Proton magnetic resonance studies in trifluoroethanol. Solvent mixtures as a means of delineating peptide protons

Pitner, T. Phil; Urry, Dan W.

doi:10.1021/ja00759a083

Cited by 183 publications

(107 citation statements)

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“…The 3 10 ‐helical conformation of l ‐ 1 was confirmed by its 1 H NMR and two‐dimensional NOESY spectra in CDCl 3 in combination with solvent‐dependent chemical shift changes of the amide NH protons of l ‐ 1 upon the addition of the hydrogen‐bond accepting [D 6 ]DMSO (Figures S3a and S4) 17. Similar [D 6 ]DMSO‐dependent chemical shift changes of the amide NH protons were also observed for l ‐ 2 (Figure S3b), indicating that l ‐ 2 possesses the identical 3 10 ‐helical structure to that of l ‐ 1 .…”

mentioning

confidence: 87%

“Helix‐in‐Helix” Superstructure Formation through Encapsulation of Fullerene‐Bound Helical Peptides within a Helical Poly(methyl methacrylate) Cavity

et al. 2016

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A one‐handed 310‐helical hexapeptide is efficiently encapsulated within the helical cavity of st‐PMMA when a fullerene (C60) derivative is introduced at the C‐terminal end of the peptide. The encapsulation is accompanied by induction of a preferred‐handed helical conformation in the st‐PMMA backbone with the same‐handedness as that of the hexapeptide to form a crystalline st‐PMMA/peptide‐C60 inclusion complex with a unique optically active helix‐in‐helix structure. Although the st‐PMMA is unable to encapsulate the 310‐helical peptide without the terminal C60 unit, the helical hollow space of the st‐PMMA is almost filled by the C60‐bound peptides. This result suggests that the C60 moiety can serve as a versatile molecular carrier of specific molecules and polymers in the helical cavity of the st‐PMMA for the formation of an inclusion complex, thus producing unique supramolecular soft materials that cannot be prepared by other methods.

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confidence: 87%

“Helix‐in‐Helix” Superstructure Formation through Encapsulation of Fullerene‐Bound Helical Peptides within a Helical Poly(methyl methacrylate) Cavity

et al. 2016

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“…Solvent composition dependences of chemical shifts of 13C resonances are useful for distinguishing between 'free' and 'intramolecularly hydrogenbonded' CO groups of peptide molecules [25,26]; the latter CO groups show little solvent dependenccs.…”

Section: Solvcnt-compositiorl Dependences Of Chemical Sliifts Of Co mentioning

confidence: 99%

Nuclear‐Magnetic‐Resonance Study of Aggregations and Conformations of Melanostatin and Related Peptides

Higashijima

Tasumi

Miyazawa

et al. 1978

European Journal of Biochemistry

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The H and 13C nuclear magnetic resonance spectra of melanostatin (Pro-Leu-Gly-NH2) and related peptides (Pro-Leu-Gly, Z-Pro-Leu-Gly, Z-Pro-Leu-Gly-NH2 and Z-Pro-Leu-Gly-OCH3, where Z = benzyloxycarbonyl) were analysed in a variety of solvents. At physiological pH, the melanostatin molecule is N-protonated in aqueous solution. The concentration dependences of the chemical shifts of amide-proton and carbonyl-carbon resonances and of proton spin-lattice relaxation times were observed in relation to molecular aggregations. In dimethylsulfoxide solution, aggregations were observed for N-protonated melanostatin and Pro-Leu-Gly prepared with HCI and for the Na salt of Z-Pro-Leu-Gly but not for N-protonated melanostatin prepared with HC104 or HN03, unprotonated melanostatin, Z-Pro-Leu-Gly-NH2, or Z-Pro-Leu-Gly-OCH3. The leucine NH and glycine CO groups of N-prolonated melanostatin are involved in the intermolecular hydrogen bonds of aggregates. The leucine NH group of N-protonated Pro-Leu-Gly also forms the intermolecular hydrogen bond. The solvent and temperature dependences of the chemical shifts of amide-proton and carbonyl-carbon resonances were measured to determine intramolecular hydrogen bonding, In dimethylsulfoxide solution, N-protonated melanostatin molecules in part take the &turn structure and the trans carboxamide NH proton and carbonyl oxygen of the proline residue form an intramolecular hydrogen bond.Melanostatin, Pro-Leu-Gly-NH2, is a tripeptide hormone inhibiting the release of pituitary melanotropin (melanocyte-stimulating hormone) [l -31, and is also found to possess additional extrapituitary activities [4 -61. An X-ray analysis [7] has shown that the melanostatin molecule takes a ten-membered hydrogen-bonded structure, namely the type I1 pturn structure [8,9]. An intramolecular hydrogen bond is formed between the carbonyl of the proline residue and the trans carboxamide proton of glycinamide. Conformational energy calculations have shown that this p-turn structure is one of the most stable conformations of melanostatin [lo, 111. Conformation studies on melanostatin in solution are also important for elucidating the correlations

