Comparison of the crystal structures of two pentadehydropeptides containing DeltaPhe residues, namely (Z,Z)-N-(tert-butoxycarbonyl)glycyl-alpha,beta-phenylalanylglycyl-alpha,beta-phenylalanylglycine (or Boc(0)-Gly(1)-Delta(Z)Phe(2)-Gly(3)-Delta(Z)Phe(4)-Gly(5)-OH) methanol solvate, C(29)H(33)N(5)O(8) x CH(4)O, (I), and (E,E)-N-(tert-butoxycarbonyl)glycyl-alpha,beta-phenylalanylglycyl-alpha,beta-phenylalanylglycine (or Boc(0)-Gly(1)-Delta(E)Phe(2)-Gly(3)-Delta(E)Phe(4)-Gly(5)-OH), C(29)H(33)N(5)O(8), (II), indicates that the Delta(Z)Phe residue is a more effective inducer of folded structures than the Delta(E)Phe residue. The values of the torsion angles phi and psi show the presence of two type-III' beta-turns at the Delta(Z)Phe residues and one type-II beta-turn at the Delta(E)Phe residue. All amino acids are linked trans to each other in both peptides. Beta-turns present in the peptides are stabilized by intramolecular 4-->1 hydrogen bonds. Molecules in both structures form two-dimensional hydrogen-bond networks parallel to the (100) plane.
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http://dx.doi.org/10.1107/S0108270110003094 | DOI Listing |
J Comput Aided Mol Des
December 2024
Amity Institute of Biotechnology, Amity University Uttar Pradesh, Sector-125, Noida, UP, 201313, India.
J Colloid Interface Sci
February 2025
Departament d'Enginyeria Química and Barcelona Research Center in Multiscale Science and Engineering, EEBE, Universitat Politècnica de Catalunya, C/ Eduard Maristany, 10-14, 08019 Barcelona, Spain; Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, 08028 Barcelona Spain. Electronic address:
Biologically inspired aromatic peptide-based materials are gaining increasing interest as novel charge transport materials for bioelectronics due to their remarkable electrical response and inherent biocompatibility. In this work, the electrochemical response of ten aromatic amino acids and eleven aromatic peptides has been evaluated to assess the potential of incorporating peptides into electrochemical sensors not as biorecognition elements but as biocompatible electronic materials. While the electrochemical response of amino acids is null in all cases, the hexapeptide of phenylalanine (Phe) capped with eight polyethylene glycol units at the N-terminus and, especially, the cyclic dipeptide formed by two dehydro-phenylalanine residues (cyclo(ΔPhe)), which organize in fibrillary self-assembled structures of nano- and submicrometric size, respectively, are the most electroactive peptides.
View Article and Find Full Text PDFTetrahedron Lett
June 2021
Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA.
Investigation of a strategy to streamline the synthesis of peptides containing α,β-dehydroamino acids (ΔAAs) is reported. The key step involves generating the alkene moiety elimination of a suitable precursor after it has been inserted into a peptide chain. This process obviates the need to prepare ΔAA-containing azlactone dipeptides to facilitate coupling of these residues.
View Article and Find Full Text PDFJ Pept Sci
August 2018
Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383, Wrocław, Poland.
N-(tert-butyloxycarbonyl) or N-(9-fluorenylmethoxycarbonyl) dipeptides with C-terminal (Z)-α,β-didehydrophenylalanine (∆ Phe), (Z)-α,β-didehydrotyrosine (∆ Tyr), (Z)-α,β-didehydrotryptophan (∆ Trp), (Z)-α,β-didehydromethionine (∆ Met), (Z)-α,β-didehydroleucine (∆ Leu), and (Z/E)-α,β-didehydroisoleucine (∆ Ile) were synthesised from their saturated analogues via oxidation of intermediate 2,5-disubstituted-oxazol-5-(4H)-ones (also known as azlactones) with pyridinium tribromide followed by opening of the produced unsaturated oxazol-5-(4H)-one derivatives in organic-aqueous solution with a catalytic amount of trifluoroacetic acid or by a basic hydrolysis. In all cases, a very strong preference for Z isomers of α,β-didehydro-α-amino acid residues was observed except of the ΔIle, which was obtained as the equimolar mixture of Z and E isomers. Reasons for the (Z)-stereoselectivity and the increased stability of the aromatic α,β-didehydro-α-amino acid residue oxazol-5-(4H)-ones over the corresponding aliphatic ones are also discussed.
View Article and Find Full Text PDFPLoS One
August 2017
Luxembourg Institute of Science and Technology (LIST), Environmental Research and Innovation (ERIN) department, Esch-sur-Alzette, Luxembourg.
The structure and the activity of proteins are often regulated by transient or stable post- translational modifications (PTM). Different from well-known, abundant modifications such as phosphorylation and glycosylation some modifications are limited to one or a few proteins across a broad range of related species. Although few examples of the latter type are known, the evolutionary conservation of these modifications and the enzymes responsible for their synthesis suggest an important physiological role.
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