In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 71, No. 6 ( 1974-06), p. 2280-2284
Abstract:
The lipid binding properties of the membrane protein cytochrome b 5 (detergent-extracted from calf liver microsomal preparations) were characterized by studying the interaction of spin-labeled lipids (5-, 12-, and 16-doxylstearic acid and 5- and 16-doxylphosphatidyl-choline, where doxyl refers to the nitroxide moiety) with cytochrome b 5 , using electron spin resonance spectroscopy. The intact cytochrome b 5 molecule immobilizes all of the lipid spin labels, while the segment of cytochrome b 5 released by trypsin does not affect lipid mobility. The immobilization of lipid spin labels on the hydrophobic surface of intact cytochrome b 5 is not appreciably altered by associating the protein with liposomes. Differences in polarity of the lipid binding sites between cytochrome b 5 and phospholipid vesicles were also observed. The lipid binding sites on cytochrome b 5 are hydrophobic by conventional criteria, but are more polar than the interior of fluid phospholipid bilayers.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.71.6.2280
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
1974
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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