Department of Human Biology
UCT/MRC RESEARCH UNIT FOR EXERCISE SCIENCE & SPORTS MEDICINE
Faculty of Health Sciences, University of Cape Town
Private Bag, Rondebosch 7700, South Africa
Tel: + 27-21-650-4561 Fax: + 27-21-686-7530
2 April 2013
Dear Staff and Postgraduate Students
CALL FOR ABSTRACTS: CLINICAL LABORATORY SCIENCES AND HUMAN
BIOLOGY RESEARCH DAY 2013
The Departments of Clinical Laboratory Sciences and Human Biology invite all MSc.
PhD, MMed and MPhil students to present their research at our Research Day:
Date:
Venue:
4 September 2013
LT1 New Learning Centre, Anatomy Building.
A number of prizes for the best oral and poster presentations as well as the Lafras
Steyn prize for innovation will be awarded.
Attached is an abstract submission form (and a sample abstract) which should be
completed and submitted via email to hub-sportsinfo@uct.ac.za by no later than
Monday 1 July 2013. Successful applicants will be notified via email by Friday 2
August 2013 whether their abstracts have been accepted for oral or poster
presentation.
All enquiries to be addressed to Debbie.Victor@uct.ac.za or telephone 021-406 6757
Yours sincerely
Prof Malcolm Collins
CHAIRPERSON: ORGANISING COMMITTEE
Phone: 021-650 4574
e-mail: malcolm.collins@uct.ac.za
_______________________________________________________________________
The University of Cape Town is committed to policies of equal opportunity and affirmative action
which are essential to its mission of promoting critical inquiry and scholarship
RESEARCH DAY 2013
DEPARTMENTS OF CLINICAL LABORATORY SCIENCES
AND HUMAN BIOLOGY
4 SEPTEMBER 2013
LT1 LEARNING CENTRE, ANATOMY BUILDING, MEDICAL SCHOOL
REGISTRATION AND ABSTRACT SUBMISSION FORM
First name:
Surname:
Division and Department:
Indicate status (tick)
MBChB
M.Phil
M.Sc.
M.Med.
Ph.D.
E-mail address:
I am applying to present my research as (indicate preference with a tick):
Oral:
Poster:
If your preference is not granted tick whether the alternative choice is acceptable
Instructions for Abstract: (see example on next page)
 Body length should be NO MORE than 250 words in 11 pt Ariel font and single
spaced.
 Full title of the presentation (IN BOLD CAPITALS)
 Authors and co-authors, with the name of the presenting student bold and
underlined. Affiliation of authors (e.g. UCT Division or Dept. name; if co-author from
another institution then name of Institution and country (but full address not required)
 A brief description of the work including:
a)
b)
c)
d)
e)

The background to the project
The aims and objectives
A statement concerning the methods used
The main results/findings
Brief discussion leading to conclusion(s)
The abstract must not include references, tables or figures, nor abbreviations, except
for standard abbreviations (e.g DNA, EDTA, PCR, amino acid codes etc.) or if defined
in the body of the abstract.
Abstracts not formatted according to the guidelines will be returned
CHARACTERISATION OF THE FLAVIN ADENOSINE DINUCLEOTIDE BINDING REGION
OF MYXOCOCCUS XANTHUS PROTOPORPHYRINOGEN OXIDASE
CLS Studenta, AV Corrigallb, MED Technicianb, ED Sturrocka, UK Collaboratorc, PN
Meissnera,b
a
Division of Medical Biochemistry & IIDMM
Porphyria Laboratories, Dept. of Medicine
c
University of Cardiff, UK
b
Protoporphyrinogen oxidase (PPOX) catalyzes the six electron oxidation of
protoporphyrinogen to protoporphyrin in haem biosynthesis. FAD is the intermediate electron
acceptor and is non-covalently bound to PPOX. The FAD-binding site displays a 50-residue
long signature motif typical of FAD-oxidases. In humans, mutations in PPOX may lead to
variegate porphyria (VP), and the aim of this study was to rationalize potential VP-causing
mutations, especially the common Arg59Trp located in the FAD-substrate interface. Based
on previous studies, and structural and alignment analyses, we investigated the roles of M.
xanthus PPOX residues Glu39, Trp408 and Asn441 using site-directed mutagenesis followed
by expression, purification and kinetic analysis.
Alteration of Glu39 to lysine and alanine resulted in an inactive enzyme while a conservative
replacement (Glu39Asp) led to a more efficient enzyme. All Glu39 mutants bound FAD,
except Glu39Lys. Removal of the aromatic ring in Trp408Leu led to a decrease in efficacy;
and replacement of the aromatic, non-polar side chain with a polar aromatic resulted in an
increased Km and 10-fold less efficient enzyme. Alteration of Asn441 to isoleucine resulted in
a lower enzyme efficiency. All Trp408 and Asn441 mutants bound FAD.
We conclude that the Glu39 interaction with FAD is vital, and that both Trp408 and Asn441
play roles in the FAD’s overall orientation. Specifically, the aromatic, non-polar Trp408
interaction with FAD is favoured for optimum binding of substrate and the Asn441 interaction
with the ribityl group of the FAD is pivotal for the alignment of the triple ring with substrate.