Control of Crystallization and Melting Behavior in Sequence Specific Polypeptoids

Rosales, Adrianne M.; Murnen, Hannah K.; Zuckermann, Ronald N.; Segalman, Rachel A.

doi:10.1021/ma1002563

Cited by 101 publications

(166 citation statements)

References 38 publications

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“…The TGA thermograms of all polypeptoid samples, except P1, reveal decomposition temperature thresholds over 200 °C, which is in accordance with earlier reports for several other polypeptoids with long-chain substituents [29]. In Figure 2, an assortment of TGA thermograms is displayed.…”

Section: Resultssupporting

confidence: 90%

“…In our case, the on-set temperatures were significantly lower than 260 °C. Unfortunately, a more detailed comparison with literature is not possible as no detailed decomposition values or thermograms were given [29]. DSC studies were carried out below the decomposition temperatures to determine glass transition temperature (T g ) and melting points (T m ).…”

Section: Resultsmentioning

confidence: 99%

“…Interestingly, Segalman studied a series of short sequence-specific polypeptoids (obtained by solid phase synthesis) in their crystallization and melting behavior [29]. As expected, melting points are lower than those of polypeptides (attributed to the lack of intermolecular H-bonding) and the crystallization behavior is strongly affected by the polymer side chain.…”

Section: Open Accessmentioning

confidence: 87%

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Thermal Properties of Aliphatic Polypeptoids

Fetsch

Luxenhofer

2013

Polymers

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A series of polypeptoid homopolymers bearing short (C 1 -C 5 ) side chains of degrees of polymerization of 10-100 are studied with respect to thermal stability, glass transition and melting points. Thermogravimetric analysis of polypeptoids suggests stability to >200 °C. The study of the glass transition temperatures by differential scanning calorimetry revealed two dependencies. On the one hand an extension of the side chain by constant degree of polymerization decrease the glass transition temperatures (T g ) and on the other hand a raise of the degree of polymerization by constant side chain length leads to an increase of the T g to a constant value. Melting points were observed for polypeptoids with a side chain comprising not less than three methyl carbon atoms. X-ray diffraction of polysarcosine and poly(N-ethylglycine) corroborates the observed lack of melting points and thus, their amorphous nature. Diffractograms of the other investigated polypeptoids imply that crystalline domains exist in the polymer powder.

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Section: Resultssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Section: Open Accessmentioning

confidence: 87%

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Thermal Properties of Aliphatic Polypeptoids

Fetsch

Luxenhofer

2013

Polymers

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“…backbone preferences of peptoids, but more work needs to be done to understand and predict nonlocal molecular packing interactions in the condensed phase, which may govern both selfassembly of longer peptoid chains (41) and binding interactions with proteins.…”

Section: Discussionmentioning

confidence: 99%

De novo structure prediction and experimental characterization of folded peptoid oligomers

Butterfoss

Yoo

Jaworski

et al. 2012

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

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108

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Peptoid molecules are biomimetic oligomers that can fold into unique three-dimensional structures. As part of an effort to advance computational design of folded oligomers, we present blind-structure predictions for three peptoid sequences using a combination of Replica Exchange Molecular Dynamics (REMD) simulation and Quantum Mechanical refinement. We correctly predicted the structure of a N-aryl peptoid trimer to within 0.2 Å rmsd-backbone and a cyclic peptoid nonamer to an accuracy of 1.0 Å rmsd-backbone. X-ray crystallographic structures are presented for a linear N-alkyl peptoid trimer and for the cyclic peptoid nonamer. The peptoid macrocycle structure features a combination of cis and trans backbone amides, significant nonplanarity of the amide bonds, and a unique "basket" arrangement of (S)-N(1-phenylethyl) side chains encompassing a bound ethanol molecule. REMD simulations of the peptoid trimers reveal that well folded peptoids can exhibit funnel-like conformational free energy landscapes similar to those for ordered polypeptides. These results indicate that physical modeling can successfully perform de novo structure prediction for small peptoid molecules.foldamer | molecular simulation F oldamers are synthetic polymers that-like proteins-have the ability to self-assemble into unique folded structures (1). Examples of foldamer systems include β-peptides, γ-peptides, azapeptides, oligoureas, arylamides, oligohydrazides, polyphenylacetylenes, and peptoids, among others (2, 3). Of these, peptoids offer an attractive platform for designing functionalized, conformationally ordered molecular architectures ( Fig. 1): they can be readily synthesized to incorporate chemically diverse side chains (4, 5), are resistant to proteolysis (6), and can retain structure and function in nonaqueous solvents. Peptoids have found capacity for diverse applications such as antimicrobials (7), drug delivery platforms (8), therapeutics (9), enantioselective catalysts (10), and nanostructured materials (11,12).Unlike peptides, peptoids lack the ability to form backbone hydrogen bonds and can readily populate both cis and trans backbone amide states. Thus, new strategies may be required to enable the rational design of ordered peptoid structures. For instance, even though the peptoid backbone is achiral, bulky chiral side chain groups such as 1-phenylethyl or 1-naphthylethyl can be used to induce stereocontrolled cis-amide helical structures resembling polyproline I (13-15). Such helices have been used to form tertiary assemblies (11, 16), and have been incorporated into enzymes with minimal loss of function (17). Alternatively, peptoid N-aryl side chains have been used to induce trans-amide helices that can mimic polyproline II structure (18,19). It remains to be determined how these local rules can be used to control the global three-dimensional structure of peptoid macromolecules (20).In order to design peptoids for applications, we need a way to predict their native structures from their sequences. Successes in designing prot...

