Circular dichroism studies on lipid-protein complexes of a hydrophobic myelin protein.

Circular dichroism spectra of lipophilin (a hydrophobic protein purified from human central nervous system myelin) were analyzed by the method of Chen et al. (1974) to obtain information on its secondary structure in aqueous and lipid environments. When introduced into phosphatidylcholine vesicles by dialysis from 2-chloroethanol, the protein possessed about 75% alpha helix. A new water-soluble form of lipophilin also containing over 70% alpha helix was obtained by a similar dialysis in the absence of lipid. This product had a higher helical content than two other water-soluble preparations derived by dialysis from phenol-acetic acid-urea. Interaction of all three aqueous forms of the protein with lysolecithin micelles resulted in increases in total helical content or in the average length of helical segments. The amount of beta sheet was at a minimum for lipophilin incorporated into vesicles, where the presence of lipid also provided some protection against thermal denaturation.

[1]  D. Papahadjopoulos,et al.  Lipid phase separation induced by a hydrophobic protein in phosphatidylserine--phosphatidylcholine vesicles. , 1977, Biochemistry.

[2]  W. Stoeckenius,et al.  Circular dichroism of biological membranes: purple membrane of Halobacterium halobium. , 1977, Biochemical and biophysical research communications.

[3]  J. Boggs,et al.  Preparation and properties of vesicles of a purified myelin hydrophobic protein and phospholipid. A spin label study. , 1976, Biochimica et biophysica acta.

[4]  A. S. Schneider,et al.  Angular scattering analysis of the circular dichroism of biological cells. 2. The red blood cell. , 1976, Biochemistry.

[5]  M. Barratt,et al.  A study of Folch-Pi apoprotein. II. Relation between polymerization state and conformation. , 1976, Biochimica et biophysica acta.

[6]  R. E. Webster,et al.  Evidence for a major conformational change of coat protein in assembly of fl bacteriophage , 1976, Nature.

[7]  R. Henderson,et al.  Three-dimensional model of purple membrane obtained by electron microscopy , 1975, Nature.

[8]  P. Laggner.  A highly α-helical structure protein in sarcoplasmic reticulum membranes , 1975, Nature.

[9]  Y H Chen,et al.  Determination of the helix and beta form of proteins in aqueous solution by circular dichroism. , 1974, Biochemistry.

[10]  D. Papahadjopoulos,et al.  Interaction of a hydrophobic protein with liposomes evidence for particles seen in freeze fracture as being proteins , 1974 .

[11]  H. Inoue.  Sedimentation equilibrium study on preferential interaction of protein with solvent components , 1973 .

[12]  R. Epand,et al.  Conformational flexibility of a myelin protein. , 1973, Biochemistry.

[13]  D. Wetlaufer,et al.  CIRCULAR DICHROISM OF NERVE MEMBRANE FRACTIONS: EFFECTS OF TEMPERATURE, pH AND ELECTROLYTES 1 , 1973, Journal of neurochemistry.

[14]  Y H Chen,et al.  Determination of the secondary structures of proteins by circular dichroism and optical rotatory dispersion. , 1972, Biochemistry.

[15]  D. Wood,et al.  Isolation of a highly purified myelin protein. , 1971, Biochemistry.

[16]  J. R. Parrish,et al.  Spectroscopic studies of random chain and α‐helical polypeptides in hexafluoroisopropanol , 1971, Biopolymers.

[17]  M. Moscarello,et al.  Conformational transition of a myelin protein , 1971, FEBS letters.

[18]  D. Wetlaufer,et al.  A new basis for interpreting the circular dichroic spectra of proteins. , 1971, Proceedings of the National Academy of Sciences of the United States of America.

[19]  C. Tanford,et al.  The solubility of amino acids and two glycine peptides in aqueous ethanol and dioxane solutions. Establishment of a hydrophobicity scale. , 1971, The Journal of biological chemistry.

[20]  J. Folch-Pi,et al.  ROTATORY DISPERSION AND CIRCULAR DICHROISM OF BRAIN ‘PROTEOLIPID’ PROTEIN 1 , 1970, Journal of neurochemistry.

[21]  G. Fasman,et al.  Computed circular dichroism spectra for the evaluation of protein conformation. , 1969, Biochemistry.

[22]  M. Moscarello,et al.  The isolation and characterization of an acid-soluble protein from myelin. , 1966, Canadian journal of biochemistry.

[23]  K. Takayama,et al.  Studies on the electron transfer system. LXVII. Polyacrylamide gel electrophoresis of the mitochondrial electron transfer complexes. , 1966, Archives of biochemistry and biophysics.

[24]  H. Hess,et al.  MICROASSAY OF BIOCHEMICAL STRUCTURAL COMPONENTS IN NERVOUS TISSUES–II , 1965, Journal of neurochemistry.

[25]  T. Mcmeekin,et al.  Specific volumes of proteins and the relationship to their amino acid contents. , 1952, Science.

[26]  M. Moscarello.  Chemical and Physical Properties of Myelin Proteins , 1976 .

[27]  L. Rothfield.  Structure and function of biological membranes , 1971 .