Chirality and helix stability of polyglutamic acid enantiomers
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Ημερομηνία
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
J Colloid Interface Sci
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
In this work the chirality and the relative thermal stability of ordered micellar aggregates of poly-L- and poly-D-glutamic acids with the cationic surfactant C(14)TAB is examined. The complexed mesophases poly-L-Glu/C(14)TAB and poly-D-Glu/C-14 TAB were characterized by circular dichroism (CD) in the temperature range 10-70 degrees C for their chirality and thermal stability as well as by X-ray diffraction (XRD) for the micellar ordered structure. Low angle XRD analysis showed that both micellar aggregates poly-L-Glu/C(14)TAB and poly-D-Glu/C(14)TAB are hexagonally packed in a MCM-41 fashion with an intermicellar distance identical and equal to 3.55 +/- 0.10 nm. The CID spectra indicated that both complexes poly-L-Glu/C(14)TAB and poly-D-Glu/C(14)TAB possess a mainly alpha-helix structure and are exact mirror images to each other. The same mirror images and a mainly a-helix configuration were also observed by CID for the free poly-L- and poly-D-glutamic acids at room temperature. As the temperature increases from 10 up to 70 degrees C the ce-helix of the poly-L-glutamic acid is gradually transformed to a mixture containing increased amounts of the 3(10)-helix while the alpha-helix structure of the poly-D-glutamic acid is constantly degenerated. In contrast the alpha-helices of the corresponding complexes poly-L-Glu/C(14)TAB and poly-D-Glu/C(14)TAB are degenerated upon heating without appreciable increase of the 3(10)-helices as an intermediate configuration. This difference in helix conservation is attributed to increase protection of the L-enantiomers, compared to D-enantiomers, which might be related to the survival of L-aminoacids in the living world. (c) 2007 Elsevier Inc. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
ordered micellar aggregates, poly-l-glutamic acid, poly-d-glutamic acid, c(14)tab, thermal stability, chirality, amino-acids, mesoporous silica, amphipathic peptides, racemic mixtures, alpha-helix, proteins, water, transition, design, conformation
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000252750400011
http://ac.els-cdn.com/S0021979707016098/1-s2.0-S0021979707016098-main.pdf?_tid=996fa3fd02ec66aef7ece443fbd22d65&acdnat=1333036361_8b537f9caa843d7030110687b21f77f8
http://ac.els-cdn.com/S0021979707016098/1-s2.0-S0021979707016098-main.pdf?_tid=996fa3fd02ec66aef7ece443fbd22d65&acdnat=1333036361_8b537f9caa843d7030110687b21f77f8
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας