scholarly journals Solid-State and Solution-Phase Conformations of Pseudoproline-Containing Dipeptides

2009 ◽  
Vol 62 (7) ◽  
pp. 711 ◽  
Author(s):  
Jack K. Clegg ◽  
James R. Cochrane ◽  
Nima Sayyadi ◽  
Danielle Skropeta ◽  
Peter Turner ◽  
...  
Keyword(s):  
Amino Acid ◽  
Solid State ◽  
Crystal Packing ◽  
Amide Bond ◽  
Side Chain ◽  
Trans Conformation ◽  
N Terminus ◽  
Structural Differences ◽  
Terminal Amino ◽  
Packing Interactions

The conformations of 14 threonine-derived pseudoproline-containing dipeptides (including four d-allo-Thr derivatives) have been investigated by NMR. In solution, the major conformer observed for all dipeptides is that in which the amide bond between the pseudoproline and the preceding amino acid is cis. For dipeptides in which the N-terminus is protected, the ratio of cis- to trans-conformers does not depend significantly on the side chain of the N-terminal amino acid, or the stereochemistry of the Thr residue. However, for dipeptides bearing a free N-terminus, there are significant differences in the ratios of cis- to trans-conformers depending on the side chain present. Three dipeptides were crystallized and their X-ray structures determined. In two cases, (benzyloxycarbonyl (Cbz)-Val-Thr(ΨMe,Mepro)-OMe and Cbz-Val-Thr(ΨMe,Mepro)-OH), the dipeptides adopt a trans-conformation in the solid state, in contrast to the structures observed in solution. In the third case, (9-fluorenylmethoxycarbonyl (Fmoc)-Val-d-allo-Thr(ΨMe,Mepro)-OH), a cis-amide geometry is observed. These structural differences are attributed to crystal-packing interactions.

scholarly journals Visualising crystal packing interactions in solid-state NMR: Concepts and applications

2017 ◽  
Vol 147 (14) ◽  
pp. 144203 ◽  
Author(s):  
Miri Zilka ◽  
Simone Sturniolo ◽  
Steven P. Brown ◽  
Jonathan R. Yates
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Crystal Packing ◽  
Packing Interactions

Synthesis of new cyclopeptide analogues of the miuraenamides

2021 ◽  
Vol 18 ◽  
Author(s):  
Sarah Kappler ◽  
Andreas Siebert ◽  
Uli Kazmaier
Keyword(s):  
Natural Products ◽  
Biological Properties ◽  
Amide Bond ◽  
Side Chain ◽  
Aromatic Side Chain ◽  
Highly Active ◽  
C Terminus ◽  
Terminal Amino ◽  
High Cytotoxicity ◽  
Derivatives Of

Introduction: Miuraenamides belong to marine natural compounds with interesting biological properties. Materials and Methods: They initiate polymerization of monomeric actin and therefore show high cytotoxicity by influencing the cytoskeleton. New derivatives of the miuraenamides have been synthesized containing a N-methylated amide bond instead of the more easily hydrolysable ester in the natural products. Results: Incorporation of an aromatic side chain onto the C-terminal amino acid of the tripeptide fragment also led to highly active new miuraenamides. Conclusion: We could show that the ester bond of the natural product miuraenamide can be replaced by an N-methyl amide. The yields in the cyclization step are high and generally much better that with the corresponding esters. On the other hand, the biological activity of the new amide analogs are lower compared to the natural products, but the activity can significantly be increased by incorporation of a p-nitrophenyl group at the C-terminus of the peptide fragment.

scholarly journals Dynamics of Serine-8 Side-Chain in Amyloid-β Fibrils and Fluorenylmethyloxycarbonyl Serine Amino Acid, Investigated by Solid-State Deuteron NMR

2020 ◽  
Vol 124 (23) ◽  
pp. 4723-4731
Author(s):  
Liliya Vugmeyster ◽  
Dan Fai Au ◽  
Dmitry Ostrovsky ◽  
Dillon Ray Lee Rickertsen ◽  
Scott M. Reed
Keyword(s):  
Amino Acid ◽  
Solid State ◽  
Amyloid Β ◽  
Side Chain ◽  
Deuteron Nmr

scholarly journals Chemical nature and sequence of alamethicin

1976 ◽  
Vol 153 (2) ◽  
pp. 181-190 ◽  
Author(s):  
D R Martin ◽  
R J P Williams
Keyword(s):  
Glutamic Acid ◽  
Chemical Nature ◽  
Chemical Compounds ◽  
Amide Bond ◽  
Side Chain ◽  
Partial Hydrolysis ◽  
Spectroscopy Study ◽  
N Terminus ◽  
Acetyl Group ◽  
New Formula

An n.m.r. spectroscopy study of pure alamethicin shows it to be a linear polypeptide of 19 residues. The N-terminus is blocked by an acetyl group, and the eighteenth residue, glutamic acid, is linked by an amide bond on its side chain to phenylalaninol (Fig. 6). The new formula is confirmed by a comparison between pure chemical compounds and the products of partial hydrolysis.

Can the Peptide Chain of a Pyoverdin be Bound by an Ester Bond to the Chromophore? - The Old Problem of Pseudobactin 7SR1

2000 ◽  
Vol 55 (3-4) ◽  
pp. 153-164 ◽  
Author(s):  
Werner Voßen ◽  
Regine Fuchs ◽  
Kambiz Taraz ◽  
Herbert Budzikiewicz
Keyword(s):  
Amino Acid ◽  
Amide Bond ◽  
Peptide Chain ◽  
Ester Bond ◽  
Terminal Amino Acid ◽  
Terminal Amino

Abstract The structure which had been proposed for the pyoverdin named pseudobactin 7SR1 (Yang and Leong, 1984) differed from those of all other pyoverdins investigated sofar: its peptide chain was supposedly linked to the chromophore not by an amide bond originating from its N-terminal amino acid, but rather by an ester bond involving one of the three Ser. It will be shown that the peptide chain of pseudobactin 7SR1 is actually bound to the chromophore amidically by its N-terminal Ser and that it comprises a cyc/odepsipeptidic substructure with an ester bond between the C-terminal Thr and the OH-group of the second Ser in the chain.

scholarly journals Carbohydrate is linked through ethanolamine to the C-terminal amino acid of Trypanosoma brucei variant surface glycoprotein

1983 ◽  
Vol 209 (1) ◽  
pp. 261-262 ◽  
Author(s):  
A A Holder
Keyword(s):  
Amino Acid ◽  
Aspartic Acid ◽  
Trypanosoma Brucei ◽  
Carboxy Group ◽  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
Side Chain ◽  
Serine Residue ◽  
Terminal Amino Acid ◽  
Terminal Amino

The C-terminal amino acid of the variant surface glycoprotein from Trypanosoma brucei is glycosylated. For two variant proteins that terminate in an aspartic acid and a serine residue respectively, it was shown that the sugar side chain is linked through ethanolamine to the alpha-carboxy group of the amino acid.

scholarly journals Does Cysteine Rule (CysR) Complete the CendR Principle? Increase in Affinity of Peptide Ligands for NRP-1 Through the Presence of N-Terminal Cysteine

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 448 ◽  
Author(s):  
Anna K. Puszko ◽  
Piotr Sosnowski ◽  
Françoise Raynaud ◽  
Olivier Hermine ◽  
Gérard Hopfgartner ◽  
...  
Keyword(s):  
Peptide Ligands ◽  
Side Chain ◽  
Amino Group ◽  
Structure Activity ◽  
C Terminus ◽  
Neuropilin 1 ◽  
Ic50 Value ◽  
N Terminus ◽  
Terminal Amino ◽  
Relationship Of

The structure-activity relationship of branched H-Lys(hArg)-Dab-Dhp-Arg-OH sequence analogues, modified with Cys-Asp or Cys at N-terminal amino acids (Lys, hArg), in VEGF-A165/Neuropilin-1 complex inhibition is presented. The addition of Cys residue led to a 100-fold decrease in the IC50 value, compared to the parent peptide. The change occurred regardless of coupling Cys to the free N-terminal amino group present in the main or the side chain. A few analogues extended by the attachment of Cys at the N-terminus of several potent NRP-1 peptide ligands documented in the literature are also presented. In all studied cases, the enhancement of inhibitory properties after the addition of Cys at the N-terminus is observed. It is particularly evident for the tetrapeptide derived from the C-terminus of VEGF-A165 (KPRR), suggesting that extending the K/RXXK/R motif (CendR) with the Cys moiety can significantly improve affinity to NRP-1 of CendR peptides.

Purification and partial chemical characterization of human pituitary lipolytic hormone

1976 ◽  
Vol 54 (9) ◽  
pp. 778-782 ◽  
Author(s):  
M. Chrétien ◽  
C. Gilardeau ◽  
N. Seidah ◽  
M. Lis
Keyword(s):  
Amino Acid ◽  
Chemical Characterization ◽  
Terminal Amino Acid ◽  
Human Pituitary ◽  
Leucine Residue ◽  
N Terminus ◽  
Pituitary Glands ◽  
Terminal Amino ◽  
Partial Chemical

Frozen human pituitary glands contain a lipotropic hormone which is similar to but not identical with ovine, bovine, and porcine beta-lipotropin. Six of the first seven residues from the N-terminus are [Formula: see text] The C-terminal amino acid is a leucine residue.

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