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Co-oligopeptides of aromatic amino acids and glycine with a variable distance between the aromatic residues. VI. Circular dichroism studies of co-oligopeptides of L-phenylalanine, L-tryptophan, and glycine

✍ Scribed by Vincenzo Rizzo; Pier Luigi Luisi; Barbara Straub; Rocco Guarnaccia

Publisher
Wiley (John Wiley & Sons)
Year
1977
Tongue
English
Weight
694 KB
Volume
16
Category
Article
ISSN
0006-3525

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✦ Synopsis

Abstract

The circular dichroic properties of H‐Gly‐Phe‐(Gly)~n~‐Trp‐Gly‐OH (II, n = 0,1,2) and of related simpler peptides, such as H‐Phe‐Gly‐OH, H‐Gly‐Phe‐OH, H‐Gly‐Phe‐Gly‐OH, H‐Phe‐Trp‐OH, H‐Phe‐Trp‐Gly‐OH, and H‐Gly‐Phe‐Trp‐OH in water and trifluoroethanol solutions are investigated. Peptides containing only one phenylalanyl residue show markedly different near‐uv dichroic signals depending on whether this residue is in the N‐terminal position or not. The possible origin of this feature is discussed. The study of the oligopeptides II (n = 0,1,2) shows that no strong intramolecular interaction between the two aromatic rings is present. However, the dichroic properties of II (n = 0) are clearly anomalous, and the analysis of H‐Gly‐Phe‐Trp‐OH, H‐Phe‐Trp‐Gly‐OH, and of H‐Phe‐Trp‐OH at different pH's, confirms that the presence of two adjacent aromatic residues may bring about chiroptical properties which indicate a restriction in the conformational equilibrium of the molecule. The limits, and the possible generalization of this finding, are discussed.

📜 SIMILAR VOLUMES

Co-oligopeptides of aromatic amino acids
Co-oligopeptides of aromatic amino acids and glycine with a variable distance between the aromatic residues. III. Co-oligopeptides of L-phenylalanine, L-tryptophan, and glycine: Synthesis and ultraviolet absorption properties
✍ Rocco Guarnaccia; Vincenzo Rizzo; Pietro Gianola; Pier Luisi Luisi 📂 Article 📅 1976 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 720 KB

## Abstract The preparation of the co‐oligopeptides of the series H‐Gly‐Phe‐(Gly)~__n__~‐Trp‐Gly‐OH (__n__ = 0, 1, 2) and of other free peptides of glycine, L‐tryptophan, and L‐phenylalanine is reported. The syntheses have been carried out by conventional methods, using __N__‐hydroxysuccinimide est

Co-oligopeptides of aromatic amino acids
Co-oligopeptides of aromatic amino acids and glycine with a variable distance between the aromatic residues. I. Synthesis of co-oligopeptides of tryptophan and glycine
✍ Rocco Guarnaccia; Gian Paolo Lorenzi; Vincenzo Rizzo; Pier Luigi Luisi 📂 Article 📅 1975 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 851 KB

## Abstract The preparation of the co‐oligopeptides of the series H‐Gly‐Trp‐(Gly)~__n__~‐Trp‐Gly‐OH (__n__ = 0, 1, and 2) and of a number of other unprotected co‐oligopeptides of glycine and tryptophan is reported. The syntheses have been carried out by conventional methods, using, in general, __N_

Co-oligopeptides of aromatic amino acids
Co-oligopeptides of aromatic amino acids and glycine with a variable distance between the aromatic residues. II. Ultraviolet absorption and circular dichroism properties of co-oligopeptides of tryptophan and glycine
✍ Pier Luigi Luisi; Vincenzo Rizzo; Gian Paolo Lorenzi; Barbara Straub; Ulrich Sut 📂 Article 📅 1975 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 791 KB

## Abstract The uv absorption and circular dichroism (CD) properties in water (pH 5.9) and trifluoroethanol of several co‐oligopeptides of glycine and tryptophan have been investigated. These compounds contain one tryptophyl residue, such as H‐Gly‐Trp‐OH, H‐Trp‐Gly‐OH, and H‐Gly‐Trp‐Gly‐OH; or two,

Co-oligopeptides of aromatic amino acids
Co-oligopeptides of aromatic amino acids and glycine with variable distance between the aromatic residues. VII. Enzymatic synthesis of N-protected peptide amides
✍ Robert Saltman; Dagmar Vlach; Pier Luigi Luisi 📂 Article 📅 1977 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 476 KB

## Abstract Several N‐protected peptide amides, containing two aromatic residues spaced by one glycyl residue, have been enzymatically synthesized starting from P‐Ar‐OH and H‐Gly‐Ar‐NH~2~ (P is the protecting group and Ar is the aromatic residue) and using α‐chymotrypsin as the catalyst for the cou

Co-oligopeptides of aromatic amino acids
Co-oligopeptides of aromatic amino acids and glycine with a variable distance between the aromatic residues. V. pH-Dependent conformational changes in peptides containing two adjacent tryptophyl residues as evidenced by circular dichroism studies
✍ Vincenzo Rizzo; Pier Luigi Luisi 📂 Article 📅 1977 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 602 KB

## Abstract The influence of pH upon CD spectra of H‐Trp‐Trp‐OH, H‐Trp‐Trp‐Gly‐OH, and H‐Gly‐Trp‐Trp‐OH is investigated and data are compared with those obtained for peptides containing only one tryptophyl residue. A negative Cotton effect at around 225 nm, which in previous work has been related t