An NMR investigation of the conformational effect of nitroxide spin labels on Ala-rich helical peptides

被引:18
作者
Bolin, KA [1 ]
Hanson, P [1 ]
Wright, SJ [1 ]
Millhauser, GL [1 ]
机构
[1] Univ Calif Santa Cruz, Dept Chem & Biochem, Santa Cruz, CA 95064 USA
关键词
D O I
10.1006/jmre.1998.1365
中图分类号
Q5 [生物化学];
学科分类号
071010 ; 081704 ;
摘要
Nitroxide spin labels, in conjunction with electron spin resonance (ESR) experiments, are extensively employed to probe the structure and dynamics of biomolecules. One of the most ubiquitous spin labeling reagents is the methanethiosulfonate spin label which attaches a spin label selectively to Cys residues via a disulfide bond (Cys-SL). However, the actual effect of the nitroxide spin label upon the conformation of the peptide or protein cannot be unambiguously determined by ESR. In this study, a series of 16-residue Ala-rich helical peptides was characterized by nuclear magnetic resonance techniques. The C alpha H chemical shift analysis, NOEs, and (3)J(NH alpha) coupling constants for peptides with no Cys, free Cys, and Cys-SL (with the N-O group reduced) were compared. These results indicate that while replacement of an Ala with a Cys residue causes a loss of overall helical structure, the Cys-SL residue is helix supporting, as would be expected for a non-beta-branched aliphatic amino acid. Thus, the Cys-SL residue does not perturb helical structure and, instead, exhibits helix-stabilizing characteristics similar to that found for Ala, Met, and Leu. (C) 1999 Academic Press.
引用
收藏
页码:248 / 253
页数:6
相关论文
共 27 条
[1]   STRUCTURAL STUDIES ON TRANSMEMBRANE PROTEINS .2. SPIN LABELING OF BACTERIORHODOPSIN MUTANTS AT UNIQUE CYSTEINES [J].
ALTENBACH, C ;
FLITSCH, SL ;
KHORANA, HG ;
HUBBELL, WL .
BIOCHEMISTRY, 1989, 28 (19) :7806-7812
[2]   Membrane structure of voltage-gated channel forming peptides by site-directed spin-labeling [J].
BarrangerMathys, M ;
Cafiso, DS .
BIOCHEMISTRY, 1996, 35 (02) :498-505
[3]  
BARTELS C, 1995, J BIOMOL NMR, V5, P1
[4]   A NOVEL REVERSIBLE THIOL-SPECIFIC SPIN LABEL - PAPAIN ACTIVE-SITE LABELING AND INHIBITION [J].
BERLINER, LJ ;
GRUNWALD, J ;
HANKOVSZKY, HO ;
HIDEG, K .
ANALYTICAL BIOCHEMISTRY, 1982, 119 (02) :450-455
[5]   LARGE DIFFERENCES IN THE HELIX PROPENSITIES OF ALANINE AND GLYCINE [J].
CHAKRABARTTY, A ;
SCHELLMAN, JA ;
BALDWIN, RL .
NATURE, 1991, 351 (6327) :586-588
[6]   A SINGLE CARBOXY-TERMINAL ARGININE DETERMINES THE AMINO-TERMINAL HELIX CONFORMATION OF AN ALANINE-BASED PEPTIDE [J].
FIORI, WR ;
LUNDBERG, KM ;
MILLHAUSER, GL .
NATURE STRUCTURAL BIOLOGY, 1994, 1 (06) :374-377
[7]   INCREASING SEQUENCE LENGTH FAVORS ALPHA-HELIX OVER 3(10)-HELIX IN ALANINE-BASED PEPTIDES - EVIDENCE FOR A LENGTH-DEPENDENT STRUCTURAL TRANSITION [J].
FIORI, WR ;
MIICK, SM ;
MILLHAUSER, GL .
BIOCHEMISTRY, 1993, 32 (45) :11957-11962
[8]   INVESTIGATION OF STRUCTURE AND DYNAMICS IN MEMBRANE-PROTEINS USING SITE-DIRECTED SPIN-LABELING [J].
HUBBELL, WL ;
ALTENBACH, C .
CURRENT OPINION IN STRUCTURAL BIOLOGY, 1994, 4 (04) :566-573
[9]  
KALLENBACH NR, 1996, CIRCULAR DICHROISM C, pCH7
[10]   CONTACT ELECTRON-SPIN COUPLING OF NUCLEAR MAGNETIC MOMENTS [J].
KARPLUS, M .
JOURNAL OF CHEMICAL PHYSICS, 1959, 30 (01) :11-15