Effect of juxtamembrane tryptophans on the immersion depth of Synaptobrevin, an integral vesicle membrane protein

被引:9
作者
Al-Abdul-Wahid, M. Sameer [2 ]
DeMill, Colin M. [1 ]
Serwin, Marzena B. [1 ]
Prosser, R. Scott [2 ,3 ]
Stewart, Bryan A. [1 ]
机构
[1] Univ Toronto, Dept Biol, Mississauga, ON L5L 1C6, Canada
[2] Univ Toronto, Dept Chem, Mississauga, ON L5L 1C6, Canada
[3] Univ Toronto, Dept Biochem, Toronto, ON M5S 1A8, Canada
来源
BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES | 2012年 / 1818卷 / 12期
关键词
Neuronal-Synaptobrevin; Membrane protein positioning; Paramagnetic contact shifts; F-19; NMR; Solvent-induced isotope shifts; Solution state NMR of membrane proteins; SNARE COMPLEX; SYNAPTIC EXOCYTOSIS; NEUROTRANSMITTER RELEASE; PROXIMAL REGION; LIPID-BINDING; RAT-BRAIN; FUSION; GENES; DROSOPHILA; RESIDUES;
D O I
10.1016/j.bbamem.2012.07.018
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
Proper positioning of membrane proteins in the host membrane is often critical to successful protein function. While hydrophobic considerations play a dominant role in determining the topology of a protein in the membrane, amphiphilic residues, such as tiyptophan, may 'anchor' the protein near the water-membrane interface. The SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) family of membrane proteins mediates intracellular membrane fusion. Correct positioning of the SNAREs is necessary if fusion is to occur. Synaptobrevins are integral vesicle membrane proteins that are well conserved across species. Interestingly, mammalian Synaptobrevins typically contain two adjacent tryptophans near the water-membrane interface whereas the Drosophila, neuronal-Synaptobrevin (n-Syb), contains a single tryptophan in this same region. To explore the role of these tryptophan residues in membrane positioning, we prepared a peptide containing residues 75-121 of D. melanogaster n-Syb in DPC micelles, biosynthetically labeled with 4-fluorophenylalanine and 5-fluorotryptophan for the examination by F-19 NMR spectroscopy. Mutations of this construct containing zero and two tryptophan residues near the water-membrane interface resulted in changes in the positioning of n-Syb in the micelle. Moreover, the addition of a second tryptophan appears to slow dynamic motions of n-Syb near the micelle-water interface. These data therefore indicate that juxtamembrane tryptophan residues are important determinants of the position of Synaptobrevin in the membrane. (C) 2012 Elsevier B.V. All rights reserved.
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页码:2994 / 2999
页数:6
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