SOLID-STATE NUCLEAR-MAGNETIC-RESONANCE DERIVED MODEL FOR DYNAMICS IN THE POLYPEPTIDE BACKBONE OF THE GRAMICIDIN-A CHANNEL

被引:44
作者
NICHOLSON, LK [1 ]
TENG, Q [1 ]
CROSS, TA [1 ]
机构
[1] FLORIDA STATE UNIV,INST MOLEC BIOPHYS,TALLAHASSEE,FL 32306
关键词
D O I
10.1016/0022-2836(91)90706-C
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
The dynamics of the backbone of the gramicidin A transmembrane cation channel in dimyristoylphosphatidylcholine bilayers have been investigated using solid state 15N nuclear magnetic resonance (n.m.r.) spectroscopy. With the temperature-dependent fluidity of the bilayer, the rates of motions in the helical gramicidin channel can be modulated. It is shown that in the gel phase, all substantial motions of the channel are slow on the timescale of the n.m.r. experiment (3.5 kHz). The use of oriented samples in which the axis of global channel rotation is aligned parallel to the magnetic field enables separation of global and local dynamics. Spectra obtained from oriented bilayer samples containing single-site 15N-labeled gramicidin at 8 °C are analyzed to yield a spatial model for local backbone motion. This model includes the axis of motion, the mean orientation, and the maximum amplitude of displacement for individual peptide planes. Specific sites in the first turn of the amino terminus were investigated, with emphasis on the Ala3 and Leu4 linkages, for which the orientation of the 15N chemical shift tensor with respect to the molecular frame has been determined. The effect of two well-characterized bilayer defect structures, parabolic focal conics and oily streaks, is included in the spectral simulations. It is found that only relatively small amplitude motions are possible at the two sites, with amplitudes of not more than ±8 ° and ±15 ° for the Ala3 and Leu4 sites, respectively. Detailed characterization of the bilayer surface geometry in the oriented samples is presently the major limiting factor in the use of this technique for probing the spatial extent of local motions in integral membrane proteins. © 1991.
引用
收藏
页码:621 / 637
页数:17
相关论文
共 49 条
[1]   ALIGNMENT AND DEFECT STRUCTURES IN ORIENTED PHOSPHATIDYLCHOLINE MULTILAYERS [J].
ASHER, SA ;
PERSHAN, PS .
BIOPHYSICAL JOURNAL, 1979, 27 (03) :393-421
[2]   PARABOLIC FOCAL CONICS AND POLYGONAL TEXTURES IN LIPID LIQUID-CRYSTALS [J].
ASHER, SA ;
PERSHAN, PS .
JOURNAL DE PHYSIQUE, 1979, 40 (02) :161-173
[3]   CHARACTERIZATION OF LEUCINE SIDE-CHAIN REORIENTATION IN COLLAGEN FIBRILS BY SOLID-STATE H-2 NMR [J].
BATCHELDER, LS ;
SULLIVAN, CE ;
JELINSKI, LW ;
TORCHIA, DA .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES, 1982, 79 (02) :386-389
[4]   INTERACTIONS OF HELICAL POLYPEPTIDE SEGMENTS WHICH SPAN HYDROCARBON REGION OF LIPID BILAYERS - STUDIES OF GRAMICIDIN ALIPID-WATER SYSTEM [J].
CHAPMAN, D ;
CORNELL, BA ;
ELIASZ, AW ;
PERRY, A .
JOURNAL OF MOLECULAR BIOLOGY, 1977, 113 (03) :517-538
[5]   WATER AND POLYPEPTIDE CONFORMATIONS IN THE GRAMICIDIN CHANNEL - A MOLECULAR-DYNAMICS STUDY [J].
CHIU, SW ;
SUBRAMANIAM, S ;
JAKOBSSON, E ;
MCCAMMON, JA .
BIOPHYSICAL JOURNAL, 1989, 56 (02) :253-261
[6]  
CHIU SW, 1991, IN PRESS BIOPHYS J
[7]   CONFORMATION AND ORIENTATION OF GRAMICIDIN-A IN ORIENTED PHOSPHOLIPID-BILAYERS MEASURED BY SOLID-STATE C-13 NMR [J].
CORNELL, BA ;
SEPAROVIC, F ;
BALDASSI, AJ ;
SMITH, R .
BIOPHYSICAL JOURNAL, 1988, 53 (01) :67-76
[8]   PROTEIN DYNAMICS BY SOLID-STATE NUCLEAR MAGNETIC-RESONANCE SPECTROSCOPY - PEPTIDE BACKBONE OF THE COAT PROTEIN IN FD BACTERIOPHAGE [J].
CROSS, TA ;
OPELLA, SJ .
JOURNAL OF MOLECULAR BIOLOGY, 1982, 159 (03) :543-549
[9]   DEUTERIUM NUCLEAR-MAGNETIC-RESONANCE INVESTIGATION OF THE EXCHANGEABLE SITES ON GRAMICIDIN-A AND GRAMICIDIN-S IN MULTILAMELLAR VESICLES OF DIPALMITOYLPHOSPHATIDYLCHOLINE [J].
DATEMA, KP ;
PAULS, KP ;
BLOOM, M .
BIOCHEMISTRY, 1986, 25 (13) :3796-3803
[10]  
FIELDS CG, 1989, INT J PEPT PROT RES, V33, P298