In the present paper we describe the synthesis, purification, and single crystal x-ray analysis of the cyclic pentapeptide cyclo-(Pro-Phe-Phe-beta-Ala-beta-Ala). This compound crystallizes in the orthorhombic space group P2I2I2I from methanol and adopts in the solid state an unusual conformation characterized by a cis beta-Ala5-Pro1 peptide bond and by an intramolecular hydrogen bond stabilizing a C11-and a C12-ring structure. The C11 structure contains the Phe3 and the beta-Ala4 at the corner position of the turn; it is the first observation of a type II beta-turn enlargement due to the insertion of an extra methylene group of the beta-alanine residue. The rest of the molecule participates in a newly characterized C12-ring structure, which incorporates a beta-Ala residue at position i of the turn.

Download full-text PDF

Source
http://dx.doi.org/10.1002/bip.360380602DOI Listing

Publication Analysis

Top Keywords

c12-ring structure
8
position turn
8
unusual conformational
4
conformational preferences
4
preferences beta-alanine
4
beta-alanine cyclic
4
cyclic peptides
4
peptides vii
4
vii paper
4
paper describe
4

Similar Publications

The capped α/γ-peptide foldamers Ac-γACHC-Ala-NH-benzyl (γα) and Ac-Ala-γACHC-NH-benzyl (αγ) were studied in the gas phase under jet-cooled conditions using single-conformation spectroscopy. These molecules serve as models for local segments of larger heterogeneous 1:1 α/γ-peptides that have recently been synthesized and shown to form a 12-helix composed of repeating C12 H-bonded rings both in crystalline form and in solution [Guo, L.; et al.

View Article and Find Full Text PDF

In connection to developing non-steroidal estrogen analogs, the present study explores the pharmacophore of triphenylacrylonitriles (Fig. 1) for binding affinity to estrogen receptor using Electrotopological State (E-State) indices of constituting atoms. The analysis shows the efficacy of E-State index in developing statistically acceptable model, which defines the electronic environment and topological states of diverse atoms in a molecule.

View Article and Find Full Text PDF

A proposed bioactive conformation of peptide T.

J Comput Aided Mol Des

January 1998

Dept. d'Enginyeria Quimica, UPC, ETS d'Enginyers Industrials, Barcelona, Spain.

The conformational profiles of Peptide T, (5-8)Peptide T, [Abu5](4-8)Peptide T and (4-8)Peptide T were computed independently to assess the geometrical characteristics of the bioactive conformation of Peptide T. The conformational profiles of the peptides were computed within the molecular mechanics framework using an effective dielectric constant of 80. The conformational space was thoroughly sampled using an iterative simulated annealing protocol.

View Article and Find Full Text PDF

In the present paper we describe the synthesis, purification, and single crystal x-ray analysis of the cyclic pentapeptide cyclo-(Pro-Phe-Phe-beta-Ala-beta-Ala). This compound crystallizes in the orthorhombic space group P2I2I2I from methanol and adopts in the solid state an unusual conformation characterized by a cis beta-Ala5-Pro1 peptide bond and by an intramolecular hydrogen bond stabilizing a C11-and a C12-ring structure. The C11 structure contains the Phe3 and the beta-Ala4 at the corner position of the turn; it is the first observation of a type II beta-turn enlargement due to the insertion of an extra methylene group of the beta-alanine residue.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!