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1.
J Org Chem ; 85(3): 1513-1524, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-31769989

RESUMO

Peptides are well-known to play a fundamental therapeutic role and to represent building blocks for numerous useful biomaterials. Stabilizing their active 3D-structure by appropriate modifications remains, however, a challenge. In this study, we have expanded the available literature information on the conformational propensities of a promising backbone change of a terminally blocked δ-amino acid residue, a dipeptide mimic, by replacing its central amide moiety with an (E) Cß═Cγ alkene unit. Specifically, we have examined by DFT calculations, X-ray diffraction in the crystalline state, and FT-IR absorption/NMR spectroscopies in solution the extended vs folded preferences of analogues of this prototype system either unmodified or possessing single or multiple methyl group substituents on each of its four -CH2-CH═CH-CH2- main-chain carbon atoms. The theoretical and experimental results obtained clearly point to the conclusion that increasing the number of adequately positioned methylations will enhance the preference of the original sequence to fold, thus opening interesting perspectives in the design of conformationally constrained peptidomimetics.

2.
Chem Sci ; 10(28): 6908-6914, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31391913

RESUMO

The unique abilities of homo-oligo-adamantyl peptides to adopt α- and γ-turn conformations are demonstrated by X-ray diffraction, and NMR and FT-IR absorption spectroscopies. Assembled by an Ugi multiple component reaction strategy, N α-formyl-adamantyl tripeptide iso-propyl and tert-butyl amides are respectively found to adopt an isolated α-turn and an incipient γ-helix conformation by X-ray diffraction crystallography. The shortest example of a single α-turn with ideal geometry is observed in the crystalline state. In solution both peptides predominantly assume γ-helical structures.

3.
Org Lett ; 21(11): 4182-4186, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31090420

RESUMO

Systems in which an external stimulus elicits a response through some sort of modification at the molecular or supramolecular level bear potential for the development of smart materials and devices. This work describes a versatile synthetic approach suitable for the stepwise incorporation of multiple, even consecutive, units of the simplest Cα,ß-unsaturated ß-amino acid, ( E/ Z)-3-aminoprop-2-enoic acid, in peptide-based foldamers. The properties of these, including photoinduced E/ Z isomerizations, were investigated.

4.
J Pept Sci ; 25(5): e3165, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30916858

RESUMO

α-Amino acid residues with a ϕ,ψ constrained conformation are known to significantly bias the peptide backbone 3D structure. An intriguing member of this class of compounds is (αMe)Aze, characterized by an Nα -alkylated four-membered ring and Cα -methylation. We have already reported that (S)-(αMe)Aze, when followed by (S)-Ala in the homochiral dipeptide sequential motif -(S)-(αMe)Aze-(S)-Ala-, tends to generate the unprecedented γ-bend ribbon conformation, as formation of a regular, fully intramolecularly H-bonded γ-helix is precluded, due to the occurrence of a tertiary amide bond every two residues. In this work, we have expanded this study to the preparation and 3D structural analysis of the heterochiral (S)-Ala/(R)-(αMe)Aze sequential peptides from dimer to hexamer. Our conformational results show that members of this series may fold in type-II ß-turns or in γ-turns depending on the experimental conditions.


Assuntos
Alanina/química , Ácido Azetidinocarboxílico/química , Oligopeptídeos/química , Oligopeptídeos/síntese química , Ressonância Magnética Nuclear Biomolecular , Conformação Proteica , Difração de Raios X
5.
Chempluschem ; 84(11): 1688-1696, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31943881

RESUMO

The influence of conformational dynamics on the self-assembly process of a conformationally constrained analogue of the natural antimicrobial peptide Trichogin GA IV was analysed by spectroscopic methods, microscopy imaging at nanometre resolution, and molecular dynamics simulations. The formation of peptide films at the air/water interface and their deposition on a graphite or a mica substrate were investigated. A combination of experimental evidence with molecular dynamics simulation was used to demonstrate that only the fully developed helical structure of the analogue promotes formation of ordered aggregates that nucleate the growth of micrometric rods, which give rise to homogenous coating over wide regions of the hydrophilic mica. This work proves the influence of helix flexibility on peptide self-organization and orientation on surfaces, key steps in the design of bioinspired organic/inorganic hybrid materials.


