Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Infrared sheds light on single protein complexes

Abstract:
Proteins are basic building blocks of life. The chemistry and structure of proteins are essential for their biological function. Indeed, the structure of proteins determines their mechanical and catalytic properties (e.g. enzymes). Such functions literally shape all living beings. Furthermore, the protein structure also plays a major role in many diseases. For example, the secondary structure of a protein (whether it has helical (alpha-) or sheet-like (beta-) internal substructures) is highly relevant in the pathogenous mechanism leading to Alzheimer, Parkinson, and other neuro-degenerative diseases. Although a variety of methods have been developed to study the protein chemistry and structure, recognizing and mapping the secondary structure on the nanometer scale, or even with single protein sensitivity, is still a major challenge. A new infrared spectroscopy technique, called nano-FTIR, has now enabled nanoscale chemical imaging and probing of protein's secondary structure with enormous sensitivity.

Infrared sheds light on single protein complexes

Usurbil, Spain | Posted on December 17th, 2013

nano-FTIR is an optical technique that combines scattering-type scanning near-field optical microscopy (s-SNOM) and Fourier transform infrared (FTIR) spectroscopy. The latter is a tool often used for studying secondary structure of proteins that, however, does not allow for nanoscale mapping of proteins by itself. In nano-FTIR, a sharp metalized tip is illuminated with a broadband infrared laser beam, and the backscattered light is analyzed with a specially designed Fourier transform spectrometer. With this technique, the researchers could now demonstrate local infrared spectroscopy of proteins with a spatial resolution of less than 30 nm.
"The tip acts as an antenna for infrared light and concentrates it at the very tip apex. The nanofocus at the tip apex can be thus considered as an ultra-small infrared light source. It is so small that it only illuminates an area of about 30x30 nm, which is the scale of large protein complexes", says project leader Rainer Hillenbrand.
In order to demonstrate the versatility of nano-FTIR for nanoscale-resolved protein spectroscopy, the researchers measured infrared spectra of single viruses, ferritin complexes, purple membranes and insulin fibrils. "They all exhibit variations of their secondary structure - describes Iban Amenabar, who performed the nanospectroscopy experiments-; viruses and ferritin are mainly made of alpha-helical structures, while insulin fibrils are mainly made of beta-sheet structures". Simon Poly, the biologist in the team, explains that "in a mixture of insulin fibrils and few viruses, standard FTIR spectroscopy did not reveal the presence of the alpha-helical viruses. By probing the protein nanostructures one by one with nano-FTIR we could clearly identify the virus, that is the alpha-helical structures within the beta-sheet ones".
An important aspect of enormous practical relevance is that the nano-FTIR spectra of proteins match extremely well with conventional FTIR spectra, while the spatial resolution is increased by more than 100. "We could measure infrared spectra of even single ferritin particles. These are protein complexes of only 24 proteins. The mass of one ferritin complex is extremely small, only 1 attogram, but we could clearly recognize its alpha-helical structure", says Amenabar.
The researchers also studied single insulin fibrils, which are a model system for neurodegenerative diseases. It is known that insulin fibrils have a core of beta-sheet structure but their complete structure is still not fully clarified. "In nano-FTIR spectra of individual fibrils we recognized not only beta-sheet structure, but also alpha-helical structures, which might be of relevance for fibril association," says Alexander Bittner, leader of the Self-Assembly Group at nanoGUNE.
"We are excited about the novel possibilities that nano-FTIR offers. With sharper tips and improved antenna function, we also hope to obtain infrared spectra of single proteins in the future. We see manifold applications, such as studies of conformational changes in amyloid structures on the molecular level, the mapping of nanoscale protein modifications in biomedical tissue or the label-free mapping of membrane proteins. This could lead to a new era in infrared nano-bio-spectroscopy", concludes Rainer Hillenbrand, head of the Nanooptics Group at nanoGUNE.

####

For more information, please click here

Contacts:
Irati Kortabitarte

34-943-363-040

Itziar Otegui
CIC nanoGUNE
Contact details:

+34 943 574 024

Copyright © Elhuyar Fundazioa

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

MIG Takes a Roll-Up-Your-Sleeves Approach with Revamped MEMS/Sensors Technical Event -- MIG welcomes technologists to MEMS Technical Congress, emphasizes working groups and breakout sessions on emerging MEMS & sensors, tech transfer and integration March 6th, 2015

Phenom-World announces the Phenom XL, world’s fastest desktop SEM to handle large samples March 6th, 2015

Air Bearing Stage / Systems Introduced by PI at Photonics West March 6th, 2015

Consistent Scalable Functionalised Graphene Capacity March 5th, 2015

Imaging

Phenom-World announces the Phenom XL, world’s fastest desktop SEM to handle large samples March 6th, 2015

Nanomedicine

Patent for the Novel Cancer Therapies – Ceramide Nanoliposomes March 4th, 2015

Arrowhead to Present at 2015 Barclays Global Healthcare Conference March 4th, 2015

Democratizing synthetic biology: New method makes research cheaper, faster, and more accessible March 3rd, 2015

Pens filled with high-tech inks for do-it-yourself sensors March 3rd, 2015

Discoveries

Enhanced Graphene Components for Next Generation Racing Yacht March 5th, 2015

American Chemical Society Presidential Symposia: nanoscience, international chemistry March 5th, 2015

Strength in numbers: Researchers develop the first-ever quantum device that detects and corrects its own errors March 4th, 2015

New research could lead to more efficient electrical energy storage March 4th, 2015

Announcements

MIG Takes a Roll-Up-Your-Sleeves Approach with Revamped MEMS/Sensors Technical Event -- MIG welcomes technologists to MEMS Technical Congress, emphasizes working groups and breakout sessions on emerging MEMS & sensors, tech transfer and integration March 6th, 2015

Phenom-World announces the Phenom XL, world’s fastest desktop SEM to handle large samples March 6th, 2015

Air Bearing Stage / Systems Introduced by PI at Photonics West March 6th, 2015

Get ready for NanoDays! March 5th, 2015

Tools

Phenom-World announces the Phenom XL, world’s fastest desktop SEM to handle large samples March 6th, 2015

Air Bearing Stage / Systems Introduced by PI at Photonics West March 6th, 2015

Keysight Technologies Shifts to Direct Sales of High-Performance Products in North America March 3rd, 2015

International research partnership tricks the light fantastic March 2nd, 2015

Nanobiotechnology

Experiment and theory unite at last in debate over microbial nanowires: New model and experiments settle debate over metallic-like conductivity of microbial nanowires in bacterium March 4th, 2015

Untangling DNA with a droplet of water, a pipet and a polymer: With the 'rolling droplet technique,' a DNA-injected water droplet rolls like a ball over a platelet, sticking the DNA to the plate surface February 27th, 2015

Bacteria network for food: Bacteria connect to each other and exchange nutrients February 23rd, 2015

Building tailor-made DNA nanotubes step by step: New, block-by-block assembly method could pave way for applications in opto-electronics, drug delivery February 23rd, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE