1
|
Maffucci I, Clayden J, Contini A. Origin of Helical Screw Sense Selectivity Induced by Chiral Constrained Cα-Tetrasubstituted α-Amino Acids in Aib-based Peptides. J Phys Chem B 2015; 119:14003-13. [PMID: 26457452 DOI: 10.1021/acs.jpcb.5b07050] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The mechanisms behind the propensity of chiral constrained Cα-tetrasubstituted amino acids (cCTAAs) to induce one particular helical screw sense, when included in the Ac-Aib2-cCTAA-Aib2-NHMe peptide model, were studied through replica exchange molecular dynamics, potential of mean force, and quantum theory of atoms in molecules calculations. We observed that cCTAAs exert their effect on helical screw sense selectivity through the positioning of the side chain to generate steric hindrance in either the (-x, +y, +z) or (+x, +y, -z) sectors of a right-handed 3D Cartesian space, where the z axis corresponds to the axis of the helix and the Cα lies on the +y semiaxis (0, +y, 0). The different strengthening of the noncovalent interactions, also comprising C-H···O interactions, exerted by the cCTAA in the right-handed or left-handed helix was also found important to define the preference of a cCTAA for a particular helix screw sense.
Collapse
Affiliation(s)
- Irene Maffucci
- Dipartimento di Scienze Farmaceutiche - Sezione di Chimica Generale e Organica "Alessandro Marchesini", Università degli Studi di Milano , Via Venezian, 21, 20133 Milano, Italy
| | - Jonathan Clayden
- School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, U.K
| | - Alessandro Contini
- Dipartimento di Scienze Farmaceutiche - Sezione di Chimica Generale e Organica "Alessandro Marchesini", Università degli Studi di Milano , Via Venezian, 21, 20133 Milano, Italy
| |
Collapse
|
2
|
Crisma M, De Zotti M, Formaggio F, Peggion C, Moretto A, Toniolo C. Handedness preference and switching of peptide helices. Part II: Helices based on noncodedα-amino acids. J Pept Sci 2015; 21:148-77. [DOI: 10.1002/psc.2743] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 12/19/2014] [Accepted: 12/19/2014] [Indexed: 12/27/2022]
Affiliation(s)
| | - Marta De Zotti
- Department of Chemistry; University of Padova; Padova Italy
| | - Fernando Formaggio
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
| | | | - Alessandro Moretto
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
| | - Claudio Toniolo
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
| |
Collapse
|
3
|
De Poli M, Byrne L, Brown RA, Solà J, Castellanos A, Boddaert T, Wechsel R, Beadle JD, Clayden J. Engineering the Structure of an N-Terminal β-Turn To Maximize Screw-Sense Preference in Achiral Helical Peptide Chains. J Org Chem 2014; 79:4659-75. [DOI: 10.1021/jo500714b] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Matteo De Poli
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Liam Byrne
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Robert A. Brown
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Jordi Solà
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | | | - Thomas Boddaert
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Romina Wechsel
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Jonathan D. Beadle
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Jonathan Clayden
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| |
Collapse
|
4
|
Solà J, Morris GA, Clayden J. Measuring Screw-Sense Preference in a Helical Oligomer by Comparison of 13C NMR Signal Separation at Slow and Fast Exchange. J Am Chem Soc 2011; 133:3712-5. [DOI: 10.1021/ja1097034] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jordi Solà
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Gareth A. Morris
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Jonathan Clayden
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| |
Collapse
|
5
|
Yang D, Chang XW, Zhang DW, Jiang ZF, Song KS, Zhang YH, Zhu NY, Weng LH, Chen MQ. Chiral alpha-aminoxy acid/achiral cyclopropane alpha-aminoxy acid unit as a building block for constructing the alpha N-O helix. J Org Chem 2010; 75:4796-805. [PMID: 20568786 DOI: 10.1021/jo100810m] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The monomer 1 derived from achiral 1-(aminoxy)cyclopropanecarboxylic acid (OAcc) and oligopeptides 2-9 consisting of a chiral alpha-aminoxy acid and an achiral alpha-aminoxy acid such as OAcc were synthesized and their structures characterized. The eight-membered-ring intramolecular hydrogen bond, namely the alpha N-O turn, was formed between adjacent residues independent of their chirality. However, the helix formation was sequence-dependent. Dipeptide 2 bearing chiral alpha-aminoxy acid (d-OAA) at the N-terminus and achiral OAcc at the C-terminus preferentially adopted a right-handed 1.8(8) helical structure, but dipeptide 3 (OAcc-d-OAA) did not. Theoretical calculation results, in good agreement with experimental ones, revealed that the biased handedness of alpha N-O turn found in OAcc residue depends on its preceding chiral residue. It was then found that the helical conformation was destroyed in the case of oligopeptides 6 and 7 [OAA-(OAcc)(n), n = 2, 3]. The crystal structure of tripeptide 8 ((i)PrCO-d-OVal-OAcc-d-OVal-NH(i)Bu) further disclosed the helical structure formed by three consecutive homochiral alpha N-O turns. This study has uncovered achiral aminoxy acid residues such as the OAcc unit as a useful building block to be incorporated into chiral aminoxy peptides to mimic chiral helix structure.
Collapse
Affiliation(s)
- Dan Yang
- Department of Chemistry, Fudan University, Shanghai 200433, China.
| | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Lisowski M, Jaremko Ł, Jaremko M, Mazur A, Latajka R, Makowski M. Effect of the ΔPhe residue configuration on a didehydropeptides conformation: A combined CD and NMR study. Biopolymers 2010; 93:1055-64. [DOI: 10.1002/bip.21522] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
7
|
Ousaka N, Inai Y. Transfer of Noncovalent Chiral Information along an Optically Inactive Helical Peptide Chain: Allosteric Control of Asymmetry of the C-Terminal Site by External Molecule that Binds to the N-Terminal Site. J Org Chem 2008; 74:1429-39. [DOI: 10.1021/jo801686m] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Naoki Ousaka
- Department of Environmental Technology and Urban Planning and Department of Frontier Materials, Shikumi College, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
| | - Yoshihito Inai
- Department of Environmental Technology and Urban Planning and Department of Frontier Materials, Shikumi College, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
| |
Collapse
|
8
|
Qu S, Wang H, Yu Z, Bai B, Li M. Helical ribbons tuned by alkoxy chains in achiral twin-tapered dihydrazide derivatives. NEW J CHEM 2008. [DOI: 10.1039/b805593a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
9
|
Lisowski M, Latajka R, Picur B, Lis T, Bryndal I, Rospenk M, Makowski M, Kafarski P. Combined effect of the ΔPhe or ΔAla residue and thep-nitroanilide group on a didehydropeptides conformation. Biopolymers 2008; 89:220-34. [DOI: 10.1002/bip.20897] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
10
|
Komori H, Inai Y. Control of peptide helix sense by temperature tuning of noncovalent chiral domino effect. J Org Chem 2007; 72:4012-22. [PMID: 17465563 DOI: 10.1021/jo0625305] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have investigated temperature effect on control of a peptide helix sense through the noncovalent chiral domino effect (NCDE: Inai, Y. et al., J. Am. Chem. Soc. 2003, 125, 8151-8162). Nonapeptide (1: Inai, Y.; Komori, H. Biomacromolecules 2004, 5, 1231-1240), which alone prefers a right-handed helix, maintained a screw-sense balance or a small imbalance at room temperature in the presence of Boc-d-amino acid. Cooling of the solution induced a left-handed helix more clearly. Conversely, heating from room temperature recovered the original right-handed sense. This helix-helix transition was essentially reversible in cooling-heating cycles. An increase in the Boc-d-amino acid concentration elevated temperature for switching CD signs based on the conformational transition. A similar thermal-driven inversion of helix sense was observed for 1 at other initial concentrations, suggesting that this behavior is insensitive to some peptide aggregation. NMR study provided direct evidence for the domino-type control of helix sense, in which Boc-Leu-OH is mainly located at the N-terminal segment. In addition, a left-handed helix induced by the d-isomer was shown to participate in equilibrium with a right-handed helix, whereas the right-handed helix was predominant in the presence of l-isomer. Consequently, we here have proposed a model for controlling a peptide helix sense (or its screw-sense bias) through temperature tuning of the external chiral interaction specific to the N-terminal sequence.
