Circular dichroism of erythrocyte membrane glycoproteins

Decker, Rolan V.; Carraway, Kermit L.

doi:10.1016/0005-2795(75)90245-7

Cited by 7 publications

(2 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both glycophorin A and neuraminidase-treated glycophorin A, termed desialylglycophorin A, show very similar CD spectra. This is consistent with previous findings, although we succeeded in removing more than 90% of the sialic acid from the glycoprotein rather than the 60% previously reported (Decker & Carraway, 1975). Some differences in the spectra appear in the wavelength region below 220 nm, and these differences cause a slight change in the estimates of protein conformation.…”

Section: Resultssupporting

confidence: 92%

Conformation of human erythrocyte glycophorin A and its constituent peptides

Schulte¹,

Marchesi²

1979

Biochemistry

View full text Add to dashboard Cite

Section: Resultssupporting

confidence: 92%

Conformation of human erythrocyte glycophorin A and its constituent peptides

Schulte¹,

Marchesi²

1979

Biochemistry

View full text Add to dashboard Cite

“…Bovine rhodopsin in situ in the rod outer segment disk membranes yielded a helical content of about 29% by the same method of estimation (C. Rafferty and J. Y. Cassim, manuscript in preparation). For comparison, the helical contents of non-photosensitive membrane proteins in situ were also estimated by this procedure utilizing previously published membrane CD parameters (35,(41)(42)(43). In all cases for which CD data was available the helical content was less than those obtained for the bacteriorhodopsin in situ.…”

Section: Far Ultraviolet Spectramentioning

confidence: 99%

Effects of light adaptation on the purple membrane structure of Halobacterium halobium

Becher¹,

Cassim²

1976

Biophysical Journal

102

View full text Add to dashboard Cite

Absorption, circular dichroism and optical rotatory dispersion of the bacteriorhodopsin containing purple membrane form Halobacterium halobium were studied in regard to the structural stability of this membrane during the photoisomerization of the retinal of the bacteriorhodopsin from the 13-cis to the all-trans configuration. The following conclusions were reached: (a) the macromolecular structure (protein-protein interaction which may result in the possible exciton interaction of the retinal pi-pi* (NV1) transition moments and protein-lipid interaction) are not significantly altered, (b) possibilities of delocalized conformation changes of the apoprotein involving secondary and/or tertiary structure can be ruled out, (c) localized secondary structure conformation changes of the apoprotein must be limited to the involvement of no more than one or two amino acid residues and localized tertiary structure conformation changes of the apoprotein must be limited to a very short segment of the protein chain containing only a few aromatic amino acid residues, and (d) the interaction between the apoprotein and retinal seems to be relatively more pronounced when the retinal is in the all-trans form than the 13-cis from and also the apoprotein seems to impose a more pronounced dissymmetric constraint on the retinal in the all-trans form than in the 13-cis form.

show abstract

Molecular organization of glycophorin A: Implications for membrane interactions

et al. 1985

View full text Add to dashboard Cite

SynopsisPhysical studies and conformational analysis of human glycophorin A suggest a revised model for its molecular organization, self-association, and interactions with the erythrocyte membrane. Intrinsic viscosity has been used to study, under more physiological conditions, the monomer-dimer equilibrium demonstrated previously by polyacrylamide-SDS gel electrophoresis. The results show that the equilibrium persists in the absence of detergent and support earlier indications that the dimer is probably the physiologically relevant form and that it is promoted by salt, inhibited by conventional denaturants, and abolished by carboxymethylation.Combined application of CD, fitted to the po1y-b-lysine) model spectra of Greenfield and Fasman, and conformational prediction, by the statistical method of Chou and Fasman and the stereochemical approach of Lim, suggests five helical sequences in glycophorin A Arg-39 to Tyr-52 (A); Gln-63 to Glu-70 (B); Glu-72 to Leu-89 (C); Ile-95 to Lys-101 (D); and Leu-118 to Asn-125 (E). Sequence A occurs only at low pH and may be stabilized by favorable noncovalent interactions of Olinked tetrasaccharide side chains. The other four helices all occur in the dimeric form of glycophorin A at physiological pH and ionic strength. Sequence D is destroyed by trypsin, and is also lost on conversion to the monomeric form of the glycoprotein at low ionic strength. Sequence E is denatured by 6Mguanidine hydrochloridel4Murea. Sequences B and C, which are jeparated by a single proline residue, are stable under all these conditions. Dimerization of the major, hydrophobic helical sequence, (C) may be promoted and directed by an adjacent short sequence of intermolecular parallel &sheet (Leu-90 to Tyr-93). It is proposed that these two structures span the lipid bilayer in uiuo, and that helices B and D lie, respectively, along the outer and inner surfaces of the membrane. Molecular organization in the N-and Cterminal regions of the molecule is discussed in terms of evidence from the present work and from other recent investigations.

show abstract

Circular dichroism of erythrocyte membrane glycoproteins

Cited by 7 publications

References 29 publications

Conformation of human erythrocyte glycophorin A and its constituent peptides

Conformation of human erythrocyte glycophorin A and its constituent peptides

Effects of light adaptation on the purple membrane structure of Halobacterium halobium

Molecular organization of glycophorin A: Implications for membrane interactions

Contact Info

Product

Resources

About