Solid State NMR

Biophysics
Student

Seminar Series

introducing

Solid State NMR

Bo Zhao

Zimeng Li

Introduction to NMR

Application

Solid State NMR

Research

Introduction to NMR

Application

Solid State NMR

Research

Physics

•
Nuclear Magnetic Resonance

Biology

•
Structure

•
Dynamics

Introduction to NMR

Physical Origin

Measurement

Introduction to NMR

•
Rabi

(1938)

•
Spin
is internal property of
particles

•
Spin can generate magnetic field

•
Protons and Neutrons have spin 1/2





Physical Origin

Xu
, Modern Physics (1993)

Physical Origin

Spin ½ System


Nuclei

Unpaired
Protons

Unpaired
Neutrons

Net Spin

γ (
MHz/T)

Abundance

1
H

1

0

1/2

42.58

99.98%

2
H

1

1

1

6.54

0.0184%

14
N

1

1

1

3.08

99.636%

15
N

1

0

1/2

-
4.316

0.34%

12
C

0

0

0

N/A

99%

13
C

0

1

1/2

10.71

1%

19
F

1

0

1/2

40.08

100%

31
P

1

0

1/2

17.25

100%

?

•
External field
–

energy splitting





Spin ½ System

Hornak
, The Basics of NMR (1997)

1
H [ppm]

•
Internal property

•
External factor

–
High Field (1964)

–
Electron shielding

–
Spin coupling

•
Chemical Shift




=
𝑣
−
𝑣
𝑟

𝑣
𝑟


ppm




Spin ½ System

?

e

p

Spin coupling

Chemical Shift Anisotropy

Shi, NMR Introduction course (2003)

Trausch

et al., Chemical Physics Letters (2008)


Spin ½ System

Chemical Shift Anisotropy

Dipole
-
Dipole coupling

𝜈

•
More shielding
-
> lower
chemical shift.

Chemical Shift Anisotropy

𝜎
↑
,
𝐵


↓
,
𝜈
↓

𝜎


𝜎


𝜎




𝐵
𝑠ℎ𝑖
𝑙

𝐵


=
𝐵
0
−
𝐵
𝑠ℎ𝑖
𝑙

Rossum
, Solid State NMR and proteins (2009)

J.
Duer
, Solid State NMR spectroscopy (2002)


•
More shielding
-
>
lower chemical shift.

•
Dependent on angular
orientation


More shielded

Chemical Shift Anisotropy

𝜎
↑
,
𝐵


↓
,
𝜈
↓


Spin ½ System

Chemical Shift Anisotropy

Dipole
-
Dipole Coupling

Nuclear

Pair

Internuclear

distance
[
Å
]

Dipolar

coupling

[
𝒌𝑯𝒛
]

1
H,
1
H

10

120

1
H,
13
C

1

30

1
H,
13
C

2

3.8

•
Dipolar coupling causes huge line broadening


Dipole
-
Dipole Coupling

J.
Duer
, Solid State NMR spectroscopy (2002)

•
(1952)
Purcell and Bloch

Spin ½
System

Equilibrium


Spin ½
System

Equilibrium

B
0

B
1

B
1

Equilibrium

𝐵
0

M

J.
Duer
, Solid State NMR spectroscopy (2002)

•
𝜔
=


∙
𝐵

Spin ½
System

Goldstein,
Classical Mechanics

𝑤
0

𝐵
0

M

𝐵
0

M

𝐵
1

Spin ½
System

M

•
Resonance
𝜔
=
𝜔
0

•
Maximum signal


𝜔
0

𝜔

ℎ𝜈
=
ℏ𝜔

ℎ
𝜈
0

ℎ𝜈

Physics Origin

Measurement

Introduction to NMR

ℎ𝜈

•
Conventional
–

Continuous Wave

•
Modern
–

Pulse Signal

Measurement

𝐵
0

𝜈

𝜈

Hornak
, The Basics of NMR (1997)

•
Conventional
–

Continuous Wave

•
Modern
–

Pulse Signal

Measurement

𝐵
0

𝜈

𝜈
+



𝜈
−



𝜈
1
𝐻
−



𝜈
1
𝐻

𝜈
1
𝐻
+



Anisotropy of
1
H


Measurement

Shi, NMR Introduction course (2003)

