Topography of the membrane-binding domain of cytochrome b sub 5 in lipids by Fourier-transform infrared spectroscopy

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00493a018· OSTI ID:5615060

Holloway, P W; Buchheit, C ^[1]

---

1. Univ. of Virginia School of Medicine, Charlottesville (USA)

Fourier-transform infrared spectroscopy was used to examine the secondary structure of the membrane-binding domain (nonpolar peptide) of rabbit liver cytochrome b{sub 5} in D{sub 2}O and in the presence of phospholipids and deoxycholate. In all situations, the predominant structure was {alpha} helix, but an examination of the components of the amide I band in the spectrum of the nonpolar peptide showed that the major peak was shifted from 1655 cm{sup {minus}1} in the lipids to 1650 cm{sup {minus}1} in deoxycholate. This shift to lower frequency, together with a decrease in intensity of the amide II band, is indicative of N-H to N-D exchange of the peptide backbone. A semiquantitative analysis indicated that the {alpha} helix of the peptide is over 95% exchanged in the presence of deoxycholate but is only 10% exchanged in the presence of lipid. These data suggest that the membrane-inserted portion of the peptide is {alpha} helical and is largely protected from N-H to N-D exchange by the bilayer. The authors suggest that this technique appears to provide a general method for determining the type of secondary structure involved in membrane interaction and the percentage of this structure which is involved in the interaction.

• OSTI ID: 5615060
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:41; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BODY
CELL CONSTITUENTS
CELL MEMBRANES
CYTOCHROMES
DIGESTIVE SYSTEM
FOURIER TRANSFORMATION
GLANDS
HEAVY WATER
HYDROGEN COMPOUNDS
INFRARED SPECTRA
INTEGRAL TRANSFORMATIONS
LIVER
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
ORGANIC COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PIGMENTS
PROTEINS
RABBITS
SPECTRA
TOPOGRAPHY
TRANSFORMATIONS
VERTEBRATES
WATER