We present an effective method for estimating the motion of proteins from the motion of attached probe particles in single-molecule experiments. The framework naturally incorporates Langevin dynamics to compute the most probable trajectory of the protein. By using a perturbation expansion technique, we achieve computational costs more than 3 orders of magnitude smaller than the conventional gradient descent method without loss of simplicity in the computation algorithm. We present illustrative applications of the method using simple models of single-molecule experiments and confirm that the proposed method yields reasonable and stable estimates of the hidden motion in a highly efficient manner.

1.
K.
Svoboda
,
C. F.
Schmidt
,
B. J.
Schnapp
, and
S. M.
Block
,
Nature (London)
365
,
721
(
1993
).
2.
H.
Noji
,
R.
Yasuda
,
M.
Yoshida
, and
K.
Kinosita
, Jr.
,
Nature (London)
386
,
299
(
1997
).
3.
M.
Rief
,
R. S.
Rock
,
A. D.
Mehta
,
M. S.
Mooseker
,
R. E.
Cheney
, and
J. A.
Spudich
,
Proc. Natl. Acad. Sci. U.S.A.
97
,
9482
(
2000
).
4.
R.
Yasuda
,
H.
Noji
,
M.
Yoshida
,
K.
Kinosita
, Jr.
, and
H.
Itoh
,
Nature (London)
410
,
898
(
2001
).
5.
W. J.
Greenleaf
,
M. T.
Woodside
, and
S. M.
Block
,
Annu. Rev. Biophys. Biomol. Struct.
36
,
171
(
2007
).
6.
K.
Shiroguchi
and
K.
Kinosita
, Jr.
,
Science
316
,
1208
(
2007
).
7.
K.
Shiroguchi
,
H. F.
Chin
,
D. E.
Hannemann
,
E.
Muneyuki
,
E. M.
De La Cruz
, and
K.
Kinosita
, Jr.
,
PLoS Biol.
9
,
e1001031
(
2011
).
8.
H.
Ueno
,
S.
Nishikawa
,
R.
Iino
,
K. V.
Tabata
,
S.
Sakakihara
,
T.
Yanagida
, and
H.
Noji
,
Biophys. J.
98
,
2014
(
2010
).
9.
L.
Nugent-Glandorf
and
T. T.
Perkins
,
Opt. Lett.
29
,
2611
(
2004
).
10.
D. E.
Smith
,
S. J.
Tans
,
S. B.
Smith
,
S.
Grimes
,
D. L.
Anderson
, and
C.
Bustamante
,
Nature (London)
413
,
748
(
2001
).
11.
S.
Uemura
and
S.
Ishiwata
,
Nat. Struct. Biol.
4
,
308
(
2003
).
12.
H.
Itoh
,
A.
Takahashi
,
K.
Adachi
,
H.
Noji
,
R.
Yasuda
,
M.
Yoshida
, and
K.
Kinosita
, Jr.
,
Nature (London)
427
,
465
(
2004
).
13.
T.
Watanabe-Nakayama
,
S.
Toyabe
,
S.
Kudo
,
S.
Sugiyama
,
M.
Yoshida
, and
E.
Muneyuki
,
Biochem. Biophys. Res. Commun.
366
,
951
(
2008
).
14.
J.
Liphardt
,
S.
Dumont
,
S. B.
Smith
,
I.
Tinoco
, Jr.
, and
C.
Bustamante
,
Science
296
,
1832
(
2002
).
15.
S.
Toyabe
,
T.
Okamoto
,
T.
Watanabe-Nakayama
,
H.
Taketani
,
S.
Kudo
, and
E.
Muneyuki
,
Phys. Rev. Lett.
104
,
198103
(
2010
).
16.
E.
Geva
and
J. L.
Skinner
,
Chem. Phys. Lett.
288
,
225
(
1998
).
17.
A. M.
Berezhkovskii
,
A.
Szabo
, and
G. H.
Weiss
,
J. Phys. Chem. B
104
,
3776
(
2000
).
19.
J. B.
Witkoskie
and
J.
Cao
,
J. Chem. Phys.
121
,
6361
(
2004
a).
20.
O.
Flomenbom
,
J.
Klafter
, and
A.
