Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Simpler way of making proteins could lead to new nanomedicine agents

Researchers found that elongating side chains with charged ends enabled short proteins to coil into a stable helix. | Image courtesy Jianjun
Researchers found that elongating side chains with charged ends enabled short proteins to coil into a stable helix. | Image courtesy Jianjun

Abstract:
Researchers have developed a simple method of making short protein chains with spiral structures that can also dissolve in water, two desirable traits not often found together. Such structures could have applications as building blocks for self-assembling nanostructures and as agents for drug and gene delivery.

Simpler way of making proteins could lead to new nanomedicine agents

Champaign, IL | Posted on February 22nd, 2011

Led by Jianjun Cheng, a professor of materials science and engineering at the University of Illinois, the research team will publish its findings in the Jan. 22 edition of the journal Nature Communications.

Materials scientists have been interested in designing large polymer molecules that could be used as building blocks for self-assembling structures. The challenge has been that the molecules generally adopt a globular, spherical shape, limiting their ability to form orderly aggregates. However, polypeptides - chains of amino acids such as proteins - can form helical structures. Short polypeptide chains that adopt a spiral shape act like cylindrical rods.

"If you have two rigid rods, one positive and one negative, right next to each other, they're going to stick to each other. If you have a way to put the charge on the surface then they can pack together in a close, compact way, so they form a three-dimensional structure," Cheng said.

However, it is difficult to make helical polypeptides that are water-soluble so they can be used in solution. Polypeptides gain their solubility from side chains - molecular structures that stem from each amino acid link in the polypeptide chain. Amino acids with positive or negative charges in their side chains are needed to make a polypeptide disperse in water.

The problem arises when chains with charged side chains form helical structures. The charges cause a strong repulsion between the side chains, which destabilizes the helical conformation. This causes water-soluble polypeptides to form random coil structures instead of the desired helices.

In exploring solutions to the riddle of helical, water-soluble polypeptides, researchers have tried several complicated methods. For example, scientists have attempted grafting highly water-soluble chemicals to the side chains to increase the polypeptides' overall solubility, or creating helices with charges only on one side.

"You can achieve the helical structure and the solubility but you have to design the helical structure in a very special way. The peptide design needs a very specific sequence. Then you're very limited in the type of polypeptide you can build, and it's not easy to design or handle these polypeptides," Cheng said.

In contrast, Cheng's group developed a very straightforward solution. Since the close proximity of the charges causes the repulsion that disrupts the helix, the researchers simply elongated the side chains, moving the charges farther from the backbone and giving them more freedom to keep their distance from one another.

The researchers observed that as they increased the length of the side chains with charges on the end, the polypeptides' propensity for forming helices also increased.

"It's such a simple idea - move the charge away from the backbone," Cheng said. "It's not difficult at all to make the longer side chains, and it has amazing properties for winding up helical structures simply by pushing the distance between the charge and the backbone."


The group found that not only do polypeptides with long side chains form helices, they display remarkable stability even when compared to non-charged helices. The helices seem immune to temperature, pH, and other denaturing agents that would unwind most polypeptides.

This may explain why amino acids with large hydrophobic side chains are not found in nature. Such immutability would preclude dynamic winding and unwinding of protein structures, which is essential to many biological processes. However, rigid stability is a desirable trait for the types of applications Cheng's group explores: nanostructures for drug and gene delivery, particularly targeting cancerous tumors and stem cells.

"We want to test the correlation of the lengths of the helices and the circulation in the body to see what's the impact of the shape and the charge and the side chains for clearance in the body," Cheng said. "Recent studies show that the aspect ratio of the nanostructures - spherical structures versus tubes - has a huge impact on their penetration of tumor tissues and circulation half-lives in the body."

Cheng plans to create a library of short helical polypeptides of varying backbone lengths, side chain lengths and types of charge. He hopes to simplify the chemistry even further and make the materials widely accessible. His lab already has demonstrated that helical structures can be effective gene delivery and membrane transduction agents, and building the library of soluble helical molecules will allow further investigation of tailoring such nanostructures for specific biomedical applications.

