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Volume 5, Issue 3(Suppl) Biochem Anal Biochem 2016
ISSN: 2161-1009, Biochem an open access journal
Page 41
Notes:
Biochemistry 2016
October 10-12, 2016
conferenceseries.com
Biochemistry
October 10-12, 2016 Kuala Lumpur, Malaysia
International Conference on
Controlling the conformation of a modified gramicidin S cyclic peptidomimetic with an azobenzene
photo-switch
John Horsley, Yuan Qi Yeoh, Jingxian Yu and Andrew Abell
University of Adelaide, Australia
Secondary structures in proteins contain motifs which are important in determining protein folding and arrangement. The unique
folding pattern creates a well-defined structure of protein which governs the function, as emphasized by the quote structure
dictates function. Thus, the ability to control the secondary structure of a protein will enable the regulation of protein activity and
function. The main objective of this research is to reversibly control the secondary structure of a cyclic peptide photochemically,
using UV and visible light. This is demonstrated by incorporating a cis-trans photoisomerizable azobenzene photo-switch into the
naturally occurring antibiotic, gramicidin S, to produce a cyclic peptidomimetic, azobenzene-gramicidin S (Azo-GS). Gramicidin
S exists as a cyclic peptide with two antiparallel β-strands, linked by two β-turns. The cis isomer of Azo-GS was found to adopt a
β-sheet with a β-turn structure, while the trans isomer exists as a random structure. While gramicidin S is active against both Gram-
positive and Gram negative bacteria, our experimental results showed that Azo-GS is only active against Gram positive bacteria. Both
isomers of Azo-GS were tested against the Gram positive bacteria, Staphylococcus aureus and the Gram negative bacteria, Escherichia
coli, respectively. The cis isomer, containing the more well-defined secondary structure, was found to be active in suppressing the
growth of S. aureus, while the trans isomer was found to be inactive. The findings of this research form the basis for photo-switches to
function as potential molecular switches to control the secondary structures and ultimately, the activity of peptides.
Biography
John Horsley has completed his PhD from the University of Adelaide and currently undertaking Post-doctoral studies from the University of Adelaide, Australia. He is working
with the Abell Group focusing on peptide synthesis and has published number of papers in the reputed scientific journals.
John Horsley et al., Biochem Anal Biochem 2016, 5:3(Suppl)