Abstract
Bovine photoreceptor membranes have been treated with proteases to determine the accessibility of rhodopsin to these large, water soluble molecules. The polypeptides that remain associated with the membranous structure after proteolysis were detected by sodium dodecyl sulfate gel electrophoresis. Thermolysin and chymotrypsin degraded rhodopsin (apparent mol wt 35,000–36,000) to fragments of 29,000 and 23,000 apparent mol wt, respectively, without affecting the chromophoric absorption of the molecule or removing the region of the polypeptide carrying carbohydrate. The two fragments were isolated and their amino acid compositions were determined. They do not appear to be more hydrophobic than rhodopsin. Subtilisin, at low concentration and temperature, produced a fragment with the same molecular weight as that produced by thermolysin. At higher concentrations, subtilisin yields major fragments of mol wt 23,000 and 20,000 without affecting the chromophoric absorption. Two intermediate fragments of apparent mol wt 29,000 and 26,000 were detected during the course of this degradation. Carbohydrate is retained by all but the smallest fragment. Bleaching of the photoreceptor pigment did not appreciably alter any of the fragmentation patterns. Trypsin did not alter the molecular weight of rhodopsin under the conditions of this study. Approximately 35–45% of rhodopsin appears to be accessible to the aqueous environment and can be removed without affecting the chromophoric properties of the retinaldehyde-carrying region which remains bound to the membrane.
Full Text
The Full Text of this article is available as a PDF (1,017.7 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Blasie J. K. Net electric charge on photopigment molecules and frog retinal receptor disk membrane structure. Biophys J. 1972 Feb;12(2):205–213. doi: 10.1016/S0006-3495(72)86080-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Blasie J. K. The location of photopigment molecules in the cross-section of frog retinal receptor disk membranes. Biophys J. 1972 Feb;12(2):191–204. doi: 10.1016/S0006-3495(72)86079-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Blaurock A. E., Wilkins M. H. Structure of retinal photoreceptor membranes. Nature. 1972 Apr 7;236(5345):313–314. doi: 10.1038/236313a0. [DOI] [PubMed] [Google Scholar]
- Bonting S. L., de Grip W. J., Rotmans J. P., Daemen F. J. Use of photoreceptor membrane suspensions for the study of rhodopsin and associated enzyme activities. Exp Eye Res. 1974 Jan;18(1):77–88. doi: 10.1016/0014-4835(74)90045-1. [DOI] [PubMed] [Google Scholar]
- Bownds D., Gordon-Walker A., Gaide-Huguenin A. C., Robinson W. Characterization and analysis of frog photoreceptor membranes. J Gen Physiol. 1971 Sep;58(3):225–237. doi: 10.1085/jgp.58.3.225. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Branton D. Fracture faces of frozen membranes. Proc Natl Acad Sci U S A. 1966 May;55(5):1048–1056. doi: 10.1073/pnas.55.5.1048. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brown P. K. Rhodopsin rotates in the visual receptor membrane. Nat New Biol. 1972 Mar 15;236(63):35–38. doi: 10.1038/newbio236035a0. [DOI] [PubMed] [Google Scholar]
- Capaldi R. A., Vanderkooi G. The low polarity of many membrane proteins. Proc Natl Acad Sci U S A. 1972 Apr;69(4):930–932. doi: 10.1073/pnas.69.4.930. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Clark A. W., Branton D. Fracture faces in frozen outer segments from the guinea pig retina. Z Zellforsch Mikrosk Anat. 1968;91(4):586–603. doi: 10.1007/BF00455276. [DOI] [PubMed] [Google Scholar]
- Cone R. A. Rotational diffusion of rhodopsin in the visual receptor membrane. Nat New Biol. 1972 Mar 15;236(63):39–43. doi: 10.1038/newbio236039a0. [DOI] [PubMed] [Google Scholar]
- Dratz E. A., Gaw J. E., Schwartz S., Ching W. M. Molecular organization of photoreceptor membranes of rod outer segments. Nat New Biol. 1972 May 24;237(73):99–102. doi: 10.1038/newbio237099a0. [DOI] [PubMed] [Google Scholar]
- Dratz E. A., Schwartz S. Where is rhodopsin? Nat New Biol. 1973 Apr 18;242(120):212–213. doi: 10.1038/newbio242212b0. [DOI] [PubMed] [Google Scholar]
- 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]
- Frank R. N., Cavanagh H. D., Kenyon K. R. Light-stimulated phosphorylation of bovine visual pigments by adenosine triphosphate. J Biol Chem. 1973 Jan 25;248(2):596–609. [PubMed] [Google Scholar]
- GOLDSTEIN I. J., HOLLERMAN C. E., SMITH E. E. PROTEIN-CARBOHYDRATE INTERACTION. II. INHIBITION STUDIES ON THE INTERACTION OF CONCANAVALIN A WITH POLYSACCHARIDES. Biochemistry. 1965 May;4:876–883. doi: 10.1021/bi00881a013. [DOI] [PubMed] [Google Scholar]
- Hagins W. A. The visual process: Excitatory mechanisms in the primary receptor cells. Annu Rev Biophys Bioeng. 1972;1:131–158. doi: 10.1146/annurev.bb.01.060172.001023. [DOI] [PubMed] [Google Scholar]