Szabo
,
Biophys. J.
88
,
3780
(
2005
).
21.
I. V.
Gopich
and
A.
Szabo
,
J. Chem. Phys.
124
,
154712
(
2006
).
22.
J. B.
Witkoskie
and
J.
Cao
,
J. Chem. Phys.
121
,
6373
(
2004
b).
23.
J. B.
Witkoskie
and
J.
Cao
,
J. Phys. Chem. B
112
,
5988
(
2008
).
24.
A.
Baba
and
T.
Komatsuzaki
,
Proc. Natl. Acad. Sci. U.S.A.
104
,
19297
(
2007
).
25.
A.
Baba
and
T.
Komatsuzaki
,
Phys. Chem. Chem. Phys.
13
,
1395
(
2011
).
26.
S.
Chung
and
R.
Kennedy
,
J. Neurosci. Methods
40
,
71
(
1991
).
27.
X.
Nan
,
P. A.
Sims
,
P.
Chen
, and
X. S.
Xie
,
J. Phys. Chem. B
109
,
24220
(
2005
).
28.
J. W. J.
Kerssemakers
,
E. L.
Munteanu
,
L.
Laan
,
T. L.
Noetzel
,
M. E.
Janson
, and
M.
Dogterom
,
Nature (London)
442
,
709
(
2006
).
29.
B. C.
Carter
,
M.
Vershinin
, and
S. P.
Gross
,
Biophys. J.
94
,
306
(
2008
).
30.
B.
Bozorgui
,
K.
Shundyak
,
S.
Cox
, and
D.
Frenkel
,
Eur. Phys. J. E
31
,
411
(
2010
).
31.
C.
Dellago
,
P. G.
Bolhuis
,
F. S.
Csajka
, and
D.
Chandler
,
J. Chem. Phys.
108
,
1964
(
1998
).
32.
P. G.
Bolhuis
,
D.
Chandler
,
C.
Dellago
, and
P. L.
Geissler
,
Annu. Rev. Phys. Chem.
53
,
291
(
2002
).
33.
E.
Autieri
,
P.
Faccioli
,
M.
Sega
,
F.
Pederiva
, and
H.
Orland
,
J. Chem. Phys.
130
,
064106
(
2009
).
34.
P.
Faccioli
,
M.
Sega
,
F.
Pederiva
, and
H.
Orland
,
Phys. Rev. Lett.
97
,
108101
(
2006
).
35.
M.
Sega
,
P.
Faccioli
,
F.
Pederiva
,
G.
Garberoglio
, and
H.
Orland
,
Phys. Rev. Lett.
99
,
118102
(
2007
).
36.
M.
Miyazaki
and
T.
Harada
,
J. Chem. Phys.
134
,
085108
(
2011
).
37.
L.
Onsager
and
S.
Machlup
,
Phys. Rev.
91
,
1505
(
1953
).
38.
S.
Machlup
and
L.
Onsager
,
Phys. Rev.
91
,
1512
(
1953
).
39.
K. L.C.
Hunt
and
J.
Ross
,
J. Chem. Phys.
75
,
976
(
1981
).
40.
K.
Adachi
,
K.
Oiwa
,
T.
Nishizaka
,
S.
Furuike
,
H.
Noji
,
H.
Itoh
,
M.
Yoshida
, and
K.
Kinosita
, Jr.
,
Cell
130
,
309
(
2007
).
41.
K.
Hayashi
,
H.
Ueno
,
R.
Iino
, and
H.
Noji
,
Phys. Rev. Lett.
104
,
218103
(
2010
).
42.
Q.
Cui
,
G.
Li
,
J.
Ma
, and
M.
Karplus
,
J. Mol. Biol
340
,
345
(
2004
).
43.
Normal Mode Analysis: Theory and Applications to Biological and Chemical Systems
, 1st ed., edited by
Q.
Cui
and
I.
Bahar
(
Chapman & Hall/CRC
,
Boca Raton, FL
,
2006
).
44.
Y.
Togashi
and
A. S.
Mikhailov
,
Proc. Natl. Acad. Sci. U.S.A.
104
,
8697
(
2007
).
45.
Y.
Togashi
,
T.
Yanagida
, and
A. S.
Mikhailov
,
PLoS Comput. Biol.
6
,
e1000814
(
2010
).
46.
F.
Jülicher
,
A.
Ajdari
, and
J.
Prost
,
Rev. Mod. Phys.
69
,
1269
(
1997
).
49.
If the system is locally equilibrated, we can adopt the Boltzmann distribution.
50.
J. D.
Gunton
,
M. S.
Miguel
, and
P. S.
Sahni
,
Phase Transitions and Critical Phenomena
, edited by
C.
Domb
and
J. L.
Lebowitz
(
Academic
,
New York
,
1983
), Vol.
8
.
51.
K.
Kawasaki
and
T.
Ohta
,
Physica
116A
,
573
(
1982
).
52.
J.
Carr
and
R.
Pego
,
Commun. Pure. Appl. Math.
XLII
,
523
(
1989
).
53.
R.
Mortensen
,
J. Stat. Phys.
1
,
271
(
1969
).
54.
When x is close to the bottom of the effective potential,
$-G_x(x, y) \simeq - G_{xx}(x_{\protect \rm b}, y) (x - x_{\protect \rm b})$
Gx(x,y)Gxx(xb,y)(xxb)
, where
$x_{\protect \rm b}$
xb
represents the bottom position. Since
$G_{xx}(x_{\protect \rm b}, y)$
Gxx(xb,y)
is positive, Eq. (11) will be destabilized if the equation is integrated in the reverse-time direction.
55.
ε is a nondimensional parameter, which guarantees the smallness of the second term in the right-hand side of Eq. (12). After the calculation, we substitute ε = 1 into the result.
56.
$\tau _{\protect \rm dim} \sim \gamma / G_{xx}(x_{\protect \rm b}) = \gamma /(a_1 + k)$
τdimγ/Gxx(xb)=γ/(a1+k)
where
$x_{\protect \rm b}$
xb
represents the bottom position of the effective potential.
57.
See supplementary material at http://dx.doi.org/10.1063/1.3574396 for the supporting figures.
58.
The standard deviation of the thermal fluctuation of x(t) is
$\protect \sqrt{2k_{\protect \mathrm{B}}T\Delta t / \gamma }$
2kBTΔt/γ
in the case of discrete t. For model A, SD = 0.2.
59.
W. H.
Press
,
S. A.
Teukolsky
,
W. T.
Vetterling
, and
B. P.
Flannery
,
Numerical Recipes: The Art of Scientific Computing
, 3rd ed. (
Cambridge University Press
,
New York
,
2007
), Chap. 20.
60.
The Go-and-Back method is not an algorithm to search the global minimum point of
$S([x,y] ; \hbox{\protect \bm {\Pi} })$
S([x,y];Π)
along [x]-space, but systematically calculates the higher order approximation of the solution of the Euler-Lagrange equation [Eq. (8)]. Therefore, a monotonic decrease of
$S([x,y] ; \hbox{\protect \bm {\Pi} })$
S([x,y];Π)
does not mean that the estimate gets stuck into the local minimum.
62.
R. B.
Best
and
G.
Hummer
,
Phys. Rev. Lett.
96
,
228104
(
2006
).
63.
S.
Yang
,
J. N.
Onuchic
, and
H.
Levine
,
J. Chem. Phys.
125
,
054910
(
2006
).
64.
R. B.
Best
and
G.
Hummer
,
Proc. Natl. Acad. Sci. U.S.A.
107
,
1088
(
2010
).
65.
H. P.
Lu
,
L.
Xun
, and
X. S.
Xie
,
Science
282
,
1877
(
1998
).
66.
B. P.
English
,
W.
Min
,
A. M.
van Oijen
,
K. T.
Lee
,
G.
Luo
,
H.
Sun
,
B. J.
Cherayil
,
S. C.
Kou
, and
X. S.
Xie
,
Nat. Chem. Biol.
2
,
87
(
2005
).
67.
T.
Harada
and
S.-i.
Sasa
,
Phys. Rev. Lett.
95
,
130602
(
2005
).
68.
69.
C. M.
Bishop
,
Pattern Recognition and Machine Learning
(
Springer
,
New York
,
2006
).

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