Introduction to NMR

Application

Solid State NMR

Research

•
Protein 3D structure and function study at
atomic resolution

•
(1976)
R
. R.
Ernst:
Multi dimensional NMR

•
(1979)

K
.
Wuthrich
:
Solve protein structure


Application

Markley, the Scientists
–

magazine of life science (2005)

•
Protein Dynamics/Protein folding
intermediates


Application

Frank, et al. Nature (2010)

•
Fast structure determination/recognition of
macromolecular compound

•
Medical
Imaging


Application

Solid

Solution

Dipolar

Coupling (10
-
100kHz)

Scalar

Coupling (10
-
100Hz)

Anisotropic interactions

Isotropic interactions

13
C detection

1
H detection

Sensitivity

low

Sensitivity

high

Require special techniques to improve

linewidth

Natural

tumbling of molecules

Solution vs. Solid State NMR

Application

Application

Introduction to NMR

Solid State NMR

Research

Problems

General Techniques

OS
-
NMR

MAS
-
NMR

•
Powder Spectra



13
C NMR of
glycine


Problems with SSNMR

Adapted from M.
Edén
,
Concepts in Magnetic Resonance
18A, 24.

D.
Lide
, G. W. A. Milne,
Handbook of Data on Organic Compounds:
Compounds 10001
-
15600 Cha
-
Hex. (CRC Press, 1994).

Solid

Liquid

Problems with SSNMR

•
Goal: simplify solid state spectra


Adapted from R.
Tycko
,
Annu
. Rev. Phys. Chem.
52, 575 (2001).

Problems

General Techniques

MAS
-
NMR

Solid State NMR

OS
-
NMR

•
Developed in 1976

•
Suppresses
1
H
-
1
H and
1
H
-
S coupling

•
Resolves dilute spins based on chemical
environment

•
Gives dipolar coupling information



Separated Local Field

R. K. Hester, J. L. Ackerman, B. L. Neff, J. S. Waugh,
Physical Review Letters
36, 1081 (1976).

•
Hartmann
-
Hahn Condition

–
Detailed in 1962

–
Between
heteroatoms

–
Same
Larmor

frequency



–
Allows for cross relaxation


L. W.
Jelinski
, M. T. Melchior,
Applied Spectroscopy Reviews
35, 25 (2004/05/24, 2004).

Cross Polarization

•
First published in 1973

•
Transfer population information from I to S

•
Detect off of dilute species

–
Cleaner spectra

–
More sensitive


Cross Relaxation

Barth
-
Jan van
Rossum
: Solid
-
state NMR and proteins, a pictorial introduction


Problems

General Techniques

MAS
-
NMR

Solid State NMR

OS
-
NMR

Magic Angle Spinning

Simulating the “tumbling” of molecules


http://www.rs2d.com/english/images/protasis/doty/doty.jpg

Magic Angle Spinning

•
Proposed in 1958

•
Coupling dependent on



–
At magic angle, 54.7356
°
, equals zero

•
Spin sample to decouple

–
1
H
-
1
H coupling ~40kHz

E. R. Andrew,
Philosophical Transactions of the Royal Society of London.
Series A, Mathematical and Physical Sciences
299, 505 (March 18, 1981,
1981).

3.6kHz

Static

MAS decoupling

Problems

General Techniques

MAS
-
NMR

Solid State NMR

OS
-
NMR

Physical Orientation



Lipids


Oriented Sample NMR

G.
Orädd
, G.
Lindblom
,
Magnetic Resonance in Chemistry
42, 123 (2004).

C. R. Sanders, K.
Oxenoid
,
Biochimica

et
Biophysica

Acta

(BBA)
-

Biomembranes

1508, 129 (2000).

http://avantilipids.com

Replacing “tumbling” with
Rf

irradiation


•
Polarization Inversion Spin Exchange at the
Magic Angle

–
Developed in 1994

•
Form of SLF with enhanced sensitivity

•
Further suppression of
1
H
-

1
H coupling

C. H. Wu, A.
Ramamoorthy
, S. J.
Opella
,
Journal of Magnetic Resonance, Series A
109, 270 (1994).

PISEMA

SLF

PISEMA

Modified SLF

PISEMA
vs

SLF

C. H. Wu, A.
Ramamoorthy
, S. J.
Opella
,
Journal of Magnetic Resonance, Series A
109, 270 (1994).

D. S.
Thiriot
, A. A.
Nevzorov
, S. J.
Opella
,
Protein
Sci

14, 1064 (Apr, 2005).