- Heller J., Lawrence M. A. Structure of the glycopeptide from bovine visual pigment 500. Biochemistry. 1970 Feb 17;9(4):864–869. doi: 10.1021/bi00806a021. [DOI] [PubMed] [Google Scholar]
- Hong K., Hubbell W. L. Lipid requirements for Rhodopsin regenerability. Biochemistry. 1973 Oct 23;12(22):4517–4523. doi: 10.1021/bi00746a033. [DOI] [PubMed] [Google Scholar]
- Hong K., Hubbell W. L. Preparation and properties of phospholipid bilayers containing rhodopsin. Proc Natl Acad Sci U S A. 1972 Sep;69(9):2617–2621. doi: 10.1073/pnas.69.9.2617. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Irreverre F., Stone A. L., Shichi H., Lewis M. S. Biochemistry of visual pigments. I. Purification and properties of bovine rhodopsin. J Biol Chem. 1969 Feb 25;244(4):529–536. [PubMed] [Google Scholar]
- Kimble E. A., Ostroy S. E. Kinetics of reaction of the sulfhydryl groups of rhodopsin. Biochim Biophys Acta. 1973 Nov 22;325(2):323–331. doi: 10.1016/0005-2728(73)90108-4. [DOI] [PubMed] [Google Scholar]
- Kühn H., Cook J. H., Dreyer W. J. Phosphorylation of rhodopsin in bovine photoreceptor membranes. A dark reaction after illumination. Biochemistry. 1973 Jun 19;12(13):2495–2502. doi: 10.1021/bi00737a020. [DOI] [PubMed] [Google Scholar]
- Marchesi V. T., Jackson R. L., Segrest J. P., Kahane I. Molecular features of the major glycoprotein of the human erythrocyte membrane. Fed Proc. 1973 Aug;32(8):1833–1837. [PubMed] [Google Scholar]
- Mathews F. S., Levine M., Argos P. Three-dimensional Fourier synthesis of calf liver cytochrome b 5 at 2-8 A resolution. J Mol Biol. 1972 Mar 14;64(2):449–464. doi: 10.1016/0022-2836(72)90510-4. [DOI] [PubMed] [Google Scholar]
- Morihara K., Tsuzuki H. Proteolytic substrate specificity and some elastolytic properties of a thermostable bacterial proteinase. Biochim Biophys Acta. 1966 Apr 12;118(1):215–218. doi: 10.1016/s0926-6593(66)80164-9. [DOI] [PubMed] [Google Scholar]
- O'Brien P. J., Muellenberg C. G. Incorporation of glucosamine into rhodopsin in isolated bovine retina. Arch Biochem Biophys. 1973 Sep;158(1):36–42. doi: 10.1016/0003-9861(73)90594-8. [DOI] [PubMed] [Google Scholar]
- Papermaster D. S., Dreyer W. J. Rhodopsin content in the outer segment membranes of bovine and frog retinal rods. Biochemistry. 1974 May 21;13(11):2438–2444. doi: 10.1021/bi00708a031. [DOI] [PubMed] [Google Scholar]
- Poo M., Cone R. A. Lateral diffusion of rhodopsin in the photoreceptor membrane. Nature. 1974 Feb 15;247(5441):438–441. doi: 10.1038/247438a0. [DOI] [PubMed] [Google Scholar]
- Pringle J. R. The molecular weight of the undegraded polypeptide chain of yeast hexokinase. Biochem Biophys Res Commun. 1970 Apr 8;39(1):46–52. doi: 10.1016/0006-291x(70)90755-2. [DOI] [PubMed] [Google Scholar]
- RADDING C. M., WALD G. The action of enzymes on rhodopsin. J Gen Physiol. 1958 Nov 20;42(2):371–383. doi: 10.1085/jgp.42.2.371. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Raubach R. A., Nemes P. P., Dratz E. A. Chemical labeling and freeze-fracture studies on the localization of rhodopsin in the rod outer segment disk membrane. Exp Eye Res. 1974 Jan;18(1):1–12. doi: 10.1016/0014-4835(74)90038-4. [DOI] [PubMed] [Google Scholar]
- Raviola E., Gilula N. B. Gap junctions between photoreceptor cells in the vertebrate retina. Proc Natl Acad Sci U S A. 1973 Jun;70(6):1677–1681. doi: 10.1073/pnas.70.6.1677. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Steinemann A., Stryer L. Accessibility of the carbohydrate moiety of rhodopsin. Biochemistry. 1973 Apr 10;12(8):1499–1502. doi: 10.1021/bi00732a005. [DOI] [PubMed] [Google Scholar]
- Trayhurn P., Mandel P., Virmaux N. Removal of a large fragment of rhodopsin without changes in its spectral properties, by proteolysis of retinal rod outer segments. FEBS Lett. 1974 Jan 15;38(3):351–353. doi: 10.1016/0014-5793(74)80089-x. [DOI] [PubMed] [Google Scholar]
- WALD G., BROWN P. K. The molar extinction of rhodopsin. J Gen Physiol. 1953 Nov 20;37(2):189–200. doi: 10.1085/jgp.37.2.189. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Wright W. E., Brown P. K., Wald G. Orientation of intermediates in the bleaching of shear-oriented rhodopsin. J Gen Physiol. 1973 Nov;62(5):509–522. doi: 10.1085/jgp.62.5.509. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wu C. W., Stryer L. Proximity relationships in rhodopsin. Proc Natl Acad Sci U S A. 1972 May;69(5):1104–1108. doi: 10.1073/pnas.69.5.1104. [DOI] [PMC free article] [PubMed] [Google Scholar]
- de Grip W. J., Daemen F. J., Bonting S. L. Biochemical aspects of the visual process. XXII. Amino group modification in bovine rod photoreceptor membranes. Biochim Biophys Acta. 1973 Sep 27;323(1):125–142. doi: 10.1016/0005-2736(73)90436-7. [DOI] [PubMed] [Google Scholar]