Präzipitate mit β-Faltblattstruktur durch Mischen wäßriger Lösungen von helicalem Poly(D-lysin) und Poly(L-lysin)

Fuhrhop, Jürgen‐Hinrich; Krull, M.; Büldt, Georg

doi:10.1002/ange.19870990728

Cited by 11 publications

(8 citation statements)

References 11 publications

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“…Another reported example is a solubility study showing that the mixing of equal amounts of water-soluble polylysine of opposite handedness results in the precipitation of the racemate. [22,23] The formation of rippled ap b-sheets and rippled p bsheets has been reported in the polymerization of racemic crystals of (RS)-Phe-NCA [11,12,24] and (RS)-Val-NCA, [13] re-spectively, suspended in an organic solvent or water containing the initiator. On the other hand, NMR spectroscopy studies of short racemic oligopeptides forming b-sheet-like architectures in chloroform have shown that the interactions between residues residing in neighboring chains of the same handedness are more stable than those of opposite handedness by 0.6-0.8 kcal per residue.…”

Section: Discussionmentioning

confidence: 99%

Racemic β‐Sheets as Templates for the Generation of Homochiral (Isotactic) Peptides from Aqueous Solutions of (RS)‐Valine or ‐Leucine N‐Carboxy‐ anhydrides: Relevance to Biochirogenesis

Rubinstein¹,

Clodic²,

Bolbach³

et al. 2008

Chemistry A European J

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As part of our program on biochirogenesis of homochiral peptides from racemic precursors, we report the feasibility of obtaining peptides with homochiral sequences composed of up to 25 residues of the same handedness in the polymerization of racemic valine or leucine N-carboxyanhydrides in aqueous solutions, as initiated by amines. The composition of the oligopeptides was determined by MALDI-TOF mass spectrometry, and the sequences of some of the heterochiral diastereoisomers were studied by MALDI-TOF MS/MS performed on samples in which the S enantiomers of the monomer were tagged with deuterium atoms. The process comprises several steps: 1) a Markov mechanism of asymmetric induction in the early stages of the polymerization yields libraries of racemic oligopeptides enriched with isotactic diastereoisomers, together with oligopeptide sequences containing enantiomeric blocks of homochiral residues; 2) the short peptides self-assemble into racemic colloidal architectures that serve as regio-enantioselective templates in the ensuing process of chain elongation; 3) homochiral residues of the amino acids located at the periphery of these colloidal aggregates exert efficient enantioselection, which results in the formation of long isotactic oligopeptides. The final diastereoisomeric distribution of the peptides depends upon the composition of the templates, which is determined by the concentration of the initiator. The racemic mixtures of isotactic peptides can be desymmetrized by using enantiopure methyl esters of alpha-amino acids as initiators.

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Section: Discussionmentioning

confidence: 99%

Racemic β‐Sheets as Templates for the Generation of Homochiral (Isotactic) Peptides from Aqueous Solutions of (RS)‐Valine or ‐Leucine N‐Carboxy‐ anhydrides: Relevance to Biochirogenesis

Rubinstein¹,

Clodic²,

Bolbach³

et al. 2008

Chemistry A European J

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“…[503] According to model studies, peptides in the form of b sheets (Scheme S17 in the Supporting Information)-at least in apolar media-are present largely in the homochiral conformation, which permits stacking between the amino acid residues R. [504] Heterochiral arrangements are preferred with basic amino acids, for example with polylysine, [505] as is to be expected because of repulsion between ionic groups in a homochiral form. [503] According to model studies, peptides in the form of b sheets (Scheme S17 in the Supporting Information)-at least in apolar media-are present largely in the homochiral conformation, which permits stacking between the amino acid residues R. [504] Heterochiral arrangements are preferred with basic amino acids, for example with polylysine, [505] as is to be expected because of repulsion between ionic groups in a homochiral form.…”

