Watching proteins fold one molecule at a time

被引:272
作者
Rhoades, E
Gussakovsky, E
Haran, G [1 ]
机构
[1] Weizmann Inst Sci, Dept Chem Phys, IL-76100 Rehovot, Israel
[2] Bar Ilan Univ, Dept Life Sci, IL-52900 Ramat Gan, Israel
关键词
D O I
10.1073/pnas.2628068100
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Recent theoretical work suggests that protein folding involves an ensemble of pathways on a rugged energy landscape. We provide direct evidence for heterogeneous folding pathways from single-molecule studies, facilitated by a recently developed immobilization technique. Individual fluorophore-labeled molecules of the protein adenylate kinase were trapped within surf ace-tethered lipid vesicles, thereby allowing spatial restriction without inducing any spurious interactions with the environment, which often occur when using direct surface-linking techniques. The conformational fluctuations of these protein molecules, prepared at the thermodynamic midtransition point, were studied by using fluorescence resonance energy transfer between two specifically attached labels. Folding and unfolding transitions appeared in experimental time traces as correlated steps in donor and acceptor fluorescence intensity. The size of the steps, in fluorescence resonance energy transfer efficiency units, shows a very broad distribution. This distribution peaks at a relatively low value, indicating a preference for small-step motion on the energy landscape. The time scale of the transitions is also distributed, and although many transitions are too fast to be time-resolved here, the slowest ones may take >1 sec to complete. These extremely slow changes during the folding of single molecules highlight the possible importance of correlated, non-Markovian conformational dynamics.
引用
收藏
页码:3197 / 3202
页数:6
相关论文
共 33 条
[1]   KINETICS OF FORMATION OF NATIVE RIBONUCLEASE DURING OXIDATION OF REDUCED POLYPEPTIDE CHAIN [J].
ANFINSEN, CB ;
HABER, E ;
SELA, M ;
WHITE, FH .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1961, 47 (09) :1309-+
[2]  
[Anonymous], 1999, RESONANCE ENERGY TRA
[3]  
Bicout DJ, 2000, PROTEIN SCI, V9, P452
[4]   Immobilization in surface-tethered lipid vesicles as a new tool for single biomolecule spectroscopy [J].
Boukobza, E ;
Sonnenfeld, A ;
Haran, G .
JOURNAL OF PHYSICAL CHEMISTRY B, 2001, 105 (48) :12165-12170
[5]  
Chan HS, 1998, PROTEINS, V30, P2, DOI 10.1002/(SICI)1097-0134(19980101)30:1<2::AID-PROT2>3.0.CO
[6]  
2-R
[7]   FORWARD-BACKWARD NONLINEAR FILTERING TECHNIQUE FOR EXTRACTING SMALL BIOLOGICAL SIGNALS FROM NOISE [J].
CHUNG, SH ;
KENNEDY, RA .
JOURNAL OF NEUROSCIENCE METHODS, 1991, 40 (01) :71-86
[8]   Single-molecule protein folding: Diffusion fluorescence resonance energy transfer studies of the denaturation of chymotrypsin inhibitor 2 [J].
Deniz, AA ;
Laurence, TA ;
Beligere, GS ;
Dahan, M ;
Martin, AB ;
Chemla, DS ;
Dawson, PE ;
Schultz, PG ;
Weiss, S .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2000, 97 (10) :5179-5184
[9]   From Levinthal to pathways to funnels [J].
Dill, KA ;
Chan, HS .
NATURE STRUCTURAL BIOLOGY, 1997, 4 (01) :10-19
[10]   Multiple pathways on a protein-folding energy landscape: Kinetic evidence [J].
Goldbeck, RA ;
Thomas, YG ;
Chen, EF ;
Esquerra, RM ;
Kliger, DS .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1999, 96 (06) :2782-2787