The transport of ligands, such as NO or O2, through internal cavities is essential for the function of globular proteins, including hemoglobin, myoglobin (Mb), neuroglobin, truncated hemoglobins, or cytoglobin. For Mb, several internal cavities (Xe1 through Xe4) were observed experimentally and they were linked to ligand storage. The present work determines barriers for xenon diffusion and relative stabilization energies for the ligand in the initial and final pocket, linking a transition depending on the occupancy state of the remaining pockets from both biased and unbiased molecular dynamics simulations. It is found that the energetics of a particular ligand migration pathway may depend on the direction in which the transition is followed and the occupancy state of the other cavities. Furthermore, the barrier height for a particular transition can depend in a non-additive fashion on the occupancy of either cavity A or B or simultaneous population of both cavities, A and B. Multiple repeats for the Xe1 → Xe2 transition reveal that the activation barrier is a distribution of barrier heights rather than one single value, which is confirmed by a distribution of transition times for the same transition from unbiased simulations. Dynamic cross correlation maps demonstrate that correlated motions occur between adjacent residues or through space, residue Phe138 is found to be a gate for the Xe1 → Xe2 transition, and the volumes of the internal cavities vary along the diffusion pathway, indicating that there is dynamic communication between the ligand and the protein. These findings suggest that Mb is an allosteric protein.

1.
M. L.
Connolly
, “
Atomic size packing defects in proteins
,”
Int. J. Pept. Protein Res.
28
,
360
363
(
1986
).
2.
R. F.
Tilton
,
I. D.
Kuntz
, and
G. A.
Petsko
, “
Cavities in proteins: Structure of a metmyoglobin-xenon complex solved to 1.9 Å
,”
Biochem
23
,
2849
2857
(
1984
).
3.
V. M.
Luna
,
J. A.
Fee
,
A. A.
Deniz
, and
C. D.
Stout
, “
Mobility of Xe atoms within the oxygen diffusion channel of cytochrome Ba3 oxidase
,”
Biochem
51
,
4669
4676
(
2012
).
4.
L.
Liu
,
M. L.
Quillin
, and
B. W.
Matthews
, “
Use of experimental crystallographic phases to examine the hydration of polar and nonpolar cavities in T4 lysozyme
,”
Proc. Natl. Acad. Sci. U. S. A.
105
,
14406
14411
(
2008
).
5.
M. L.
Quillin
,
P. T.
Wingfield
, and
B. W.
Matthews
, “
Determination of solvent content in cavities in IL-1β using experimentally phased electron density
,”
Proc. Natl. Acad. Sci. U. S. A.
103
,
19749
19753
(
2006
).
6.
A. E.
Eriksson
,
W. A.
Baase
,
X. J.
Zhang
,
D. W.
Heinz
,
M.
Blaber
,
E. P.
Baldwin
, and
B. W.
Matthews
, “
Response of a protein structure to cavity-creating mutations and its relation to the hydrophobic effect
,”
Science
255
,
178
183
(
1992
).
7.
E.
Gabellieri
,
E.
Balestreri
,
A.
Galli
, and
P.
Cioni
, “
Cavity-creating mutations in Pseudomonas aeruginosa azurin: Effects on protein dynamics and stability
,”
Biophys. J.
95
,
771
781
(
2008
).
8.
T.
Ohmura
,
T.
Ueda
,
K.
Ootsuka
,
M.
Saito
, and
T.
Imoto
, “
Stabilization of hen egg white lysozyme by a cavity-filling mutation
,”
Phys. Scr.
10
,
313
320
(
2001
).
9.
E.
Marcos
,
B.
Basanta
,
T. M.
Chidyausiku
,
Y.
Tang
,
G.
Oberdorfer
,
G.
Liu
,
G. V. T.
Swapna
,
R.
Guan
,
D.-A.
Silva
,
J.
Dou
 et al, “
Principles for designing proteins with cavities formed by curved β sheets
,”
Science
355
,
201
206
(
2017
).