Section: Stacking Of Peptidesmentioning

confidence: 99%

“…The folding of peptides is determined largely by interactions between aromatic amino acid side chains. [503] According to model studies, peptides in the form of b sheets (Scheme S17 in the Supporting Information)-at least in apolar media-are present largely in the homochiral conformation, which permits stacking between the amino acid residues R. [504] Heterochiral arrangements are preferred with basic amino acids, for example with polylysine, [505] as is to be expected because of repulsion between ionic groups in a homochiral form. A contribution of about 2 kJ mol À1 has been derived with hairpin models for the Phe-Phe intrastrand interaction.…”

Section: Stacking Of Peptidesmentioning

confidence: 99%

Binding Mechanisms in Supramolecular Complexes

2009

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Supramolecular chemistry has expanded dramatically in recent years both in terms of potential applications and in its relevance to analogous biological systems. The formation and function of supramolecular complexes occur through a multiplicity of often difficult to differentiate noncovalent forces. The aim of this Review is to describe the crucial interaction mechanisms in context, and thus classify the entire subject. In most cases, organic host-guest complexes have been selected as examples, but biologically relevant problems are also considered. An understanding and quantification of intermolecular interactions is of importance both for the rational planning of new supramolecular systems, including intelligent materials, as well as for developing new biologically active agents.

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“…[504] Heterochirale Anordnungen werden bei basischen Aminosäuren, z. B. bei Polylysin bevorzugt, [505] wie aufgrund der Abstoßung zwischen den ionischen Gruppen in einer homochiralen Form zu erwarten ist. In Haarnadel-Modellen wurde für die Phe-Phe-Wechselwirkung innerhalb des Peptidstrangs ein Beitrag von etwa 2 kJ mol À1 abgeleitet.…”

Section: Stapelwechselwirkungen Bei Peptidenunclassified

Bindungsmechanismen in supramolekularen Komplexen

Schneider

2009

Angewandte Chemie

185

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Kräfte‐Sammelsurium: Supramolekulare Komplexe, wie der gezeigte, beruhen meist auf einer Kombination unterschiedlichster Wechselwirkungen, wie Ionenpaarbildung, Wasserstoffbrücken und Stapelwechselwirkungen. Die nicht immer einfache Charakterisierung von Natur und Stärke der intermolekularen Kräfte liefert Beiträge zum Verständnis biomimetischer Systeme wie auch zum Design von synthetischen Rezeptoren, Wirkstoffen und intelligenten Materialien. Die supramolekulare Chemie hat in den letzten Jahren eine enorme Ausdehnung erfahren, sowohl mit Blick auf mögliche Anwendungen wie auch auf analoge biologische Systeme. Bildung und Funktion supramolekularer Komplexe werden durch eine Vielzahl von oft schwer zu differenzierenden nichtkovalenten Kräften bestimmt. Ziel dieses Aufsatzes ist es, die entscheidenden Wechselwirkungsmechanismen zusammenhängend darzustellen und das Gesamtgebiet auf diese Weise zu klassifizieren. Als Beispiele werden meist organische Wirt‐Gast‐Komplexe gewählt, unter Berücksichtigung auch von biologisch relevanten Fragestellungen. Das Verständnis und die Quantifizierung der intermolekularen Wechselwirkungen ist für die rationale Planung neuer supramolekularer Systeme, einschließlich intelligenter Materialien, ebenso von Bedeutung wie für die Entwicklung neuer Wirkstoffe.

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Präzipitate mit β-Faltblattstruktur durch Mischen wäßriger Lösungen von helicalem Poly(D-lysin) und Poly(L-lysin)

Cited by 11 publications

References 11 publications

Racemic β‐Sheets as Templates for the Generation of Homochiral (Isotactic) Peptides from Aqueous Solutions of (RS)‐Valine or ‐Leucine N‐Carboxy‐ anhydrides: Relevance to Biochirogenesis

Racemic β‐Sheets as Templates for the Generation of Homochiral (Isotactic) Peptides from Aqueous Solutions of (RS)‐Valine or ‐Leucine N‐Carboxy‐ anhydrides: Relevance to Biochirogenesis

Binding Mechanisms in Supramolecular Complexes

Bindungsmechanismen in supramolekularen Komplexen

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