Corporate Banner
Satellite Banner
Scientific Community
Become a Member | Sign in
Home>News>This Article

Watching a Signaling Protein Function in Real Time via 100-ps Time-Resolved Laue Crystallography

Published: Wednesday, December 05, 2012
Last Updated: Wednesday, December 05, 2012
Bookmark and Share
Researchers from the NIH propose a model for the PYP photocycle that is both chemically and mechanistically sensible accounting for much of the kinetic complexity observed in prior studies.

To understand how signaling proteins function, it is crucial to know the time-ordered sequence of events that lead to the signaling state. We recently developed on the BioCARS 14-IDB beamline at the Advanced Photon Source the infrastructure required to characterize structural changes in protein crystals with near-atomic spatial resolution and 150-ps time resolution, and have used this capability to track the reversible photocycle of photoactive yellow protein (PYP) following trans-to-cis photoisomerization of its p-coumaric acid (pCA) chromophore over 10 decades of time. The first of four major intermediates characterized in this study is highly contorted, with the pCA carbonyl rotated nearly 90° out of the plane of the phenolate. A hydrogen bond between the pCA carbonyl and the Cys69 backbone constrains the chromophore in this unusual twisted conformation. Density functional theory calculations confirm that this structure is chemically plausible and corresponds to a strained cis intermediate. This unique structure is short-lived (∼600 ps), has not been observed in prior cryocrystallography experiments, and is the progenitor of intermediates characterized in previous nanosecond time-resolved Laue crystallography studies. The structural transitions unveiled during the PYP photocycle include trans/cis isomerization, the breaking and making of hydrogen bonds, formation/relaxation of strain, and gated water penetration into the interior of the protein. This mechanistically detailed, near-atomic resolution description of the complete PYP photocycle provides a framework for understanding signal transduction in proteins, and for assessing and validating theoretical/computational approaches in protein biophysics.

The article is published online in the Proceedings of the National Academy of Sciences of the United States of America and is free to access. 

Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,800+ scientific posters on ePosters
  • More than 4,000+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Proteomics for Systems Toxicology
MS-based proteomics is maturing into a robust technology for the measurement of proteome-wide exposure effects.
Monday, November 24, 2014
Identification of Psoriatic Arthritis Mediators in Synovial Fluid
This study represents the most comprehensive proteomic analysis of psoriatic arthritis synovial fluid, to date.
Friday, August 08, 2014
The Role of Mass Spectrometry in the "Omics" Era
The tremendous developments of the MS technology and concurrent gene sequencing efforts have made the “-omic” revolution possible.
Tuesday, February 18, 2014
Predictors of Obesity: The "Power" of the Omics
Diet and nutrient biomarkers should provide objective measures of dietary intake and nutritional status, as well as an integrated measure of intake, absorption and metabolism.
Friday, October 25, 2013
Label-free MS Proteome Quantification of Human Embryonic Kidney Cells Following 24 Hours of Sialic Acid Overproduction
Researchers have identified 1802 distinct proteins of which 105 proteins showed reliable expression changes.
Tuesday, August 13, 2013
Solid-Phase Glycan Isolation for Glycomics Analysis
In this article researchers from John Hopkins University reviewed current glycomics technologies for glycan purification, isolation, separation, and detection.
Thursday, June 27, 2013
A Nano LC-MALDI Mass Spectrometry Droplet Interface for the Analysis of Complex Protein Samples
In this article researchers from ETH Zürich have demonstrated a novel droplet-based interface between Nano–liquid chromatography and matrix assisted laser desorption ionisation mass spectrometry.
Thursday, June 06, 2013
Whole Gel Processing Procedure for GeLC-MS/MS Based Proteomics
The procedure will enable clinical proteomics for which GeLC-MS/MS is a popular workflow and sample numbers are relatively high.
Tuesday, May 14, 2013
Mass Spectrometry-Based Proteomics in Molecular Diagnostics: Discovery of Cancer Biomarkers Using Tissue Culture
Rapid development of MS-based proteomic techniques in the last decade that has immensely helped researchers in candidate biomarker discovery.
Monday, May 13, 2013
MultiAlign: A Multiple LC-MS Analysis Tool for Targeted Omics Analysis
This article demonstrates how two dissimilar LC-MS feature maps could be analyzed using MultiAlign’s MS/MS traceback and spectral clustering capability.
Tuesday, April 30, 2013
Identification of Plasma Lipid Biomarkers for Prostate Cancer by Lipidomics and Bioinformatics
This study explores a new approach to seeking biomarkers for prostate cancer and other diseases.
Monday, April 08, 2013
The HUPO Proteomics Standards Initiative- Mass Spectrometry Controlled Vocabulary
In this article, researchers describe the overall structure of the controlled vocabularies, the process by which it has been developed and is maintained and the dependencies on other ontologies.
Monday, March 25, 2013
Development and Characterization of a Novel Plug and Play LC-MS Source
This article reports the development and characterization of a novel, vendor neutral, ultra-high pressure compatible (~10,000 psi) LC-MS source.
Tuesday, March 12, 2013
'Omics' Approaches to Understanding Interstitial Cystitis/Painful Bladder Syndrome/Bladder Pain Syndrome
This review describes the current state of 'omics' studies and available data sets relevant to IC/PBS/BPS.
Monday, March 11, 2013
Optimal Precursor Ion Selection for LC-MALDI MS/MS
Researchers present two algorithms for inclusion list creation that formulate precursor ion selection as an optimization problem.
Tuesday, February 26, 2013
Scientific News
Non-Disease Proteins Kill Brain Cells
Scientists at the forefront of cutting-edge research into neurodegenerative diseases such as Alzheimer’s and Parkinson’s have shown that the mere presence of protein aggregates may be as important as their form and identity in inducing cell death in brain tissue.
Closing the Loop on an HIV Escape Mechanism
Research team finds that protein motions regulate virus infectivity.
New Class of RNA Tumor Suppressors Identified
Two short, “housekeeping” RNA molecules block cancer growth by binding to an important cancer-associated protein called KRAS. More than a quarter of all human cancers are missing these RNAs.
Gut Microbes Signal to the Brain When They're Full
Don't have room for dessert? The bacteria in your gut may be telling you something.
Turning up the Tap on Microbes Leads to Better Protein Patenting
Mining millions of proteins could become faster and easier with a new technique that may also transform the enzyme-catalyst industry, according to University of California, Davis, researchers.
Exploring the Causes of Cancer
Queen's research to understand the regulation of a cell surface protein involved in cancer.
Measuring microRNAs in Blood to Speed Cancer Detection
A simple, ultrasensitive microRNA sensor holds promise for the design of new diagnostic strategies and, potentially, for the prognosis and treatment of pancreatic and other cancers.
Novel Proteins Linked to Huntington's Disease
University of Florida Health researchers have made a new discovery about Huntington's disease, showing that the gene that causes the fatal disorder makes an unexpected "cocktail" of mutant proteins that accumulate in the brain.
Enzyme Critical to Maintaining Telomere Length Discovered
New method expected to speed understanding of short telomere diseases and cancer.
New Method Identifies Up to Twice as Many Proteins and Peptides
An international team of researchers developed a method that identifies up to twice as many proteins and peptides in mass spectrometry data than conventional approaches.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,800+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,000+ scientific videos