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Gebreslasie HG, Jacobsen Ø, Görbitz CH. N-(tert-butoxycarbonyl)-α-aminoisobutyryl-α-aminoisobutyric acid methyl ester: two polymorphic forms in the space group P2(1)/n. Acta Crystallogr C 2011; 67:o283-7. [PMID: 21817793 DOI: 10.1107/s0108270111024322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 06/21/2011] [Indexed: 11/11/2022] Open
Abstract
The title compound (systematic name: methyl 2-{2-[(tert-butoxycarbonyl)amino]-2-methylpropanamido}-2-methylpropanoate), C(14)H(26)N(2)O(5), (I), crystallizes in the monoclinic space group P2(1)/n in two polymorphic forms, each with one molecule in the asymmetric unit. The molecular conformation is essentially the same in both polymorphs, with the α-aminoisobutyric acid (Aib) residues adopting ϕ and ψ values characteristic of α-helical and mixed 3(10)- and α-helical conformations. The helical handedness of the C-terminal residue (Aib2) is opposite to that of the N-terminal residue (Aib1). In contrast to (I), the closely related peptide Boc-Aib-Aib-OBn (Boc is tert-butoxycarbonyl and Bn is benzyl) adopts an α(L)-P(II) backbone conformation (or the mirror image conformation). Compound (I) forms hydrogen-bonded parallel β-sheet-like tapes, with the carbonyl groups of Aib1 and Aib2 acting as hydrogen-bond acceptors. This seems to represent an unusual packing for a protected dipeptide containing at least one α,α-disubstituted residue.
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KARLE ISABELLAL, FLIPPEN-ANDERSON JUDITHL, SUKUMAR M, BALARAM P. Parallel and antiparallel aggregation of α-helices. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1990.tb00256.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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VERTUANI G, FALCOMER C, BOGGIAN M, POCHETTI G, CERRINI S, RICCI M, ROSS C, SCATTURIN A. Structural studies of leucinostatin A and its Boc-Aib-Leu-Leu-Aib-OMe tetrapeptide fragment. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1989.tb00205.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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FRANCIS A, VIJAYAKUMAR E, BALARAM P, VIJAYAN M. A helical peptide containing a majority of valyl residues. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1985.tb03199.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Nguyen HH, Imhof D, Kronen M, Gräfe U, Reissmann S. Circular dichroism studies of ampullosporin-A analogues. J Pept Sci 2003; 9:714-28. [PMID: 14658791 DOI: 10.1002/psc.459] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Ampullosporin A (AmpA), a 15mer peptalbol containing seven Aib residues is able to induce pigmentation on Phoma destructiva and hypothermia in mice, as well as to exhibit a neuroleptic effect. A circular dichroism study of ampullosporin A and its analogues was carried out in organic solvents with different polarities and detergent micelles to determine the relationship between their conformational flexibility and biological activities. The analogues were obtained by modifying the N- and C-termini of ampullosporin A. Furthermore, Gln and Leu were systematically substituted by Ala and Aib residues were replaced by Ala and/or Ac6c. To estimate the helicity of the analogues, the CD spectrum of AmpA recorded in acetonitrile was correlated to its crystal structure. All analogues displayed similar CD curve shapes in organic solvents with the ratio between two negative band intensities R = [theta]n-pi*/[theta]pi-pi* < 1. In acetonitrile, most of the analogues adopted a 70%-85% helical structure, which was higher than the average of 40%-60% obtained in TFE. In detergent micelles, the analogues were distinguishable by their CD profiles. For most of the biologically active analogues, the CD spectra in detergent micelles were characterized by a R ratio > 1 and increased helicity compared with those recorded in TFE, suggesting that the interaction of the peptides with the membrane and peptide association was necessary for their hypothermic effect.