Polar Index Slant Angle Wheel

S. Kim, T. A. Cross,
Journal of Magnetic Resonance
168, 187 (2004).

G. A. Cook, S. J.
Opella
,
Methods Mol
Biol

637, 263 (2010).

PISA Wheel

Limitations of PISEMA

A. A.
Nevzorov
, S. J.
Opella
,
Journal of Magnetic Resonance
185, 59 (2007).

•
Compliments PISEMA

–
Developed in 2003

•
Averages out
homonuclear

spin
-
spin interaction

•
More uniform over wide range
linewidths



A. A.
Nevzorov
, S. J.
Opella
,
Journal of Magnetic Resonance
164, 182 (2003).

SAMMY

Limitations of SAMMY

A. A.
Nevzorov
, S. J.
Opella
,
Journal of Magnetic Resonance
185, 59 (2007).

•
Slight modification of SAMMY

–
Developed in 2007

•
Combines pros of PISEMA and SAMMY

–
Sensitivity of PISEMA

–
Range of SAMMY

•
Can be implemented generally

A. A.
Nevzorov
, S. J.
Opella
,
Journal of Magnetic Resonance
185, 59 (2007).

SAMPI4

Application

Introduction to NMR

Solid State NMR

Research

Sensitivity Enhancement

Spectroscopic Assignment

Structure Calculations

•
What is mosaic spread?

Reducing the effects of mosaic spread


Sensitivity Enhancement

C. R. Sanders, K.
Oxenoid
,
Biochimica

et
Biophysica

Acta

(BBA)
-

Biomembranes

1508, 129 (2000).

M. J.
Duer
,
Solid
-
state NMR spectroscopy: principles and applications.
(Blackwell Science, 2001).

A. A.
Nevzorov
,
The Journal of Physical Chemistry B
115, 15406 (2011/12/29, 2011).

Sensitivity Enhancement

Static

Slow diffusion

Fast diffusion

Uniaxial

Diffusion


Sensitivity Enhancement

Spectroscopic Assignment

Structure Calculations

Research

Spectroscopic Assignment

D. S.
Thiriot
, A. A.
Nevzorov
, S. J.
Opella
,
Protein
Sci

14, 1064 (Apr, 2005).

Assigning peaks in uniformly labeled proteins


Spectroscopic Assignment

A. A. De Angelis, S. C. Howell, A. A.
Nevzorov
, S. J.
Opella
,
Journal of the
American Chemical Society
128, 12256 (2006/09/01, 2006).

R. W. Knox, G. J. Lu, S. J.
Opella
, A. A.
Nevzorov
,
Journal of the American
Chemical Society
132, 8255 (2010/06/23, 2010).

•
Can identify coupling up to


6.7Å away

•
Previous methods only


identify coupling < 5Å

Sensitivity Enhancement

Spectroscopic Assignment

Structure Calculations

Research




Determining structure from “shiftless” data

Y. Yin, A. A.
Nevzorov
,
Journal of Magnetic Resonance
212, 64 (2011).

Structure Calculations


C. H. Wu, S. J.
Opella
,
J
Chem

Phys
128, 052312 (Feb 7, 2008).

Y. Yin, A. A.
Nevzorov
,
Journal of Magnetic Resonance
212, 64 (2011).

Structure Calculations

Acknowledgement:

•
Dr. Sharon Campbell

•
Dr. Barry Lentz

•
Dr
. Alexander
Nevzorov

Thank you!

•
W
hy SSNMR is important?

•
What do you
think
the next development for
solid state NMR is
?

•
Can you briefly compare the two major
structure determination techniques: NMR and
X
-
ray crystallography?



Discussion Questions

C.
Glaubitz
, A. Watts,
Journal of Magnetic Resonance
130, 305 (1998).

MAOSS

Compare methods of solving Protein Structure

Discussion

NMR

X
-
ray Crystallography

No

crystal needed

Crystal

Can be used in solution

Solid only

Not good for large proteins, smaller

molecules are comparable to X
-
ray

Generally higher solution

Can measure

dynamics

Stationary

In

vivo

possible (imaging)

In

vitro

D. S.
Thiriot
, A. A.
Nevzorov
, S. J.
Opella
,
Protein
Sci

14, 1064 (Apr, 2005).

PISA Wheel