Lipid binding to the amphipathic membrane protein cytochrome b5
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Date
1974-06
Authors
Dehlinger, P. J.
Jost, P. C.
Griffith, O. H.
Journal Title
Journal ISSN
Volume Title
Publisher
Proceedings of the National Academy of Sciences
Abstract
ABSTRACT The lipid hinding properties of the membrane
protein cytochrome b:. (detergent-extracted from
calf liver microsomal preparations) were characterized by
studying the interaction of spin-labeled lipid,- (5-, 12-,
and 16-doxylstcaric acid and 5- and 16-cloxylphosphatidylcholine,
where cloxyl refers to the nitroxide moiety)
with cytochrome b :, using electron "pin resonance
spectroscopy. The intact cytochrome b, n1olec11lc immobilizes
all of the lipid spin label,;, while the segment of
cytochrome b, released by trypsin doei. not afTcct lipid
mobility. The immobilization of lipid spin label,-; on the
h) ·drophohic surface of intact cytochrome b:, is not appreciably
altered by associating the protein with liposomc"
· DHTcrcnccs in polarity of the lipid binding site"
between c, ·tochromc b, and phospholipid vc,.icles were also
ob,-cr\'ed. The lipid binding sites on cytochrome b.; arc
hydrophobic by conventional criteria, but arc more polar
than the interior of fluid phospholipid bilayers.
Description
6 pages
Keywords
Citation
Dehlinger, P. J., Jost, P. C. & Griffith, O. H. (1974) Lipid binding to the amphipathic membrane protein cytochrome b5. Proc. Natl. Acad. Sci. USA 71, 2280‑2284.