Assuntos
Silicatos de Alumínio/química , Grafite/química , Lipopeptídeos/química , Nanoestruturas/química , Sequência de Aminoácidos , Microscopia de Força Atômica , Simulação de Dinâmica Molecular , Propriedades de Superfície , Água/química , Difração de Raios X
6.
Org Biomol Chem ; 16(42): 7947-7958, 2018 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-30318540

RESUMO

Unlike the extensively investigated relationship between the peptide ß-bend ribbon and its prototypical 310-helix conformation, the corresponding relationship between the narrower γ-bend ribbon and its regular γ-helix counterpart still remains to be studied, as the latter 3D-structures have not yet been experimentally authenticated. In this paper, we describe the results of the first characterization, both in the crystal state and in solution, of the γ-bend ribbon conformation using X-ray diffraction and FT-IR absorption, electronic CD and 2D-NMR spectroscopies applied to an appropriate set of synthetic, homo-chiral, sequential dipeptide oligomers based on (S)-Ala and the known γ-bend inducer, Cα-tetrasubstituted, N-alkylated α-amino acid residue (S)-Cα-methyl-azetidine-carboxylic acid.

7.
Angew Chem Int Ed Engl ; 57(32): 10217-10220, 2018 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-29944774

RESUMO

A simple, unsaturated, E-Z photoisomerizable ß-amino acid, (Z)-3-aminoprop-2-enoic acid, has been introduced into peptide foldamers through a one-pot chemical coupling, based on Pd/Cu-catalyzed olefin oxidative amidation, between two peptide segments carrying, respectively, a -Gly-NH2 residue at the C-terminus and an acryloyl group at the N-terminus. Reversible conversion between the Z and E configurations of the 3-aminoprop-2-enoic linkage was achieved photochemically. A crystallographic analysis on two model compounds shed light on the consequences, in terms of 3D structure and self-association properties, brought about by the different configuration of the unsaturated linkage. As a proof of concept, E-Z photoisomerization of a 3-aminoprop-2-enoic acid residue, inserted as the junction between two conformationally distinct peptide domains (one helical while the other ß-sheet promoter), allowed supramolecular self-association to be reversibly turned on/off.


Assuntos
Peptídeos/química , Cristalografia por Raios X , Modelos Moleculares , Processos Fotoquímicos , Conformação Proteica , Dobramento de Proteína
8.
ChemMedChem ; 13(11): 1131-1145, 2018 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-29570944

RESUMO

Five new AuIII -peptidodithiocarbamato complexes of the type [AuIII Br2 (dtc-AA1 -AA2 -OR] (in which AA1 =N-methylglycine (Sar), l/d-Pro; AA2 =l/d-Ala, α-aminoisobutyric acid (Aib); R=OtBu, triethylene glycol methyl ether), differing with regard to the amino acid sequence and/or the chiral amino acid configuration, were designed to enhance tumor selectivity and bioavailability. The gold(III)-based moiety was functionalized to exploit the targeting properties of the peptidomimetic ligand toward two peptide transporters (namely PEPT1 and PEPT2), which are upregulated in several tumor cells. The compounds were synthesized and fully characterized, mainly by means of elemental analysis, one- and two-dimensional NMR spectroscopy, FT-IR, and UV/Vis spectrophotometry. The crystal structures of three compounds were also solved by X-ray diffraction. In vitro cytotoxicity studies using a panel of human tumor cell lines (A549 [non-small-cell lung carcinoma], MCF-7 [breast cancer], A2780 [ovarian carcinoma], H1975 [non-small-cell lung carcinoma], H460 [large-cell lung carcinoma], and A431 [human epidermoid carcinoma]) showed the dtc-Pro-Aib-OtBu derivative to be very effective, with GI50 values much lower than those of cisplatin. This complex was thus selected for evaluating stability under physiological conditions and possible interactions with serum albumin, as well in PARP-1 enzyme inhibition assays and preliminary ex vivo toxicity experiments on healthy rat tissues.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Ouro/química , Peptidomiméticos/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Antineoplásicos/toxicidade , Bovinos , Linhagem Celular Tumoral , Colo/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/metabolismo , Complexos de Coordenação/toxicidade , Ensaios de Seleção de Medicamentos Antitumorais , Ensaios Enzimáticos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/toxicidade , Humanos , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Peptidomiméticos/síntese química , Peptidomiméticos/metabolismo , Peptidomiméticos/toxicidade , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Ligação Proteica , Ratos , Soroalbumina Bovina/metabolismo , Estereoisomerismo
9.
J Org Chem ; 83(1): 236-243, 2018 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-29172495