The National Science Foundation and the National Institutes of Health supported this work. Illinois co-authors were graduate students Hua Lu and Yugang Bai and undergraduate student Jason Lang. "Hua Lu, a fifth year graduate student in my group, is the first author of the publication and made the most significant contribution to this work," Cheng said. Yao Lin and Jin Wang, of the University of Connecticut, and professor Shiyong Liu, of the University of Science and Technology of China, also collaborated with Cheng's group on the paper.

####

For more information, please click here

Contacts:
Jianjun Cheng
217-244-3924

Copyright © University of Illinois

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

SEMATECH to Showcase Innovation and Advances in Manufacturing at SEMICON Japan 2014: SEMATECH experts will share the latest techniques, emerging trends and best practices in advanced manufacturing strategies and methodologies November 26th, 2014

Australian startup creates world’s first 100% cotton hydrophobic T-Shirts November 26th, 2014

The mysterious 'action at a distance' between liquid containers November 26th, 2014

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Lawrence Livermore researchers develop efficient method to produce nanoporous metals November 25th, 2014

Renishaw receives Queen's Award for spectroscopy developments November 25th, 2014

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Possible Futures

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Researchers discern the shapes of high-order Brownian motions November 17th, 2014

VDMA Electronics Production Equipment: Growth track for 2014 and 2015 confirmed: Business climate survey shows robust industry sector November 14th, 2014

Open Materials Development Will Be Key for HP's Success in 3D Printing: HP can make a big splash in 3D printing, but it needs to shore up technology claims and avoid the temptation of the razor/razor blade business model in order to flourish November 11th, 2014

Academic/Education

SUNY Poly Student Awarded Fellowship with the U.S. Department of Energy's Postgraduate Research Program: Ph.D. Candidate Accepts Postmaster's Appointment To Conduct Research At Albany NanoTech Complex November 13th, 2014

SUNY Polytechnic Institute Hosts Massive Crowd of More Than 3,000 People Who Attended Community Day Activities Across New York State: CNSE’s ‘NANOvember’ kickoff event highlights New York State’s growing high-tech sector with open house events in Albany, Utica, and Rochester November 3rd, 2014

SUNY Polytechnic Institute Invites the Public to Attend its Popular Statewide 'NANOvember' Series of Outreach and Educational Events October 23rd, 2014

First Canada Excellence Research Chair gets $10 million from the federal government for oilsands research at the University of Calgary: Federal government announces prestigious research chair to study improving oil production efficiency October 19th, 2014

Self Assembly

Live Images from the Nano-cosmos: Researchers watch layers of football molecules grow November 5th, 2014

Outsmarting Thermodynamics in Self-assembly of Nanostructures: Berkeley Lab reports method for symmetry-breaking in feedback-driven self-assembly of optical metamaterials November 4th, 2014

NYU Researchers Break Nano Barrier to Engineer the First Protein Microfiber October 23rd, 2014

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Nanomedicine

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Research reveals how our bodies keep unwelcome visitors out of cell nuclei November 24th, 2014

ASU, IBM move ultrafast, low-cost DNA sequencing technology a step closer to reality November 24th, 2014

An Inside Job: UC-Designed Nanoparticles Infiltrate, Kill Cancer Cells From Within November 24th, 2014

Announcements

SEMATECH to Showcase Innovation and Advances in Manufacturing at SEMICON Japan 2014: SEMATECH experts will share the latest techniques, emerging trends and best practices in advanced manufacturing strategies and methodologies November 26th, 2014

Australian startup creates world’s first 100% cotton hydrophobic T-Shirts November 26th, 2014

The mysterious 'action at a distance' between liquid containers November 26th, 2014

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Nanobiotechnology

Quantum mechanical calculations reveal the hidden states of enzyme active sites November 20th, 2014

Tokyo Institute of Technology research: Protein-engineered cages aid studies of cell functions November 19th, 2014

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Implementation of DNA Chains in Designing Nanospin Pieces November 9th, 2014

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 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE