Featured Research

from universities, journals, and other organizations

Physical model describes structures of viral capsids

Date:
June 21, 2010
Source:
Universidad de Barcelona
Summary:
The genetic material of viruses is shielded by a protective protein covering called a capsid. Researchers in Spain have uncovered the strict selection rules that define capsid structure in spherical and bacilliform viruses.

Gallery of the bacilliform structures proposed by the physical model for the different sizes of alfalfa mosaic virus.
Credit: Image courtesy of Universidad de Barcelona

The genetic material of viruses is shielded by a protective protein covering called a capsid. The UB researchers David Reguera and Antoni Luque, of the Department of Fundamental Physics, have uncovered the strict selection rules that define capsid structure in spherical and bacilliform viruses, which they report in two papers published in the Proceedings of the National Academy of Sciences and the Biophysical Journal.

Related Articles


The main conclusion of the study is that viral capsids can only adopt a finite range of radii, lengths and protein numbers, making it possible to calculate and characterize all of their possible structures. "This model marks an important step towards understanding the viral assembly process and opens the way for controlling this process for applications in biotechnology, such as gene therapy, and applications in nanotechnology, for example in the creation of nanoscale moulds with highly precise dimensions for designing nanostructures," explains David Reguera.

Viral capsids are formed through a process of self-assembly governed by a universal physical principle: energy minimization. Based on this knowledge, it was possible to identify the potentially optimal architectures of viral capsids; that is, those structures which minimize the energy requirement. As Reguera explains, "we have found that the well-defined geometry observed in different spherical and bacilliform viruses is a product of free-energy minimization in the interaction between the different structural units of which the capsid is composed."

Since the 1960s scientsts have known that spherical viruses adopt a clearly defined structure with icosahedral symmetry, formed by groups of six and five proteins (hexamers and pentaments, respectively), similar to the panel structure of a football, for example. In the case of bacilliform viruses, however, the structure had not been clearly identified. The results of this new study suggest that the capsids of bacilliform viruses are generally formed by a tube-like central body, the ends of which are closed by isocahedral caps centred on one of the three axes of symmetry. These structures are similar to those of fullerenes and carbon nanotubes and have the advantage of being highly stable and resistant.

Reguera and Luque, with support from the researcher Roya Zandi, of the University of California, applied a simple physical model and found that the local energy is minimal for bacilliform capsids formed by a specific, discrete number of proteins distributed in a cylindrical body of hexamers and closed by isocahedral caps centred along the 5-, 3- and 2-fold axes.

The study corroborates the existence of this type of viral structure and, with the complimentary geometric model, serves as the basis for reproducing the architecture of spherical and bacilliform viruses in vivo and in vitro and for making informed predictions. The models have been successfully applied to several known viruses and confirm many of the hypotheses from earlier studies regarding the structure of the alfala mosaic virus, which adopts different lengths depending on the quantity of genetic material contained. Given that the different lengths correspond to the rules set out in the model, it has been possible to obtain definitive models of the finite possible structures.


Story Source:

The above story is based on materials provided by Universidad de Barcelona. Note: Materials may be edited for content and length.


Journal References:

  1. Antoni Luque, David Reguera. The Structure of Elongated Viral Capsids. Biophysical Journal, 2010; 98 (12): 2993 DOI: 10.1016/j.bpj.2010.02.051
  2. Antoni Luque, Roya Zandi, David Reguera. Optimal architectures of elongated viruses. Proceedings of the National Academy of Sciences, 2010; 107 (12): 5323 DOI: 10.1073/pnas.0915122107

Cite This Page:

Universidad de Barcelona. "Physical model describes structures of viral capsids." ScienceDaily. ScienceDaily, 21 June 2010. <www.sciencedaily.com/releases/2010/06/100616090221.htm>.
Universidad de Barcelona. (2010, June 21). Physical model describes structures of viral capsids. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2010/06/100616090221.htm
Universidad de Barcelona. "Physical model describes structures of viral capsids." ScienceDaily. www.sciencedaily.com/releases/2010/06/100616090221.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) — The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) — Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Cambodian Capital's Only Working Elephant to Retire in Jungle

Cambodian Capital's Only Working Elephant to Retire in Jungle

AFP (Nov. 25, 2014) — Phnom Penh's only working elephant was blessed by a crowd of chanting Buddhist monks Tuesday as she prepared for a life of comfortable jungle retirement after three decades of giving rides to tourists. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com
Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Buzz60 (Nov. 24, 2014) — A Swedish Adventure racing team travels to try and win a world title, but comes home with something way better: a stray dog that joined the team for much of the grueling 430-mile race. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins