Time-resolved fluorescence observation of di-tyrosine formation in horseradish peroxidase upon ultrasound treatment leading to enzyme inactivation.
The application of ultrasound to a solution can induce cavitional phenomena and generate high localised temperatures and pressures. These are dependent of the frequency used and have enabled ultrasound application in areas such as synthetic, green and food chemistry. High frequency (100kHz to 1MHz) in particular is promising in food chemistry as a means to inactivate enzymes, replacing the need to use periods of high temperature. A plant enzyme, horseradish peroxidase, was studied using time-resolved fluorescence techniques as a means to assess the effect of high frequency (378kHz and 583kHz) ultrasound treatment at equivalent acoustic powers. This uncovered the fluorescence emission from a newly formed species, attributed to the formation of di-tyrosine within the horseradish peroxidase structure caused by auto-oxidation, and linked to enzyme inactivation.
Division of Food & Drink, School of Science, Engineering and Technology, University of Abertay Dundee, Bell Street, Dundee DD1 1HG, UK.
Konstantina
K
Tsikrika
Division of Food & Drink, School of Science, Engineering and Technology, University of Abertay Dundee, Bell Street, Dundee DD1 1HG, UK.
M Adília
MA
Lemos
Division of Food & Drink, School of Science, Engineering and Technology, University of Abertay Dundee, Bell Street, Dundee DD1 1HG, UK.
Boon-Seang
BS
Chu
Division of Science, School of Science, Engineering and Technology, University of Abertay Dundee, Bell Street, Dundee DD1 1HG, UK.
David H
DH
Bremner
HORIBA Jobin-Yvon IBH Ltd, 133 Finnieston Street, Glasgow G3 8HB, UK. Electronic address: graham.hungerford@horiba.com.
Graham
G
Hungerford
D004789:Enzyme Activation; D006735:Horseradish Peroxidase / Q000737:chemistry* / Q000378:metabolism; D011489:Protein Denaturation; D012997:Solvents / Q000737:chemistry; D013010:Sonication; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014443:Tyrosine / Q000737:chemistry*; D014465:Ultrasonics / Q000379:methods*
D012997:Solvents; D014443:Tyrosine; D006735:Horseradish Peroxidase
Decay associated spectra; Excitation-emission matrix; High frequency ultrasound; Metal catalysed oxidation; Time-resolved emission spectrum