Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Highly Active Enzymes on Graphene Oxide Surface

Abstract:
Chemically reduced graphene oxide is a good substrate for high enzyme loads, and activities comparable with those found in solution can be achieved on this surface, as shown by Chinese scientists.

Highly Active Enzymes on Graphene Oxide Surface

Germany | Posted on November 10th, 2011

Graphene oxide (GO) is an interesting substrate for absorption and immobilization of biological compounds because of its stability, low toxicity, and unique chemical, electrical, and mechanical properties. It has been used in biomolecule detection and as a drug carrier, and more recently as a substrate on which to immobilize enzymes for catalytic use. However until now, such attachment has had to be done either covalently, or via electrostatic interactions between the enzyme and the GO surface. Covalent bonding may alter the properties of the enzyme by changing its shape, but the electrostatic interactions can also affect enzyme activity.

Scientists have started to experiment with a modified kind of GO called chemically reduced graphene oxide (CRGO) to overcome this problem of attachment. CRGO has fewer surface functional groups than GO, so should perturb the enzyme on it less. Now, a team led by Jingyan Zhang at East China University of Science and Technology and Shouwu Guo at Shanghai Jiao Tong University, China, has looked systematically at the loading and activity of enzymes on CRGO with varying degrees of reduction.

The team found that the more reduced the CRGO, the higher the possible loading of the enzyme, and that loadings of up to 60 times those possible on classically used materials were possible with CRGO. They found that the high loading was caused by hydrophobic interactions between the CRGO surface and the surface of the enzyme molecules, rather than the electrostatic interactions present with regular GO.

But when the team looked at the activity of the enzymes, they got quite a surprise. While one enzyme (horseradish peroxidase; HRP) was much less active than in solution, another (oxalate oxidase; OxOx) was nearly as active and retained up to 90% of its activity even after ten cycles of use, depending on the extent of CRGO reduction. Previous studies on immobilization of OxOx, e.g., on solid beads, have yielded much lower activities. The scientists attribute this finding to the particular structures of the two enzymes and how they bind to the surface. Some enzymes will change conformation on binding to the hydrophobic surface, which involves a dehydration step; this may affect the activity of the enzyme, while it appears that OxOx does not alter so much.

This new way to immobilize OxOx on CRGO while retaining high activity is very promising for clinical determinations of oxalate. The team believe that their method can be extended to use for other enzymes that retain their structure upon hydrophobic binding and dehydration, and that it has applications in detection and as a molecular carrier.

####

For more information, please click here

Copyright © Wiley-VCH Materials Science Journals

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 Links

Y. Zhang et al., Small ; DOI: 10.1002/smll.201101695

Related News Press

News and information

Conductive Inks: booming to $2.8 billion by 2024 April 17th, 2014

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

INSCX™ exchange to present Exchange trade reporting mechanism for engineered nanomaterials (NMs) to UK regulation agencies, insurers and upstream/downstream users April 17th, 2014

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 2014

Graphene

Thinnest feasible membrane produced April 17th, 2014

Chemistry

Thinnest feasible membrane produced April 17th, 2014

Discoveries

Novel stapled peptide nanoparticle combination prevents RSV infection, study finds April 17th, 2014

Thinnest feasible membrane produced April 17th, 2014

More effective kidney stone treatment, from the macroscopic to the nanoscale April 17th, 2014

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

Announcements

More effective kidney stone treatment, from the macroscopic to the nanoscale April 17th, 2014

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

INSCX™ exchange to present Exchange trade reporting mechanism for engineered nanomaterials (NMs) to UK regulation agencies, insurers and upstream/downstream users April 17th, 2014

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 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