Bcl-XL is a membrane-associated protein that inhibits programmed cell death
(apoptosis) in mammalian cells. Very little is known about the membrane topology of
Bel-XL or how its association with membranes contributes to its function. It was the aim
of this thesis to use fluorescence spectroscopy to investigate the location of a specific
amino acid ofBcl-XL relative to the membrane.
Bel-XL purified from E. coli could bind both to large unilamellar vesicles and
endoplasmic reticulum (ER) microsomes isolated from canine pancreas. A cysteine
residue at position 151 in Bcl-XL could be covalently labelled with the environmentally
sensitive fluorescent molecule NBD. Emission intensity measurements in the presence
and absence of membranes, combined with aqueous and lipophilic quenching
experiments, indicate that Cys 151 is inserted into the interior of the membrane bilayer
when Bcl-XL is bound to membranes. The methods outlined in this thesis form the basis
for an experimental system that can be used to determine the membrane topology ofBclXL
under a variety of conditions. / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/22686 |
| Date | 10 1900 |
| Creators | Atkinson, Helen A. |
| Contributors | Andrews, David W., Biochemistry |
| Source Sets | McMaster University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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