. Biochem., 51, (1975), 511– 519. 5 G.M. Cohen, G.J. Mannering, Mol. Pharmacol., 9, (1973), 383– 397. 6 A.L. Ibbetson, R.B. Freedman, Biochem. Soc. Trans., 2, (1974), 343– 345. 7 A.P. Alvares, G.R. Schilling, R. Kuntzman, Biochem. Biophys. Res. Commun., 30, (1968), 588– 595. 8 A.Y.H. Lu, S.B. West, Mol. Pharmacol., 8, (1972), 490– 500. 9 C.A. Blyth, R.B. Freedman, B.R. Rabin, Nature New Biol., 230, (1971), 136– 139. 10 A.H. Conney, Pharmacol. Rev., 19, (1967), 317– 366. 11 N. Borgese, W. Mok, G. Kreibich, D.D. Sabatini, J. Mol. Biol., 88, (1974), 539– 580. 12 C. Huang, Biochemistry, 8, (1969), 344– 352. Citing Literature Volume67, Issue2August 15, 1976Pages 123-129 ReferencesRelatedInformation

Conference Article| February 01 1975 Endoplasmic Membrane as a Source and a Target for Chemically Reactive Metabolic Intermediates D. J. WILLIAMS; D. J. WILLIAMS 1Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, U.K. Search for other works by this author on: This Site PubMed Google Scholar G. PARRY G. PARRY 1Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, U.K. Search for other works by this author on: This Site PubMed Google Scholar Biochem Soc Trans (1975) 3 (1): 69–72. https://doi.org/10.1042/bst0030069 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation D. J. WILLIAMS, G. PARRY; Endoplasmic Membrane as a Source and a Target for Chemically Reactive Metabolic Intermediates. Biochem Soc Trans 1 February 1975; 3 (1): 69–72. doi: https://doi.org/10.1042/bst0030069 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1975 Biochemical Society1975 Article PDF first page preview Close Modal You do not currently have access to this content.

Protein synthesis in the cell, involves particulate elements called ribosomes which translate the information coded as specific nucleotide sequences in messenger RNA molecules into amino-acid sequences of proteins [1]. Ribosomes are frequently found in the cell in the form of aggregates called polysomes. The ribosomes in a polysome are believed to be attached to a single messenger RNA molecule and simultaneously to translate the encoded information to give polypeptides with a specific amino-acid sequence [2]. The basic mechanisms of the control of protein synthesis at the level of translation are not well understood.

The effects of aflatoxin B(1) on the endoplasmic reticulum of rat liver has been examined in vivo. Electron microscopy has shown a disorganization and degranulation of rough surfaced membrane under these conditions and evidence is presented that this is a primary effect of the toxin, and results from the direct attack of the aflatoxin on the steroid-dependent ribosome binding sites on the membrane. A technique is described by which the presence of degranulated rough membrane may be detected in microsomal preparations.

FEBS LettersVolume 26, Issue 1-2 p. 245-248 Full-length articleFree Access Endoplasmic membrane degranulationin vivo as a result of ethionine intoxication D.J. Williams, D.J. Williams Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, EnglandSearch for more papers by this authorB.R. Rabin, B.R. Rabin Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, EnglandSearch for more papers by this authorR. Kisilevsky, R. Kisilevsky Department of Experimental Pathology, University College Hospital Medical School, University Street, London WC1E 6JJ, EnglandSearch for more papers by this author D.J. Williams, D.J. Williams Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, EnglandSearch for more papers by this authorB.R. Rabin, B.R. Rabin Department of Biochemistry, University College London, Gower Street, London WC1E 6BT, EnglandSearch for more papers by this authorR. Kisilevsky, R. Kisilevsky Department of Experimental Pathology, University College Hospital Medical School, University Street, London WC1E 6JJ, EnglandSearch for more papers by this author First published: October 01, 1972 https://doi.org/10.1016/0014-5793(72)80583-0Citations: 11 Department of Pathology, Queen's University Kingston, Ontario, Canada. 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 onFacebookTwitterLinked InRedditWechat Citing Literature Volume26, Issue1-2October 01, 1972Pages 245-248 ReferencesRelatedInformation

FEBS LettersVolume 4, Issue 2 p. 103-107 Full-length articleFree Access The effects of aflatoxin B1 and steroid hormones on polysome binding to microsomal membranes as measured by the activity of an enzyme catalysing disulphide interchange D.J. Williams, D.J. Williams Department of Biochemistry, University College London, London W.C. 1, EnglandSearch for more papers by this authorB.R. Rabin, B.R. Rabin Department of Biochemistry, University College London, London W.C. 1, EnglandSearch for more papers by this author D.J. Williams, D.J. Williams Department of Biochemistry, University College London, London W.C. 1, EnglandSearch for more papers by this authorB.R. Rabin, B.R. Rabin Department of Biochemistry, University College London, London W.C. 1, EnglandSearch for more papers by this author First published: July 01, 1969 https://doi.org/10.1016/0014-5793(69)80207-3Citations: 59AboutPDF 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 onEmailFacebookTwitterLinkedInRedditWechat References 1 R.F. Goldberger, C.J. Epstein, C.B. Anfinsen, J. Biol. Chem., 238, (1963), 628– 2 P. Venetianer, F.B. Straut, Acta Physiol. Hung, 24, (1963), 41– 3 F. De Lorenzo, G. Molea, Biochim. Biophys. Acta, 146, (1967), 593– 4 D.J. Williams, D. Gurari, B.R. Rabin, FEBS Letters, 2, (1968), 133– 5 W.H. Butler, Amer. J. Path., 49, (1966), 113– 6 R.H. Smith, Biochem. J., 88, (1963), 50P– 7 E.H. Harley, K.R. Rees and A. Cohen, Biochem. J., in press. 8 R. Süss, G. Blobel, H.C. Pitot, Biochem. Biophys. Res. Commun., 23, (1966), 299– 9 O.H. Lowry, N.J. Rosebrough, A.L. Farr, R.J. Randall, J. Biol. Chem., 193, (1951), 265– 10 H.N. Munro, A. Fleck, Meth. Biochem. Anal., 14, (1966), 113– 11 H. Bloemendal, W.S. Bont, M. De Vries, E.L. Benedetti, Biochem. J., 103, (1967), 177– Citing Literature Volume4, Issue2July 01, 1969Pages 103-107 ReferencesRelatedInformation

FEBS LettersVolume 2, Issue 2 p. 133-135 Full-length articleFree Access The effects of ribosomes on the activity of a membrane bound enzyme catalysing thiol-disulphide interchange D.J. Williams, D.J. Williams University College London, Gower Street, London, W.C.1, U.K.Search for more papers by this authorD. Gurari, D. Gurari University College London, Gower Street, London, W.C.1, U.K.Search for more papers by this authorB.R. Rabin, B.R. Rabin University College London, Gower Street, London, W.C.1, U.K.Search for more papers by this author D.J. Williams, D.J. Williams University College London, Gower Street, London, W.C.1, U.K.Search for more papers by this authorD. Gurari, D. Gurari University College London, Gower Street, London, W.C.1, U.K.Search for more papers by this authorB.R. Rabin, B.R. Rabin University College London, Gower Street, London, W.C.1, U.K.Search for more papers by this author First published: December 1968 https://doi.org/10.1016/0014-5793(68)80123-1Citations: 38AboutPDF 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 No abstract is available for this article. References 1 D. Givol, F. De Lorenzo, R.F. Goldberger, C.B. Anfinsen, Biochemistry, 53, (1963), 676– 2 P. Venetianer, F.B. Straub, Acta Physiol. Hung., 24, (1963), 41– 3 F. De Lorenzo, G. Molea, Biochim. Biophys. Acta, 146, (1967), 593– 4 D. Gurari and D.J. Williams, unpublished observations. 5 C.J. Epstein, R.F. Goldberger, C.B. Anfinsen, Cold Spring Harbor Symp. Quant. Biol., 28, (1963), 439– 6 R.F. Goldberger, C.J. Epstein, C.B. Anfinsen, J. Biol. Chem., 238, (1963), 628– 7 H. Bloemendal, W.S. Bont, M. De Vries, E.L. Benedetti, Biochem. J., 103, (1967), 177– 8 D. Givol, R.F. Goldberger, C.B. Anfinsen, J. Biol. Chem., 239, (1964), PC 3114– 9 M. Sela, C.B. Anfinsen, W.F. Harrington, Biochim. Biophys. Acta, 26, (1957), 502– 10 O.H. Lowry, N.J. Rosebrough, A.L. Farr, R.J. Randall, J. Biol. Chem., 193, (1951), 265– 11 G. Schmidt, S.J. Thannhauser, J. Biol. Chem., 161, (1945), 84– 12 A. Fleck, D.J. Begg, Biochim. Biophys. Acta, 108, (1965), 333– 13 D. Givol, F. De Lorenzo, R.F. Goldberger, C.B. Anfinsen, Proc. Natl. Acad. Sci. U.S., 53, (1965), 676– 14 F. De Lorenzo, S. Fuchs, C.B. Anfinsen, Biochemistry, 5, (1966), 3961– 15 D.D. Sabatini, Y. Tashiro, G.E. Palade, J. Mol. Biol., 19, (1966), 503– 16 Y. Tashiro, P. Siekevitz, J. Mol. Biol., 11, (1965), 174– Citing Literature Volume2, Issue2December 1968Pages 133-135 ReferencesRelatedInformation