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Affiliation(s)
- Hoai-Huong Nguyen
- Institut für Biochemie und Biophysik, Friedrich-Schiller-Universität Jena, Philosophenweg 12, D-07743 Jena, Germany
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Tycko R, Smith SO. Symmetry principles in the design of pulse sequences for structural measurements in magic angle spinning nuclear magnetic resonance. J Chem Phys 1993. [DOI: 10.1063/1.465078] [Citation(s) in RCA: 120] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Beck-Sickinger AG, Jung G, Gaida W, Köppen H, Schnorrenberg G, Lang R. Structure/activity relationships of C-terminal neuropeptide Y peptide segments and analogues composed of sequence 1-4 linked to 25-36. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 194:449-56. [PMID: 2176597 DOI: 10.1111/j.1432-1033.1990.tb15638.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
C-terminal analogues of neuropeptide Y have been synthesized. The influence of chain length, single-amino-acid substitutions and segment substitutions on receptor binding, biological activity and conformational properties has been investigated. Receptor binding and in vivo assays revealed biological activity already for amino acids 28-36 of neuropeptide Y [neuropeptide Y-(Ac-28-36)-peptide] which increased with increasing chain length. Replacement of Arg25 in neuropeptide Y-(Ac-25-36)-peptide had no influence on binding, whereas Arg33 and Arg35 cannot be replaced by lysine or ornithine without considerable decrease in receptor binding. The introduction of conformational constraints by the 2-aminoisobutyric acid residue (Aib) in position 30 and replacing the amino acids 28-32 by Ala-Aib-Ala-Aib-Ala decreased receptor binding. However, the corresponding Aib-Ala-Aib-Ala-Aib-substituted analogue and a more flexible analogue with Gly5 at position 28-32 exhibited considerable affinity for the receptor. All these substitutions led to a decrease in postsynaptic activity. Strong agonistic activities could be detected in a series of 10 discontinuous analogues, which are constructs of N-terminal parts linked via different spacer molecules to C-terminal segments. One of the most active molecules was neuropeptide Y amino acids 1-4 linked to amino acids 25-36 through aminohexanoic acid (Ahx) [neuropeptide Y-(1-4-Ahx-25-36)-peptide].
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Affiliation(s)
- A G Beck-Sickinger
- Institut für Organische Chemie, Universität Tübingen, Federal Republic of Germany
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Valle G, Crisma M, Formaggio F, Toniolo C, Jung G. Geometry and Conformation of the α-Aminoisobutyric Acid Residue in Simple Derivatives and Dipeptides. Four New X-ray Structural Analyses and a Statistical Analysis from Known Crystal Data. ACTA ACUST UNITED AC 1987. [DOI: 10.1002/jlac.198719870872] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Voges KP, Jung G, Sawyer WH. Depth-dependent fluorescent quenching of a tryptophan residue located at defined positions on a rigid 21-peptide helix in liposomes. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 896:64-76. [PMID: 3790588 DOI: 10.1016/0005-2736(87)90357-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Five lipophilic 21-peptide analogs of the potential-dependent pore-former, alamethicin, were synthesized bearing tryptophan residues at the position 1, 6, 11, 16 and 21 on a long, conformationally rigid, alpha-helix. The alpha-helical conformation was induced and stabilized using the sequential oligomers (Ala-Aib-Ala-Aib-Ala)n as analyzed by CD and NMR. The partitioning of the N-t-butoxycarbonyl 21-peptide methyl esters and the N-terminally deprotected alpha-helices was followed by fluorescence enhancement in phospholipid bilayer vesicles. Quenching experiments were performed by titrating with n-doxyl stearic acids bearing the nitroxide label at positions 5, 7, 10, 12 and 16. This well-defined system revealed that the N- and C-terminal tryptophan residues become situated in the hydrophilic region. Tryptophan at position 11 was found in the lipophilic core, whereas the tryptophan at positions 6 and 16 were localized at intermediate depths of the lipid membrane. Therefore, the helices span the lipid bilayer with their long axis normal to the membrane surface.
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Menestrina G, Voges KP, Jung G, Boheim G. Voltage-dependent channel formation by rods of helical polypeptides. J Membr Biol 1986; 93:111-32. [PMID: 2433450 DOI: 10.1007/bf01870804] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The voltage-dependence of channel formation by alamethicin and it natural analogues can be described by a dipole flip-flop gating model, based on electric field-induced transbilayer orientational movements of single molecules. These field-induced changes in orientation result from the large permanent dipole moment of alamethicin, which adopts alpha-helical conformation in hydrophobic medium. It was, therefore, supposed that the only structural requirement for voltage-dependent formation of alamethicin-type channels might be a rigid lipophilic helical segment of minimum length. In order to test this hypothesis we synthesized a family of lipophilic polypeptides--Boc-(Ala-Aib-Ala-Aib-Ala)n-OMe, n = 1-4--which adopt alpha-helical conformation for n = 2-4 and studied their interaction with planar lipid bilayers. Surprisingly, despite their large difference in chain length, all four polypeptides showed quantitatively similar behavior. At low field strength of the membrane electric field these polypeptides induce a significant, almost voltage-independent increase of the bilayer conductivity. At high field strength, however, a strongly voltage-dependent conductance increase occurs similar to that observed with alamethicin. It results from the opening of a multitude of ion translocating channels within the membrane phase. The steady-state voltage-dependent conductance depends on the 8th-9th power of polypeptide concentration and involves the transfer of 4-5 formal elementary