Collapse
Affiliation(s)
- Hisatoshi Komori
- Department of Environmental Technology and Urban Planning, Shikumi College, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
| | | |
Collapse
|
11
|
Inai Y, Komori H, Ousaka N. Control of helix sense in protein-mimicking backbone by the noncovalent chiral effect. CHEM REC 2007; 7:191-202. [PMID: 17551949 DOI: 10.1002/tcr.20116] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We have reviewed our previous work regarding induction or control of a peptide helix sense through chiral stimulus to the peptide chain terminus. An optically inactive 3(10)-helix designed mainly with unusual alpha-amino acid residues was commonly employed. Such an N-terminal-free peptide generates a preferred helix sense by chiral acid molecule. A helix sense pre-directed in chiral sequence is also influenced or controlled by the chiral sign of such external molecule. Here free amide groups in the 3(10)-helical N-terminus participate in the formation of a multipoint coordinated complex. The terminal asymmetry produces the noncovalent chiral domino effect (NCDE) to influence the whole helix sense. The NCDE-mediated control of helicity provides the underlying chiral nature of protein-mimicking helical backbones: notably, chiral recognition at the terminus and modulation of helical propensity through chiral stimulus. The above items from our previous reports have been outlined and reviewed together with their significance in biopolymer science and chiral chemistry.
Collapse
Affiliation(s)
- Yoshihito Inai
- Department of Environmental Technology and Urban Planning; Shikumi College, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan.
| | | | | |
Collapse
|
12
|
Ousaka N, Inai Y. Induction of a Heterochiral Helix through the Covalent Chiral Domino Effect Originating in the “Schellman Motif”. J Am Chem Soc 2006; 128:14736-7. [PMID: 17105246 DOI: 10.1021/ja063873n] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report unique phenomena where the transition from a homochiral helix to a heterochiral helix occurs by increasing the chain length of the l-sequence. Peptides composed of the l-Leu sequences with different lengths and the achiral nona-sequence at the C-terminal side were used here. Conformation of their peptides in solution was investigated mainly by using CD analysis in various solvents, or additionally by IR and NMR. When the l-sequence has a sufficient length, a left-handed helicity was induced in the achiral sequence. Notably, the polymeric l-sequence produced a heterochiral helix that switches the helix sense around the boundary of the chiral/achiral sequence. Energy calculation demonstrated that a stable heterochiral helix favors a bending form, while a homochiral helix takes a relatively straight form. Such a bending form was suggested to be advantageous to solvent effects. The "Schellman motif" has been recognized as a local heterochiral structure in protein helices. We propose a nucleation model of a heterochiral helix through the covalent chiral domino effect derived from the Schellman motif. The present findings not only offer us novel design of a heterochiral helix but also support an elementary model for the origins of homochiral-heterochiral structures from primitive chiral/achiral sequences.
