PUBLICATION
Cytoplasmic Domain of Zebrafish Myelin Protein Zero: Adhesive Role Depends on {beta}-Conformation
- Authors
- Luo, X., Inouye, H., Gross, A.A., Hidalgo, M.M., Sharma, D., Lee, D., Avila, R.L., Salmona, M., and Kirschner, D.A.
- ID
- ZDB-PUB-070820-3
- Date
- 2007
- Source
- Biophysical journal 93(10): 3515-3528 (Journal)
- Registered Authors
- Kirschner, Daniel A.
- Keywords
- circular dichroism, lipids, membrane models, protein-protein interactions, teleost, x-ray diffraction
- MeSH Terms
-
- Amino Acid Sequence
- Animals
- Cytoplasm/metabolism
- Lipid Bilayers/chemistry
- Lipids/chemistry
- Models, Statistical
- Molecular Sequence Data
- Myelin P0 Protein/chemistry*
- Peptides/chemistry
- Protein Binding
- Protein Conformation
- Protein Structure, Secondary
- Protein Structure, Tertiary
- X-Ray Diffraction
- Zebrafish
- PubMed
- 17693467 Full text @ Biophys. J.
Citation
Luo, X., Inouye, H., Gross, A.A., Hidalgo, M.M., Sharma, D., Lee, D., Avila, R.L., Salmona, M., and Kirschner, D.A. (2007) Cytoplasmic Domain of Zebrafish Myelin Protein Zero: Adhesive Role Depends on {beta}-Conformation. Biophysical journal. 93(10):3515-3528.
Abstract
Solution spectroscopy studies on the cytoplasmic domain of human myelin P0 (hP0-cyt) suggest that H-bonding between beta-strands from apposed molecules is likely responsible for the tight cytoplasmic apposition in compact myelin. As a follow-up to these findings, in the current study we used circular dichroism and x-ray diffraction to analyze the same type of model membranes previously used for hP0-cyt to investigate the molecular mechanism underlying the zebrafish cytoplasmic apposition. This space is significantly narrower in teleosts compared with that in higher vertebrates, and can be accounted for in part by the much shorter cytoplasmic domain in zebrafish (zP0-cyt). CD measurements on zP0-cyt showed similar structural characteristics as those of hP0-cyt, i.e., the protein underwent a beta-->alpha structural transitions at lipid/protein (L/P) molar ratios >50, and adopted a beta-conformation at lower L/P molar ratios. X-ray diffraction was carried out on lipid vesicle solutions with zP0-cyt before and after dehydration to study the effect of protein on membrane lipid packing. Solution diffraction revealed the typical electron density profile for a single membrane bilayer. Diffraction patterns of dried samples suggested a multilamellar structure with the beta-folded P0-cyt located at the inter-membrane space. Our findings support the idea that the adhesive role of P0 at the cytoplasmic apposition in compact myelin depends on the cytoplasmic domain of P0 being in the beta-conformation.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping