Spatial Configuration of Macromolecular Chains

Flory, Paul J.

doi:10.1126/science.188.4195.1268

Cited by 83 publications

(45 citation statements)

References 47 publications

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“…[47] In fact, the enthalpy change observed during lipid main transition can mostly be ascribed to the extent of the interaction between guest molecules and hydrophobic tails of lipids. [48] Moreover, it has been shown that T m increases with the rigidity of the membrane, due to an interfacial lipid/peptide interaction. [48,49] With this in mind, DSC experiments were performed on both zwitterionic (DPPC; 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine) and negatively charged (DPPS; 1,2-dipalmitoyl-sn-glycero-3-phosphoserine) lipid bilayers.…”

Section: Differential Scanning Calorimetry Of the Vdac Peptide In A Cmentioning

confidence: 99%

Determination of the Conformation of the Human VDAC1 N‐Terminal Peptide, a Protein Moiety Essential for the Functional Properties of the Pore

et al. 2007

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Mitochondrial porin or VDAC (voltage-dependent anion-selective channel) is the most abundant protein in the mitochondrial outer membrane. The structure of VDAC has been predicted to be a transmembrane beta-barrel with an alpha-helix at the N terminus. It is a matter of debate as to whether this putative alpha-helix plays a structural role as a component of the pore walls or a function in the pore activity. We have synthesised the human VDAC1 (HVDAC1) N-terminal peptide Ac-AVPPTYADLGKSARDVFTK-NH2 (Prn2-20) and determined its structure by CD and NMR spectroscopy. CD studies show that the Prn2-20 peptide exists in aqueous solvent as an unstructured peptide with no stable secondary structure. In membrane-mimetic SDS micelles or water/trifluoroethanol, however, it assumes an amphipathic alpha-helix conformation between Tyr5 and Val16, as deduced from NMR. No ordered structure was observed in dodecyl beta-maltoside. Differential scanning calorimetric measurements were carried out in order to examine the membrane affinity of the peptide. Upon interaction with the negatively charged 1,2 dipalmitoyl-sn-glycero-3-phosphoserine membrane, Prn2-20 exhibited distinctive behaviour, suggesting that electrostatics play an important role. Interaction between the peptide and artificial bilayers indicates that the peptide lies on the membrane surface. Recombinant HVDAC1 deletion mutants, devoid of seven or 19 N-terminal amino acids, were used for transfection of eukaryotic cells. Over-expression of HVDAC1 increases the number of Cos cells with depolarised mitochondria, and this effect is progressively reduced in cells transfected with HVDAC1 lacking those seven or 19 amino acids. The mitochondrial targeting of the deletion mutants is unaffected. The overall picture emerging from our experiments is that the VDAC N-terminal peptide plays a role in the proper function of this protein during apoptotic events.

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Section: Differential Scanning Calorimetry Of the Vdac Peptide In A Cmentioning

confidence: 99%

Determination of the Conformation of the Human VDAC1 N‐Terminal Peptide, a Protein Moiety Essential for the Functional Properties of the Pore

et al. 2007

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“…This model, sometimes called the spaghetti model, is due to Flory [31]. It can be viewed as an analog of the CRN and the RCP models, subject to the same types of limitations, and especially designed for organic polymeric glasses such as polystyrene.…”

Section: Random Coil Model For Polymeric Glassesmentioning

confidence: 99%

“…For many transition metal/metalloid glasses (such as Ni3B), there seems to be even more ordering, with polyhedral building blocks suct as tetrahedral, octahedral, or tricapped trigonal prismatic units of atoms forming the solid by random close packing [30]. Finally, in the random coils of a polymeric organic glass [31], the long and flexible coils are intermeshed in random-walk configurations as illustrated in Fig. 6, but each individual coil is formed by the repetition (up to --lO times) of a monomeric molecular unit, so that the local environment of each atom, formed by those atoms (all within the same coil) to which it is bonded, is quite well-defined.…”