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“…The physicochemical properties of polypeptoids can be tailored by the N-substituent structures, enabling control over the hydrophilicity and lipophilicity balance (HLB), charge characteristics, [13,14] backbone conformation, [1][2][3][4][5][6][7][8][9][10][11][12] solubility, [15][16][17][18][19][20] thermal and crystallization properties of the polypeptoids. [21][22][23][24] Without extensive hydrogen bonding, polypeptoids are thermally processable similar to conventional thermoplastics, [20][21][22][23][24] whereas polypeptides undergo thermal degradation before they can be melt-processed due to the extensive hydrogen bonding interactions. While polypeptoids exhibited enhanced proteolytic stability relative to peptides, [25,26] they can be oxidatively degraded under conditions that mimic tissue inflammation, [27] suggesting their potential in vivo uses as biodegradable materials.…”

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confidence: 99%

Polypeptoid polymers: Synthesis, characterization, and properties

et al. 2017

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Polypeptoids, a class of peptidomimetic polymers, have emerged at the forefront of macromolecular and supramolecular science and engineering as the technological relevance of these polymers continues to be demonstrated. The chemical and structural diversity of polypeptoids have enabled access to and adjustment of a variety of physicochemical and biological properties (eg, solubility, charge characteristics, chain conformation, HLB, thermal processability, degradability, cytotoxicity and immunogenicity). These attributes have made this synthetic polymer platform a potential candidate for various biomedical and biotechnological applications. This review will provide an overview of recent development in synthetic methods to access polypeptoid polymers with well-defined structures and highlight some of the fundamental physicochemical and biological properties of polypeptoids that are pertinent to the future development of functional materials based on polypeptoids. | I N TR ODU C TI ONPolypeptoids composed of N-substituted polyglycine backbones are structural mimics of polypeptides ( Figure 1). Because of N-substitution, polypeptoids lack stereogenic centers and hydrogen bonding interactions along the main chains, in sharp contrast to polypeptides.As a result, the global conformations of polypeptoids are strongly dependent on the N-substituent structures, giving rise to random coils or well-defined secondary structures [eg, polyproline I (PPI) helix [1][2][3][4][5][6] and R-sheets] [7][8][9][10][11][12] that are reminiscent of those of polypeptides. The polypeptoid backbone containing tertiary amide linkages is highly polar and hydrophilic. The physicochemical properties of polypeptoids can be tailored by the N-substituent structures, enabling control over the hydrophilicity and lipophilicity balance (HLB), charge characteristics, [13,14] backbone conformation, [1][2][3][4][5][6][7][8][9][10][11][12] solubility, [15][16][17][18][19][20] thermal and crystallization properties of the polypeptoids. [21][22][23][24] Without extensive hydrogen bonding, polypeptoids are thermally processable similar to conventional thermoplastics, [20][21][22][23][24] whereas polypeptides undergo thermal degradation before they can be melt-processed due to the extensive hydrogen bonding interactions. While polypeptoids exhibited enhanced proteolytic stability relative to peptides, [25,26] they can be oxidatively degraded under conditions that mimic tissue inflammation, [27] suggesting their potential in vivo uses as biodegradable materials.Recent advances in the controlled polymerization methods have enabled access to a suite of structurally well-defined polypeptoids with various N-substituent structures and molecular architectures, setting the stage for the future development of polypeptoid materials for various targeted applications. Several review articles on the synthesis, properties, and application of polypeptoids for biomedical or nonbiomedical uses have been published in recent years. [28][29][30][31][32] As a result, this...

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Control of Crystallization and Melting Behavior in Sequence Specific Polypeptoids

Cited by 101 publications

References 38 publications

Thermal Properties of Aliphatic Polypeptoids

Thermal Properties of Aliphatic Polypeptoids

De novo structure prediction and experimental characterization of folded peptoid oligomers

Polypeptoid polymers: Synthesis, characterization, and properties

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