Inquiry2015-2

Inqui r y I ssue 2

2015

Inqui r y I s sue

| 201 5

material,” said Emily Smith, Ames Laboratory scientist and

ISU associate professor of chemistry. “That means using

imaging techniques that provide exquisite spatial resolution

that shows you structures and molecules. You also want to

get chemical information, to know exactly what chemical

compounds are present. “

“The STED gives us good spatial resolution so we can

look at subcellular structures,” Smith continued. “The

Raman imaging gives us the chemical analysis so we know,

for example, what fatty acids are present.”

In addition to these techniques by Smith’s group and

ISU researcher Jacob Petrich, the team is aided by ISU

associate professor of chemistry Art Winter who has

developed molecular probes that selectively “light up” or

“turn on” certain elements within the cell that can then be

captured by the STED imaging. Ames Laboratory scientists

Sam Houk and Young-Jin Lee provide additional chemical

analysis through advanced mass-spectroscopy methods, and

provide a means of validating the images obtained by the

other imaging technologies.

“One of the downsides to using the techniques we’ve

developed is that you can get so much information that one

person couldn’t begin to sort out what’s important,” Smith said.

“That’s where the computational techniques developed by Eve

Syrkin Wurtele and Diane Bassham come into play to sort out

the needle of useful information in the haystack of data to

address the particular biological question we’re posing.”

Wurtele and Bassham, both professors of Genetics,

Development and Cell Biology at ISU, use an integrated

experimental/biocomputational approach to understand the

factors that regulate plant development and composition.

That includes an award-winning computer visualization

program – yep, a video game – calledMeta!Blast. Data can be

imported into the program and it provides a visual depiction

of what’s taking place within the plant at the appropriate

cellular or molecular scale.

“The idea is that you have this visual environment

that’s new to most people and you can do things like scan

structures or molecules if you don’t understand them,

get an explanation of the analytical technologies, and

see multiple vantage points,” Wurtele said. “The various

chemical and biological (analytical) techniques let you

create an image of the plant and its molecular components

that is at a resolution from a multicellular level, like the

surface of a leaf, to the cellular, into the organelles within

individual cells, and ultimately the individual molecules.”

All involved say the project perfectly melds the strengths

of ISU and Ames Laboratory.

“In our group, we’re all experts in our own domains,

but I don’t think there’s one person who fully understands

the other people’s technologies,” Wurtele said. “The idea

behind this is to create a system where the actual data that’s

obtained at different resolutions and spatial compartments

is integrated so that anyone is able to access the data in an

understandable form.”

“It’s a highly collaborative project,” Nikolau added, “and a

very good fit between the biological and the analytical sides.”

“We developed these various analytical techniques for

other purposes,” Smith concluded. “With this project,

we’re able to apply them to biological materials. ISU is

extremely strong in plant science and Ames Lab has vast

analytical expertise, and it’s been great to see this synergy

develop. Hopefully we can leverage that down the road on

future projects.”

This image from the Meta!Blast program shows structures

within the cells of plant. The program is used to visually

represent huge volumes of data collected from living plants to

accurately depict what takes place chemically and physically

within the plant.

All involved say the project

perfectly melds the strengths

of ISU andAmes Laboratory.

n just a little over a year of operation,

Ames

Laboratory’s dynamic nuclear polarization (DNP) solid-

state nuclear magnetic resonance (NMR) spectrometer

has successfully characterized materials at the atomic

scale level with more speed and precision than ever possible

before. Spectra for materials important to catalysis, solar

energy, and hydrogen storage have helped scientists better

understand how these materials work.

Conventional NMR detects the responses of atomic

nuclei to direct excitation by radio frequency waves. DNP-

NMR offers faster and more detailed spectra over traditional

NMR by first exciting unpaired electrons at their microwave

resonance frequency and then transferring the resulting spin

polarization to the material’s nuclei. This additional step

results in much stronger signal intensities from these “hyper-

polarized” nuclei than is available by conventional means.

The advanced capabilities of DNP-NMR have already

made it possible for Ames Laboratory NMR experts to

answer questions that were out of reach before.

For example, in a paper in the Journal of the American

Chemical Society, Ames Laboratory scientist Marek

Pruski and his research team reported on DNP studies

of natural abundance

O in several materials. Oxygen is

practically undetectable by conventional NMR due to its

DNP-enhanced

O (a and b) and

195

solid-state NMR spectra (c) of surface

species. In (a) a natural abundance

H-

HETCOR spectrum of silica surface

allowed for the distinction of hydrogen-

bonded and non-hydrogen-bonded silanol

sites. In (b) natural-abundance

O NMR

enabled, for the first time, the detection of

defect sites in MOFs. In (c)

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Pt NMR

experiments of surface-bound Pt sites

enabled the unambiguous characterization

of their binding environment.

Higher Speed,

More Precision

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