Section: Comparisons With Experimentsmentioning

confidence: 99%

Theory of the structures of non-crystalline solids

Bicerano¹,

Adler²

1987

Pure and Applied Chemistry

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-The study of the structures and properties of non-crystalline solids and their interrelationships is a rapidly growing field of research, involving interdisciplinary efforts at the frontiers of chemistry, solid state physics, and materials science. These materials differ from the better-understood crystalline solids by the lack of long range three-dimensional translational periodicity in their atomic arrangements.Consequently, this study cannot make use of the simplification attendant with the use of repetitions of a small unit cell. We present a review of the state-of-the-art in the theoretical study of the structures of such non-crystalline solids. The topics covered include structural models, the nature of order and disorder, model systems of low dimensionality, chemical bonding considerations, thermodynamic and kinetic considerations, dynamic simulations, elastic and vibrational properties, electronic structure and properties, amorphous metals and alloys, silica glasses and related alloys, liquids and superlattices. It is our hope that this review will generate more interest among chemists in the scientific and technological problems and challenges presented by these materials.

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“…A well-known example is the gauche-trans equilibrium in n-butane. It was argued (6) that in the disordered liquid phase the intramolecular potential averages to that in the isolated molecule. Experimental data for the energy difference between the trans and gauche forms overlap for the liquid and gaseous states (1).…”

Section: Introductionmentioning

confidence: 99%

¹H nuclear magnetic resonance and molecular orbital studies of the structure and internal rotations in ethylbenzene

Schaefer¹,

Penner²,

Sebastian³

1987

Can. J. Chem.

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6-31G levels of ab initio molecular orbital theory suggest that the fourfold component of the barrier to internal rotation about the C,~-C,Ibond in ethylbenzene amounts to about 20% of the twofold component. The 'H nuclear magnetic resonance spectral parameters, extracted by complete analyses of the spectra arising from the ten protons, are reported for ethylbenzene in acetone-d6, CC14, CS2, and perfluoromethylcyclohexane solutions. The long-range proton-proton spin-spin coupling constants demonstrate that the internal barrier is insensitive to the polarity of the solvent, in contrast to polar solute molecules such as benzyl fluoride. The coupling constants do not support a dependence of the internal barrier on the internal pressure of the solvent. TED SCHAEFER, GLENN H. PENNER et RUDY SEBASTIAN. Can. J. Chem. 65, 873 (1987). Des calculs ab initio d'orbitales molCculaires ont Ct C effectuts d'une f a~o n relativement approfondie aux niveaux STO-3G, 4-2lC, 4-3 1G et 6-3 1G et on les a optirnisCs par rapport a la gComCtrie; les rtsultats suggbrent que la barribre la rotation interne autour de la liaison CSp2-CSpl de l'tthylbenzbne comporte une composante quadruple qui correspond 2 20% de la composante binaire. On a dCtermin6 les spectres rmn 'H de 1'Cthylbenzbne en solutions dans I'acCtone-d6, dans le CC14, dans le CS2 et dans le perfluoromtthylcyclohexane et on a dttermint les parambtres spectraux en procCdant a des analyses complbtes des spectres provenant des dix protons. Les constantes de couplage spin-spin, proton-proton a longue distance dCmontrent que la banibre interne n'est pas sensible B la polarit6 du solvant; ce rCsultat est en opposition avec ce qui est obsewt avec des moltcules polaires comme le fluorure de benzyle. Les constantes de couplage ne prtsentent pas de relation entre la barribre interne et la pression interne du solvant.[Traduit par la revue]

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Spatial Configuration of Macromolecular Chains

Cited by 83 publications

References 47 publications

Determination of the Conformation of the Human VDAC1 N‐Terminal Peptide, a Protein Moiety Essential for the Functional Properties of the Pore

Determination of the Conformation of the Human VDAC1 N‐Terminal Peptide, a Protein Moiety Essential for the Functional Properties of the Pore

Theory of the structures of non-crystalline solids

¹H nuclear magnetic resonance and molecular orbital studies of the structure and internal rotations in ethylbenzene

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Spatial Configuration of Macromolecular Chains

Cited by 83 publications

References 47 publications

Determination of the Conformation of the Human VDAC1 N‐Terminal Peptide, a Protein Moiety Essential for the Functional Properties of the Pore

Determination of the Conformation of the Human VDAC1 N‐Terminal Peptide, a Protein Moiety Essential for the Functional Properties of the Pore

Theory of the structures of non-crystalline solids

1H nuclear magnetic resonance and molecular orbital studies of the structure and internal rotations in ethylbenzene

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¹H nuclear magnetic resonance and molecular orbital studies of the structure and internal rotations in ethylbenzene