Collapse
Affiliation(s)
- Naoki Ousaka
- Department of Environmental Technology and Urban Planning, Shikumi College, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
| | | |
Collapse
|
13
|
Komori H, Inai Y. Electronic CD Study of a Helical Peptide Incorporating Z-Dehydrophenylalanine Residues: Conformation Dependence of the Simulated CD Spectra. J Phys Chem A 2006; 110:9099-107. [PMID: 16854021 DOI: 10.1021/jp056501u] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Electronic circular dichroism (CD) spectra as well as transitions from ground to excited states were predicted for a helical nonapeptide based on alternative sequence--[Z-alpha,beta-dehydrophenylalanine (Delta(Z)Phe)-X]--through semiempirical molecular orbital computation combined with time-dependent (TD) method. The simulation was performed for its various conformers that differ in helix type, helix sense, and Delta(Z)Phe side-chain orientation. These conformational variations have been shown to depend largely on its CD spectra. Comparison between simulated and observed CD profiles reveals that peptide 1 in solution favors a right-handed 3(10)-helix that adopts phenyl (Delta(Z)Phe) planes basically in a vertical orientation with respect to the helix axis. These predictions were essentially supported from CD simulation of a shorter helical analogue at ab inito or density functional TD levels. The theoretical CD-conformation relationship should provide us useful guideline for determination of helix sense in the dehydropeptide, and for estimation of its conformations statistically averaged in solution.
Collapse
Affiliation(s)
- Hisatoshi Komori
- Department of Environmental Technology and Urban Planning, Shikumi College, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan
| | | |
Collapse
|
14
|
Inai Y, Ousaka N, Miwa Y. Theoretical Comparison between Three-Point and Two-Point Binding Modes for Chiral Discrimination upon the N-Terminal Sequence of 310-Helix. Polym J 2006. [DOI: 10.1295/polymj.38.432] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
15
|
Jia H, Bagherzadeh A, Hartzoulakis B, Jarvis A, Löhr M, Shaikh S, Aqil R, Cheng L, Tickner M, Esposito D, Harris R, Driscoll PC, Selwood DL, Zachary IC. Characterization of a bicyclic peptide neuropilin-1 (NP-1) antagonist (EG3287) reveals importance of vascular endothelial growth factor exon 8 for NP-1 binding and role of NP-1 in KDR signaling. J Biol Chem 2006; 281:13493-13502. [PMID: 16513643 DOI: 10.1074/jbc.m512121200] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neuropilin-1 (NP-1) is a receptor for vascular endothelial growth factor-A165 (VEGF-A165) in endothelial cells. To define the role of NP-1 in the biological functions of VEGF, we developed a specific peptide antagonist of VEGF binding to NP-1 based on the NP-1 binding site located in the exon 7- and 8-encoded VEGF-A165 domain. The bicyclic peptide, EG3287, potently (K(i) 1.2 microM) and effectively (>95% inhibition at 100 microM) inhibited VEGF-A165 binding to porcine aortic endothelial cells expressing NP-1 (PAE/NP-1) and breast carcinoma cells expressing only NP-1 receptors for VEGF-A, but had no effect on binding to PAE/KDR or PAE/Flt-1. Molecular dynamics calculations, a nuclear magnetic resonance structure of EG3287, and determination of stability in media, indicated that it constitutes a stable subdomain very similar to the corresponding region of native VEGF-A165. The C terminus encoded by exon 8 and the three-dimensional structure were both critical for EG3287 inhibition of NP-1 binding, whereas modifications at the N terminus had little effect. Although EG3287 had no direct effect on VEGF-A165 binding to KDR receptors, it inhibited cross-linking of VEGF-A165 to KDR in human umbilical vein endothelial cells co-expressing NP-1, and inhibited stimulation of KDR and PLC-gamma tyrosine phosphorylation, activation of ERKs1/2 and prostanoid production. These findings characterize the first specific antagonist of VEGF-A165 binding to NP-1 and demonstrate that NP-1 is essential for optimum KDR activation and intracellular signaling. The results also identify a key role for the C-terminal exon 8 domain in VEGF-A165 binding to NP-1.
