Featured Research

from universities, journals, and other organizations

Key Mechanics Of Cell Membrane Fusion Revealed

Date:
April 27, 2001
Source:
University Of North Carolina School Of Medicine
Summary:
Scientists at the University of North Carolina School of Medicine in Chapel Hill have developed a new working model of cell membrane fusion.

CHAPEL HILL - Scientists at the University of North Carolina School of Medicine in Chapel Hill have developed a new working model of cell membrane fusion.

Related Articles


The model, which apparently mimics the biochemical machinery of fusion in mammalian nerve membranes, offers researchers guidance for studying the biophysics of a process fundamental to all life.

In the future, knowledge gained from this research may also be applied to human disease control. It could help enhance development of fusion-blocking agents aimed at preventing infection by HIV, influenza, Ebola and other viruses. These viruses use membrane fusion machinery to enter cells. A report of the study appears in the April 10 issue of the journal Biochemistry. It details how a group of lipids, including cholesterol, can be combined in optimal ratios so that membrane fusion can occur experimentally.

Within living cells other than bacteria are compartments that carry out different functions such as protein production and processing. And those compartments are surrounded by a lipid bilayer membrane. Fusion allows movement from one compartment to another.

"The question of concern was how does the mix of lipids in a membrane make it more or less able to fuse with another membrane," said the study's lead author Barry R. Lentz, PhD, professor of biochemistry and biophysics at UNC.

Lentz, who heads UNC's Program in Molecular and Cellular Biophysics, and his collaborators approached the question by looking at a highly "fusagenic" membrane, one that's central to nervous system functioning: the synaptic vesicle membrane. Synaptic vesicles fuse with the surface membrane of the neuron, releasing neurotransmitters that bind to the adjacent neuron.

Lentz and his colleagues have developed a fusion model for that membrane based on liposomes, lipid sacs they produced in the laboratory from pure lipids. The researchers found that the addition of the polymer polyethylene glycol forced the liposomes close together and that they could then manipulate them to make them fuse. They had already discovered that fusion between these liposomes behaved in a remarkably similar fashion to fusion reported by other scientists between biological membranes.

By mixing several pure lipids in different proportions, Lentz and Md. Emdadul Haque, PhD, of UNC and Thomas J. McIntosh, PhD of Duke University Medical Center found they could optimize fusion with a mix of lipids (cholesterol, phosphatidylcholine, sphingomyelin, phosphatydilethanolamine and phosphatidylserine) basically in the same proportions found in natural synaptic vesicle membranes.

"What we found was really mind-blowing. The optimal mix that allows membranes to fuse to the greatest extent and rupture or lose their contents to the least extent was exactly the mix Nature has designed for the synaptic vesicle in mammalian cells. Very little is known about how lipid compositions affect fusion. This report offers the first insights into how Nature has optimized membranes for fusion and should help scientists better design liposomes for delivery of drugs into cells by fusion," Lentz said

"This is one more piece of evidence for what I see as the predominant hypothesis in the field now -- that fusion in a biological membrane is a process by which lipids undergo physical changes just like they undergo in the lab," Lentz noted.

But Lentz points out that lipids are not enough to drive fusion. The chemical machine that makes those changes occur also involve proteins. "And that's what we're studying now with our liposome model," he said.

The research was supported by grants from the U.S. Public Health Service.


Story Source:

The above story is based on materials provided by University Of North Carolina School Of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

University Of North Carolina School Of Medicine. "Key Mechanics Of Cell Membrane Fusion Revealed." ScienceDaily. ScienceDaily, 27 April 2001. <www.sciencedaily.com/releases/2001/04/010427071332.htm>.
University Of North Carolina School Of Medicine. (2001, April 27). Key Mechanics Of Cell Membrane Fusion Revealed. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2001/04/010427071332.htm
University Of North Carolina School Of Medicine. "Key Mechanics Of Cell Membrane Fusion Revealed." ScienceDaily. www.sciencedaily.com/releases/2001/04/010427071332.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

AFP (Nov. 21, 2014) Toyota presented its hydrogen fuel-cell compact car called "Mirai" to US consumers at the Los Angeles auto show. The car should go on sale in 2015 for around $60.000. It combines stored hydrogen with oxygen to generate its own power. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Google Announces Improvements To Balloon-Borne Wi-Fi Project

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Newsy (Nov. 21, 2014) In a blog post, Google said its balloons have traveled 3 million kilometers since the start of Project Loon. Video provided by Newsy
Powered by NewsLook.com
Raw: Paralyzed Marine Walks With Robotic Braces

Raw: Paralyzed Marine Walks With Robotic Braces

AP (Nov. 21, 2014) Marine Corps officials say a special operations officer left paralyzed by a sniper's bullet in Afghanistan walked using robotic leg braces in a ceremony to award him a Bronze Star. (Nov. 21) Video provided by AP
Powered by NewsLook.com
British 'Bio-Bus' Is Powered By Human Waste

British 'Bio-Bus' Is Powered By Human Waste

Buzz60 (Nov. 21, 2014) British company GENeco debuted what its calling the Bio-Bus, a bus fueled entirely by biomethane gas produced from food scraps and sewage. Jen Markham explains. 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


Space & Time

Matter & Energy

Computers & Math

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