charges. From the power dependences on polypeptide concentration and applied voltage of the time constants in voltage-jump current-relaxation experiments, it is concluded that channels could be formed from preexisting dodecamer aggregates by the simultaneous reorientation of six formal elementary charges. Channels exhibit large conductance values of several nS, which become larger towards shorter polypeptide chain length. A mean channel diameter of 19 A is estimated corresponding roughly to the lumen diameter of a barrel comprised of 10 alpha-helical staves. Similar to experiments with the N-terminal Boc-derivative of alamethicin we did not observe the burst sequence of nonintegral conductance steps typical of natural (N-terminal Ac-Aib)-alamethicin. Saturation in current/voltage curves as well as current inactivation in voltage-jump current-relaxation experiments are found. This may be understood by assuming that channels are generated as dodecamers but, while reaching the steady state, reduce their size to that of an octamer or nonamer. We conclude that the overall behavior of these synthetic polypeptides is very similar to that of alamethicin.(ABSTRACT TRUNCATED AT 400 WORDS)
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Bosch R, Jung G, Schmitt H, Winter W. Crystal structure of Boc-Leu-Aib-Pro-Val-Aib-Aib-Glu(OBzl)-Gln-Phl × H2O, the C-terminal nonapeptide of the voltage-dependent ionophore alamethicin. Biopolymers 1985. [DOI: 10.1002/bip.360240606] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Katz E, Jung G, Aydin M, Lucht N, A. König W, Ooka T. Sequence and Conformation of Suzukacillin A. ACTA ACUST UNITED AC 1985. [DOI: 10.1002/jlac.198519850518] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Katz E, Schmitt H, Jung G, Aydin M, König WA. The C-Terminal Heptapeptides of Suzukacillin A and Alamethicin F30 — Sequence, Conformation, and Synthesis. ACTA ACUST UNITED AC 1985. [DOI: 10.1002/jlac.198519850212] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Schmitt H, Jung G. 13C NMR Spectroscopic Control of the Synthesis of Alamethicin F 30 and its Segments. ACTA ACUST UNITED AC 1985. [DOI: 10.1002/jlac.198519850211] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Schmitt H, Jung G. Total Synthesis of the α-Helical Eicosapeptide Antibiotic Alamethicin. ACTA ACUST UNITED AC 1985. [DOI: 10.1002/jlac.198519850210] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Brückner H, König WA, Aydin M, Jung G. Trichotoxin A40. Purification by counter-current distribution and sequencing of isolated fragments. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 827:51-62. [PMID: 2578292 DOI: 10.1016/0167-4838(85)90100-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The isolation of the membrane-modifying polypeptide antibiotics from the mycelium of Trichoderma viride 5242 was optimized via extraction with dichloromethane and chromatography on Sephadex LH-20. The components trichotoxin A40 and A50 were separated from each other and purified by multiplicative counter-current distribution. The sequence of proteinase-resistant trichotoxin A40 was determined by combined gas chromatography and mass spectrometry of three isolated N-acetylated dodecapeptides and two N-prolylhexapeptides obtained after selective trifluoroacetolysis. Including amino acid exchanges due to natural microheterogeneity, the sequence is Ac-Aib-Gly(LAla)-Aib-LLeu-Aib-LGln-Aib-Aib-Aib(LAla )-LAla-Aib-Aib-LPro-LLeu -Aib-DIva(Aib)-LGlu-LValol. In contrast to the eicosapeptide alamethicin, trichotoxin A40 contains only 18 residues, with a higher proportion of alpha-aminoisobutyric acid (Aib), C-terminal L-valinol (Vol), one D-isovaline (Iva) and no proline at the N-terminal part.
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Das MK, Balaram P. Interactions of the channel forming peptide alamethicin with artificial and natural membranes. J Biosci 1984. [DOI: 10.1007/bf02703892] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bosch R, Jung G, Voges KP, Winter W. Conformation of Boc-L-Ala-Aib-L-Ala-OMe in the Crystal and in Solution. ACTA ACUST UNITED AC 1984. [DOI: 10.1002/jlac.198419840609] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Bosch R, Jung G, Schmitt H, Sheldrik GM, Winter W. Peptide Structures of the Alamethicin Sequence: TheC-Terminal ?/310 Helical Nonapeptide and Two Pentapeptides with Opposite 310 Helicity. ACTA ACUST UNITED AC 1984. [DOI: 10.1002/anie.198404501] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Benedetti E, Bavoso A, Di Blasio B, Pavone V, Pedone C, Toniolo C, Bonora GM, Crisma M. Protected 1-3 segment of the peptaibol antibiotics alamethicin and hypelcin. Solid-state and solution study of a stereochemically constrained linear peptide. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1983; 22:385-97. [PMID: 6654585 DOI: 10.1111/j.1399-3011.1983.tb02107.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A study of the modes of folding and self-association of Z-Aib-L-Pro-Aib-OMe (the protected 1-3 segment of the peptaibol antibiotics alamethicin and hypelcin) in the solid state was performed using i.r. absorption and X-ray diffraction. The stereochemically constrained tripeptide molecules adopt a 4 leads to 1 intramolecularly H-bonded form (beta-turn), where the single intramolecular H-bond is found between the peptide N-H group of the Aib3 residue and the urethane C = O group of the N-blocking benzyloxycarbonyl moiety. This folded structure is stabilized by an intermolecular H-bond between the urethane N-H group of the Aib1 residue and the peptide C = O group of the Pro2 residue of a symmetry related molecule. According to the i.r. absorption data, in CH2Cl2 and TMP solutions the same intramolecularly H-bonded form occurs as that found in solid state. Compared to the situation in the solid state, in CH2Cl2 and TMP solvation of the urethane N-H group replaces self-association (through the same N-H group). The results are also discussed in relation to those obtained for other protected -Aib-X-Aib- (X = Aib, L-Ala, L-Val) tripeptide segments of peptaibol antibiotics.