10.
M.
Milani
,
A.
Pesce
,
Y.
Ouellet
,
S.
Dewilde
,
J.
Friedman
,
P.
Ascenzi
,
M.
Guertin
, and
M.
Bolognesi
, “
Heme-ligand tunneling in group I truncated hemoglobins
,”
J. Biol. Chem.
279
,
21520
21525
(
2004
).
11.
P.-A.
Cazade
and
M.
Meuwly
, “
Oxygen migration pathways in NO-bound truncated hemoglobin
,”
ChemPhysChem
13
,
4276
4286
(
2012
).
12.
M.
Brunori
and
B.
Vallone
, “
Neuroglobin, seven years after
,”
Cell. Mol. Life Sci.
64
,
1259
1268
(
2007
).
13.
J. M.
Kriegl
,
A. J.
Bhattacharyya
,
K.
Nienhaus
,
P.
Deng
,
O.
Minkow
, and
G. U.
Nienhaus
, “
Ligand binding and protein dynamics in neuroglobin
,”
Proc. Natl. Acad. Sci. U. S. A.
99
,
7992
7997
(
2002
).
14.
S.
Lutz
,
K.
Nienhaus
,
G. U.
Nienhaus
, and
M.
Meuwly
, “
Ligand migration between internal docking sites in photodissociated carbonmonoxy neuroglobin
,”
J. Phys. Chem. B
113
,
15334
15343
(
2009
).
15.
K.
Nienhaus
,
S.
Lutz
,
M.
Meuwly
, and
G. U.
Nienhaus
, “
Structural identification of spectroscopic substates in neuroglobin
,”
ChemPhysChem
11
,
119
129
(
2010
).
16.
D.
De Sanctis
,
S.
Dewilde
,
A.
Pesce
,
L.
Moens
,
P.
Ascenzi
,
T.
Hankeln
,
T.
Burmester
, and
M.
Bolognesi
, “
Mapping protein matrix cavities in human cytoglobin through Xe atom binding
,”
Biochem. Biophys. Res. Commun.
316
,
1217
1221
(
2004
).
17.
J. S.
Olson
,
J.
Soman
, and
G. N.
Phillips
, “
Ligand pathways in myoglobin: A review of Trp cavity mutations
,”
IUBMB Life
59
,
552
562
(
2007
).
18.
E. E.
Scott
,
Q. H.
Gibson
, and
J. S.
Olson
, “
Mapping the pathways for O2 entry into and exit from myoglobin
,”
J. Biol. Chem.
276
,
5177
5188
(
2001
).
19.
G. S.
Kachalova
,
A. N.
Popov
, and
H. D.
Bartunik
, “
A steric mechanism for inhibition of CO binding to heme proteins
,”
Science
284
,
473
476
(
1999
).
20.
Y.
Nishihara
,
M.
Sakakura
,
Y.
Kimura
, and
M.
Terazima
, “
The escape process of carbon monoxide from myoglobin to solution at physiological temperature
,”
J. Am. Chem. Soc.
126
,
11877
11888
(
2004
).
21.
J.
Monod
and
F.
Jacob
, “
General conclusions: Teleonomic mechanisms in cellular metabolism, growth, and differentiation
,” in
Cold Spring Harbor Symposia on Quantitative Biology
(
Cold Spring Harbor Laboratory Press
,
1961
), pp.
389
401
.
22.
L.
Pauling
, “
The oxygen equilibrium of hemoglobin and its structural interpretation
,”
Proc. Natl. Acad. Sci. U. S. A.
21
,
186
191
(
1935
).
23.
D. E.
Koshland
, Jr.
,
G.
Némethy
, and
D.
Filmer
, “
Comparison of experimental binding data and theoretical models in proteins containing subunits
,”
Biochem
5
,
365
385
(
1966
).
24.
C.-J.
Tsai
,
A.
Del Sol
, and
R.
Nussinov
, “
Allostery: Absence of a change in shape does not imply that allostery is not at play
,”
J. Mol. Biol.
378
,
1
11
(
2008
).
25.
J.-P.
Changeux
and
S. J.
Edelstein
, “
Allosteric mechanisms of signal transduction
,”
Science
308
,
1424
1428
(
2005
).
26.
H.
Link
,
D.
Christodoulou
, and
U.
Sauer
, “
Advancing metabolic models with kinetic information
,”
Curr. Opin. Biotechnol.
29
,
8
14
(
2014
).
27.
B.
Giardina
,
P.
Ascenzi
,
M. E.
Clementi
,
G.
De Sanctis
,
M.
Rizzi
, and
M.
Coletta
, “
Functional modulation by lactate of myoglobin: A monomeric allosteric hemoprotein
,”
J. Biol. Chem.
271
,
16999
17001
(
1996
).
28.
H.
Frauenfelder
,
B. H.
McMahon
,
R. H.
Austin
,
K.
Chu
, and
J. T.
Groves
, “
The role of structure, energy landscape, dynamics, and allostery in the enzymatic function of myoglobin
,”
Proc. Natl. Acad. Sci. U. S. A.
98
,
2370
2374
(
2001
).
29.
B. R.
Brooks
,
R. E.
Bruccoleri
,
B. D.
Olafson
,
D. J.
States
,
S.
Swaminathan
, and
M.
Karplus
, “
CHARMM: A program for macromolecular energy, minimization, and dynamics calculations
,”
J. Comput. Chem.
4
,
187
217
(
1983
).
30.
J.
Cohen
,
A.
Arkhipov
,
R.
Braun
, and
K.
Schulten
, “
Imaging the migration pathways for O2, CO, NO, and Xe inside myoglobin
,”
Biophys. J.
91
,
1844
1857
(
2006
).
31.
E.
Hairer
,
C.
Lubich
, and
G.
Wanner
, “
Geometric numerical integration illustrated by the Störmer–Verlet method
,”
Acta Numer.
12
,
399
450
(
2003
).
32.
J.-P.
Ryckaert
,
G.
Ciccotti
, and
H. J. C.
Berendsen
, “
Numerical integration of the cartesian equations of motion of a system with constraints: Molecular dynamics of n-alkanes
,”
J. Comput. Phys.
23
,
327
341
(
1977
).
33.
P. J.
Steinbach
and
B. R.
Brooks
, “
New spherical-cutoff methods for long-range forces in macromolecular simulation
,”
J. Comput. Chem.
15
,
667
683
(
1994
).
34.
R. F.
Tilton
,
U. C.
Singh
,
S. J.
Weiner
,
M. L.
Connolly
,
I. D.
Kuntz
,
P. A.
Kollman
,
N.
Max
, and
D. A.
Case
, “
Computational studies of the interaction of myoglobin and xenon
,”
J. Mol. Biol.
192
,
443
456
(
1986
).
35.
C.
Bossa
,
A.
Amadei
,
I.
Daidone
,
M.
Anselmi
,
B.
Vallone
,
M.
Brunori
, and
A.
Di Nola
, “
Molecular dynamics simulation of sperm whale myoglobin: Effects of mutations and trapped CO on the structure and dynamics of cavities
,”
Biophys. J.
89
,
465
474
(
2005
).
36.
S.-Y.
Park
,
T.
Yokoyama
,
N.
Shibayama
,
Y.
Shiro
, and
J. R. H.
Tame
, “
1.25 Å resolution crystal structures of human hemoglobin in the oxy, deoxy and carbonmonoxy forms
,”
J. Mol. Biol.
360
,
690
701
(
2006
).
37.
M.
Anselmi
,
A.
Di Nola
, and
A.
Amadei
, “
The kinetics of ligand migration in crystallized myoglobin as revealed by molecular dynamics simulations
,”
Biophys. J.
94
,
4277
4281
(
2008
).
38.
