Effects of ergosterol on the structure and activity of Neurospora mitochondrial porin in liposomes

被引:0
作者
Bay, Denice C. [1 ]
Court, Deborah A. [1 ]
机构
[1] Univ Manitoba, Dept Microbiol, Winnipeg, MB R3T 2N2, Canada
关键词
mitochondrial porin; VDAC; liposome; ergosterol; beta barrel; DEPENDENT ANION CHANNEL; MEMBRANE-PROTEIN VDAC; OUTER-MEMBRANE; BETA-BARREL; PHOSPHOLIPID-MEMBRANES; UNILAMELLAR VESICLES; CATALYZED INSERTION; CIRCULAR-DICHROISM; LIPID-COMPOSITION; INNER MEMBRANES;
D O I
10.1139/W09-088
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Mitochondrial porins (also known as voltage-dependent anion-selective channels (VDACs)) regulate and contribute to cellular metabolism. These proteins copurify with sterols, and some purified forms of the protein require sterol for insertion into planar artificial membranes. Recently, interactions between detergent-solubilized mitochondrial porins and sterols have been detected by NMR and spectroscopic methods, but the effects of sterols on pore function remained to be assessed. Therefore, in this work, a freeze-thaw technique was used to introduce recombinant Neurospora porin into liposomes containing, or lacking, the native fungal sterol ergosterol. In both types of liposomes, insertion of the protein converts it to a protease-resistant state and low levels of dimeric and trimeric forms are observed. There are only minor differences between the secondary structural components of the protein in the presence or absence of sterol. Ergosterol in proteoliposomes alters their osmotic responses to sucrose, possibly due to increased membrane rigidity or interactions with the protein that were not revealed by the methods used in this study. The presence of ergosterol is associated with an increased change in conformation and loss of function of liposome-embedded porin at high temperature. Taken with other evidence for direct interactions of sterols with porins, these results support a link between these two molecules in mitochondrial membrane activity.
引用
收藏
页码:1275 / 1283
页数:9
相关论文
共 42 条
[1]   Quantitation of ergosterol content:: Novel method for determination of fluconazole susceptibility of Candida albicans [J].
Arthington-Skaggs, BA ;
Jradi, H ;
Desai, T ;
Morrison, CJ .
JOURNAL OF CLINICAL MICROBIOLOGY, 1999, 37 (10) :3332-3337
[2]   TRANSPORT-PROPERTIES AND INHIBITOR SENSITIVITY OF ISOLATED AND RECONSTITUTED PORIN DIFFER FROM THOSE OF INTACT MITOCHONDRIA [J].
BATHORI, G ;
SAHINTOTH, M ;
FONYO, A ;
LIGETI, E .
BIOCHIMICA ET BIOPHYSICA ACTA, 1993, 1145 (01) :168-176
[3]   Two-step folding of recombinant mitochondrial porin in detergent [J].
Bay, Denice C. ;
O'Neil, Joe D. ;
Court, Deborah A. .
BIOPHYSICAL JOURNAL, 2008, 94 (02) :457-468
[4]   The influence of sterols on the conformation of recombinant mitochondrial porin in detergent [J].
Bay, Denice C. ;
O'Neil, Joe D. ;
Court, Deborah A. .
BIOCHEMISTRY AND CELL BIOLOGY, 2008, 86 (06) :539-545
[5]   Structure of the human voltage-dependent anion channel [J].
Bayrhuber, Monika ;
Meins, Thomas ;
Habeck, Michael ;
Becker, Stefan ;
Giller, Karin ;
Villinger, Saskia ;
Vonrhein, Clemens ;
Griesinger, Christian ;
Zweckstetter, Markus ;
Zeth, Kornelius .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2008, 105 (40) :15370-15375
[6]   PERMEATION OF HYDROPHILIC SOLUTES THROUGH MITOCHONDRIAL OUTER MEMBRANES - REVIEW ON MITOCHONDRIAL PORINS [J].
BENZ, R .
BIOCHIMICA ET BIOPHYSICA ACTA-REVIEWS ON BIOMEMBRANES, 1994, 1197 (02) :167-196
[7]  
Blachly-Dyson E, 2001, IUBMB LIFE, V52, P113
[8]   THE DISTRIBUTION OF CHOLESTEROL AND PHOSPHOLIPID-COMPOSITION IN SUBMITOCHONDRIAL MEMBRANES FROM BOVINE ADRENAL-CORTEX - FUNDAMENTAL-STUDIES OF STEROIDOGENIC MITOCHONDRIA [J].
CHENG, B ;
KIMURA, T .
LIPIDS, 1983, 18 (09) :577-584
[9]  
Colombini M, 1980, Ann N Y Acad Sci, V341, P552, DOI 10.1111/j.1749-6632.1980.tb47198.x
[10]   LIPID-COMPOSITION AND PROTEIN PROFILES OF OUTER AND INNER MEMBRANES FROM PIG HEART-MITOCHONDRIA - COMPARISON WITH MICROSOMES [J].
COMTE, J ;
MAISTERRENA, B ;
GAUTHERON, DC .
BIOCHIMICA ET BIOPHYSICA ACTA, 1976, 419 (02) :271-284