Features | Partner Sites | Information | LinkXpress
Sign In
GLOBETECH PUBLISHING LLC
GLOBETECH MEDIA
GLOBETECH PUBLISHING LLC

Molecular X-Ray Camera Probes Biomolecules to Individual Atoms

By BiotechDaily International staff writers
Posted on 11 Jun 2012
Image: This rendering shows a lysozyme structural model against its X-ray diffraction pattern from SLAC’s Linac Coherent Light Source (LCLS), a powerful X-ray laser facility (Photo courtesy of Anton Barty/DESY).
Image: This rendering shows a lysozyme structural model against its X-ray diffraction pattern from SLAC’s Linac Coherent Light Source (LCLS), a powerful X-ray laser facility (Photo courtesy of Anton Barty/DESY).
Researchers have captured high-resolution images of simple lysozyme biomolecules using sophisticated X-ray crystallography technology.

An international team led by the US Department of Energy’s (DOE) SLAC National Accelerator Laboratory (Menlo Park, CA, USA) has proved how the world’s most powerful X-ray laser can assist in decoding the structures of biomolecules, and in the processes helped to forge vital new research paths in biology.

The researcher’s experiments, reported online May 31, 2012, in Science, used SLAC’s linac coherent light source (LCLS) to capture ultra-high-resolution views of crystallized biomolecules, including a small protein found in egg whites called lysozyme. For many years, scientists have reconstructed the shape of biologic molecules and proteins by illuminating crystallized samples with X-rays to study how they scatter the light. The scientists’ work with lysozyme represents the first-ever high-resolution experiments employing serial femtosecond crystallography--the split-second imaging of tiny crystals using ultrashort, ultrabright X-ray laser pulses.

The technique utilized a higher resolution than earlier achieved using X-ray lasers, allowing scientists to use smaller crystals than typical with other methods, and could also enable researchers to view molecular dynamics in a way never before possible. “We were able to actually visualize the structure of the molecule at a resolution so high we start to infer the position of individual atoms,” said Dr. Sébastien Boutet, a staff scientist at LCLS who led the research. “Not only that, but the structure we observed matches the known structure of lysozyme and shows no significant sign of radiation damage, despite the fact that the pulses completely destroy the sample. This is the first high-resolution demonstration of the ‘diffraction-before-destruction’ technique on biological samples, where we’re able to measure a sample before the powerful pulses of the LCLS damage it.”

The scientists selected lysozyme as the first sample for their research because it is easy to crystallize and has been widely studied. Their research not only determined lysozyme’s structure at such high resolution that it showed individual amino acids, but also demonstrated the ability to utilize very small crystals for a range of applications. Dr. Boutet reported that the team has also studied more complex proteins and systems that they are analyzing now.

Ultimately, scientists using LCLS are driving toward an atomic- and molecular-scale understanding of complex biologic systems--such as the membrane proteins that are critical in cell functions and the processes that fuel photosynthesis--which could lead to findings in a range of sciences, from pharmaceutical advances to new sources of alternative energy.

The experiment was the first study performed on the new coherent X-ray imaging (CXI) instrument, a “molecular camera” designed, constructed, and commissioned by SLAC and now available to the scientific community. Also key to the study was a novel custom-made detector, the Cornell-SLAC pixel array detector (CSPAD), developed in collaboration between Cornell University (Ithaca, NY, USA) and SLAC for use at the CXI instrument. “This important demonstration shows that the technique works, and it paves the way for a lot of exciting experiments to come,” concluded Dr. Boutet.

Related Links:

SLAC US National Accelerator Laboratory


Channels

Genomics/Proteomics

view channel
Image: Many molecular biology studies begin with purified DNA and RNA extracted from complex environments such as the human gut (Photo courtesy of Los Alamos [US] National Laboratory).

New Metagenomics Analysis Tool Reduces False Discovery Rates

Genomic researchers recently described a novel new tool for analyzing the complex data generated during DNA screens of mixed populations of organisms such as the human gut microbiome. DNA screening... Read more

Drug Discovery

view channel
Image: Wafers like the one shown here are used to create “organ-on-a-chip” devices to model human tissue (Photo courtesy of Dr. Anurag Mathur, University of California, Berkeley).

Human Heart-on-a-Chip Cultures May Replace Animal Models for Drug Development and Safety Screening

Human heart cells growing in an easily monitored silicon chip culture system may one day replace animal-based model systems for drug development and safety screening. Drug discovery and development... Read more

Biochemistry

view channel
Image:  Model depiction of a novel cellular mechanism by which regulation of cryptochromes Cry1 and Cry2 enables coordination of a protective transcriptional response to DNA damage caused by genotoxic stress (Photo courtesy of the journal eLife, March 2015, Papp SJ, Huber AL, et al.).

Two Proteins Critical for Circadian Cycles Protect Cells from Mutations

Scientists have discovered that two proteins critical for maintaining healthy day-night cycles also have an unexpected role in DNA repair and protecting cells against genetic mutations that could lead... Read more

Business

view channel

“Softer” Mass Spec Techniques Gain Advantage in Biomarker Discovery

Two mass spectrometry (MS) technologies, MALDI and DESI, are increasing in applications as their effectiveness is established, according to Kalorama Information (New York, NY, USA) in its report “Proteomics Markets for Research and IVD Applications (Mass Spectrometry, Chromatography, Microarrays, Electrophoresis, Immunoassays,... Read more
 
Copyright © 2000-2015 Globetech Media. All rights reserved.