Collapse
Affiliation(s)
- Haiyan Jia
- Centre for Cardiovascular Biology and Medicine, Department of Medicine, University College London, London WC1E 6JJ, United Kingdom; Ark Therapeutics Limited, The Rayne Institute, University College London, London WC1E 6JJ, United Kingdom
| | - Azadeh Bagherzadeh
- Centre for Cardiovascular Biology and Medicine, Department of Medicine, University College London, London WC1E 6JJ, United Kingdom; Ark Therapeutics Limited, The Rayne Institute, University College London, London WC1E 6JJ, United Kingdom
| | | | - Ashley Jarvis
- NCE Discovery Ltd., Cambridge CB4 0PA, United Kingdom
| | - Marianne Löhr
- Wolfson Institute for Biomedical Research, University College London, London WC1E GBT United Kingdom
| | | | - Rehan Aqil
- NCE Discovery Ltd., Cambridge CB4 0PA, United Kingdom
| | - Lili Cheng
- Centre for Cardiovascular Biology and Medicine, Department of Medicine, University College London, London WC1E 6JJ, United Kingdom; Ark Therapeutics Limited, The Rayne Institute, University College London, London WC1E 6JJ, United Kingdom
| | - Michelle Tickner
- Centre for Cardiovascular Biology and Medicine, Department of Medicine, University College London, London WC1E 6JJ, United Kingdom; Ark Therapeutics Limited, The Rayne Institute, University College London, London WC1E 6JJ, United Kingdom
| | - Diego Esposito
- Bloomsbury Centre for Structure Biology, Department of Biochemistry and Molecular Biology, University College London, London WC1E 6BT, United Kingdom
| | - Richard Harris
- Bloomsbury Centre for Structure Biology, Department of Biochemistry and Molecular Biology, University College London, London WC1E 6BT, United Kingdom
| | - Paul C Driscoll
- Bloomsbury Centre for Structure Biology, Department of Biochemistry and Molecular Biology, University College London, London WC1E 6BT, United Kingdom
| | - David L Selwood
- Wolfson Institute for Biomedical Research, University College London, London WC1E GBT United Kingdom
| | - Ian C Zachary
- Centre for Cardiovascular Biology and Medicine, Department of Medicine, University College London, London WC1E 6JJ, United Kingdom.
| |
Collapse
|
16
|
Ousaka N, Inai Y, Okabe T. Chiral interaction in Gly-capped N-terminal motif of 310-helix and domino-type induction in helix sense. Biopolymers 2006; 83:337-51. [PMID: 16767770 DOI: 10.1002/bip.20557] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Chiral interaction of helical peptide with chiral molecule, and concomitant induction in its helix sense have been demonstrated in optically inactive nonapeptide (1) possessing Gly at its N-terminus: H-Gly-(Delta(Z)Phe-Aib)(4)-OCH(3) (1: Delta(Z)Phe = Z-dehydrophenylalanine; Aib = alpha-aminoisobutyric acid). Spectroscopic measurements [mainly nuclear magnetic resonance (NMR) and circular diochroism (CD)] as well as theoretical simulation have been carried out for that purpose. Peptide 1 in the 3(10)-helix tends to adopt preferentially a right-handed screw sense by chiral Boc-L-amino acid (Boc: t-butoxycarbonyl). Induction in the helix sense through the noncovalent chiral domino effect should be derived primarily from the complex supported by the three-point coordination on the N-terminal sequence. Thus the 3(10)-helical terminus consisting of only alpha-amino acid residues enables chiral recognition of the Boc-amino acid molecule, leading to modulation of the original chain asymmetry. Dynamics in the helix-sense induction also have been discussed on the basis of a low-temperature NMR study. Furthermore, the inversion of induced helix sense has been achieved through solvent effects.
Collapse
Affiliation(s)
- Naoki Ousaka
- Department of Environmental Technology and Urban Planning, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan
| | | | | |
Collapse
|
17
|
Synthesis and conformational properties of model dipeptides containing novel axially chiral α,β-didehydroamino acids at the (i+1) position of a β-turn conformation. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.09.066] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
18
|
Inai Y, Komori H. External Chirality-Triggered Helicity Control Promoted by Introducing a β-Ala Residue into the N-Terminus of Chiral Peptides. Biomacromolecules 2004; 5:1231-40. [PMID: 15244435 DOI: 10.1021/bm0344001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The noncovalent chiral domino effect (NCDE), defined as chiral interaction upon an N-terminus of a 3(10)-helical peptide, will provide a unique method for structural control of a peptide helix through the use of external chirality. On the other hand, the NCDE has not been considered to be effective for the helicity control of peptides strongly favoring a one-handed screw sense. We here aim to promote the NCDE on peptide helicity using two types of nonapeptides: H-beta-Ala-Delta(Z)Phe-Aib-Delta(Z)Phe-X-(Delta(Z)Phe-Aib)(2)-OCH(3) [Delta(Z)Phe = alpha,beta-didehydrophenylalanine, Aib = alpha-aminoisobutyric acid], where X as the single chirality is L-leucine (1) or L-phenylalanine (2). NMR, IR, and CD spectroscopy as well as energy calculation revealed that both peptides alone form a right-handed 3(10)-helix. The original CD amplitudes or signs in chloroform, irrespective of a strong screw-sense preference in the central chirality, responded sensitively to external chiral information. Namely added Boc-L-amino acid stabilized the original right-handed helix, while the corresponding d-isomer destabilized it or transformed it into a left-handed helix. These peptides were also shown to bind more favorably to an L-isomer from the racemate. Although similar helicity control was observed for analogous nonapeptides bearing an N-terminal Aib residue (Inai, Y.; et al. Biomacromolecules 2003, 4, 122), the present findings demonstrate that the N-terminal replacement by the beta-Ala residue significantly improves the previous NCDE to achieve more effective control of helicity. Semiempirical molecular orbital calculations on complexation of peptide 2 with Boc-(L or D)-Pro-OH reasonably explained the unique conformational change induced by external chirality.
Collapse
Affiliation(s)
- Yoshihito Inai
- Department of Environmental Technology and Urban Planning, Shikumi College, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
| | | |
Collapse
|
19
|
Nandel FS, Khare B. Conformation of peptides constructed from achiral amino acid residues Aib and ?ZPhe: Computational study of the effect ofL/D- Leu at terminal positions. Biopolymers 2004; 77:63-73. [PMID: 15593284 DOI: 10.1002/bip.20128] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Conformational studies of the peptides constructed from achiral amino acid residues Aib and Delta(Z)Phe (I) Ac-Aib-Delta(Z)Phe-NHMe (II), and Ac-(Aib-Delta(Z)Phe)(3)-NHMe; peptides III-VI having L-Leu or D-Leu at either the N- or the C-terminal position and of peptides VII-X having Leu residues in different enantiomeric combinations at both the N- and the C-terminal positions in peptide II have been studied to design the peptide with the required helical sense. Peptide II, as expected, adopts degenerate left- and right-handed helical structures. It has been shown that the peptides IV and VI having D-Leu at either the N or the C terminus can be realized in the right-handed helical structure with the phi,psi values of -20 degrees and -60 degrees for the Aib/Delta(Z)Phe residues. L-Leu and D- Leu at both the terminals in peptides VII and VIII, respectively, have hardly any effect as both the left- and the right-handed structures are found to be degenerate. Peptides III and IX can be realized in right- and left-handed helical structures, respectively, in solvents of low polarity whereas peptides V and X are predicted to be in the right-handed helical structures stabilized by carbonyl-carbonyl interactions without the formation of hydrogen bonds. The conformational states with the phi,psi values of 0 degrees and -85 degrees in peptide V are characterized by rise per residue of 2.03 A, rotation per residue of 117.5 degrees , and 3.06 residues per turn. In all peptides having Leu residue at the N terminus, the methyl moiety of the acetyl group is involved in the CH/pi interactions with the Cepsilon--Cdelta edge of the aromatic ring of Delta(Z)Phe (3) and the amino group NH of Delta(Z)Phe is involved in the NH/pi interactions with its own aromatic ring. The CH(3) groups of the Aib residues are also involved in CH/pi interactions with the i + 1th and i + 3th Delta(Z)Phe's aromatic side chains.
Collapse
|