ΜΕΛΕΤΗ ΤΗΣ ΔΙΑΜΟΡΦΩΣΗΣ ΚΑΙ ΤΗΣ ΜΟΡΙΑΚΗΣ ΔΥΝΑΜΙΚΗΣ ΤΩΝ ΕΓΚΕΦΑΛΙΝΩΝ ΜΕ ΦΑΣΜΑΤΟΣΚΟΠΙΑ ΠΥΡΗΝΙΚΟΥ ΜΑΓΝΗΤΙΚΟΥ ΣΥΝΤΟΝΙΣΜΟΥ (17Ο-NMR) ΚΑΙ ΥΠΕΡΥΘΡΟΥ...

IN THIS STUDY THE RESULTS OF 17O-NMR STUDIES OF LEU-ENKEPHALIN SELECTIVELY ENRICHED IN 17O IN POSITIONS GLY-2, GLY-3 AND THE TERMINAL CARBOXYL GROUP ARE REPORTED. FROM STUDIES IN AQUEOUS SOLUTIONS AND IN CH3CH/DMSO (4:1) MIXTURES, IN SEVERAL PH AND TEMPERATURE VALUES IT IS CONCLUDED THAT BOTH PEPTIDE OXYGENS ARE NOT INTRAMOLECULARLY HYDROGEN BONDED AND IN WATER EXIST MAINLY IN MONOHYDRATED FORM. THUS A B-TURN STRUCTURE SHOULD BE EXCLUDED. IT WAS ALSO DEMONSTRATED THAT IN CH3CN/DMSO MIXTURE, LEU-ENKEPHALIN EXISTS AT PH 5,6 NOT IN THE ZWITTERIONIC FORM BUT IN THE NEUTRAL. THIS WAS CONFIRMED BY IR-FT STUDIES. IN ORDER TO STUDY SIDE- CHAIN CONFORMATION OF TYROSINE CONTAINING PEPTIDES, SEVERAL 17O SELECTIVELY ENRICHED MODEL COMPOUNDS WERE PREPARED. 17O-NMR SPECTROSCOPY WAS PROVED TO BE A VALUABLE TOOL FOR THE INVESTIGATION OF THE IONIZATION STATE OF THE PHENOL GROUP. IR-FT STUDIES REVEALED THAT THE IN PLANE C-O-H BENDING FREQUENCIES ARE VERY SENSITIVE IN HYDROGEN BONDING INTERACTIONS AND DISCRETE HYDROGEN BONDING SPECIES COULD BE IDENTIFIED. IR-FT STUDIES OF LEU-ENKEPHALIN IN H2O HAVE SHOWN THAT TYROSINE PHENOL GROUP IS DIHYDRATED AND NOT INTRAMOLECULARLY HYDROGEN BONDED.

Grantor dc:publisher

Πανεπιστήμιο Ιωαννίνων

Year dc:date

1990

Author dc:creator

• Μπιρλιράκης, Νικόλαος

• CONFORMATION OF PEPTIDES
• ENKEPHALINS
• HYDRATION OF PEPTIDES
• Hydrogen bonding
• Infrared spectroscopy
• Nuclear magnetic resonance spectroscopy
• Peptides synthesis
• SELECTIVE ISOTOPIC ENRICHEMENT
• Δεσμοί υδρογόνου
• ΔΙΑΜΟΡΦΩΣΗ ΤΩΝ ΠΕΠΤΙΔΙΩΝ
• ΕΓΚΕΦΑΛΙΝΕΣ
• ΕΚΛΕΚΤΙΚΟΣ ΙΣΟΤΟΠΙΚΟΣ ΕΜΠΛΟΥΤΙΣΜΟΣ
• ΕΝΥΔΑΤΩΣΗ ΤΩΝ ΠΕΠΤΙΔΙΩΝ
• Πεπτιδική σύνθεση
• Φασματοσκοπία πυρηνικού μαγνητικού συντονισμού
• Φασματοσκοπία υπερύθρου
• Φυσικές Επιστήμες
• Natural Sciences
• Χημεία
• Chemical Sciences

Language dc:language

gre

Identifier

10.12681/eadd/1502

OAI identifier oai:identifier

oai:10442/1502