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“…Nevertheless, the conformational analysis involves several approximations: (1) the relationship between the dihedral angle 0 (NH-CaH) and the measured three-bond coupling constant 3JHNCH (8,9)-a spectral parameter most useful when considered in combination with potential energy maps (10,11); (2) temperature (12) and solvent (13,14) dependences of chemical shifts and proton exchange rates (15)(16)(17) of peptide hydrogens as related to their solvent-exposed or solvent-shielded state.…”

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Conformational Studies of Oxytocin, Lysine Vasopressin, Arginine Vasopressin, and Arginine Vasotocin by Carbon-13 Nuclear Magnetic Resonance Spectroscopy

Walter

Prasad

Deslauriers

et al. 1973

Proc. Natl. Acad. Sci. U.S.A.

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Oxytocin, arginine vasopressin, lysine vasopressin, arginine vasotocin, as well as their cyclic and acyclic analogs, were studied by carbon-13 nuclear magnetic resonance spectroscopy in deuterium oxide and deuterated dimethylsulfoxide. Fourier-transformed spectra were obtained at 25. 16 MHz. The resonances of all carbon atoms have been assigned in both solvent systems; this includes tentative assignments of the carbonyl carbons. The spectra of arginine vasopressin and lysine vasopressin are essentially identical when compared in D20 or dimethylsulfoxide, but they differ from those of oxytocin. The spectrum of arginine vasotocin in D20 is intermediate between those of oxytocin and the vasopressins. These spectral differences are not only due to variations in constituent amino acids but are also a reflection of conformational differences of oxytocin, arginine vasotocin, and the vasopressins. All hormones are sensitive to changes in hydrogen ion concentration in both solvents; this was not observed with deamino analogs, which lack the terminal amino group.Conformational analysis of data from proton nuclear magnetic resonance ('H NMR) spectroscopy has contributed significantly to elucidation of the preferred solution conformations of oxytocin (1, 2) and lysine vasopressin ([Lys8]VP) (3-7). Nevertheless, the conformational analysis involves several approximations: (1) the relationship between the dihedral angle 0 (NH-CaH) and the measured three-bond coupling constant 3JHNCH (8, 9)-a spectral parameter most useful when considered in combination with potential energy maps (10, 11); (2)

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Proton magnetic resonance studies in trifluoroethanol. Solvent mixtures as a means of delineating peptide protons

Cited by 183 publications

References 1 publication

“Helix‐in‐Helix” Superstructure Formation through Encapsulation of Fullerene‐Bound Helical Peptides within a Helical Poly(methyl methacrylate) Cavity

“Helix‐in‐Helix” Superstructure Formation through Encapsulation of Fullerene‐Bound Helical Peptides within a Helical Poly(methyl methacrylate) Cavity

Nuclear‐Magnetic‐Resonance Study of Aggregations and Conformations of Melanostatin and Related Peptides

Conformational Studies of Oxytocin, Lysine Vasopressin, Arginine Vasopressin, and Arginine Vasotocin by Carbon-13 Nuclear Magnetic Resonance Spectroscopy

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