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Sudha TS, Vijayakumar EK, Balaram P. Circular dichroism studies of helical oligopeptides. Can 3(10) and alpha-helical conformations be chiroptically distinguished? INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1983; 22:464-8. [PMID: 6654594 DOI: 10.1111/j.1399-3011.1983.tb02116.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Circular dichroism studies of seven helical oligopeptides containing alpha-aminoisobutyric acid (Aib) in methanol and trifluoroethanol (TFE) solutions are reported. Peptides ranging from 10 to 21 residues in length have been examined. In all cases distinct negative CD bands characteristic of helical peptides are obtained at approximately 220 and 205 nm corresponding to the n-pi and pi-pi transitions, respectively. The ratio R = [theta] pi-pi is less than 1.0 for all peptides studied. Using crystal structure and n.m.r. results for a 10 residue 3(10) helical peptide and literature values for an alpha-helical 11-residue peptide, it is shown that both helical conformations yield R values of approximately 0.8 in alcoholic solvents. The CD data are considered in the light of 1H n.m.r. studies on these oligopeptides. The results suggest that 3(10) and alpha-helical conformations cannot be distinguished by CD methods.
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Van Roey P, Smith GD, Balasubramanian TM, Czerwinski EW, Marshall GR, Mathews FS. Crystal and molecular structure of tert.-butyloxycarbonyl-L-prolyl-alpha-aminoisobutyryl-L-alanyl-alpha- aminoisobutyrate methyl ester. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1983; 22:404-9. [PMID: 6654587 DOI: 10.1111/j.1399-3011.1983.tb02109.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Boc-Pro-Aib-Ala-Aib-OMe crystallizes in the orthorhombic space group P2(1)2(1)2 with cell dimensions a = 17.701 (3) A, b = 17.476 (4) A, c = 9.686 (2) A, V = 2996.3 A3. The first three residues form a single turn of a 3(10)-helix stabilized by two intramolecular hydrogen bonds. Comparison of the conformation of the methyl ester of the tetrapeptide with that of its benzyl ester shows differences in the individual torsion angles of up to 29 degrees, although the overall conformation is conserved.
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Jung G, Brückner H, Bosch R, Winter W, Schaal H, Strähle J. Ac-L-Ala-Aib-L-Ala-OMe: X-Ray Analysis of a Distorted β-Bend and Magnetic Nonequivalence of Aib-Methyl Groups. ACTA ACUST UNITED AC 1983. [DOI: 10.1002/jlac.198319830703] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Jung G, Bosch R, Katz E, Schmitt H, Voges KP, Winter W. Stabilizing effects of 2-methylalanine residues on ?-turns and ?-helices. Biopolymers 1983. [DOI: 10.1002/bip.360220133] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Brückner H, Jung G. Synthesis of L-Prolyl-leucyl-α-aminoisobutyryl-α-amino-isobutyryl-glutamyl-valinol and Proof of Identity with the Isolated C-Terminal Fragment of Trichotoxin A-40. ACTA ACUST UNITED AC 1982. [DOI: 10.1002/jlac.198219820909] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bosch R, Jung G, Winter W. Conformation of peptides containing α-Aminoisobutyric acid the crystal structure of Boc-Gly-l-Ala-Aib-OMe. ACTA ACUST UNITED AC 1982. [DOI: 10.1002/jlac.198219820709] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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(−)-isovaline: confirmation of its D-(R)-configuration by X-ray analysis of its N-chloroacetyl derivative. Tetrahedron 1982. [DOI: 10.1016/0040-4020(82)80063-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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