Dean of Postgraduate Research
Vice-Chancellor’s Office
Extension: 7285
Email:
lucy.johnston@canterbury.ac.nz
Summer Research Scholarship Scheme
2015-2016
Project Application Form
Please complete and submit the application form as a WORD document and send to
summerscholarships@canterbury.ac.nz
The Project
Title of Project (max 30 words):
Measurement of urinary dityrosine as a quantitative marker of oxidative stress in patients.
Project Leader(s): A/Prof Steven Gieseg
Host Department/Organization:
School of Biological Sciences, University of Canterbury.
Other persons involved in this topic/activity:
Name
Affiliation to project
Dr Angus Lindsay
Assistant Supervisor, School of Sport &
Physical Education.
Dr Carl Peterson
Collaborator on exercise component of
project, School of Sport & Physical
Education
Dr Geoff Shaw
Collaborator on clinical part of project.
Christchurch Hospital and Dept. Mech. Eng.
Brief outline of project
Physical trauma, surgery, disease and strenuous activity (exercise) all cause increased
levels of oxidative stress within the body. The methods available to measure clinically
relevant levels of the resulting oxidative damage involve either long assay times or costly
reagents. This projects sets out to develop a rapid urine based assay to measure dityrosine,
a key oxidation product of tyrosine. Dityrosine forms when free radicals cause two tyrosine
amino acids to be covalently bond together. As dityrosine is very stable it can only be
removed from the body by degradation of the protein and excreting the resulting free
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dityrosine in the urine. As dityrosine is highly fluorescent it can be detected by high
performance liquid chromatography (HPLC) using fluorescent detection after extensive
processing of the urine. The level of protein bound and free dityrosine has been shown to
increase in a range of oxidative conditions in both in vitro and in vivo studies.
Our laboratory has considerable experience measuring dityrosine formation in a range of
oxidised proteins. The assay requires acid degradation of the proteins to release the free
dityrosine before the HPLC analysis. We have measured protein bound dityrosine formation
in; proteins exposed to radiation generated free radicals, macrophages cells treated with
peroxyl radicals and oxidised cholesterol particles (oxLDL). We now wish to develop the
procedure further to directly measure free dityrosine in the urine of volunteers and patients
experiencing increased levels of oxidative stress.
Published urinary dityrosine assays describe the use of complex clean up procedures of the
urine before injection into HPLC or HPLC-mass spectrometry detectors. These methods are
both time consuming, expense and require considerable skill from the researcher. Our
previous experience developing urine based assays to measure inflammation markers 7,8dihydroneopterin/neopterin, and the muscle damage marker myoglobin, suggests that we
can develop a similar procedure for the measurement of urinary dityrosine.
The assay will be initial developed using urine to which known amounts of dityrosine are
added. The assay will then be used to measure dityrosine levels from volunteers who
completed an exercise study earlier in the year. If this is successful the study will move to
analysing urine from patients at Christchurch Hospital Intensive Care Unit.
Measurement of dityrosine will provide clinicians and researchers new information on
patients’ oxidative stress levels during medical procedures. This technology could also be
applied to the health/sports arena to monitor players oxidative stress levels during sporting
events.
If the project involves work away from the University campus (e.g., at fieldwork sites) please detail all locations.
The research will be conducted within the Free Radical Biochemistry Laboratory in the
School of Biological Sciences. Samples may be collected from the hospital ICU.
If the student be required to work outside of normal university hours (8am-5pm) please provide details
It is possible that the analytic equipment will need to be serviced in the evening depending
on the number of samples. The student would be given after hours access to the laboratory.
Benefits student will gain from involvement in the project
Describe the research experience and skills that the student will acquire through involvement in this research project –
maximum of 100 words.
The student will learn how to operate an analytical chromatography machine and handle
clinical samples. They will be part of a multidiscipline group of postgraduates and
researchers. They will have the opportunity to interact with medical staff and learn how to
carry out clinical research and development. The laboratory has extensive experience in the
development of HPLC methods with links to industry.
Specific student requirements
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Please provide details of all requirements you have for the student to work on this project – for example, if specific
courses/experience are necessary.
The student should have experience in either physiology, biochemistry or organic chemistry
to a third year level.
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