M.
Anselmi
,
A.
Di Nola
, and
A.
Amadei
, “
The effects of the L29F mutation on the ligand migration kinetics in crystallized myoglobin as revealed by molecular dynamics simulations
,”
Proteins
79
,
867
879
(
2011
).
39.
S.
Kumar
,
J. M.
Rosenberg
,
D.
Bouzida
,
R. H.
Swendsen
, and
P. A.
Kollman
, “
The weighted histogram analysis method for free-energy calculations on biomolecules. I. The method
,”
J. Comput. Chem.
13
,
1011
1021
(
1992
).
40.
M.
Souaille
and
B.
Roux
, “
Extension to the weighted histogram analysis method: Combining umbrella sampling with free energy calculations
,”
Comput. Phys. Commun.
135
,
40
57
(
2001
).
41.
T.
Ichiye
and
M.
Karplus
, “
Collective motions in proteins: A covariance analysis of atomic fluctuations in molecular dynamics and normal mode simulations
,”
Proteins: Struct., Funct., Genet.
11
,
205
217
(
1991
).
42.
G. E.
Arnold
and
R. L.
Ornstein
, “
Molecular dynamics study of time-correlated protein domain motions and molecular flexibility: Cytochrome P450BM-3
,”
Biophys. J.
73
,
1147
1159
(
1997
).
43.
B. J.
Grant
,
A. P. C.
Rodrigues
,
K. M.
ElSawy
,
J. A.
McCammon
, and
L. S. D.
Caves
, “
Bio3d: An R package for the comparative analysis of protein structures
,”
Bioinformatics
22
,
2695
2696
(
2006
).
44.
R. A.
Laskowski
, “
SURFNET: A program for visualizing molecular surfaces, cavities, and intermolecular interactions
,”
J. Mol. Graph.
13
,
323
330
(
1995
).
45.
P.
Banushkina
and
M.
Meuwly
, “
Free-energy barriers in MbCO rebinding
,”
J. Phys. Chem. B
109
,
16911
16917
(
2005
).
46.
Y.
Nishihara
,
S.
Hayashi
, and
S.
Kato
, “
A search for ligand diffusion pathway in myoglobin using a metadynamics simulation
,”
Chem. Phys. Lett.
464
,
220
225
(
2008
).
47.
N.
Plattner
and
M.
Meuwly
, “
The role of higher CO-multipole moments in understanding the dynamics of photodissociated carbonmonoxide in myoglobin
,”
Biophys. J.
94
,
2505
2515
(
2008
).
48.
N.
Plattner
,
J. D.
Doll
, and
M.
Meuwly
, “
Spatial averaging for small molecule diffusion in condensed phase environments
,”
J. Chem. Phys.
133
,
044506
(
2010
).
49.
N.
Plattner
and
M.
Meuwly
, “
Quantifying the importance of protein conformation on ligand migration in myoglobin
,”
Biophys. J.
102
,
333
341
(
2012
).
50.
M.
Ceccarelli
,
R.
Anedda
,
M.
Casu
, and
P.
Ruggerone
, “
CO escape from myoglobin with metadynamics simulations
,”
Proteins: Struct., Funct., Genet.
71
,
1231
1236
(
2008
).
51.
V.
Zoete
,
M.
Meuwly
, and
M.
Karplus
, “
A comparison of the dynamic behavior of monomeric and dimeric insulin shows structural rearrangements in the active monomer
,”
J. Mol. Biol.
342
,
913
929
(
2004
).
52.
F.
Schotte
,
M.
Lim
,
T. A.
Jackson
,
A. V.
Smirnov
,
J.
Soman
,
J. S.
Olson
,
G. N.
Phillips
,
M.
Wulff
, and
P. A.
Anfinrud
, “
Watching a protein as it functions with 150-ps time-resolved x-ray crystallography
,”
Science
300
,
1944
1947
(
2003
).

Supplementary Material

You do not currently have access to this content.