RESUMO

The reactivity of ß-aminocarbonates as anisotropic electrophiles has been investigated with several phenols. Products distribution shows that the regioselectivity of the anchimerically driven alkylation reaction depends on the nucleophiles. The results suggest that in the presence of nucleophiles that are also good leaving groups, the reaction takes place under thermodynamic control favoring the attack on the most sterically hindered carbon of the cyclic aziridinium intermediate. Furthermore, when an enantiomerically pure pyrrolidine-based carbonate was used, the reaction with phenols proceeds via a bicyclic aziridinium intermediate leading to the stereoselective synthesis of optically active 3-substituted piperidines via ring expansion reaction. These results were confirmed both by NMR spectroscopy and X-ray diffraction analysis.

10.
Soft Matter ; 13(23): 4231-4240, 2017 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-28509927

RESUMO

Two appropriately functionalized nucleobases, thymine and adenine, have been covalently linked at the N- and C-termini, respectively, of two α-aminoisobutyric acid-rich helical peptide foldamers, aiming at driving self-assembly through complementary recognition. A crystal-state analysis (by X-ray diffraction) on the shorter, achiral foldamer 1 unambiguously shows that adeninethymine base pairing, through Watson-Crick intermolecular H-bonding, does take place between either end of each peptide molecule. In the crystals, π-stacking between base pairs is also observed. Evidence for time-dependent foldameroldamer associations for the longer, chiral foldamer 2 in solution is provided by circular dichroism measurements. The self-assembly of foldamer 2, through living supramolecular polymerization, eventually leads to the formation of twisted fibers. Such a supramolecular organization can be affected by addition of either pristine adenine or thymine, that acts as a "terminator" by selectively matching a pairing nucleobase at one end of the foldamer. The co-assembly of foldamer 2 with a porphyrin-derivatized thymine, under appropriate experimental conditions, leads to the formation of vesicles which, in turn, can be converted to the fiber morphology by changing the environmental polarity. Conversely, dendrimeric, star polymer-like microstructures are generated when the supramolecular assembly of foldamer 2 is seeded by adenine-capped gold nanoparticles.

11.
Biopolymers ; 108(1)2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27404945

RESUMO

In this study, we performed a detailed literature survey of the ɛ-turn in peptides and proteins. This three-dimensional structural feature is characterized by an eleven-membered pseudo-cycle closed by an intramolecular backbone…backbone H-bond. Interestingly, in this motif the direction of the N-H…O = C H-bond runs opposite to that of the much more popular and extensively investigated α-, ß-, and γ-turns. We did not authenticate unequivocally the ɛ-turn main-chain reversal topology in any linear short peptide. However, it is frequently observed in small cyclic peptides formed by four, five, and six amino acid residues with stringent geometric requirements. Rather surprisingly, ɛ-turns do occur in proteins, although to a relatively moderate extent, as an isolated feature or in the turn segment of hairpin motifs based on two antiparallel, pleated ß-strands. Moreover, the ɛ-turn may also host not only the seven-membered, intramolecularly H-bonded, pseudo-cycle termed γ-turn, either of the classic or inverse type, but also one (or even two) cis peptide bond(s) or a ß-bulge conformation. Based on their ϕ, ψ backbone torsion angles, we were able to classify the protein ɛ-turns in six different families. Conformational energy computations using the DFT methodology were also performed on the ɛ-turns adopted by the amino acid triplet -Gly-Gly-Gly- (Gly is the most commonly found residue at each of the three positions in our analysis of proteins). Again, in this computational study, six families of turns were identified, but only some of them resemble rather closely those extracted from our investigation on proteins.


Assuntos
Peptídeos/química , Sequência de Aminoácidos , Cristalografia por Raios X , Ligação de Hidrogênio , Isomerismo , Espectroscopia de Ressonância Magnética , Oligopeptídeos/química , Peptídeos Cíclicos/química , Estrutura Secundária de Proteína , Proteínas/química
12.
Amino Acids ; 49(1): 139-150, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27726008

RESUMO

Antimicrobial peptides (AMPs) play a key role in the defence mechanism of living organisms against microbial pathogens, displaying both bactericidal and immunomodulatory properties. They are considered as a promising alternative to the conventional antibiotics towards which bacteria are becoming highly resistant. Recently, a derivative of the frog skin AMP esculentin-1a, esculentin-1a(1-21)NH2 [Esc(1-21)], showed a strong and fast membranolytic activity against Gram-negative bacteria but with a lower efficacy against Gram-positive ones. Here, with the aim to increase the α-helicity of Esc(1-21) and the expected potency against Gram-positive bacteria, we designed an analog bearing three α-aminoisobutyric acid (Aib) residues at positions 1, 10, and 18 of its primary structure. We demonstrated that the incorporation of Aib residues: (1) promoted the α-helix conformation of Esc(1-21), as confirmed by circular dichroism and two-dimensional nuclear magnetic resonance spectroscopies; (2) was sufficient to make this analog more active than the parent peptide against several Gram-positive bacterial strains without affecting its activity against Gram-negative bacteria; and (3) resulted to be devoid of toxic effect toward epithelial cells at the active antimicrobial concentrations. These results suggest that replacement of L-amino acids with Aib residues has beneficial effects on the structure and properties of the membrane-active peptide Esc(1-21), making it a better candidate for the design and development of selective drugs against Gram-positive bacteria.


Assuntos
Ácidos Aminoisobutíricos/química , Proteínas de Anfíbios/farmacologia , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Células A549 , Sequência de Aminoácidos , Proteínas de Anfíbios/síntese química , Proteínas de Anfíbios/química , Animais , Antibacterianos/síntese química , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/síntese química , Peptídeos Catiônicos Antimicrobianos/química , Linhagem Celular Transformada , Sobrevivência Celular/efeitos dos fármacos , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/crescimento & desenvolvimento , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Engenharia de Proteínas , Ranidae/fisiologia , Relação Estrutura-Atividade
13.
J Pept Sci ; 23(4): 346-362, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28004461

RESUMO

We performed the solution-phase synthesis of a set of model peptides, including homo-oligomers, based on the 2-aminoadamantane-2-carboxylic acid (Adm) residue, an extremely bulky, highly lipophilic, tricyclic, achiral, Cα -tetrasubstituted α-amino acid. In particular, for the difficult peptide coupling reaction between two Adm residues, we took advantage of the Meldal's α-azidoacyl chloride approach. Most of the synthesized Adm peptides were characterized by single-crystal X-ray diffraction analyses. The results indicate a significant propensity for the Adm residue to adopt γ-turn and γ-turn-like conformations. Interestingly, we found that a -CO-(Adm)2 -NH- sequence is folded in the crystal state into a regular, incipient γ-helix, at variance with the behavior of all of the homo-dipeptides from Cα -tetrasubstituted α-amino acids already investigated, which tend to adopt either the ß-turn or the fully extended conformation. Our density functional theory conformational energy calculations on the terminally blocked homo-peptides (n = 2-8) fully confirmed the crystal-state data, strongly supporting the view that this rigid Cα -tetrasubstituted α-amino acid residue is largely the most effective building block for γ-helix induction, although to a limited length (anti-cooperative effect). Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.


