NMR Detected HydrogenDeuterium Exchange Reveals Differential Dynamics of Antibiotic and Nucleotide B

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NMR Detected Hydrogen-Deuterium Exchange Reveals
Differential Dynamics of Antibiotic and
Nucleotide Bound Aminoglycoside
Phosphotransferase 3'-IIIa
Adrianne Norris Department of Biochemistry,
Cellular and Molecular Biology Thesis Advisor
Dr. Engin Serpersu
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Introduction Aminoglycoside Antibiotics

• Broad spectrum
• Meningitis
• Tuberculosis
• Diverse size/structure

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Introduction Antibiotic Resistance

• Enzyme catalyzed covalent modification
• Aminoglycoside Phosphotransferase (3')-IIIa
  (APH)
• targets at least 10 different aminoglycosides of
  various size/structure

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Research Goals

• How is APH so promiscuous?
• How is APH affected when interacting with
  different antibiotics?

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No significant change in structure from apo to
antibiotic bound?
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NMR detected Hydrogen-Deuterium Exchange In
solution dynamics
Conclusion Flexibility of APH allows
modification of structurally diverse antibiotics.
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Nuclear Magnetic Resonance (NMR)
Suggests A flexible apo-enzyme is the secret!
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Kanamycin
Little change in XL structures of APH-neomycin
and APH-kanamycin complexes.
Neomycin
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NMR
Kanamycin Neomycin
gt 40 amino acids with different environments
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NMR Hydrogen-Deuterium Exchange
Neomycin induces greater solvent protection of
APH than kanamycin.
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Green Different Chemical Environment Yellow
Different Solvent Exchange Properties
Conclusion Neomycin Induces Greater
Structural/Dynamic Stability than Kanamycin
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• The broad substrate selectivity of APH is due to
  structural flexibility.
• Neomycin creates greater stability in APH than
  kanamycin

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Dr. Engin Serpersu Thesis advisor Dr. Dan
Roberts Dr. Nitin Jain Dr. David Baker Dr. Jeremy
Smith Can Ozen BCMB Department