Assuntos
Peptídeos/química , Cristalografia por Raios X , Modelos Moleculares , Peptídeos/síntese química , Conformação Proteica , Teoria Quântica , Soluções
14.
J Am Chem Soc ; 138(25): 8007-18, 2016 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-27258674

RESUMO

An E unsaturated fumaramide linkage may be introduced into Aib peptide foldamer structures by standard coupling methods and photoisomerized to its Z (maleamide) isomer by irradiation with UV light. As a result of the photoisomerization, a new hydrogen-bonded contact becomes possible between the peptide domains located on either side of the unsaturated linkage. Using the fumaramide/maleamide linker to couple a chiral and an achiral fragment allows the change in hydrogen bond network to communicate a conformational preference, inducing a screw sense preference in the achiral domain of the maleamide-linked foldamers that is absent from the fumaramides. Evidence for the induced screw sense preference is provided by NMR and CD, and also by the turning on by light of the diastereoselectivity of a peptide chain extension reaction. The fumaramide/maleamide linker thus acts as a "conformational photodiode" that conducts stereochemical information as a result of irradiation by UV light.

15.
Biopolymers ; 106(5): 697-713, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27353976

RESUMO

Although thionamides would have been first prepared two centuries ago and their chemical and spectroscopic properties extensively investigated, only much more recently (since about 1985) a well deserved but still insufficient attention has been paid to their endothioxopeptide subfamily which nonetheless currently represents a rapidly emerging area of great scientific interest in the broader field of foldameric compounds based on biologically relevant building blocks. After two brief sections offering information on the unfortunately still limited number of endothioxopeptides discovered from natural sources but also on the impressive advancements registered in the last few years in their synthetic methods, this review article outlines the results of a detailed literature survey on the ongoing great, but not systematic, progress related to the conformational consequences generated by incorporating one (or more) thionamide group(s) into a polypeptide chain. Finally, a short discussion of the growing, but still in its infancy, class of the endoselenoxopeptide congeners is also presented.


Assuntos
Técnicas de Química Sintética/métodos , Peptídeos/química , Peptídeos/síntese química , Compostos de Sulfidrila/química , Estrutura Secundária de Proteína
16.
Soft Matter ; 12(1): 238-45, 2016 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-26463728

RESUMO

A terminally protected, hydrophobic dipeptide Boc-L-Cys(Me)-L-Leu-OMe (1) was synthesized and its 3D-structure was determined by single crystal X-ray diffraction analysis. This peptide is able to hierarchically self-assemble in a variety of superstructures, including hollow rods, ranging from the nano- to the macroscale, and organogels. In addition, 1 is able to drive fullerene (C60) or multiwalled carbon nanotubes (MWCNTs) in an organogel by co-assembling with them. A hybrid 1-C60­MWCNT organogel was prepared and converted (through a high vacuum-drying process) into a robust, high-volume, water insoluble, solid material where C60 is well dispersed over the entire superstructure. This ternary material was successfully tested as a catalyst for: (i) the reduction reaction of water-soluble azo compounds mediated by NaBH4 and UV-light with an overall performance remarkably better than that provided by C60 alone, and (ii) the NaBH4-mediated reduction of benzoic acid to benzyl alcohol. Our results suggest that the self-assembly properties of 1 might be related to the occurrence in its single crystal structure of a sixfold screw axis, a feature shared by most of the linear peptides known so far to give rise to nanotubes.


Assuntos
Dipeptídeos/química , Fulerenos/química , Nanotubos/química , Ácido Benzoico/química , Álcool Benzílico/química , Boroidretos/química , Catálise , Cristalização , Cisteína/análogos & derivados , Leucina/análogos & derivados , Oxirredução
17.
Nanoscale ; 7(37): 15495-506, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26274368

RESUMO

A helical hexapeptide was designed to link in a rigid parallel orientation to a gold surface. The peptide sequence of the newly synthesized compound is characterized by the presence of two 4-amino-1,2-dithiolane-4-carboxylic acid (Adt) residues (positions 1 and 4) to promote a bidentate interaction with the gold surface, two L-Ala residues (positions 2 and 5) and two-aminoisobutyric acid (Aib) residues (positions 3 and 6) to favor a high population of the 310-helix conformation. Furthermore, a ferrocenoyl (Fc) probe was inserted at the N-terminus to investigate the electronic conduction properties of the peptide. X-Ray photoelectron spectroscopy and scanning tunneling microscopy techniques were used to characterize the binding of the peptide to the gold surface and the morphology of the peptide layer, respectively. Several electrochemical (cyclic voltammetry, chronoamperometry, square wave voltammetry) techniques were applied to analyze the electrochemical activity of the Fc probe, along with the influence of the peptide 3D-structure and the peptide layer morphology on electron transfer processes.


Assuntos
Ouro/química , Sondas Moleculares/química , Peptídeos/química , Aminoácidos/química , Propriedades de Superfície , Tiofenos/química , Difração de Raios X
18.
Chemistry ; 21(40): 13866-77, 2015 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-26243713

RESUMO

Among the various types of α-peptide folding motifs, δ-turn, which requires a central cis-amide disposition, has been one of the least extensively investigated. In particular, this main-chain reversal topology has been studied in-depth neither in linear/cyclic peptides nor in proteins. This Minireview article assembles and critically analyzes relevant data from a literature survey on the δ-turn conformation in those compounds. Unpublished results from recent conformational energy calculations and a preliminary solution-state analysis on a small model peptide, currently ongoing in our laboratories, are also briefly outlined.


Assuntos
Peptídeos Cíclicos/química , Peptídeos/química , Proteínas/química , Peptídeos/metabolismo , Conformação Proteica , Estrutura Terciária de Proteína , Proteínas/metabolismo , Inquéritos e Questionários , Temperatura
19.
Eur J Med Chem ; 96: 458-66, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25916907

RESUMO

This work was aimed to the development of a set of new naphtoquinone derivatives that can act against glioma. The compounds were tested in order to find out their ability to inhibit the growth of glioma cells, and the results of these assays were correlated with electrochemical analysis and NMR-based reoxidation kinetic studies, suggesting that a redox mechanism underlies and may explain the observed biological behavior. In addition to a full description of the synthetic pathways, electrochemistry, NMR and single crystal X-ray diffraction data are provided.


Assuntos
Antineoplásicos/farmacologia , Glioma/tratamento farmacológico , Naftoquinonas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Glioma/patologia , Humanos , Modelos Moleculares , Estrutura Molecular , Naftoquinonas/síntese química , Naftoquinonas/química , Relação Estrutura-Atividade
20.
J Pept Sci ; 21(3): 148-77, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25640955

RESUMO

In this second part of our review article on the preferred screw sense and interconversion of peptide helices, we discuss the most significant computational and experimental data published on helices formed by the most extensively investigated categories of noncoded α-amino acids. They are as follows: (i) N-alkylated Gly residues (peptoids), (ii) C(α) -alkylated α-amino acids, (iii) C(α,ß) -sp(2) configurated α-amino acids, and (iv) combinations of residues of types (ii) and (iii). With confidence, the large body of interesting papers examined and classified in this editorial effort will stimulate the development of helical peptides in many diverse areas of biosciences and nanosciences.


Assuntos
Aminoácidos/química , Peptídeos/química , Peptidomiméticos/química , Peptoides/química , Alquilação , Aminoácidos/síntese química , Cristalografia por Raios X , Código Genético , Cinética , Ressonância Magnética Nuclear Biomolecular , Peptídeos/síntese química , Peptidomiméticos/síntese química , Peptoides/síntese química , Estrutura Secundária de Proteína , Termodinâmica
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